CN109329043B

CN109329043B - Breeding method of small-seed type pumpkin rootstock variety

Info

Publication number: CN109329043B
Application number: CN201811450482.5A
Authority: CN
Inventors: 王毓洪; 邢乃林; 王迎儿; 应泉盛; 严蕾艳; 张华峰; 黄芸萍; 张蕾琛; 古斌权
Original assignee: Ningbo Academy of Agricultural Sciences
Current assignee: Ningbo Academy of Agricultural Sciences
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2021-07-02
Anticipated expiration: 2038-11-30
Also published as: CN109329043A

Abstract

The invention discloses a method for breeding small-seed type pumpkin rootstock varieties, and belongs to the field of melon rootstock variety breeding. The breeding method comprises the following specific steps: and (4) researching the genetic rule of the size of the pumpkin seeds and the number of the single pumpkin seeds according to the segregation population, and selecting parents and matching combinations according to the genetic rule. The male parent is a stable inbred line which is screened out by introducing a stock variety 'fire phoenix' from Shandong through 7-generation inbreeding, and is characterized by developed root system, moderate growth vigor, oblate fruit, earthy yellow peel and good drought resistance; the female parent is a stable inbred line screened from a Shandong watermelon grafting stock variety 'snow white' fertile plant through 6-generation inbreeding, and is characterized in that fruits are nearly round, main roots are developed, peels are orange, and are early-maturing, and high-temperature and low-temperature resistant properties are strong; the male parent and the female parent are selectively hybridized and combined to obtain the male and female parent. The obtained variety cotyledon is suitable for 50-hole tray seedling, has high resistance to watermelon fusarium wilt, regular germination, long grafting period, convenient grafting and high grafting survival rate.

Description

Breeding method of small-seed type pumpkin rootstock variety

Technical Field

The invention belongs to the technical field of melon stock breeding, and particularly relates to a small-seed type pumpkin stock variety breeding method.

Background

The melon grafting cultivation has at least 3000 years of history in China, and the book Sheng book written by agriculturists Sheng in China 100 years ago by public yuan has the record of producing large bottle gourds by grafting. In 1925, the research on melon grafting disease prevention begins, and in the 90 s, the grafting cultivation area of the Japanese melons reaches 60% of the total area and the cultivation area of the protected area is more than 90%. The research and application of melon grafting cultivation in China began in the 70 s, but the development is slow. Since the 80 s, the growing area of watermelon is continuously enlarged, the crop rotation period is shortened, and the blight is getting more and more serious, the watermelon main producing area becomes a main obstacle restricting production, so far, the melon grafting cultivation begins to be popularized. The melon can overcome continuous cropping obstacles caused by soil-borne diseases, enhance the resistance of plants to adverse circumstances, improve the utilization of scions to soil, fertilizer and water and reduce the use amount of chemical fertilizers and pesticides by grafting. At present, the grafting technology is widely applied to melon production, not only large-area watermelons are subjected to grafting cultivation, but also other melons such as melons, cucumbers, bottle gourds, bitter gourds and the like are simulated, so that good economic benefits are obtained, meanwhile, the concept of melon grafting is gradually accepted by farmers, and the grafting cultivation technology is further developed.

Intensive seedling culture with high quality, high speed and stable quality has become an important component of fine variety engineering construction in China, and has huge demand space for grafted seedlings in production, and industrialized intensive seedling culture of melon grafting will become a trend. The selection of the grafting stock is a vital part for grafting cultivation. At present, the varieties of stocks for grafting watermelons on domestic markets are many, and common stocks include cucurbits, Chinese pumpkins, Indian pumpkins, Chinese pumpkin hybrid pumpkins and the like. Due to the fact that the CGMMV is easily available in the cucurbit stocks, the problem of irregular germination is caused by dry heat treatment of seeds, manual seed selection cost is increased, and root rot is easily caused in low-temperature rainy days; although the cotyledon of the Chinese pumpkin rootstock is smaller, the comprehensive resistance of the rootstock is worse than the hybridization of the Indian pumpkin and the Chinese pumpkin, and the scion quality is easily influenced; the seeds of the conventional hybrid pumpkin of the pumpkin of India and the pumpkin of China have large seeds, the cotyledons of the stock are also large, the stock grows strongly, the growth is fast, the hypocotyl is easy to hollow, the grafting period is short, and the cotyledons are easy to shade each other, and half of the cotyledons are required to be removed during grafting, so that the labor cost is increased, and the morbidity is increased; the intensive seedling culture requires high yield per unit area, strong disease resistance and stress resistance of seedlings and consistent seed germination. At present, the domestic cotyledon is more suitable for intensive seedling culture, the comprehensive resistance is better, and the melon stock variety which does not reduce the quality of scion fruits is less. Meanwhile, the genetic rule of the pumpkin seed size is not clear, and the breeding difficulty of small seed varieties is increased.

Aiming at the production reality that the intensive seedling culture is more and more popularized, the breeding method of Ningbo city agricultural institute vegetable system is suitable for the intensive grafting seedling culture and the breeding target of the special stock variety for the main planting watermelon variety grafting: the genetic rule of the pumpkin seed size is researched, and on the basis, the small cotyledon (the thousand seeds weigh 100 g-120 g) is selected and cultured, the method is suitable for 50-hole tray seedling culture, high in watermelon fusarium wilt resistance, neat in sprouting, not easy to grow excessively, long in grafting adaptability, convenient to graft, high in grafting survival rate and free of influence on scion quality. On the basis of widely introducing germplasm resources at home and abroad, a segregation population is constructed, the genetic rule of grain size is researched, and then systematic breeding, characteristic feature identification, hybridization combination matching, variety comparison tests and regional production tests are carried out, so that the problem to be solved urgently is to be solved for breeding the intensive seedling small-seed pumpkin rootstock variety suitable for watermelon grafting in Zhejiang.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings in the prior art and provide a method for breeding a small-seed pumpkin rootstock variety.

The purpose of the invention is realized by the following technical scheme: a method for breeding small-seed pumpkin rootstock varieties comprises the following steps:

(1) acquisition of genetic rules

Through the investigation of pumpkin germplasm resources and the combination of breeding targets, two materials NMO83 and XBZM with obvious grain size difference are selected, and the thousand seed weight is 110g and 160g respectively; hybridizing the two parents to obtain hybrid seeds F1 and RF1, then selfing F1 to obtain F2 generation, and backcrossing F1 and NM083 to obtain BC1 generation; simultaneously planting NMO83, XBZM, F1, RF1, F2 and BC1 in the next season; when the fruit is ripe, the thousand seed weight of the seed is inspected, and the thousand seed weight of F1 and RF1 is 178g and 214g respectively, which are relatively close to the large-grain parent XBZM, and the F2 population and the BC1 population are continuously distributed and biased to be large-grain; therefore, the pumpkin seeds have quantitative characters, and small grains are recessive relative to large grains; meanwhile, the number of seeds of the single melon is inspected, the number of the parents NMO83 and XBZM of the group, the number of the seeds of the single melon of F1 and RF1 are 327, 229, 250 and 245 respectively, the seeds are obviously close to the parent XBZM with less seeds, and the F2 group and the BC1 group are both distributed in a skewed state and tend to the parent with less seeds; therefore, the seeds of a single melon are invisible when the number of the seeds is larger than that of the seeds of a small melon; therefore, for breeding stock varieties with small seeds and a large number of single melon seeds, the parents need to select materials with small seeds and a large number of single melon seeds;

(2) male parent breeding

The male parent of the small seed type pumpkin rootstock variety is derived from a rootstock variety 'Huofenghuang' collected from Shandong and is numbered as SD 08; carrying out systematic breeding on the rootstock material from the spring of the first year; according to the male parent breeding target: the method has the advantages that the root system is developed, the disease resistance and the stress resistance are strong, premature senility is not prone to occurring, the number of single melon seeds is large, the seeds are small and full, through strict selfing screening of 7 generations in 2 seasons each year, the bred single melon seeds are good in low temperature resistance, blossoming and fruit setting are earliest, the field stress resistance is good, the number of single melon seeds is large, plants are sprawly, the root system is developed, the growth potential is moderate, leaves are white, and the self-bred line SD08-5-2-11-8-3-4(P63) with proper fruit appearance indexes meets the male parent breeding target of small seed stock variety breeding; the thousand seed weight is 95-105g, and the seed number of a single melon seed is 220-300;

(3) female parent breeding

The female parent of the small-seed pumpkin stock variety is derived from Shandong watermelon grafting stock variety 'snow white' and is numbered as XB 07; finding male flower fertile pumpkin plants in seedlings of the XB07 snow white rootstock variety in the spring of the next year, and respectively carrying out strict selfing on the male flower fertile pumpkin plants to obtain F2 seeds, wherein the numbers of the seeds are XB 07-1-5; then according to the female parent breeding target: the comprehensive resistance is strong, the root system is developed, the growth vigor is good, female flowers bloom early, the seeds are small, and the number of seeds of a single melon is large; through strict selfing screening for 6 generations in 2 seasons per year, a selfing line XB07-4-16-3-8-5(P73) with developed main roots, sprawling plants, medium growth vigor, precocity, nearly round fruits, 1.6-2.0kg of single fruit weight, light orange peel and strong high-temperature resistance and low-temperature resistance is bred, the thousand seed weight is 100-110g, and the seed number is 300-grains;

(4) breeding of small seed type pumpkin stock variety

In the fifth autumn, the small-seed pumpkin XB07-4-16-3-8-5(P73) obtained in the step (3) is used as a female parent, the Chinese pumpkin SD08-5-2-11-8-3-4(P63) obtained in the step (2) is used as a male parent for hybridization matching, and a small-seed pumpkin rootstock hybrid of the Indian pumpkin and the Chinese pumpkin is obtained, wherein the thousand seed weight is 115g, and the single melon seed number is 300 grains; and confirming the shape of the bred variety through a variety comparison test.

The appearance indexes of the fruits in the step (2) are suitable for selecting the fruits with oblate shape, earthy yellow peels, wax powder and 1.4-1.6 kg weight of a single fruit.

The disease resistance in the step (2) comprises watermelon fusarium wilt resistance, and the identification of the watermelon fusarium wilt resistance is carried out by inoculating and identifying by using a bacterial soil method.

And (3) the comprehensive resistance comprises watermelon fusarium wilt resistance, and the identification of the watermelon fusarium wilt resistance is carried out by inoculating and identifying by using a bacterial soil method.

And (4) performing hybridization matching according to the genetic rule of the grain size and the single melon seed number obtained in the step (1).

Confirming the shape of the bred variety through a variety comparison test in the step (4), and specifically comprises the following steps: the small-seed pumpkin stock variety obtained by hybridizing the Indian pumpkin and the Chinese pumpkin is subjected to grafting 'early-good' watermelon variety comparison test in spring, and the test result shows that the pumpkin stock variety obtained by the invention has excellent performance: the grafting survival rate is high, the grafted scion plant has strong growth vigor, the leaves are dark green, the scion plant grows well in early spring under the low-temperature condition, the flowering and fruit setting are 1-3 days earlier than the self-rooted seedlings, the single fruit weight, sugar degree and taste of the scion fruit are not obviously different from those of the self-rooted seedlings, the sugar degree is higher than that of the self-rooted seedlings, the meat quality is crisp, and no peculiar smell is generated; the quality ratio test of the grafted watermelon is carried out again in autumn, and the result shows that the small-seed pumpkin stock variety obtained by the invention has normal plant growth and is resistant to the growth of the small-seed pumpkin stock varietyThe high temperature is good, the taste and sugar degree of the fruit are not obviously different from those of the self-rooted seedlings, and deformed fruits are few; the small-seed pumpkin rootstock variety obtained by the invention has the optimal expression in the annual product ratio test result; in 2013, 7363 was named as 'Yongzhu No. 10' (changed to 'Sizhang No. 10' after 2016), and large-area tests, test seeds, demonstration and multipoint variety comparison tests were started in the whole province; the average yield in 2016-2017 reaches 3203.36kg 667m^-2The yield is increased by 15.88 percent compared with that of the self-rooted seedlings.

The breeding (introduction) process of the small seed type pumpkin stock variety 'Sizhang No. 10' obtained by breeding in the invention is summarized as follows: the female parent (Indian pumpkin) of 'Sizhang No. 10' is a stable inbred line XB07-4-16-3-8-5 screened from Shandong watermelon grafting stock variety (snow white) in autumn of 2011 after 6 generations of inbreeding in spring of 2009. The male parent of 'Sizhang No. 10' (Chinese pumpkin) is a stable inbred line SD08-5-2-11-8-3-4 which is screened by 7-generation inbreeding from Shandong introduced stock varieties (fire phoenix) in spring of 2008 and is characterized by developed root system, moderate growth vigor, oblate fruit, earthy yellow peel and good drought resistance. The autumn selective hybridization combination in 2012, the number of 7363, the quality ratio test of the grafted watermelon in 2013, and the best performance among various combinations. The watermelon variety is named as 'Yongzhu No. 10' (changed to 'Sizhang No. 10' in 2016), and a grafting 'Zaojia' watermelon variety comparison test and a multipoint production test are carried out in 2016-2017.

The invention breeds the suitable planting area of the obtained small-seed type pumpkin stock variety 'Sizhang No. 10': 'Sizhuang No. 10' can be used for grafting 'Zaojia' watermelons and other melons, and is suitable for facility cultivation in Zhejiang and the same ecological areas.

The main grafting cultivation technical key points of the small seed type pumpkin stock variety 'Sizhang No. 10' obtained by breeding in the invention are as follows: the seedling culture is started in the first ten days of 12 months to 2 months in spring, and the seedling culture is started in 7 months in autumn. The method is recommended to adopt a grafting method, and the rootstock is sowed 7-10 days earlier than the scion. The temperature of the grafted product is controlled to be 25-28 ℃ before 3d, the relative humidity of air is about 95%, and direct strong light irradiation is avoided; gradually reducing the temperature from the 4 th day after grafting, and ventilating and cooling(ii) a And managing according to the common seedlings after 7-10 days. By climbing the ground, 667m²300-500 plants are planted, the planting can not be too deep, and the distance between the grafting part and the soil surface is more than 1 cm. The fertilizer needs to be applied by about 20 percent less than that of self-rooted seedlings, so that the fruit setting is difficult due to excessive nutrition, less nitrogen fertilizer is applied, and phosphorus and potassium fertilizer is additionally applied.

The main seed production technical key points of the small seed type pumpkin stock variety 'Sizhang No. 10' obtained by breeding are as follows: 1. sowing in 3 months, wherein the male parent is sowed 10-15 days earlier than the female parent. 2. The cultivation proportion of the male parent and the female parent is 1: 8. 3. planting 330 plants per mu of female parent, pinching when 4 leaves of female parent seedling are 1 heart, reserving 2 vines, and removing other subsidiary vines, all grand vines and male flowers as soon as possible. 4. After 7 am, male flowers were collected from the father, pollinated, and flowers were clipped and marked after pollination. 5. And (3) topdressing 10kg of compound fertilizer per mu after fruit setting, and topdressing 15kg of compound fertilizer per mu after the fruits grow to the middle and later stages. 6. Harvesting 45-50 days after pollination, and after-ripening for 7-10 days. 7. Before breaking melon, the melon is soaked in copper aqua regia to prevent bacterial diseases. 8. Seed is taken and washed and then 2% H is used₂O₂Treated and dried in the sun.

The small-seed pumpkin rootstock variety 'Sizhang No. 10' obtained by the invention is different from other rootstock varieties:

1) the hybrid first generation of the pumpkin from India pumpkin and the Chinese pumpkin has small seeds, the thousand seed weight is 110g (' the thousand seed weight of the totipotent armored variety is 250g), the transverse diameter of the seeds is 7.70mm, the longitudinal diameter is 13.51mm, the thickness is 3.32mm (the totipotent armored is 10.12 multiplied by 19.09 multiplied by 3.82mm), the transverse diameter of the cotyledon in the flattening period is 3.0cm, the longitudinal diameter is 4.4cm, and the thickness is 0.88cm (the totipotent armored is 4.2 multiplied by 5.7 multiplied by 0.96 cm);

2) the area of cotyledon is small, and the cotyledon is not shaded mutually after grafting, so that the density of the leaves can be effectively reduced, the disease caused by overlarge humidity of seedlings can be prevented, and the grafting and the management after grafting are easy.

3) The method is suitable for 50-hole tray seedling, the germination is neat, the hypocotyl is not easy to hollow and overgrow, the growth vigor is stable, and the grafting survival rate is high.

Compared with the prior art, the invention has the following advantages and effects:

1. the invention researches the genetic rule of the size of the pumpkin seeds and the number of the single pumpkin seeds according to the segregation population, and selects parents and matches according to the genetic rule.

2. The small-seed pumpkin stock variety 'Sizhang No. 10' of the invention has excellent performance of the quality ratio and the production test yield in the past year, and concretely comprises the following steps: in 2016-2017, variety comparison tests are carried out in Ningbo, Pinghu, Deqing and other places. The yield of 'Sizhang No. 10' grafting 'Zaojia' in 2016 is 2869-3184 kg.667 m^-2Average value of 3002kg 667m^-2Compared with 'all-round armour' (average yield is 2971g kg 667 m)^-2) The yield is increased by 1.04 percent compared with that of self-rooted seedlings (the average yield is 2536 kg.667 m)^-2) The yield is increased by 18.37 percent. The yield of grafting 'Zaojia' of 'Sizhang No. 10' in 2017 is 3213-3660 kg.667 m^-2Average of 3404kg 667m^-2Compared with 'totipotent armored' (average yield is 3370kg 667 m)^-2) The yield is increased by 1.01 percent compared with the self-rooted seedlings (the average yield is 2992 kg.667 m)^-2) The yield is increased by 13.76%. The yield of 'Sizhang No. 10' grafting 'Zaojia' is 2869-3660 kg.667 m^-2Average of 3203kg 667m in 2 years^-2Compared with the contrast 'all-round armored' grafting 'early and good' (the average yield is 3171kg 667 m)^-2) 1.02% higher than that of the control (average yield 2764kg 667 m)^-2) The height is 15.88 percent.

3. The small-seed pumpkin rootstock variety obtained by breeding has the main excellent characteristic characteristics that:

the small-seed pumpkin stock variety 'Sizhuang No. 10' obtained by breeding has developed main root, strong fertilizer absorption capacity, steady growth vigor and long grafting adaptability, the hypocotyl is not easy to overgrow and hollow, the grafting affinity is good, and the grafting survival rate of watermelon varieties such as 'Zaojia' is more than 94%; the symbiotic affinity is strong, the low temperature resistance and the high temperature resistance are both strong, the growth vigor of the grafted early-good watermelon is stronger than that of self-rooted seedlings, and the fruit setting is easy; the first batch of melons in spring bloom to harvest for 35-38 days and 25-27 days in summer and autumn.

4. The small-seed pumpkin stock variety obtained by the breeding method is the first filial generation of the Indian pumpkin and the Chinese pumpkin, has small seeds, the thousand seed weight is 110g, the cotyledon area is small, mutual shading is avoided after grafting, the leaf density is effectively reduced, diseases caused by overlarge seedling humidity are prevented, and the cotyledon does not need to be cut during grafting, so that the grafting operation and the management after grafting are facilitated; is suitable for 50-hole tray seedling, has regular budding, ensures that the hypocotyl is not easy to hollow and overgrow, has stable growth vigor and high grafting survival rate.

'Sizhuang No. 10' is a first generation hybrid of Indian pumpkin and Chinese pumpkin, the plant is vinous, and the root system is developed; the stem is pentagonal and dark green; a blade palm shape; aborting anthers; the main vines can bear fruits, the first female flower nodes are 9-12 nodes of the main vines, the fruits are oblate, tender fruit peels are yellow and have white spots, and the aged melons are orange and have white spots; the fruit development period is about 45 days, and the weight of a single fruit is 0.8-1.2 kg; the seed coat is white, and the thousand seed weight of the seeds is 105-115 g. Identified by the plant of Zhejiang agricultural department, the watermelon wilt disease can be resisted highly.

Drawings

FIG. 1 is a spectrogram of a small-seed type pumpkin stock variety 'Sizhang No. 10' female parent breeding line.

FIG. 2 is a spectrum diagram of a small-seed type pumpkin stock variety 'Sizhang No. 10' male parent breeding line.

FIG. 3 is a flow chart of small seed type pumpkin stock variety 'Sizhang No. 10' breeding and popularization.

FIG. 4 is a picture of a small-seed pumpkin stock variety 'Sizhuang No. 10' grafted seedling and a grafted watermelon substance. Wherein: a is field expression of the Sizhang No. 10 grafted watermelon, B is seedling expression of the grafted watermelon, and C is fruit expression of the grafted watermelon.

FIG. 5 is a pictorial representation of seedlings, seeds and fruits of a small seed type pumpkin rootstock variety 'Sizhang No. 10'. Wherein: a is the leaf expression of the Sizhang No. 10 seedling, B is the root expression of the stock seedling, C is the seed expression of the stock seedling, D is the seedling stage expression of the stock seedling (wherein the upper row is the Sizhang No. 10 and the lower row is other stocks), and E is the fruit expression of the stock.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 Breeding method of small-seed type pumpkin rootstock variety

The invention relates to a method for breeding a small-seed pumpkin rootstock variety, which comprises the following steps:

(1) acquisition of genetic rules

(2) male parent breeding

The spectrum of the male parent breeding line is shown in fig. 2, the male parent of the small seed type pumpkin rootstock variety is derived from the rootstock variety 'fiery phoenix' (SD08) collected from Shandong in 2008; the material is systematically bred in spring of 2008, the breeding target of the male parent is developed root system, strong disease resistance and stress resistance, difficult premature senility, large number of single melon seeds and full seeds; 30 plants are planted in spring in 2008, and the 5 th plant is selected according to the selection standard of the male parent breeding target; in autumn of 2008, SD08-5(F2) is inoculated to seedlings, no watermelon fusarium wilt germ is found after 15 days, 200 plants are planted, plants, fruits and seeds are observed to be greatly separated, and 4 single melons are selected according to breeding targets and fruit appearance differences and are numbered as SD 08-5-1-SD 08-5-4; 50 plants are planted in each of 4 plant lines in spring of 2009, and the SD08-5-2 plant line is observed to have better early spring low temperature resistance, the earliest flowering and fruit setting, better field stress resistance and more single melon seeds, wherein the 11 th plant is the best; 30 SD08-5-2-11 plants are planted in autumn in 2009, and the 8 th plant is selected by referring to the selection standard of the male parent breeding target; planting 30 SD08-5-2-11-8 plants in spring of 2010, and selecting the 3 rd plant; 30 plants are planted in autumn in 2010, the 4 th plant is selected, 30 plants are planted in SD08-5-2-11-8-3-4 in spring in 2011, and the plants, the fruit type and other characters are stable through field observation; obtaining a purer inbred line SD08-5-2-11-8-3-4(P63) by 7-generation inbreeding in 2 seasons per year; the inbred line is characterized in that the plant is sprawling, the root system is developed, the growth vigor is moderate, the leaves have white spots, the fruit is oblate, the peel is earthy yellow and has wax powder, and the weight of a single fruit is about 1.5 kg;

(3) female parent breeding

The female parent breeding pedigree is shown in figure 1, the female parent of the small-seed pumpkin rootstock variety is derived from a Shandong watermelon grafting rootstock variety 'snow white' (XB07) collected in spring of 2009, 5 male flower fertile Indian pumpkin plants are found in seedlings of the 'snow white' (XB07) in spring of 2009, and the 5 single plants are respectively subjected to strict selfing to obtain 5 parts of F2 seeds (XB 07-1-5); in autumn of 2009, the 5 parts of seeds are subjected to watermelon fusarium wilt resistance identification in seedling stage, the result shows that all high resistance is achieved, and 100 parts of XB 07-1-5 are planted in each part of material for strict single plant selfing; observing the whole growth period, and eliminating plants with weak root systems, poor plant growth potential, late flowering of female flowers, poor stress resistance and disease resistance and small quantity of single melon seeds in the seedling period to obtain F3 seeds; the observation shows that the sizes of F3 seeds of different strains are different, the thousand seed weight is between 100g and 250g, wherein the strain XB07-4 has smaller seeds, the number of single melon seeds numbered 16 is large, the thousand seed weight is 100g, the seeds are full and have white seed coats, and the seeds are selected; 50 XB07-4-16 plants are planted in spring of 2010, strict individual plant selfing is carried out, and the 3 rd plant is selected according to the selection standard; continuing systematic breeding in autumn in 2010, and planting 30 plants and selecting the 8 th plant; planting 30 plants in spring in 2011, and selecting the 5 th plant; 2011, 30 plants are planted in autumn, and the characters of the plants, the fruit types and the like are stable through field observation; obtaining a purer inbred line XB07-4-16-3-8-5(P73) by 6 generations of inbreds in 2 seasons per year; the inbred line is characterized by developed main roots, sprawling plants, medium growth vigor, early maturity, nearly round fruits, 1.8kg of single fruit weight, light orange peel, and strong high temperature resistance and low temperature resistance;

(4) breeding of small seed type pumpkin stock variety

Autumn of 2012In the season, 15 hybrid combinations of the pumpkin India and the pumpkin China are obtained by taking the pumpkin XB07-4-16-3-8-5(P73) with small seeds as a female parent and taking 15 pumpkin China such as SD08-5-2-11-8-3-4(P63) and the like as male parents; in 2013, in spring, 33 pumpkin rootstock combinations including the 15 combinations are subjected to a watermelon variety grafting 'early-good' comparison test, and the watermelon variety grafting is located in Ningbo high-tech agricultural technology experimental park; the test results show that combination 7363 performs well: the grafting survival rate is high, the grafted scion plant has strong growth vigor, the leaves are dark green, the scion plant grows well in early spring under the low-temperature condition, the flowering and fruit setting are 1-3 days earlier than the self-rooted seedlings, the single fruit weight, sugar degree and taste of the scion fruit are not obviously different from those of the self-rooted seedlings, the sugar degree is higher than that of the self-rooted seedlings, the meat quality is crisp, and no peculiar smell is generated; the quality ratio test of the grafted watermelons is carried out again in autumn of 2013, 5 combinations with better spring performance are jointly tested, and the results show that 7363 plants grow normally and have good high temperature resistance, the taste and sugar degree of fruits have no obvious difference with self-rooted seedlings, and deformed fruits are few; summary analysis 2013 grade test results throughout the year found that combination 7363 performed the best of all combinations; in 2013, 7363 was named as 'Yongzhu No. 10' (changed to 'Sizhang No. 10' after 2016), and large-area tests, test seeds, demonstration and multipoint variety comparison tests were started in the whole province; the average yield in 2016-2017 reaches 3203.36kg 667m^-2The yield is increased by 15.88 percent compared with that of the self-rooted seedlings. (as shown in fig. 3).

Second, grade test results

Wherein the grafted seedling of the small-seed type pumpkin stock variety 'Sizhang No. 10' obtained by seed selection and the grafted watermelon are shown in figure 4; the seedling, seed and fruit of the small seed type pumpkin rootstock variety 'Sizhang No. 10' obtained by seed selection are shown in figure 5.

(I) grafting Properties

The small-seed pumpkin stock variety 'Sizhuang No. 10' has stable growth vigor of seedlings, the hypocotyl is not easy to hollow and grow excessively, the grafting is easy, the affinity with the watermelon is good, the average survival rate of the grafted 'Zaojia' (8424) is 94.10%, and the survival rate is improved by 4.43% compared with the control of the totipotent armored armor.

(II) phenological period

The small-seed pumpkin stock variety 'Sizhuang No. 10' grafting 'early good' (8424) has strong growth vigor, the growth is faster than that of a self-rooted seedling in early spring, the flowering time of the small-seed pumpkin stock variety is the same as that of 'totipotent armored' grafted watermelon, the small-seed pumpkin stock variety blooms 1-3 days earlier than the self-rooted seedling, and the first batch of small-seed pumpkin stocks in early spring is 35-38 days in fruit development.

(III) fruit yield

In 2016-2017, variety comparison tests are carried out in Ningbo, Pinghu, Deqing and other places.

The yield of the 'Sizhang No. 10' grafting 'Zaojia' of 2016 small-seed type pumpkin stock variety is 2869-3184 kg-667 m^-2Average value of 3002kg 667m^-2Compared with 'all-round armour' (average yield is 2971g kg 667 m)^-2) The yield is increased by 1.04 percent compared with that of self-rooted seedlings (the average yield is 2536 kg.667 m)^-2) The yield is increased by 18.37 percent.

The yield of a small-seed pumpkin stock variety 'Sizhang No. 10' grafting 'Zaojia' in 2017 is 3213-3660 kg.667 m^-2Average of 3404kg 667m^-2Compared with 'totipotent armored' (average yield is 3370kg 667 m)^-2) The yield is increased by 1.01 percent compared with the self-rooted seedlings (the average yield is 2992 kg.667 m)^-2) The yield is increased by 13.76%.

The yield of the small-seed pumpkin stock variety 'Sizhang No. 10' grafting 'Zaojia' is 2869-3660 kg-667 m^-2Average of 3203kg 667m in 2 years^-2Compared with the contrast 'all-round armored' grafting 'early and good' (the average yield is 3171kg 667 m)^-2) 1.02% higher than that of the control (average yield 2764kg 667 m)^-2) The height is 15.88 percent.

(IV) grafted seedling plant character

The small-seed pumpkin stock variety 'Sizhuang No. 10' has developed main roots, strong low-temperature resistance and rapid growth in spring, the main tendrils grow 205.17cm when the 'early-good' grafting blossoms, 0.41cm longer than the 'totipotent armored' and 28.83cm longer than self-rooted seedlings, and the performance difference of a plurality of test points is obvious. The transverse diameter of the main vine of 'Sizhuang No. 10' grafting 'early good' is 0.56cm, is 0.02cm thinner than the contrast 'totipotent armored nail', and is 0.03cm thicker than the self-rooted seedling. The 'Sizhang No. 10' grafting 'early good' growth vigor is stronger than that of self-rooted seedlings, and is similar to that of 'all-round armored' grafted seedlings.

(V) fruit Properties

The average single fruit weight of the small seed type pumpkin stock variety 'Sizhuang No. 10' grafting 'early good' fruit is 5.34kg, which is increased by 0.05kg compared with the 'early good' 5.28kg of the 'totipotent armored' grafting, and is increased by 0.50kg compared with the 'early good' fruit from 4.84kg of the root seedling, and the fruit shape (fruit type index) is basically unchanged. The average thickness of 'Sizhang No. 10' grafting 'Zaojia' peel is 1.13cm, and the thickness of 'Zaojia' peel is 0.04cm, which is 0.08cm thicker than that of 'all-round armored' grafting. The central sugar degree of the 'Sizhang No. 10' grafted 'early-excellent' fruit is 11.40-12.50%, the average sugar degree is 11.93%, and the fruit is higher than that of 'all-round armored' grafted 'early-excellent' (11.83%) and self-rooted seedlings (11.80%). The sugar content of the edge of the 'Sizhang No. 10' grafted 'early-good' fruit is 7.48-8.06%, the average is 7.71%, and the sugar content is higher than that of 'all-round armored' grafted 'early-good' (7.66%). 'Sizhang No. 10' grafting 'early good' fruits are crisp in taste, and have no obvious difference with self-rooted seedlings, and 'all-round armored' grafted parts have harder fruits at test points.

(VI) disease resistance

The comparison test result shows that the small-seed pumpkin stock variety 'Sizhang No. 10' grafting 'early and good' does not find the plants infected with the watermelon fusarium wilt, the incidence rate of the fusarium wilt of self-rooted seedlings is 0-20%, the average incidence rate is 11.1%, and the 'Sizhang No. 10' grafting can be used for effectively preventing and treating the watermelon fusarium wilt.

Thirdly, the characteristic characteristics of the small seed type pumpkin rootstock variety obtained by the invention

The small-seed pumpkin stock variety 'Sizhang No. 10' is a first-generation hybrid of Indian pumpkin and Chinese pumpkin, the plant is vining, and the root system is developed; the stem is pentagonal and dark green; a blade palm shape; aborting anthers; the first female flower nodes are 9-12 sections of main vines, the main vines can bear fruits, the fruits are oblate, tender fruit peels are yellow and have white spots, and the aged melons are orange and have white spots; the fruit development period is about 45 days, and the weight of a single fruit is 0.8-1.2 kg; the seed coat is white, and the thousand seed weight of the seeds is 105-115 g. Identified by the plant of Zhejiang agricultural department, the watermelon wilt disease can be resisted highly.

The small-seed pumpkin stock variety 'Sizhuang No. 10' has developed main root, strong fertility absorption, steady growth vigor, long grafting adaptability, little possibility of overgrowth and hollowness of hypocotyl, good grafting affinity and more than 94% of grafting survival rate with watermelon varieties such as 'Zaojia'; the symbiotic affinity is strong, the low temperature resistance and the high temperature resistance are both strong, the growth vigor of the grafted early-good watermelon is stronger than that of self-rooted seedlings, and the fruit setting is easy; the first batch of melons bloom in spring to be harvested for 35-38 days and 25-27 days in summer and autumn; 'Sizhang No. 10' is slightly less resistant to moisture.

The small seed type pumpkin stock variety 'Sizhang No. 10' is different from other stock varieties:

1. the pumpkin hybrid generation is the first filial generation of the pumpkin from India and the pumpkin from China, the seeds are small, the thousand seed weight is 110g (the totipotent armored is 250g), the transverse diameter of the seeds is 7.70mm, the longitudinal diameter is 13.51mm, the thickness is 3.32mm (the totipotent armored is 10.12 multiplied by 19.09 multiplied by 3.82mm), the transverse diameter of the cotyledon in the flattening period of the cotyledon is 3.0cm, the longitudinal diameter is 4.4cm, and the thickness is 0.88cm (the totipotent armored is 4.2 multiplied by 5.7 multiplied by 0.96;

2. the cotyledon area is small, mutual shading is avoided after grafting, the leaf density can be effectively reduced, diseases caused by overlarge seedling humidity are prevented, and grafting and post-grafting management are easy.

3. Is suitable for 50-hole tray seedling, has regular budding, ensures that the hypocotyl is not easy to hollow and overgrow, has stable growth condition and high grafting survival rate.

Fourthly, the suitable planting range

The small-seed pumpkin stock variety 'Sizhang No. 10' is suitable for the grafting of watermelons such as 'Zaojia' (8424) and the like and is suitable for facility cultivation in similar ecological areas around Zhejiang. The variety has weak moisture resistance, and is not suitable for being planted in rainy areas and in plots and open field cultivation with high soil moisture.

Fifth, the technical points of grafting cultivation

1. Grafting seedling raising

The stock and the scion adopt seeds which are sterilized. The seedlings are grown from 12 to 2 months in spring and 7 months in autumn. Seedling is cultivated by using 50-hole plug trays. Grafting is preferably carried out by adopting a grafting method, and the rootstock is sowed 5-7 days earlier than the scion. The grafting tools are often sterilized during grafting. The temperature is controlled to be 25-28 ℃ in the first 3 days after grafting, the relative humidity of air is about 95%, and direct strong light irradiation is avoided; gradually reducing the temperature from the 4 th day after grafting, and ventilating and cooling; and managing according to the common seedlings after 7-10 days. 3-4 leaves and 1 heart field planting in spring, wherein hardening off seedlings is carried out 25-35 days after general grafting; 1-2 leaves and 1-heart permanent planting in autumn, and generally 10-15 days after grafting.

2. Soil preparation and field planting

The width of the ridge is 2.5m (with the ditch), and the height of the ridge is more than 20 cm. Soil preparation and fertilization are carried out 30 days before planting. Compared with the self-rooted seedlings, the fertilizer needs to be applied by more than 20 percent less, nitrogen fertilizer is applied less, and phosphorus and potassium fertilizer is applied additionally. Applying base fertilizer per mu: 1000kg of decomposed organic fertilizer, 25-30 kg of Norway compound fertilizer, 10kg of potassium sulfate and 25 kg of calcium magnesium phosphate fertilizer, wherein 70 percent of the decomposed organic fertilizer, the Norway compound fertilizer and the calcium magnesium phosphate fertilizer are turned into soil, and 30 percent of the decomposed organic fertilizer, the Norway compound fertilizer and the calcium magnesium phosphate fertilizer are applied in ditches. Leveling the ridge surface, watering in proper amount, laying drip irrigation, and covering with mulching film. The planting distance is 40-50 cm, and each 667m²Planting 300-500 plants, wherein the grafting port is 1cm higher than the soil surface during planting.

3. Management of fertilizer and water

7-10 days after fruit setting, every 667m²15kg of multi-element compound fertilizer and 10kg of potassium sulfate (water fertilizer) are applied.

4. Pruning

Generally, a three-vine pruning method is adopted, 2 strong lateral vines are selected and reserved among 5-8 main vines, and the rest are removed completely. The soil cannot be buried to press the vines so as to avoid the diseases caused by the generation of adventitious roots on the nodes.

5. Pollination melon

And (3) timely removing the 1 st female flower, selecting the female flower at the 2 nd or 3 rd node for pollination, keeping the melon, pollinating within 3 hours after the male flower is opened in the morning, slightly pinching the stem of the male flower by hands, removing the petals of the male flower, uniformly coating pollen on 3 stigma heads of the female pistils until obvious yellow pollen grains are on the stigma heads of the female pistils. If the stems of the female cucumbers stretch and bend in afternoon on the 2 nd day, the ovaries are obviously expanded, which indicates successful pollination; if the cucumber stem is stretched upwards or forwards, no pollination is given, and then pollination is carried out on the next female flower. 1 melon is sat for each batch.

6. Harvesting at the right time

The Zaojia watermelon seed is thin in melon peel and easy to crack, and can be harvested 30-40 days after pollination when the small ear leaves are yellow and withered and the melon peel is bright and ripe.

7. Pest control

The watermelon diseases mainly comprise downy mildew, powdery mildew, bacterial angular leaf spot, blight and the like, and insect pests comprise leaf miner, aphid and the like.

Sixthly, the technical points of seed production

1. Number of seedlings grown

The planting proportion of the male parent to the female parent is 1: 8. the cultivation density of female parents per mu in Ningbo areas is 330 plants, and the number of the male parents needing seedling is calculated according to the cultivation density.

2. Seedbed preparation

The sowing time is 3 middle ten days, and seed soaking and germination accelerating are carried out before sowing. Soaking seeds in warm water at 30 ℃ for 4-6 hours, cleaning the seeds after soaking, wrapping the seeds with a wet towel, accelerating germination at 25-28 ℃, and sowing when the seeds are exposed to the white. And (3) picking the germinated seeds, sowing the seeds into a 10cm nutrition pot (paving an electric heating line below the nutrition pot before sowing), well performing seedling stage management work, cultivating strong seedlings, and planting 2-3 true leaves.

3. Preparation before planting

The pumpkin seeds are planted in the soil with good drainage, good illumination and fertile soil, and the pumpkin seeds are not planted in 1000 meters around the soil. And (3) ploughing the land in the middle ten days of 3 months to fully dry the soil, making furrows in the last ten days of 3 months, wherein the furrow width is 3.0m, the furrow width is 0.4m, the furrow depth is 0.3m, and ditching and applying a base fertilizer near the two sides of the furrow. Base fertilizer per mu: 2000kg of decomposed animal manure, 15kg of compound fertilizer, 20kg of calcium superphosphate and 1kg of borax, and a black mulching film with the width of 135cm is paved in the center of the furrow.

4. Father Honda management

In order to ensure that the male flowers are more differentiated and completely developed, the high temperature in the small arched shed is kept, and the temperature is controlled to be 20-35 ℃ in the daytime. All the melon vines are allowed to grow freely, and a large number of male flowers are guaranteed for pollination.

5. Female parent cultivation

And (4) topping the seedlings when the seedlings have 1 leaf and 1 heart, reserving 2 strong vines for each plant, and discarding the rest as early as possible. And in the process of extending the minor tendrils, the grand tendrils are timely wiped off, male buds at axilla parts of each leaf are thoroughly wiped off until topping is carried out, and the tendrils are pressed at the positions of 0.5m and 1.5m of the minor tendrils, so that the adventitious roots are promoted to rapidly occur. The length of the seed vines is 2.5-3 m. And (4) when each vine has 2-3 female buds, the tops of the subsidiary vines can be pinched off.

6. Artificial pollination

7, every day: about 00, female flowers of the female parent are opened. Pollination should be immediate. Taking 1 flower of the male parent, removing the remaining stamen of the corolla, and lightly and uniformly smearing the stamen on the stigma of the female parent. To improve the setting rate. Every male parent male flower can be pollinated for 1 ~ 3 female parent female flowers, and the female parent corolla is carried with the iron wire after the pollination is finished, prevents that insect and other pollen from getting into to guarantee seed purity. The pollination period is 15-20 days.

7. Topdressing

And (3) topdressing 10kg of compound fertilizer per mu after fruit setting, and topdressing 15kg of compound fertilizer per mu after the fruits grow to the middle and later stages.

8. Pest control

The diseases are mainly used for preventing and treating virus diseases and powdery mildew. The virus diseases can be controlled by alternately spraying virus A, ribavirin and the like: before and after the powdery mildew occurs, the powdery mildew is alternately prevented and controlled by fenamidote, difenoconazole and the like. The pests mainly control aphids, cotton bollworms, diamondback moths and the like. The aphids can be controlled by imidacloprid and pymetrozine by alternate spraying; cotton bollworm, diamondback moth, etc. are alternatively controlled by 20% chlorantraniliprole, cyflufenamide, etc.

9. Harvesting

And when the female parent female flowers pollinate for 45-50 days, the pumpkin peels of the pumpkins are aged to be orange, and the pumpkin seedlings are basically dry (about 7 ten days later). Firstly picking the melons, intensively placing the melons in a cool and dry place, and fully after-ripening the melons for 7-10 days. Before breaking melon, the melon is soaked in copper aqua regia to prevent bacterial diseases. Cutting melon, taking seed, rinsing seed in clear water, and adding 2% H₂O₂Treating for 15-20 min, repeatedly airing on the suspended gauze for about 3d, and storing after the seeds are completely dried. The melon can not be dissected and seeds can not be taken in rainy days, and the wet seeds are strictly prohibited to be directly sunned on the cement ground.

10. Yield of the product

In northwest seed production, the seed yield per mu is 30-40 kg, the purity is 98%, the germination rate is more than 85%, and the water content is less than 8%.

Example 2 comparison test of Small seed type pumpkin stock variety 'Sizhang No. 10' obtained by seed selection

The summary content of the comparative test results of 'Sizhang No. 10' varieties in 2016-2017 years

1 general description of the test

In order to examine and identify the adaptability, disease resistance and grafting performance of a newly bred small-seed pumpkin rootstock variety 'Sizhang No. 10' as well as the properties such as watermelon quality, yield and the like, a 'totipotent armored' rootstock (CK1) and a 'early-excellent' self-rooted seedling (CK2) are used as controls. A multi-point test is carried out for many years in 2016-2017. The test points are Ningbo high and new agricultural technology laboratory park (Ningbo), Green wild fruit and vegetable professional cooperative society of Pinghu city (Pinghu), and Deqing Xintian agricultural science and technology Limited (Deqing), respectively.

2 results and analysis

1) Phenological period

Table 1 multipoint species comparison test phenological period summary units: day/month/day

As can be seen from table 1, the small-seed type pumpkin stock variety ' sizhang No. 10 ' early-good ' blooms 1 to 2 days earlier than ' all-round armored ' control, blooms 1 to 3 days earlier than the self-rooted seedling, and the main reason is that the grafted seedling has better low temperature resistance and grows faster than the self-rooted seedling in early spring. The fruit development period is basically consistent and is 33-35 days.

2) Grafting character

The test results show (as shown in table 2), the small-seed type pumpkin stock variety 'Sizhuang No. 10' seedling has stable growth vigor, is not easy to hollow and overgrow, is favorable for grafting operation, the average survival rate of the grafted 'Zaojia (8424)' is 94.10%, the survival rate is improved by 4.43% compared with the whole year armored nail, and the grafting affinity with the 'Zaojia (8424)' watermelon is good.

Table 2 'xizhang No. 10' comparison unit with plant traits: % and cm

3) Plant character of grafted seedling

The small-seed pumpkin stock variety 'Sizhuang No. 10' obtained by the invention has developed main root, strong low temperature resistance and rapid growth in spring, the main vine is 205.17cm long when the flower is opened by grafting 'early and good', the main vine is 0.41cm long compared with a contrast 'totipotent armored', and the main vine is 28.83cm long compared with a self-rooted seedling, and the performance difference of a plurality of test points is obvious. The transverse diameter of the main vine of 'Sizhuang No. 10' grafting 'early good' is 0.56cm, is 0.02cm thinner than the contrast 'totipotent armored nail', and is 0.03cm thicker than the self-rooted seedling. The 'Sizhang No. 10' grafting 'early good' has strong growth vigor of self-rooted seedlings, and the growth vigor of the 'all-round armored' grafted seedlings is close to that of the 'all-round armored' grafted seedlings. (as shown in table 2).

4) Fruit character

The character comparison of the ' Sizhang No. 10 ' grafted ' early-good ' fruits of the small-seed pumpkin stock variety obtained by the invention can be seen from the table 3, and the test result shows that the average single fruit weight of the ' Sizhang No. 10 ' grafted ' early-good ' fruits is 4.78-6.10 kg, the average single fruit weight is increased by 0.05kg compared with the average single fruit weight of ' early-good ' (4.75-5.89 kg) grafted by an all-round armored nail ', the average fruit weight is increased by 0.50kg compared with the average fruit weight of ' early-good ' self-rooted seedlings (4.01-5.41 kg), the longitudinal diameter and the transverse diameter of the corresponding fruits are both larger than the self-rooted seedlings, but the shapes (aspect ratio) of. The average thickness of 'Sizhang No. 10' grafting 'Zaojia' peel is 1.13cm, and the thickness of 'Zaojia' peel is 0.04cm, which is 0.08cm thicker than that of 'all-round armored' grafting. The central sugar degree of the 'Sizhang No. 10' grafted 'early-excellent' fruit is 11.40-12.50%, the average sugar degree is 11.93%, and the sugar degree is higher than that of 'all-round armored' grafted 'early-excellent' (11.83%) and self-rooted seedlings (11.80%). The sugar content of the edge of the 'Sizhang No. 10' grafted 'early-good' fruit is 7.48-8.06%, the average is 7.71%, and the sugar content is higher than that of 'all-round armored' grafted 'early-good' (7.66%). 'Sizhang No. 10' grafting 'early good' fruits are crisp in taste, and have no obvious difference with self-rooted seedlings, and 'all-round armored' grafted parts have harder fruits at test points.

Table 3 comparison of the fruit characteristics of Simiao No. 10 'grafting' Zaojia 'and' Universal armored

Unit: kg. cm%

5) Fruit yield

In 2016-2017, variety comparison tests are carried out in Ningbo, Pinghu, Deqing and other places. The statistical result of the yield shows that the 'Sizhang No. 10' grafting 'early good' yield in 2016 (table 4) is 2869-3184 kg.667 m^-2Average value of 3002kg 667m^-2Compared with 'all-round armour' (average yield is 2971g kg 667 m)^-2) The yield is increased by 1.04 percent compared with that of self-rooted seedlings (the average yield is 2536 kg.667 m)^-2) The yield is increased by 18.37 percent. The yield of grafting 'Zaojia' of 'Sizhang No. 10' in 2017 is 3213-3660 kg.667 m^-2Average of 3404kg 667m^-2Compared with 'totipotent armored' (average yield is 3370kg 667 m)^-2) The yield is increased by 1.01 percent compared with the self-rooted seedlings (the average yield is 2992 kg.667 m)^-2) The yield is increased by 13.76%.

The yield of 'Sizhang No. 10' grafting 'Zaojia' is 2869-3660 kg.667 m^-2Average of 3203kg 667m in 2 years^-2Compared with the contrast 'all-round armored' grafting 'early and good' (the average yield is 3171kg 667 m)^-2) 1.02% higher than that of the control (average yield 2764kg 667 m)^-2) The height is 15.88 percent.

Table 4 comparison of 'Sizhang No. 10' grafting 'Zaojia' with 'Universal armored' yield

Unit kg/667m²、％

6) Disease resistance

The blight is the most serious disease in watermelon cultivation, and the watermelon blight can be effectively prevented and controlled by grafting. The grade test results (table 2) show that the small-seed pumpkin stock varieties 'Sizhang No. 10' and 'all-round armored' grafting 'early-good' obtained by the method do not find the plants infected with the watermelon fusarium wilt, the self-rooted seedlings all have diseases in different test fields, the disease incidence is 0-20%, the average disease in 2 years is 11.11%, and the 'Sizhang No. 10' is used as the stock grafting 'early-good' to basically prevent and treat the watermelon fusarium wilt.

3 conclusion of the test

A product ratio test result of 'Sizhang No. 10' grafting 'early-good' of the small-seed pumpkin stock variety obtained in 2016-2017 shows that 'Sizhang No. 10' is stable in growth, hypocotyls are not easy to hollow, excessive growth is resistant, grafting affinity with 'early-good' of a medium-fruit watermelon variety is strong, and grafting survival rate is high; the symbiotic affinity is strong, and the 'Sizhang No. 10' grafting shows high resistance to the prevention and treatment effect of watermelon fusarium wilt. The development period of the grafted early-good fruit is 32-35 days, the average weight of a single melon is 5.34kg, and the early-good fruit is increased by 0.05kg and 0.50kg respectively compared with the 'all-round armored' grafting and the self-rooted seedling; the average sugar degree of the center is 11.93 percent, the average sugar degree of the edge is 7.71 percent, the average sugar degree of the center is higher than that of the early-excellent and self-rooted seedlings grafted by the all-round armored armor, and the taste is not different from that of the self-rooted seedlings. The yield of 'Sizhang No. 10' grafting 'Zaojia' is 2868-3660 kg.667 m^-2Average 3203kg 667m^-2Compared with the contrast of 'all-round armored' grafting 'early-good' is 1.02 percent higher, and compared with the self-rooted seedling is 15.88 percent higher.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A method for breeding small-seed pumpkin stock varieties is characterized in that: the method comprises the following steps:

(1) acquisition of genetic rules

(2) male parent breeding

The male parent of the small seed type pumpkin rootstock variety is derived from a rootstock variety 'Huofenghuang' collected from Shandong and is numbered as SD 08; carrying out systematic breeding on the rootstock material from the spring of the first year; according to the male parent breeding target: the method has the advantages that the root system is developed, the disease resistance and the stress resistance are strong, premature senility is not prone to occurring, the number of single melon seeds is large, the seeds are small and full, through strict selfing screening of 7 generations in 2 seasons per year, the bred single melon seeds have good low temperature resistance, the blossom and fruit setting are earliest, the field stress resistance is good, the number of single melon seeds is large, plants are sprawly, the root system is developed, the growth potential is moderate, leaves have white spots, and the appearance index of fruits is proper, so that the selfing line SD08-5-2-11-8-3-4 meets the male parent breeding target of small seed stock variety breeding; the thousand seed weight is 95-105g, and the seed number of a single melon seed is 220-300;

(3) female parent breeding

The female parent of the small-seed pumpkin stock variety is derived from Shandong watermelon grafting stock variety 'snow white' and is numbered as XB 07; finding male flower fertile pumpkin plants in seedlings of the XB07 snow white rootstock variety in the spring of the next year, and respectively carrying out strict selfing on the male flower fertile pumpkin plants to obtain F2 seeds, wherein the numbers of the seeds are XB 07-1-5; then according to the female parent breeding target: the comprehensive resistance is strong, the root system is developed, the growth vigor is good, female flowers bloom early, the seeds are small, and the number of seeds of a single melon is large; strict selfing screening is carried out for 6 generations in 2 seasons each year, and an inbred line XB07-4-16-3-8-5 with developed main roots, sprawling plants, moderate growth vigor, precocity, nearly round fruits, 1.6-2.0kg of single fruit weight, light orange peel, strong high temperature resistance and low temperature resistance is bred, the thousand seed weight is 110g, and the seed number is 300 grains of 250 grains;

(4) breeding of small seed type pumpkin stock variety

In the fifth autumn, the small-seed pumpkin XB07-4-16-3-8-5 obtained in the step (3) is used as a female parent, the Chinese pumpkin SD08-5-2-11-8-3-4 obtained in the step (2) is used as a male parent for hybridization matching, and a small-seed pumpkin rootstock variety hybridized with the Indian pumpkin and the Chinese pumpkin is obtained, wherein the thousand seed weight is 105-115g, and the single pumpkin seed number is 250-300 grains; and confirming the shape of the bred variety through a variety comparison test.

2. The method for breeding a small-seed pumpkin rootstock variety according to claim 1, characterized in that: the appearance indexes of the fruits in the step (2) are suitable for selecting the fruits with oblate shape, earthy yellow peels, wax powder and 1.4-1.6 kg weight of a single fruit.

3. The method for breeding a small-seed pumpkin rootstock variety according to claim 1, characterized in that: the disease resistance in the step (2) comprises watermelon fusarium wilt resistance, and the identification of the watermelon fusarium wilt resistance is carried out by inoculating and identifying by using a bacterial soil method.

4. The method for breeding a small-seed pumpkin rootstock variety according to claim 1, characterized in that: and (3) the comprehensive resistance comprises watermelon fusarium wilt resistance, and the identification of the watermelon fusarium wilt resistance is carried out by inoculating and identifying by using a bacterial soil method.

5. The method for breeding a small-seed pumpkin rootstock variety according to claim 1, characterized in that: and (4) performing hybridization matching according to the genetic rule of the grain size and the single melon seed number obtained in the step (1).

6. The method for breeding a small-seed pumpkin rootstock variety according to claim 1, characterized in that: confirming the shape of the bred variety through a variety comparison test in the step (3), and specifically comprises the following steps: the small-seed pumpkin stock variety obtained by hybridizing the Indian pumpkin and the Chinese pumpkin is subjected to grafting 'early-good' watermelon variety comparison test in spring, and the test result shows that the pumpkin stock variety obtained by the invention has excellent performance: the grafting survival rate is high, the grafted scion plant has strong growth vigor, the leaves are dark green, the scion plant grows well in early spring under the low-temperature condition, the flowering and fruit setting are 1-3 days earlier than the self-rooted seedlings, the single fruit weight, sugar degree and taste of the scion fruit are not obviously different from those of the self-rooted seedlings, the sugar degree is higher than that of the self-rooted seedlings, the meat quality is crisp, and no peculiar smell is generated; the quality ratio test of the grafted watermelon is carried out again in autumn, and the result shows that the small-seed pumpkin stock variety obtained by the invention has normal plant growth, good high temperature resistance, no obvious difference between the taste and sugar degree of the fruit and the self-rooted seedling, and few malformed fruits; the small-seed pumpkin rootstock variety obtained by the invention has optimal performance in the annual quality ratio test result.