CN111165114A

CN111165114A - Corn seed priming method

Info

Publication number: CN111165114A
Application number: CN202010053764.2A
Authority: CN
Inventors: 郝楠; 王延波; 王成; 李月明; 孙楠; 孙丽惠; 孙甲; 贾卓; 马云祥; 毕文博
Original assignee: Liaoning Academy of Agricultural Sciences
Current assignee: Liaoning Academy of Agricultural Sciences
Priority date: 2020-01-17
Filing date: 2020-01-17
Publication date: 2020-05-19

Abstract

The invention discloses a corn seed priming method, which comprises the following steps: selecting corn seeds, and carrying out disinfection, cleaning and drying treatment; dissolving polyamine in water to obtain polyamine aqueous solution, and mixing to obtain a treatment solution; adding a treatment fluid into the corn seeds, and then carrying out low-temperature initiation; and (3) cleaning and drying the initiated corn seeds, and then sowing or low-temperature storage. The method is simple to operate, easy to master and short in period, and can promote the germination and growth of seedlings and improve the cold resistance under the condition of low temperature after corn sowing.

Description

Corn seed priming method

Technical Field

The invention relates to the technical field of corn planting, in particular to a corn seed priming method.

Background

Corn (Zea maysL.) is the first major food crop in our country and is also an important feed crop, energy crop and industrial raw material in addition to being eaten. Corn belongs to typical temperature-preference crops, low-temperature cold damage is a main limiting factor for high and stable yield of regional corn, and is also one of important natural disasters for damaging corn production in high latitude areas and local hills. The low temperature can reduce the seed vitality, delay the time of seedling emergence, seriously cause the death of seeds or seedlings, cause the shortage and ridge breaking of the seedlings of the corns and poor uniformity of the seedlings emergence, and is one of the important reasons for reducing the corn yield.

In order to eliminate the influence of low-temperature cold damage on the high and stable yield of the corn, the seed activity is improved by adopting a seed initiation technology at the present stage. The seed priming can control the slow water absorption of the seeds, so that the seeds stay in the second stage of imbibition, the pre-germination physiological and biochemical metabolism and repair action of the seeds are performed, the repair of cell membranes, organelles and DNA and the activation of enzyme are promoted, the seeds are in a preparation state of germination, but the radicle is prevented from extending out, the seed vitality and resistance after the seed priming are enhanced, the seed priming is low-temperature resistant, the seedling emergence is fast and uniform, and the seedling rate is high. However, the existing seed priming technology cannot achieve the expected effect and cannot effectively improve the cold resistance of the corn.

Accordingly, providing a seed priming method that promotes germination of corn seeds under low temperature conditions would be a problem that those skilled in the art would be urgently required to solve.

Disclosure of Invention

In view of the above, the invention provides a corn seed initiation method, which is simple to operate, easy to master, and short in period, and can promote seedling germination and growth and improve cold resistance under low temperature conditions after corn sowing.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method of priming corn seeds comprising the steps of:

(1) selecting corn seeds, and carrying out disinfection, cleaning and drying treatment;

(2) dissolving polyamine in water to obtain polyamine aqueous solution, and mixing to obtain a treatment solution;

(3) adding a treatment fluid into the corn seeds, and then carrying out low-temperature initiation;

(4) and (3) cleaning and drying the initiated corn seeds, and then sowing or low-temperature storage.

The beneficial effects of the preferred technical scheme are as follows: the method comprises the steps of mixing polyamine aqueous solution to form treatment liquid, adding the treatment liquid into corn seeds, and enabling the corn seeds to absorb the treatment liquid through low-temperature initiation, so that endosperm is fully swelled; and then the seeds are cleaned and dried to be in a germination preparation state, the restoration of cell membranes, organelles and DNA and the activation of enzyme are promoted under the physiological and biochemical metabolism and restoration effects of pre-germination, but the radicle is prevented from extending out, the vitality and the resistance of the initiated seeds are enhanced, the seeds are low-temperature resistant, the emergence is fast and uniform, and the seedling rate is high.

Preferably, the selected corn seeds in step (1) are full and have no damage; the disinfection is carried out by soaking and standing for 5-10 min by adopting a sodium hypochlorite solution with the mass concentration of 0.3-1%; the cleaning is to take out corn seeds and wash the corn seeds with distilled water; the drying is to firstly suck the moisture on the surface of the corn seeds by using filter paper and then naturally air-dry the corn seeds until the moisture content is less than 13 percent.

The beneficial effects of the preferred technical scheme are as follows: because the seeds are extremely easy to be corroded by insect pests or infected by bacteria in the growth, transportation and storage processes, and simultaneously, the corn embryos are easy to mildew, and the normal growth of the corn is influenced by the mildew caused in the germination process of the seeds. The invention adopts sodium hypochlorite as a disinfectant, can release active chloride ions so as to kill thalli, and can quickly and effectively kill insect pests and bacteria in corn seeds and prevent corn embryos from mildewing due to strong disinfection capability; and the chlorine generated after disinfection is easy to volatilize, and disinfectant residue is not generated, so that the material is not damaged, and the environment is not damaged. The seeds can be dried after being cleaned, so that the contact time of the seeds and the moisture can be reduced, the seeds are quickly dried back to the standard moisture, and the occurrence of imbibition reaction is avoided.

Preferably, the polyamine aqueous solution in step (2) comprises an aqueous spermidine solution, an aqueous spermine solution or an aqueous putrescine solution; the concentration of the spermidine aqueous solution, the spermine aqueous solution and the putrescine aqueous solution is 0.1-0.4 mmol/L.

The beneficial effects of the preferred technical scheme are as follows: the polyamine shows high activity in plants, participates in the main process of plant growth and development, has important relation with the processes of plant seed germination, growth and differentiation, flower development, fruit formation, senescence and the like, and can also improve the stress resistance of plants. The invention adopts polyamine to treat corn seeds, which is beneficial to improving the germination performance, stress resistance and the like of the corn seeds.

Preferably, the treatment solution in the step (2) is prepared by mixing any two of a spermidine aqueous solution, a spermine aqueous solution and a putrescine aqueous solution according to a volume ratio of 1: 1.

The beneficial effects of the preferred technical scheme are as follows: after the plant is stressed by low temperature, the polyamine can be combined to the phospholipid part of the cell membrane, so that the exosmosis of intracellular solutes is prevented, the cold resistance is improved, and the like; meanwhile, trace polyamine plays an important role in rapidly growing tissues (such as radicles, hypocotyls and coleoptiles), and particularly putrescine, spermidine and spermine are closely related to the elongation speed of the growing tissues.

Preferably, the volume ratio of the corn seeds to the treatment liquid in the step (3) is 1 (1.2-1.5).

The beneficial effects of the preferred technical scheme are as follows: under the volume ratio disclosed by the invention, the treatment liquid can immerse the seeds, so that the seeds are completely contacted with the treatment liquid, and the treatment effect is most excellent.

Preferably, the low-temperature initiation in the step (3) is carried out under a dark condition, the temperature is 10-15 ℃, and the time is 48-72 hours.

The beneficial effects of the preferred technical scheme are as follows: the seed initiation is a method for improving the seed vitality, also called osmotic adjustment, the method is initiated for 48-72 hours under the low temperature condition (10-15 ℃), the seeds can stay in the stage 2 of imbibition and water absorption by controlling the slow water absorption of the seeds, and the seeds are in the preparation state of germination through the physiological and biochemical metabolism and restoration effects of pre-germination.

Preferably, the washing in the step (4) is to wash the initiated corn seeds with distilled water quickly; the step of drying back is to suck the moisture on the surface of the corn seeds, and then naturally air-dry the corn seeds at normal temperature until the moisture content is less than 13%.

The beneficial effects of the preferred technical scheme are as follows: the time for contacting the seeds with the moisture can be shortened by cleaning and drying, so that the seeds are quickly dried back to the standard moisture, and the occurrence of imbibition reaction is avoided.

Preferably, the low-temperature storage temperature in the step (4) is 4-10 ℃ and the time is 1-2 months.

The beneficial effects of the preferred technical scheme are as follows: the most easily infected microorganisms of the corn seeds stored at low temperature in the storage process are moulds, the optimal temperature of most of the moulds is 20-40 ℃, and the most of the moulds are lower than the growth temperature of the most of the moulds, so that the growth and the propagation are stopped, the metabolic activity is reduced, and the toxicity is inhibited. Therefore, the corn is stored at 4-10 ℃, the environmental temperature of the corn organisms can be controlled, the growth and the propagation of harmful organisms are limited, and the aging of the corn quality is delayed.

According to the technical scheme, compared with the prior art, the corn seed priming method disclosed by the invention has the following beneficial effects:

(1) the method disclosed by the invention is simple to operate, the process is easy to control, the adopted raw materials are simple, and the cost is low;

(2) can promote the germination and growth of seedlings under the condition of low temperature after the corn is sowed, and improve the cold resistance.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 accompanying drawing is the effect of priming corn seeds of example 1 or comparative example 1 on corn emergence rate (-ck for treatment according to comparative example 1 and-SpdSpm for treatment according to example 1);

FIG. 2 accompanying drawings is the effect of priming corn seeds of example 1 or comparative example 1 on shoot height (-ck for treatment according to comparative example 1 method, -SpdSpm for treatment according to example 1);

FIG. 3 is a graph showing the effect of priming corn seeds in example 1 or comparative example 1 on root length (ck for treatment according to comparative example 1 and SpdSpm for treatment according to example 1);

FIG. 4 is a graph showing the effect of priming corn seeds of example 1 or comparative example 1 on the fresh weight of seedlings at seedling stage of corn (ck for treatment according to comparative example 1 and SpdSpm for treatment according to example 1);

FIG. 5 is a graph showing the effect of priming corn seeds of example 1 or comparative example 1 on the fresh weight of corn seedling roots (-ck for treatment according to comparative example 1 and-SpdSpm for treatment according to example 1);

FIG. 6 is a graph showing the effect of priming corn seeds of example 1 or comparative example 1 on the dry weight of seedlings at seedling stage of corn (ck for treatment according to comparative example 1 and SpdSpm for treatment according to example 1);

FIG. 7 accompanying drawing is the effect of priming corn seeds of example 1 or comparative example 1 on dry weight of corn seedling stage roots (-ck for treatment by comparative example 1 method, -SpdSpm for treatment by example 1 method);

FIG. 8 is a photograph of a corn seedling from a seed of corn according to example 1 or comparative example 1 (ck for treatment according to comparative example 1 and SpdSpm for treatment according to example 1);

FIG. 9 accompanying drawing shows POD activity of primed corn seeds of example 1 or comparative example 1 (-ck for treatment by the method of comparative example 1, -SpdSpm for treatment by the method of example 1);

FIG. 10 accompanying figures is the SOD activity of seed corn from example 1 or comparative example 1 (ck for comparative example 1 treatment and-SpdSpm for example 1 treatment);

FIG. 11 accompanying drawing is MDA activity of corn seed primed according to example 1 or comparative example 1 (-ck for treatment according to comparative example 1 method, -SpdSpm for treatment according to example 1);

FIG. 12 accompanying drawing is the effect of priming corn seed on corn emergence rate of example 2 or comparative example 2 (-ck for treatment by comparative example 2 method, -SpmPut for treatment by example 2 method);

FIG. 13 accompanying drawing is the effect of priming corn seeds for example 2 or comparative example 2 on shoot length (-ck for treatment by comparative example 2 method, -SpmPut for treatment by example 2 method);

FIG. 14 accompanying graph shows the effect of priming corn seeds for example 2 or comparative example 2 on shoot weight (-ck for treatment by comparative example 2 method, -SpmPut for treatment by example 2 method);

FIG. 15 accompanying drawing is the effect of priming corn seed for example 2 or comparative example 2 on root length (-ck for comparative example 2 method treatment, -SpmPut for example 2 method treatment);

FIG. 16 accompanying graph shows the effect of priming corn seeds for example 2 or comparative example 2 on root weight (-ck for treatment by comparative example 2 method, -SpmPut for treatment by example 2 method);

FIG. 17 is a graph showing the effect of priming corn seeds of example 3 or comparative example 3 on corn germination (ck for comparative example 3 treatment and SpdPut for example 3 treatment);

FIG. 18 accompanying figure is the effect of priming corn seeds for example 3 or comparative example 3 on shoot length (-ck for treatment by comparative example 3 method, -SpdPut for treatment by example 3 method);

FIG. 19 is a graph showing the effect of priming corn seeds in example 3 or comparative example 3 on shoot weight (-ck for treatment by the method of comparative example 3, -SpdPut for treatment by the method of example 3);

FIG. 20 is a photograph of a corn seedling from a corn seed in accordance with example 3;

FIG. 21 accompanying figure is the effect of priming corn seeds for example 3 or comparative example 3 on root length (-ck for treatment by comparative example 3 method, -SpdPut for treatment by example 3 method);

FIG. 22 is a graph showing the effect of priming corn seeds for example 3 or comparative example 3 on root weight (-ck for treatment by comparative example 3 method, -SpdPut for treatment by example 3 method);

FIGS. 23-26 accompanying drawings show the effect of priming corn seeds of example 1 or comparative example 1 on field germination rate (-CK represents treatment by comparative example 3 method, -treatment represents treatment by example method);

FIGS. 27-35 are graphs showing the effect of priming corn seeds in example 1 or comparative example 1 on malondialdehyde content of various corn hybrids under low temperature stress (-ck for treatment by the method of comparative example 3 and-SpdPut for treatment by the method of example 3).

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention discloses a corn seed priming method, which comprises the following steps:

(1) selecting full and undamaged corn seeds, adding a sodium hypochlorite solution with the mass concentration of 0.3-1%, soaking and disinfecting for 5-10 min, taking out the corn seeds, and washing the corn seeds with clean water; then, absorbing the moisture on the surface of the corn seeds by using filter paper, and naturally drying the corn seeds until the moisture content is less than 13%;

(2) respectively dissolving spermidine, spermine or putrescine in water to prepare a spermidine aqueous solution, a spermine aqueous solution or a putrescine aqueous solution with the concentration of 0.1-0.4 mmol/L, and mixing any two of the spermidine aqueous solution, the spermine aqueous solution and the putrescine aqueous solution according to the volume ratio of 1:1 to obtain a treatment solution;

(3) uniformly arranging corn seeds with downward embryos, adding a treatment solution into the corn seeds according to a volume ratio of 1 (1.2-1.5), and initiating for 48-72 hours at 10-15 ℃ in the dark;

(4) and (3) rapidly washing the initiated corn seeds with distilled water, then sucking the surface water of the corn seeds, naturally drying at normal temperature until the water content is less than 13%, thus obtaining the initiated corn seeds, and directly sowing or sowing after storing at low temperature of 4-10 ℃ for 1-2 months.

Example 1

The embodiment 1 of the invention discloses a corn seed priming method, which comprises the following steps:

(1) selecting full and undamaged corn seeds, adding a sodium hypochlorite solution with the mass concentration of 0.3%, soaking and sterilizing for 10min, taking out the corn seeds, and washing the corn seeds with clean water; then, absorbing the moisture on the surface of the corn seeds by using filter paper, and naturally drying the corn seeds until the moisture content is less than 13%;

(2) respectively dissolving spermidine (Spd) in water to prepare a spermidine aqueous solution with the concentration of 0.25mmol/L, simultaneously dissolving spermine (Spm) in water to prepare a spermine aqueous solution with the concentration of 0.25mmol/L, and mixing according to the volume ratio of 1:1 to obtain a treatment solution;

(3) uniformly arranging 50 corn seeds in each germination box filled with two layers of filter paper, adding 0.25mmol L of downward embryo^-1Spermidine and 0.25mmol L^-110mL of the treatment solution of the spermine solution is added with 1mL of 0.3% NaClO, and the mixture is initiated for 72 hours at 15 ℃ in the dark;

(4) quickly washing the initiated corn seeds with distilled water, then sucking the surface water of the corn seeds, naturally drying at 25 ℃ until the water content is less than 13%, and immediately sowing.

Example 2

The embodiment 2 of the invention discloses a corn seed priming method, which comprises the following steps:

(1) selecting full and undamaged corn seeds, adding a sodium hypochlorite solution with the mass concentration of 0.1%, soaking and sterilizing for 10min, taking out the corn seeds, and washing the corn seeds with clean water; then, absorbing the moisture on the surface of the corn seeds by using filter paper, and naturally drying the corn seeds until the moisture content is less than 13%;

(2) respectively dissolving putrescine (Put) and spermine (Spm) in water to prepare a putrescine aqueous solution and a spermine aqueous solution with the concentration of 0.1 mmol/L;

(3) in the germination box padded with two layers of filter paper, 50 corn seeds are uniformly arranged in each germination box, and 10mL of 0.1mmol L of embryo is added downwards^-1Putrescine, 10mL of 0.1mmol L^-1Spermine solutions were mixed with 1mL of 0.1% NaClO, and then the mixture was initiated in the dark at 10 ℃ for 48 hours;

(4) and (3) rapidly washing the initiated corn seeds with distilled water, then sucking the surface water of the corn seeds, naturally drying at 25 ℃ until the water content is less than 13%, thus obtaining the initiated corn seeds, and performing field sowing after low-temperature storage for 1-2 months.

Example 3

The embodiment 3 of the invention discloses a corn seed priming method, which comprises the following steps:

(1) selecting full and undamaged corn seeds, adding a sodium hypochlorite solution with the mass concentration of 0.2%, soaking and sterilizing for 10min, taking out the corn seeds, and washing the corn seeds with clean water; then, absorbing the moisture on the surface of the corn seeds by using filter paper, and naturally drying the corn seeds until the moisture content is less than 13%;

(2) respectively dissolving spermidine (Spd) and putrescine (Put) in water to prepare a spermidine aqueous solution and a putrescine aqueous solution with the concentration of 0.4 mmol/L;

(3) adding 10mL of 0.4mmol L into a germination box filled with two layers of filter paper^-1Spermidine, 10mL of 0.4mmol L^-1Putrescine solution and 1mL of 0.2% NaClO, 50 seeds were uniformly arranged in each germination box, and the germination was initiated at 13 ℃ in the dark for 70 hours, during which no radicle sticking out was observed.

(4) After the initiation is finished, the seeds are quickly washed clean by distilled water, and surface water is sucked dry and dried back to the original water content at 25 ℃.

Comparative example 1

The steps (2) to (4) in example 1 were omitted, and the other operations and technical parameters were the same as those in example 1.

Comparative example 2

The steps (2) to (4) in example 2 were omitted, and the other operations and technical parameters were the same as those in example 2.

Comparative example 3

The steps (2) to (4) in example 3 are omitted, and the other operations and technical parameters are the same as those in example 3.

Effect verification

Seed germination effect

1. Materials and methods

1) The tested materials are a cold-resistant inbred line 2386 and a cold-sensitive inbred line 6082 of the corn screened in the early stage experiment;

2) priming corn seeds by the methods disclosed in example 1 and comparative example 1, respectively;

3) and (3) low-temperature imbibition germination of seeds: after the seeds are imbibed for 48h at a low temperature of 5 ℃, the seeds are transferred to a temperature of 25 ℃ for germination for 7d, the germination rate is counted, and the property indexes of seedling length, root length, seedling weight, root weight and the like are measured, and the obtained results are shown in attached figures 1-7;

4) and (3) measuring physiological and biochemical indexes: after the priming and control seeds were imbibed in the dark in an illumination incubator at 5 ℃ for 0h, 12h, 24h, 36h and 48h, the maize embryos were manually peeled off for determination of the SOD and POD activities and the MDA content of the embryos, and the results obtained were repeated three times as shown in FIG. 3.

As can be seen from the results in fig. 1 to 8, the results of statistical analysis of the germination rate of the seeds after low-temperature treatment show that the germination rate (90.67%) of the jeao 2386 is significantly higher than that (83.33%) of the jeao 6082, and the germination rate of the seeds after being treated with polyamine initiator is significantly increased, wherein the germination rate of the jeao 6082 is significantly increased by 12%. Analysis results of seedling height, root length, seedling fresh weight, root fresh weight, seedling dry weight, root dry weight and the like show that after the seeds are initiated by polyamine, the seedling height, the seedling fresh weight and the seedling dry weight are obviously improved, and the root length, the root fresh weight and the root dry weight are obviously reduced, which indicates that the root of the corn in the seedling stage is more sensitive to polyamine. The germination rate, seedling height, fresh weight and dry weight of the seedling of the Liao 6082 cold-sensitive inbred line are greatly improved, which shows that the polyamine initiator with the concentration has good promotion effect on the growth and development of the seeds under the low-temperature condition.

From the results of fig. 9 to 11, it can be known that, when physiological index measurement is performed on maize seed embryos initiated by polyamine at different times under low temperature, the activities of SOD and POD of the uninitiated seed (CK) in comparative example 1 are significantly higher than those of the jew 2386 embryo in 0h, 12h, 24h, 36h and 48h 5 imbibition periods, while the MDA content is relatively low, which indicates that the jew 2386 has stronger low temperature stress resistance compared with the jew 6082. With the extension of low-temperature imbibition time, the SOD activity generally shows a trend of rising first and then falling, wherein the SOD activity is more remarkably improved after polyamine initiation, and the SOD activity reaches a peak in 36h, while the SOD activity reaches a peak in 12h, which indicates that the SOD activity is more sensitive to polyamine initiators in Liao 2386. POD activity generally shows a decreasing trend, but POD activity reached the second peak at 36h after polyamine initiation in Liao 6082.

In addition, tests verify that the two corn materials used have difference in cold resistance during seed imbibition, and the strong adaptability of the Liao 2386 embryo to oxygen free radical scavenging capacity and low temperature adversity is better than Liao 6082 in low temperature stress period in imbibition as can be seen from indexes such as antioxidant enzyme activity and malonaldehyde content. And the polyamine initiators Spd and Spm can effectively improve the activities of antioxidant enzymes SOD and POD of the maize embryos under the stress of medium and low temperature in imbibition, reduce the content of malondialdehyde, enhance the antioxidant capacity of seeds and improve the germination capacity of the seeds.

Second, field test effect

1. Materials and methods

1) The tested materials are two corn hybrids of Liaoning Suzhou cultivars Liaodan 565 and Liaodan 575;

2) priming corn seeds by the methods disclosed in example 2 and comparative example 2, respectively;

3) and (3) seed field emergence investigation: the results of the field germination rates of the seeds obtained by sowing in 2018, 5 and 6 days in the experimental base of the rural institute of liaoning province and surveying the dry matter accumulation amount of the corn root and seedling traits and the like respectively during the period and after the seedlings emerge stably are shown in fig. 12.

As can be seen from the results in fig. 12, both corn varieties had higher field rates of emergence after priming (example 2) than the untreated (comparative example 2) seed. The germination rate of Liaodan 575 (85%) was higher than that of the untreated control (77%), and the germination rate of Liaodan 565 (64%) was higher than that of the untreated control (48%), and the stress encountered by the seeds in the actual field situation was greater than that given in the laboratory. After the seeds are treated by the polyamine initiator, the germination rate is obviously improved, which shows that the polyamine initiator with the concentration has good promotion effect on the growth and development of the seeds of the corn in the early spring low-temperature environment.

From the results shown in fig. 13 to 16, it can be known that, when the dry matter accumulation index of field seedling emergence is measured for corn seeds of different varieties initiated by polyamine under low temperature, the analysis results of seedling height, root length, seedling dry weight, root dry weight and the like show that, after the seeds are initiated by polyamine, the seedling height and seedling fresh weight are significantly higher than those of the uninitiated seeds (CK). Whereas the effects of polyamine-induced root length and root dry weight are not significant. The result shows that the polyamine initiator with the concentration has a remarkable overground promoting effect on the field growth of the corn.

Third, seed germination effect

1. Materials and methods

1) The tested materials are 9 varieties of maize hybrids, namely Beijing 968, Beijing 665, GL1409, MC278, MC703, Liaodan 575, Liaodan 565, Liaodan 707 and Liaodan 1281.

2) Priming corn seeds by the methods disclosed in example 3 and comparative example 3, respectively;

3) and (3) low-temperature imbibition germination of seeds: and after the seeds are imbibed for 48h at a low temperature of 5 ℃, the seeds are transferred to a temperature of 25 ℃ for germination for 7d, the germination rate is counted, and the property indexes of seedling length, root length, seedling weight, root weight and the like are measured, and the obtained results are shown in attached figures 17-26.

4) And (3) measuring physiological and biochemical indexes: after the priming and control seeds were imbibed in the dark in an illumination incubator at 5 ℃ for 0h, 12h, 24h, 36h and 48h, the maize embryos were manually peeled off for determination of the MDA content of the embryos, and the results obtained were repeated three times as shown in FIGS. 27-35.

FIG. 17 shows the statistical results of seed germination traits after initiation treatment, and the germination rates of various hybrid seeds are improved after polyamine initiator treatment, wherein the germination rates are improved by 14% and 9% after Peking 665 and Liaodan 1281 treatment; the difference between GL1409 and Liaodan 565 is obviously increased by 7%; the germination rate of other varieties is improved after polyamine treatment.

FIGS. 18 to 19 show the results of the aerial part seedling trait analysis, after most of the hybrid seeds are initiated by polyamine, the dry weight of the high seedling is increased to some extent, and the varieties have differences, wherein the length of the Jingke 665 seedling is increased significantly, but the increase of the dry weight is not significant; no increase in seedling height was observed after polyamine treatment with Liaodan 565 and Liaodan 707, and no increase in the weights of GL1409, MC278 and MC703 seedlings. Indicating that the application of this concentration of polyamine initiator did not promote growth and development in these several varieties.

Fig. 21 to 22 show root property analysis results of underground parts, the root length and the root dry weight of kyoto 665, GL1409, MC278, MC703 and liao single 1281 after polyamine treatment are obviously improved, and the root shape of other varieties after polyamine treatment is not changed greatly. Indicating that the application of polyamine initiator at this concentration has a different effect on seed root growth under the appropriate conditions.

And FIGS. 23-26 show that the field germination rate is the most direct index which truly reflects the activity level of the seeds, the polyamine low-temperature treated and untreated corn hybrid seeds are sowed in the field in 2019 spring, and the field germination rates are counted at 10d, 15d and 20d respectively. The germination rate trend of each variety after polyamine treatment is higher than that of the variety without polyamine treatment, and the average air temperature of the Shenyang region in May is calculated to be 19.4 ℃ according to meteorological data, so that the activity of the seeds can be improved and the germination rate can be increased by polyamine treatment under the condition of low-temperature stress.

Fig. 27 to 35 show the results of measuring physiological indexes of maize seed embryos induced by polyamines at four imbibition periods of 0h, 12h, 24h and 48h under low temperature conditions, which indicate that the MDA content of five varieties of kyoto 968, kyoto 665, GL1409, MC278 and MC703 is in a reduction trend after polyamine treatment, and indicate that the cell self-repair capacity of the varieties is improved, the membrane lipid peroxidation degree is reduced, the cells are less damaged, and the cold resistance is enhanced after polyamine treatment. However, the MDA content of the Liaodan 575, Liaodan 565, Liaodan 707 and Liaodan 1281 is not reduced by polyamine treatment with the concentration, which is probably related to that the MDA content of the four varieties is lower at each time point and the varieties have stronger cold resistance. After the seeds are initiated by polyamine, the polyamine can effectively improve the content of malondialdehyde of the maize embryos under low-temperature stress, enhance the oxidation resistance of the seeds, improve the germination capacity of the seeds and improve the vitality of the seeds. Thus, it was shown that: the polyamine not only has an important regulation and control function on the growth and development of corn seedlings, but also has an important significance on the aspect of improving the stress resistance of plants.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of priming corn seeds comprising the steps of:

2. The method of claim 1, wherein said selected corn seeds in step (1) are full and have no breakage; the disinfection is carried out by soaking and standing for 5-10 min by adopting a sodium hypochlorite solution with the mass concentration of 0.3-1%; the cleaning is to take out corn seeds and wash the corn seeds with clean water; the drying is to firstly suck the moisture on the surface of the corn seeds by using filter paper and then naturally air-dry the corn seeds until the moisture content is less than 13 percent.

3. The method of claim 1, wherein the polyamine aqueous solution in step (2) comprises an aqueous spermidine solution, an aqueous spermine solution, or an aqueous putrescine solution; the concentration of the spermidine aqueous solution, the spermine aqueous solution and the putrescine aqueous solution is 0.1-0.4 mmol/L.

4. The method for initiating corn seeds as claimed in claim 3, wherein the treating solution in step (2) is a mixture of any two of spermidine aqueous solution, spermine aqueous solution and putrescine aqueous solution at a volume ratio of 1: 1.

5. The corn seed priming method of claim 1, wherein the volume ratio of the corn seeds to the treatment solution in step (3) is 1 (1.2-1.5).

6. The method for initiating corn seeds as claimed in claim 5, wherein the low temperature initiation in step (3) is performed under dark conditions at 10-15 ℃ for 48-72 hours.

7. The method of claim 6, wherein the corn seeds in step (3) are uniformly aligned with the embryos facing downward.

8. The method for priming corn seeds as recited in claim 1, wherein said washing in step (4) is a quick rinsing of the primed corn seeds with distilled water; the step of drying back is to suck the moisture on the surface of the corn seeds, and then naturally air-dry the corn seeds at normal temperature until the moisture content is less than 13%.

9. The method for priming corn seeds as recited in claim 8, wherein said low temperature storage in step (4) is at a temperature of 4-10 ℃ for 1-2 months.