Composite initiator for improving germination rate of broccoli seeds and application thereof

Abstract

The invention discloses a composite initiator for improving the germination rate of broccoli seeds and application thereof, relates to the technical field of seed science, and is characterized in that the composite initiator is a mixed solution of potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000). Exemplary experimental data provided by the invention show that the potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000) composite initiator provided by the invention is very remarkable in improving the germination rate of old broccoli seeds, and the effect of the potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000) composite initiator is higher than that of a monoinitiator independently used with a potassium dihydrogen phosphate solution or a polyethylene glycol solution; the problems that the activity of broccoli seeds is reduced, the germination rate is low, seedlings emerge irregularly, the growth vigor is weak and the like due to factors such as unsuitable storage conditions or too long storage time in production can be efficiently solved.

Description

Technical Field

[0001] The invention belongs to the field of seed science and technology, and particularly relates to a composite initiator for improving the germination rate of broccoli seeds and application thereof. Background Art

[0002] Seeds are important agricultural production materials. Seeds reach their highest vitality when they are physiologically mature. When seeds enter the storage or dormancy stage, due to unsuitable storage conditions or long storage time, seed vitality gradually decreases and inevitably ages, resulting in reduced seed quality and uneven seed vitality, which in turn will cause phenomena such as reduced seed germination rate, uneven seedling emergence, and slow growth, causing field management difficulties and huge economic losses for growers. Therefore, how to improve seed vitality and effectively reduce the amount of seeds used is a problem that most producers are concerned about.

[0003] Seed priming is an effective method to improve seed vitality and promote seed germination. This technology is used to improve seed germination rate and uniformity of seed germination. Seed priming can be carried out through a variety of methods such as hormone regulation, osmotic regulation, temperature regulation, etc. Commonly used liquid initiators include inorganic salts and organic compounds, among which inorganic salts include MgCl2, CaCl2, KCl, NaCl, KH2PO4, K2HPO4, K3PO4, etc.; organic compounds include organic macromolecular compounds such as polyethylene glycol (PEG) and chitosan (CTS), as well as various plant growth regulators. For different crop seeds, the chemical reagent composition and effective concentration of the initiator vary greatly. At present, more research is on initiators of single chemical reagents, and there are few reports on initiators of chemical reagent combinations that improve seed germination rate.

[0004] Broccoli is one of the most important vegetable crops that is widely cultivated in the world. The quality of broccoli seeds is directly related to the yield and quality of broccoli products. Unsuitable storage conditions or long storage time will reduce the vitality of broccoli seeds, leading to low germination rate of broccoli seeds, uneven germination of broccoli seedlings, weak growth of seedlings, etc., which will eventually seriously affect the yield and quality of broccoli.

[0005] Although there are many studies on initiators that promote the growth of vegetable crop seeds, there are few reports on the development of efficient initiators for broccoli seeds. Currently, there is no suitable initiator for old broccoli seeds in production. Summary of the invention

[0006] In view of the needs and gaps in the above-mentioned field, the present invention provides a composite initiator capable of improving the germination rate of broccoli seeds, which has important production significance for improving the vitality of broccoli seeds.

[0007] The solution provided by the present invention is as follows:

[0008] A composite initiator for improving the germination rate of broccoli seeds is characterized in that it is a mixed solution of potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000).

[0009] Preferably, the mass volume concentration of potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000) in the composite initiator is: potassium dihydrogen phosphate (KH2PO4) is 500 mg·L -1 ~1×10 3 mg·L -1 , polyethylene glycol (PEG8000) is 1×10 5 mg·L -1 ~2×10 5 mg·L -1 .

[0010] Preferably, the mass volume concentration of potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000) in the composite initiator is: potassium dihydrogen phosphate (KH2PO4) is 0.5×10 3 mg·L -1 , polyethylene glycol (PEG8000) is 1×10 5 mg·L -1 .

[0011] The second aspect of the present invention provides the use of any of the above composite initiators in promoting germination of broccoli seeds, comprising the following steps:

[0012] (1) Pretreatment: Select broccoli seeds of uniform size and fullness, sterilize with 0.5% sodium hypochlorite for 5 min, rinse the seed surface with distilled water 3 times, and dry the moisture on the seed surface;

[0013] (2) Initiation treatment: soaking the broccoli seeds pretreated in step (1) with the composite initiator, wherein the soaking temperature is 18 to 22° C. and the time is 18 to 24 hours.

[0014] (3) Cleaning: After the priming treatment is completed, remove the seeds, rinse with clean water for 2 minutes, and use paper to absorb the moisture on the seed surface.

[0015] Preferably, in step (2), the soaking temperature is 22° C. and the soaking time is 22 hours.

[0016] Preferably, after step (3), the method further comprises placing the seeds in a constant temperature of 30° C. and drying them for 48 hours and then storing them for later use.

[0017] Preferably, after step (3), the broccoli seeds are directly placed in a culture dish covered with two layers of filter paper, an appropriate amount of clean water is added, and the dish is placed in a 25° C. incubator in a dark environment to promote germination of the broccoli seeds.

[0018] The broccoli seed composite initiator provided by the present invention adds potassium dihydrogen phosphate, and the joint action of phosphorus and potassium elements is conducive to improving the seed germination rate, wherein polyethylene glycol can adjust the osmotic potential, and can significantly increase the seed germination rate. The exemplary experimental data provided by the present invention show that the mixed initiator using the chemical reagent combination of potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000), especially the reagent 4 of the specific concentration combination, is very significant for improving the germination rate of old broccoli seeds, and is higher than the effect of using potassium dihydrogen phosphate solution or polyethylene glycol solution single initiator alone. It can efficiently solve the problems of decreased vitality, low germination rate, uneven emergence, weak growth, etc. of broccoli seeds caused by factors such as unsuitable storage conditions or long storage time in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The germination of broccoli seeds of "variety 1" treated with different initiators after germination at 25℃ for 72h;

[0020] Figure 2 The germination rate of broccoli seeds of "variety 1" treated with different initiators was counted after germination at 25℃ for 72h.

[0021] Figure 3 The germination of broccoli seeds of "variety 2" treated with different initiators after germination at 25℃ for 72h;

[0022] Figure 4 The germination rate of broccoli seeds of "variety 2" treated with different initiators was counted after germination at 25℃ for 72h.

[0023] Figure 1-Figure 4 In the experiment, reagent 1 was 1×103mg·L-1 KH2PO4; reagent 2 was 2×105mg·L-1 PEG-8000; reagent 3 was a mixture of KH2PO4 and PEG-8000 with a final concentration of 1×103mg·L-1; reagent 4 was a mixture of KH2PO4 and PEG-8000 with a final concentration of 0.5×10 3 mg·L -1 KH2PO4 and 1×10 5 mg·L -1 PEG-8000 mixture. "**" means that the P value of the two groups of experimental data after t-test is <0.01, that is, the difference is extremely significant. "*" means that the P value of the two groups of experimental data after t-test is <0.05, that is, the difference is significant.

[0024] Figure 5The germination of broccoli seeds of "variety 1" treated with reagent 4 and then dried and then germinated for 72 hours. The treatment reagent in Figure a is pure water; the treatment reagent in Figure b is 0.5×10 3 mg·L -1 KH2PO4 and 1×10 5 mg·L -1 A mixture of PEG-8000.

[0025] Figure 6 The germination rate of broccoli seeds of "variety 1" treated with reagent 4 was counted after drying and germination for 72 hours. The final concentration of reagent 4 was 0.5×10 3 mg·L -1 KH2PO4 and 1×10 5 mg·L -1 Mixture of PEG-8000. “**” indicates that the P value of the two groups of experimental data after t-test is <0.01, that is, the difference is extremely significant.

[0026] Figure 7 The germination of broccoli seeds of "variety 2" treated with reagent 4 and then dried and germinated for 72 hours. The treatment reagent in Figure a is pure water; the treatment reagent in Figure b is 0.5×10 3 mg·L -1 KH2PO4 and 1×10 5 mg·L -1 A mixture of PEG-8000.

[0027] Figure 8 The germination rate of broccoli seeds of "variety 2" treated with reagent 4 was counted after drying and germination for 72 hours. The final concentration of reagent 4 was 0.5×10 3 mg·L -1 KH2PO4 and 1×10 5 mg·L -1 Mixture of PEG-8000. “*” indicates that the P value of the two groups of experimental data after t-test is <0.05, that is, the difference is significant. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto, and the following embodiments are not intended to limit the protection scope of the present invention.

[0029] Unless otherwise specified, all reagents used were commercially available and all methods used were conventional experimental methods.

[0030] The test materials are broccoli varieties 1 and 2 promoted for cultivation in North China;

[0031] The two types of broccoli seeds were deliberately stored for a long time under conditions that are not suitable for preservation, which greatly reduced the vitality of the seeds and resulted in a low germination rate of the two broccoli seeds: the germination rate of broccoli variety 1 seeds after soaking in pure water at room temperature was about 25%; the germination rate of broccoli variety 2 seeds after soaking in pure water at room temperature was about 70%.

[0032] Example 1 Configuration of different types of initiators

[0033] In the present invention, the control reagent for the experiment of promoting germination of broccoli seeds by different types of initiators is pure water. Other initiating agents are all dissolved in pure water, and the specific concentrations are shown in Table 1.

[0034] Table 1 Chemical composition and reagent concentration of different types of initiators

[0035]

[0036] Example 2 Experiment on promoting germination of un-dried broccoli seeds by different types of initiators

[0037] In order to more comprehensively test the efficiency of different types of initiators in promoting germination of broccoli seeds, two types of old broccoli seeds with large differences in germination rates were selected:

[0038] The germination rate of broccoli variety 1 was extremely low, about 25% after being soaked in pure water at room temperature;

[0039] The germination rate of broccoli variety 2 was lower, and the germination rate after being soaked in pure water at room temperature was about 70%.

[0040] The specific experimental operation is as follows: select broccoli seeds of the same size and fullness, soak the broccoli seeds with different initiators in Table 1, the soaking temperature is 20°C, the suitable time is 24 hours, after the treatment, remove the seeds, rinse with clean water for 2 minutes, use absorbent paper to absorb the moisture on the surface of the seeds, and directly carry out the subsequent seed germination treatment without drying the seeds.

[0041] The broccoli seeds after the above initiation treatment were placed in culture dishes covered with two layers of filter paper, and appropriate amount of clean water was added. The dishes were placed in a 25°C constant temperature box in a dark environment to promote germination of the broccoli seeds. After 72 hours, the germination rates of the broccoli seeds after treatment with each initiator were counted.

[0042] Experimental results:

[0043] The germination of two varieties of broccoli seeds treated with different initiators and germinated for 72 hours at 25℃ is as follows Figure 1-Figure 4It can be seen that the germination of the same variety of broccoli seeds under different treatments is better than that of the control (pure water), among which the treatment with reagent 4 makes the germination rate of broccoli seeds the highest; specifically,

[0044] The germination rate of old broccoli variety 1 under pure water treatment was 26.3%, and the germination rate of old broccoli variety 1 after immersion in reagent 4 reached 54.0%, which was 105% higher than that under pure water treatment. Figure 1 and Figure 2 shown.

[0045] The germination rate of old broccoli variety 2 under pure water treatment was 68.7%, and the germination rate of old broccoli variety 2 after immersion in reagent 4 reached 89.3%, which was about 30.0% higher than that under pure water control. Figure 3 and Figure 4 shown.

[0046] Comprehensive analysis shows that the initiator using a combination of potassium dihydrogen phosphate (KH2PO4) and polyethylene glycol (PEG8000) is very effective in improving the germination rate of old broccoli seeds, and is higher than the effect of using potassium dihydrogen phosphate solution or polyethylene glycol solution alone. 3 mg·L -1 KH2PO4 and 1×10 5 mg·L - 1 After the priming treatment with a mixture of PEG-8000 and PEG-1000, the germination rate of old broccoli seeds increased most significantly.

[0047] Example 3 Experiment on promoting germination of broccoli seeds after initiation and drying by the initiator obtained by screening reagent 4

[0048] Based on the research of Example 2, we further studied the treatment of old broccoli seeds (variety 1 and variety 2) with reagent 4 for drying, then accelerated the germination of the dried broccoli seeds, and tested the germination rate of the seeds.

[0049] The results showed that for the broccoli seeds of variety 1 with extremely low germination rate, after being immersed in reagent 4 and then dried, the germination rate of broccoli seeds of variety 1 after drying reached 35.0%, which was 41.7% higher than the 24.7% germination rate of the control. Figure 5 and Figure 6 As shown in the figure, for the broccoli seeds of variety 2 with a lower germination rate, after being immersed in the initiating reagent 4 and then dried, the germination rate of the broccoli seeds of variety 2 after drying reached 78.0%, which was 15.2% higher than the germination rate of 67.7% of the control. Figure 7and Figure 8 shown.

[0050] The above experimental results show that old broccoli seeds were treated with priming reagent 4 (final concentration 0.5×10 3 mg·L - 1 KH2PO4 and 1×10 5 mg·L -1 After the seed drying treatment was induced by the mixture of PEG-8000, the germination rate of seeds could still be improved.

Claims

1. A composite initiator for improving the germination rate of broccoli seeds, characterized in that: It is a mixture of potassium dihydrogen phosphate and polyethylene glycol PEG8000.

2. The composite initiator according to claim 1, characterized in that The mass volume concentration of potassium dihydrogen phosphate and polyethylene glycol PEG8000 in the composite initiator is: potassium dihydrogen phosphate is 500 mg·L -1 ~1×10 3 mg·L -1 PEG8000 is 1×10 5 mg·L -1 ~2×10 5 mg·L -1 .

3. The composite initiator according to claim 1, characterized in that The mass volume concentration of potassium dihydrogen phosphate and polyethylene glycol PEG8000 in the composite initiator is: potassium dihydrogen phosphate is 0.5×10 3 mg·L -1 PEG8000 is 1×10 5 mg·L -1 .

4. Use of the composite initiator according to any one of claims 1 to 3 in promoting germination of broccoli seeds, characterized in that: The following steps are involved: (1) Pretreatment: Select broccoli seeds of uniform size and fullness, sterilize with 0.5% sodium hypochlorite for 5 min, rinse the seed surface with distilled water 3 times, and dry the moisture on the seed surface; (2) Initiation treatment: soaking the broccoli seeds pretreated in step (1) with the composite initiator, wherein the soaking temperature is 18 to 22° C. and the time is 18 to 24 hours. (3) Cleaning: After the priming treatment is completed, remove the seeds, rinse with clean water for 2 minutes, and use paper to absorb the moisture on the seed surface.

5. The use according to claim 4, characterized in that: In step (2), the soaking temperature is 22° C. and the soaking time is 22 hours.

6. The use according to claim 3 or 4, characterized in that: After step (3), the method further includes placing the seeds in a constant temperature of 30° C. and drying them for 48 hours and then storing them for later use.

7. The use according to claim 3 or 4, characterized in that: After step (3), the broccoli seeds are directly placed in a culture dish covered with two layers of filter paper, an appropriate amount of clean water is added, and the dish is placed in a 25° C. constant temperature box in a dark environment to promote germination of the broccoli seeds.

Images