CN111869362A - Method for breaking dormancy of hard seeds - Google Patents

Abstract

The invention discloses a method for breaking dormancy of hard seed, belonging to the technical field of seedling breeding. Alternatively treating seeds at 50 deg.C or above with hot water containing penetrant and at 0 deg.C or below by quenching to make seed coat have more and larger capillaries or pores, soaking seeds in oxygen-releasing agent, and soaking in CO₂The absorbent soaking liquid is soaked alternately, and the soaking liquid contains penetrant to facilitate the solution to penetrate the seed coat to facilitate absorption and expansion. The method has low cost, is easy to operate and is suitable for popularization.

Description

Method for breaking dormancy of hard seeds

Technical Field

The present invention belongs to the field of seedling breeding technology. In particular to a method for increasing permeability of seed coats and promoting oxygen and carbon dioxide exchange of seeds to release dormancy of hard seeds.

Background

Seeds which are difficult to be subjected to imbibition germination due to the hard seed coat (sometimes including the pericarp) are called hard seed, and hard seeds are widely present in plant seeds and are commonly found in leguminosae, liliaceae, malvaceae, Convolvulaceae, Theaceae, Palmaceae and the like. The degree of firmness is related to the hierarchy and arrangement of the seed coat cells, the type and content of pigments, and the deposition of impermeable substances (including cutin, colloid, wax, suberin, hemicellulose, etc.) (the poplar stage, et al. mechanism and method of elimination of dormancy of hard seed. botany report, 2006,23 (1): 108-118). "the seed coat of hard seed often limits the gas exchange of the embryo and hinders O₂And CO₂Thereby inhibiting respiration and not ensuring energy required for germination. Generally, the water permeability of seeds having poor air permeability is weak, but some plants have hard seeds with strong water permeability and can absorb water, but the air permeability is weak, and even if the seeds absorb enough water, the seeds can absorb enough water due to O₂Failure to inhale, possible CO₂Can not be discharged, thus resulting in gas exchange disorder and biochemical reaction which can not be smoothly carried out (Yang time,the mechanism and the method for eliminating dormancy of hard seeds, the report on botany, 2006,23 (1): 108-118). Some hard seed also accompany physiological dormancy of embryos, so that dormancy of hard seed is often the result of interaction of multiple factors. The hard material is treated by mechanical damage, low temperature and high temperature treatment, wet and dry treatment, radiation, high pressure treatment, etc. and chemical treatment, such as acid etching, alkali soaking, organic solvent, etc.

The cutin, wax, colloid and other hydrophobic substances of the seed coat form a low-energy surface, and the surface energy of water is large, the surface tension is higher than the critical surface tension of the seed coat, so that the seed coat is not easy to be soaked and permeated by water, and the wetting agent mainly reduces the solid-liquid interfacial tension and increases the wetting and contact of the liquid medicine on the surface of a treatment object (harmful organisms, plants and the like). The penetrant increases the penetration of the liquid medicine to the surface of the treated object and promotes the absorption of the liquid medicine (Zhang zong. application and research progress of pesticide adjuvant. pesticide science and management, 2009, 30 (1): 42-47). Osmosis refers to the phenomenon that liquid enters capillary or porous solid, osmotic agents have good wetting effect, and only a few kinds of wetting agents have good osmotic effect (Zhonghongxiang, talk about wetting and osmosis, Jiangsu silk, 1995, (2) 20-51, Weigning, et al, discussion of pesticide wetting osmotic agents, surfactant industry, 1994(1):19-24, 14), such as nekal, osmotic agent JFC.

The hard seed coat is made of hydrophobic substances, and the seed coat does not have enough capillaries or pores, so that water is not easy to permeate into the seed coat and is absorbed by the embryo. Therefore, in order to allow the solution to penetrate the seed coat and be absorbed by the embryo, it is necessary to satisfy the two conditions of the seed coat having sufficiently large and numerous pores and the solution surface tension being reduced by the penetrating agent.

Disclosure of Invention

The invention mainly aims to provide a method for releasing dormancy of hard seeds, which enables the seed coats to have more capillaries or pores, enables solution to easily permeate the seed coats and be absorbed by the seed embryos, enhances gas exchange of the seed embryos, promotes releasing dormancy, and is beneficial to absorbing expansion and germination of the seeds.

A method for releasing dormancy of hard seed features that the seed is immersed in hot water containing penetrant which is favorable to the penetration of hot water into seed shell via capillary or pore space and can dissolve part of wax and ester of seed shell, then the seed is taken out and dried, and then frozen at low temp. the material is known to change from toughness to brittleness (especially in metal and high-molecular organic substance) and become crisp, and the water in seed shell is frozen.

Another problem to be solved by the present invention is that the seed soaking solution contains oxygen releasing agent, CO₂The absorbent is added with the penetrating agent, the solution penetrates the seed coat, oxygen is provided for the seed embryo and carbon dioxide released by the seed is absorbed, smooth respiration of the seed embryo is ensured, and metabolism is promoted. The hydrogen peroxide solution can be slowly decomposed into water and oxygen at normal temperature, is a common oxygen release agent, stimulates a pentose phosphate pathway of endosperm substance metabolism by hydrogen peroxide with a certain concentration, can also participate in signal marks of hormones, has a synergistic effect with gibberellin, and has an important effect on relieving seed dormancy (Marangong, and the like, the hydrogen peroxide oxygenation causes the influence on the activity of tobacco seeds. Chinese tobacco science 2015, 36 (5): 8-12) and can be used as a seed germination promoter. The application of alcohol amine solution for absorbing CO currently₂The main trapping method has the advantages of fast absorption, large absorption capacity, low cost, desorption and regeneration of alcohol amine, etc. in addition, the alcohol amine solution is alkaline, and the alkali liquor soaking is one of the first-choice methods for softening the wax on the seed skin, so that the moisture can easily permeate the seed coat to be absorbed by the seed embryo.

The technical scheme provided by the invention is as follows:

a method for relieving dormancy of hard seed comprises adding penetrant into hot water of 50 deg.C or above, soaking seed, stirring while continuing for 10-30 min, taking out seed, draining water, freezing at 0 deg.C or below for 3-30 min, immediately soaking in hot water containing penetrant, freezing at 0 deg.C or below, and heatingSoaking in water, and freezing for 2-8 times. Soaking seeds in oxygen releasing agent seed soaking liquid containing penetrant and CO containing penetrant₂The absorbent soaking liquid is alternately soaked, and one soaking liquid is replaced every 12 or 24 hours until the seeds are sucked and swelled.

The oxygen releasing agent is hydrogen peroxide, and the concentration of the oxygen releasing agent in the seed soaking liquid is 0.05-0.5%.

Said CO₂The absorbent is an alcohol amine solution, ethanolamine or ethanolamine and N-methyldiethanolamine are selected to be mixed in equal volume, and the concentration of the alcohol amine in the seed soaking solution is 0.5-5%.

The penetrant is stable in hard water and acid and alkali resistant, one of diisobutyl naphthalene sulfonate and polyoxyethylene lauryl ether or the mixture of the diisobutyl naphthalene sulfonate and the polyoxyethylene lauryl ether in the volume ratio of 2-8:1 is selected, and the concentration of the penetrant in the seed soaking solution is 0.03-0.3%.

The invention has the beneficial effects that: the hard seed is repeatedly frozen in hot water containing penetrant, and the seed coat is torn more and has larger pores, thus creating conditions for seed soaking liquid penetration. Penetrant for making oxygen releasing agent and CO of seed soaking liquid₂The absorbent is easy to permeate seed coat and seed embryo to absorb, promotes respiratory metabolism, and the oxygen-releasing agent hydrogen peroxide has certain physiological effect of relieving dormancy, and CO₂The absorbent alcohol amine also has the functions of softening seed coats and facilitating water penetration. The method has low cost, is easy to operate and is suitable for popularization.

Detailed Description

Example one

1. Method of producing a composite material

Canna indica (A)Canna indica) The hard seed rate of the seeds is more than 90 percent, and the seeds can germinate only by scratching the seed coats or soaking the seeds in concentrated sulfuric acid. Seeds are soaked in tap water for 48 hours, and the seeds with hard and non-imbibition peel are selected and dried for testing. The seeds are divided into 4 groups, the processing method is shown in the table, the temperature-changing processing refers to that the seeds are soaked in hot water with 80 ℃ for 15 minutes, a penetrating agent is a mixed solution of sodium diisobutylnaphthalenesulfonate and polyoxyethylene lauryl ether (the volume ratio is 4: 1), the concentration is 0.2 percent of the seed soaking solution, the seeds are stirred during the period, then the seeds are fished out, the water is drained, and the seeds are immediately transferred into a freezing boxFreezing at (-20 deg.C) for 20 min, immediately soaking in 80 deg.C hot water containing penetrant, and rapidly heating and quenching for 5 times. "active ingredient of seed soaking liquid" refers to seed soaking liquid containing 0.1% hydrogen peroxide oxygen releasing agent and 2% ethanolamine CO₂The soaking liquid of the absorbent is added with mixed liquid (volume ratio is 4: 1) of sodium diisobutylnaphthalenesulfonate and polyoxyethylene lauryl ether, the concentration is 0.2% of the soaking liquid, the seeds are alternately soaked in the two soaking liquids, and one seed is replaced every 24 hours.

After the seeds are soaked for 4 days, the seeds are obviously enlarged, the seeds with the volume being twice of the original volume are taken into the seed soaking machine, and the seed soaking rate is not larger than the (the number of the seeds to be soaked/the number of the seeds to be tested) multiplied by 100 percent. And 4 groups of the imbibition seeds germinate in a dark incubator at the temperature of 25 ℃, wherein the germination standard is that the length of the protruded seed coat of the radicle is half of the length of the seeds, the germination vigor is counted on the 6 th day, and the germination rate is counted on the 24 th day.

2. Results

The results of the four seed treatments are shown in the table.

3. Conclusion

The seed soaking liquid contains active component and penetrant, and has no temperature varying treatment, low seed sucking rate and very low germination rate.

Secondly, the seeds are subjected to temperature change treatment, and the imbibition rate is obviously improved compared with that of the first group. The repeated shock heating and quenching (and penetrating agent) effect of the seeds is demonstrated, so that the permeability of the seed coat is increased, and the water absorption is facilitated.

The temperature-changing treatment of the seeds and the synergistic effect of the penetrating agent of the seed soaking liquid are achieved, the absorption rate is obviously improved compared with that of the seeds in the group II, the use of the penetrating agent is proved, and the water absorption capacity of the seeds is further improved.

The temperature-changing treatment, the synergistic effect of the active components of the seed soaking liquid and the penetrating agent and the further improved absorption-expansion rate compared with the third group are performed on the seed soaking liquid, and the alkaline alcohol amine contained in the seed soaking liquid is favorable for softening seed coat cutin, absorbing and expanding seeds, releasing oxygen agent and CO₂The absorbent can promote metabolism (hydrolysis of nutrient components in seed), and is beneficial to relieving dormancy and water swelling. The germination potential of the fourth group is higher than that of the third group, namelyThe active ingredient (hydrogen peroxide) of the soaking solution enhances the seed activity and leads the seeds to germinate faster.

Example two

1. Method of producing a composite material

Rhus chinensis Mill (A)Rhus chinensis) The hard seed rate is about 90%. Seeds are soaked in tap water for 24 hours, and the seeds with hard and non-imbibition peel are selected and dried for testing. The seeds are divided into 4 groups, the processing method is shown in the table, the 'temperature changing processing' means that the seeds are soaked in hot water at 70 ℃ for 20 minutes, the penetrant is sodium diisobutylnaphthalenesulfonate, the concentration is 0.2%, the seeds are stirred in the period, the seeds are taken out, the water is drained, the seeds are put into liquid nitrogen (-196 ℃) for freezing for 5 minutes, the seeds are immediately soaked in the hot water at 70 ℃ containing the penetrant, and the quick heating and the quick cooling are repeated for 3 times. "active ingredient of seed soaking liquid" refers to seed soaking liquid containing 0.1% hydrogen peroxide as oxygen releasing agent and 2% ethanolamine in CO₂The two seed soaking liquids of the absorbent are both added with sodium diisobutylnaphthalenesulfonate serving as a penetrant, the concentration of the sodium diisobutylnaphthalenesulfonate is 0.2 percent, the seeds are alternately soaked in the two seed soaking liquids, and one seed soaking liquid is replaced every 12 hours.

The seeds are obviously enlarged after being soaked for 2 days, the seeds with the volume being twice of the original volume are taken into the seed bag, and the imbibition rate is not larger than (the number of the imbibition seeds/the number of the seeds to be tested) multiplied by 100 percent. The imbibition seeds all germinate in a constant temperature incubator at 25 ℃, the illumination is carried out for 12 hours every day, the germination standard is that the length of the radicle protruding seed coat is half of the length of the seeds, the germination vigor is counted on the 5 th day, and the germination rate is counted on the 12 th day.

2. Results

The results of the four seed treatments are shown in the table.

3. Conclusion

Firstly, the seeds in the seed group are not subjected to temperature change treatment, the seed soaking liquid contains active ingredients and does not contain a penetrating agent, and the seed imbibition rate and germination are low.

And secondly, the temperature change treatment of the seeds is performed, the imbibition rate and the germination rate are obviously improved compared with the first step, the repeated sudden heating and quenching temperature change (and penetrating agent) effect of the seeds is demonstrated, the permeability of the seed coat is increased, and the water absorption is facilitated.

The temperature-changing treatment of the seeds and the synergistic effect of the penetrating agent of the seed soaking liquid improve the absorption rate compared with the seeds in the group II, which shows that the penetrating agent is used to further improve the water absorption capacity of the seeds.

The temperature change treatment, the synergistic effect of the active ingredients and the penetrating agent and the obvious increase of the absorption-expansion rate compared with the third group show that the alkaline alcohol amine contained in the seed soaking liquid of the group is favorable for softening the cutin of the seed coat and absorbing and expanding the seed, and the oxygen releasing agent and the CO are favorable for absorbing and expanding the seed₂The absorbent can promote metabolism (hydrolysis of nutritional seed components) and relieve dormancy. The germination vigor of the group IV is higher than that of the group III and the group III, which shows that the active ingredient (hydrogen peroxide) of the soak solution of the group IV enhances the vitality of the seeds and leads the seeds to germinate faster.

Claims (1)

1. A method of breaking dormancy of hard seeds, comprising: soaking the seeds in hot water containing penetrant at a temperature above 50 deg.C for 10-30 min, freezing at a temperature below 0 deg.C for 3-30 min, repeating the soaking and freezing for 2-8 times, soaking the seeds in oxygen releasing agent containing penetrant and CO containing penetrant₂Alternately soaking the absorbent soaking liquid, and replacing one soaking liquid every 12 or 24 hours until the seeds are swelled;

the oxygen releasing agent is hydrogen peroxide, and the concentration of the oxygen releasing agent in the seed soaking liquid is 0.05-0.5%;

said CO₂The absorbent is an alcohol amine solution, ethanolamine or ethanolamine and N-methyldiethanolamine are selected to be mixed in equal volume, and the concentration of the alcohol amine in the seed soaking solution is 0.5-5%;

the penetrant is stable in hard water and acid and alkali resistant, one of diisobutyl naphthalene sulfonate and polyoxyethylene lauryl ether or the mixture of the diisobutyl naphthalene sulfonate and the polyoxyethylene lauryl ether in the volume ratio of 2-8:1 is selected, and the concentration of the penetrant in the seed soaking solution is 0.03-0.3%.