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CN-121970566-A - Dormancy breaking and germination accelerating method for wild lespedeza seeds

CN121970566ACN 121970566 ACN121970566 ACN 121970566ACN-121970566-A

Abstract

The invention discloses a dormancy breaking and germination accelerating method for wild lespedeza seeds, belonging to the technical field of plant seed breeding. The invention comprises physical skin breaking, surface cleaning and disinfection, warm water seed soaking, chemical dormancy breaking, gradient germination accelerating, batch seeding and intelligent water and fertilizer management. Aiming at the problems of low natural germination rate, irregular emergence and the like caused by double barriers of hard seed coats and shallow physiological dormancy of wild lespedeza seeds, the invention constructs a water penetration channel through physical skin breaking, chemically breaks dormancy to relieve dormancy and gradient germination accelerating to simulate a multistage cooperative mechanism of environmental signals, synchronously breaks double dormancy barriers, effectively improves the germination rate and emergence uniformity of seeds and inhibits mildew. The method has stable process and strong operability, is suitable for large-scale seedling cultivation of wild lespedeza, and provides reliable technical support for ecological restoration engineering.

Inventors

  • ZHANG QIAOXIAN
  • ZHANG NA
  • CAO LIJUAN
  • ZHOU JINGJING
  • YANG JIE
  • SUN DONG
  • HUA RONG
  • CAO JUAN
  • LAN JIAN
  • WANG BIN
  • WANG SHUNXIA
  • MA LIJUAN
  • QIAN ZHIHAO
  • HU YIFEI

Assignees

  • 宁夏回族自治区草原工作站

Dates

Publication Date
20260505
Application Date
20260403

Claims (10)

  1. 1. The dormancy breaking and germination accelerating method for the wild lespedeza seeds is characterized by comprising the following steps of: The physical crust breaking step of mixing the dried wild lespedeza seeds with a wet physical friction medium according to the mass ratio of 1:3-1:5, rolling and friction treatment in a rotary container for 15-30 min to break the hard and solid structure of the seed crust, and screening and recycling the seeds after the treatment is finished; the seed pretreatment, namely cleaning and sterilizing the surface of the wild lespedeza seeds subjected to friction treatment; soaking seeds in warm water, namely soaking the sterilized seeds in warm water at 35-45 ℃ for 6-12 hours; chemical dormancy breaking, namely immersing the seed subjected to seed soaking in a chemical dormancy breaking agent solution for 4-10 hours at the temperature of 18-28 ℃, wherein the chemical dormancy breaking agent solution consists of gibberellin (0.02-0.08%, w/v) and a penetration regulator (0.2-0.8%, w/v); Mixing the chemically treated seeds with a moisturizing germination accelerating matrix with the humidity of 60% -80% according to the volume ratio of 1:2-1:5 to form a mixed germination accelerating bed, culturing for 48-96 hours in a constant temperature environment with the temperature of 18-25 ℃, keeping a light-shielding condition during germination, and keeping the matrix humidity of the mixed germination accelerating bed at 60% -80%; the first batch of seeding, namely screening germinated seeds in the gradient germination accelerating process and partial matrixes, uniformly spreading the seeds on a seedbed, covering a moisturizing material after seeding and carrying out light-shielding management, and finishing the first batch of seeding; Secondary germination accelerating and second batch sowing, namely re-mixing the ungerminated seeds remained in the first batch sowing with the original matrix to form a secondary mixed germination accelerating bed, and carrying out second batch sowing after continuously accelerating germination for 36-60 hours in a light-shielding environment with the temperature of 20-28 ℃ and the humidity of 65-85% of the matrix; Reseeding treatment, namely soaking residual seeds which are not germinated after secondary germination and second batch sowing in a gibberellin solution with the concentration of 0.01% -0.03% (w/v) for 3-9 hours, and then intensively sowing in a reseeding area of a seedbed; And (3) seedling emergence management, namely after seeding of all batches is completed, covering a 1 cm-3 cm thick sterilization and moisture preservation covering material on the surface of the seed, implementing drip irrigation and micro-spraying cooperative regulation and control according to soil humidity sensor data, maintaining the humidity of a matrix by 40% -80%, and performing warm light environment management until the seedling emergence is finished.
  2. 2. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1, wherein the surface cleaning and disinfection treatment comprises the steps of screening and removing light impurities, shrunken seeds and seeds with particle sizes smaller than 1.2 mm, flushing the seeds with clear water for 2-3 times, immersing the seeds in sodium hypochlorite solution with the concentration of 0.5% -1.0% (w/v) at 18-25 ℃ for 8-12 min in a dark place, flushing the seeds until effluent is neutral by sterile clear water after the seeds are taken out, and draining the surface water for 30-60 min in a ventilation environment with the temperature of 25-30 ℃.
  3. 3. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1, wherein the warm water seed soaking is carried out in a constant temperature water bath device, the temperature fluctuation is controlled within +/-1 ℃, in the seed soaking process, the seeds are stirred for 15 min-20 min at the rotating speed of 30 r/min-50 r/min every 2h, isothermal sterile clean water is supplemented every 3h, the supplementing amount is 5% -8% of the initial seed soaking water amount, and blighted grains and inferior seeds floating on the liquid surface are removed after seed soaking is finished.
  4. 4. The method for dormancy breaking and accelerating germination of wild lespedeza seeds according to claim 1, wherein the physical friction medium is coarse river sand with the particle size of 2-5 mm, the dry heat sterilization is carried out for 20-30 min at the temperature of 120-130 ℃ before the use, the rolling friction treatment is carried out in a horizontal roller with the rotating speed of 15 r-25 r/min, the breakage rate of the seeds is monitored in real time to be not more than 5%, and after the treatment is finished, double-layer vibration screening with the pore diameter of 4-6 mm of an upper layer screen hole and the pore diameter of 1.5 mm of a lower layer screen hole is adopted to separate the seeds from the friction medium.
  5. 5. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1, wherein the penetration regulator in the chemical dormancy breaking agent solution is potassium bicarbonate or potassium bisulfate, the pH value of the chemical dormancy breaking agent solution is adjusted to 5.5-6.5, the soaking process is carried out under the condition of avoiding light, the stirring is continuously carried out at the rotating speed of 20 r/min-30 r/min, and the liquid level is always 2 cm-3 cm higher than the surface of the seeds.
  6. 6. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1 or 5, wherein the osmotic regulator in the chemical dormancy breaking agent solution is a compound osmotic regulator comprising potassium nitrate, potassium citrate, proline and disodium ethylenediamine tetraacetate, wherein the total mass of the compound osmotic regulator is 40% -60%, the potassium nitrate is 20% -35%, the proline is 5% -15%, the disodium ethylenediamine tetraacetate is 1% -5%, and the adding amount of the compound osmotic regulator in the chemical dormancy breaking agent solution is 0.3% -1.0% (w/v); the preparation method of the compound osmotic regulator comprises the steps of dissolving all components in a phosphoric acid buffer solution with the pH value of 6.0-6.8 in proportion, uniformly mixing the components under the light-shielding condition with the temperature of lower than 10 ℃ to prepare a compound regulator mother solution, and mixing the compound regulator mother solution and gibberellin mother solution in proportion to prepare the chemical dormancy breaking agent solution.
  7. 7. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1, wherein the moisturizing germination accelerating matrix is formed by compounding sterilized humus soil, river sand and vermiculite according to a volume ratio of 3:2:1, and composite particles are added into the moisturizing germination accelerating matrix, wherein the addition amount of the composite particles is 0.4% -0.7% (w/w) of the total mass of the matrix, and the particle size of the composite particles is 0.1-0.5 mm; The composite particle is of a core-shell structure, wherein a core layer is porous starch loaded with carbendazim and accounts for 15% -25% of the total mass of the composite particle, an intermediate layer is a polymer film formed by crosslinking sodium alginate and chitosan and accounts for 10% -20%, and a shell layer is an acrylamide-acrylic acid copolymer grafted and crosslinked on a carboxymethyl cellulose skeleton and accounts for 55% -75%.
  8. 8. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1, wherein the environment relative humidity in the constant-temperature germination accelerating stage is maintained at 75% -80%, ventilation is carried out 3-4 times a day for 30-50 min each time, and the whole germination accelerating process is kept in a dark place.
  9. 9. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1, wherein after the secondary mixed germination accelerating bed is formed and before germination accelerating is continued, fresh moisturizing germination accelerating matrix accounting for 10% -15% of the total mass of the secondary mixed germination accelerating bed is supplemented, the humidity of the matrix is adjusted to 65% -85%, in the process of germination accelerating, each 12h turns once, the turning depth is 5 cm-8 cm, the rest ungerminated seeds after sowing in the second batch are subjected to secondary physical friction treatment for 8 min-12 min before being soaked in gibberellin solution, the secondary physical friction treatment adopts the same friction medium and operation condition as the physical skin breaking step, after soaking, the seeds and the fresh moisturizing germination accelerating matrix are mixed according to the volume ratio of 1:3, and the seeds are sowed in the reseeded area of the seedbed.
  10. 10. The method for dormancy breaking and germination accelerating of wild lespedeza seeds according to claim 1, wherein in the step of seedling emergence management, the humidity of a substrate is dynamically maintained at 40% -80% according to real-time monitoring data, the moisture-preserving covering material is crushed straws or rice hulls subjected to 120 ℃ -130 ℃ dry heat sterilization treatment, the covering thickness is 1 cm-3 cm, the temperature of the seedling raising environment is controlled at 18 ℃ -28 ℃, the day-night temperature difference is maintained at 5 ℃ -8 ℃, and ventilation is carried out for 2-3 times a day for 20-40 min each time.

Description

Dormancy breaking and germination accelerating method for wild lespedeza seeds Technical Field The invention relates to the technical field of seed breeding. More specifically, the invention relates to a method for dormancy breaking and germination accelerating of wild lespedeza seeds. Background The wild Lespedeza bicolor turcz is a shrub of the genus Lespedeza of the family Leguminosae, has extremely high ecological value and application prospect, has developed root system and strong soil fixing capability, can effectively reduce surface runoff and soil loss after being planted in sloping fields, is excellent in water and soil conservation and barren mountain greening tree species, has high drought resistance, barren resistance and cold resistance, good regeneration capability, is suitable for ecological restoration engineering application, has rich nutrition of branches and leaves, high crude protein content, can be used as a high-quality feed resource, has higher oil content of seeds, and has edible and economic values. Therefore, the wild lespedeza has wide development and application prospect in the fields of ecological restoration, water and soil conservation, feed production and the like. However, efficient breeding of wild lespedeza seed has been a bottleneck limiting its large-scale application. The system of the 'five wild flower introduction and cultivation researches' of the university Zheng Jian of Hebei agriculture (2003) researches the dormancy characteristics of the lespedeza seeds, and the result shows that the dormancy of the lespedeza seeds is forced dormancy caused by solidity instead of embryo dormancy, the optimal germination temperature is 20-25 ℃, and the illumination has obvious inhibition effect on the germination of the lespedeza seeds and belongs to the light-proof seeds. The research confirms the germination characteristics of the lespedeza seeds and provides scientific basis for the development of a seed treatment method. The existing treatment method for the lespedeza seeds mainly comprises high-temperature seed soaking, concentrated sulfuric acid etching treatment, single hormone soaking and the like. However, these methods have the following drawbacks in practical applications: (1) The dormancy breaking is incomplete, namely, a single physical treatment (such as hot water soaking) can soften the seed coats, but has limited effect on the seeds with high partial hardening rate, and a single chemical treatment (such as gibberellin soaking) does not aim at the characteristic of hard and dormant of the lespedeza, so that the core obstacle of the seed coats, which is impermeable to water, cannot be solved, and a large number of seeds still cannot germinate after the treatment. (2) The seed damage rate is high, although the concentrated sulfuric acid etching treatment can effectively break hard, the treatment time and concentration are difficult to control accurately, the seed embryo is easy to damage, the seed vitality is reduced, and the seed embryo is subjected to physical friction after seed soaking, at the moment, the seed embryo is softened after absorbing water, the friction is extremely easy to cause mechanical damage, and the germination rate is reduced. (3) The existing method does not effectively regulate the germination process of the seeds, the problem of asynchronous germination of the seeds is common, the seeds which germinate in advance are easy to be damaged by water and nutrient competition in a seedbed, the seeds which germinate after the germination are likely to be mildewed and inactivated, and the high mildew rate of the seeds is caused by the lack of effective antibacterial water-retaining measures. (4) The method is difficult to be applied on a large scale, the existing method is mostly single batch processing under laboratory conditions, and the method lacks systematic process flow and cannot meet the batch requirement of ecological restoration engineering on high-quality seedlings. In summary, a method for treating wild lespedeza seeds based on seed germination characteristic diagnosis, accurate sleep breaking step by step and consideration of germination rate and emergence uniformity is not available at present, the problems of low germination rate, uneven emergence, low seed utilization rate and the like in the prior art are solved, and technical support is provided for large-scale breeding of wild lespedeza. Disclosure of Invention The invention provides a method for dormancy breaking and germination accelerating of wild lespedeza seeds, which can construct a water penetration channel through physical skin breaking, remove dormancy through chemical dormancy breaking and simulate a multistage cooperative mechanism of environmental signals through gradient germination accelerating, synchronously break double dormancy barriers, effectively improve the germination rate and the uniformity of seedlings, inhibit mildew, and has stable process and strong opera