10种牧草种子生物学特性和超低温处理对发芽的影响

[Objective]The biological characteristics of 10 herbage species seeds and germination characteristics of seeds after ultra-low temperature(liquid nitrogen)treatment were studied,the influence of ultra-low temperature treatment on the germination vigor of herbage seeds was analyzed,and the changes of thermodynamic characteristics of herbage seeds before and after ultra-low temperature treatment were explored,which provided technical reference for the cryopreservation of herbage species germplasm resources.[Method]Ten herbage seeds were used as materials to determine the biological characteristics of seeds,the thousand grain weight,seed length,seed width,width-length ratio,surface area,plumpness rate and seed germination rate were measured.The moisture content of seeds was reduced to 5%by weight reduction method,and the germination rate of seeds before and after ultra-low temperature treatment was measured.Based on differential scanning calorimetry,the thermodynamic characteristics of herbage seeds were analyzed.[Result]1)The seed morphology of 10 herbage species was different,which were roughly Avena sativa、Lolium multiforum、Festuca atundinacea、Leymus chinensis、Panicum intortum、Allium mongolicum、Dendrolobium triangulare、Medicago sativa、Astragalus adsurgens、Trifolium repens.2)There is a positive correlation between seed plumpness and germination rate.3)The germination rate of 10 herbage seeds did not decrease after cryopreservation in liquid nitrogen,but the germination ability was decreased and the germination time was longer.4)The differential scanning calorimetry analysis before and after ultra-low temperature treatment showed that the moisture content and water state of herbage seeds did not change.[Conclusion]The biological characteristics of 10 herbage species seeds were different.Seed plumpness rate can be used as an important indicator of seed germination ability.When preserving herbage germplasm resources,attention should be paid to selecting seeds with high plumpness rate.When the moisture content of herbage seeds is reduced to 5%,the seed germination rate will not decrease.Based on the differential scanning calorimetry technology,the water state of seeds will not change during ultra-low temperature treatment,so cryopreservation can be achieved for herbage seeds.