Studies On Physiological-Biochemical Characteristics And Mechanism Of Storability Of Three Forage Seeds During Ultra-dry Storage

Appling the silica gel drying method at room temperature, following by the water balance method, three forage species, Astragalus adsurgens Pall., Hedysarum leave Maxim., and Elymus dahuricus Turcz. , were used in this study.①to investigate the physiological and biochemical responses of H. laeve and E. dahuricus seeds under different moisture content before storage, and discuss the optimal moisture content and desiccation tolerance.②to determined the changes of physiological and biochemical indexes of two species under different moisture content, discussed the storability, optimal moisture content, and physiological and biochemical characteristics and the relationship between the optimal moisture content and storage temperature by sealing the H. leave and A. adsurgens seeds with different moisture content using aluminum foil bags, and stored at -4℃, 4℃, room temperature and 45℃for 12 months③to discuss the responses of physiological and biochemical characteristics,determined the storability mechanism of this species by sealing the E. dahuricus seeds under different moisture content with aluminum foil bags, and store at -4℃, 4℃, room temperature and 45℃for 0, 3, 12 months for the purpose of providing a theoretical basis for the conservation of forage germplasm resources. Results are showed as follow:1. A. adsurgens seeds were orthdox protein seeds. According to the results of principal component analysis, A. adsurgens seeds has a good desiccation tolerance and its optimal moisture content was 3.69%. Its optimal moisture content maintained the same level in comparison with other protein seeds. E. dahuricus seeds were orthdox starch seeds. The optimal moisture content of the species seeds was 4.97%, and its desiccation tolerance was lower than the A. adsurgens seeds and also lower that that of other starch seeds.2. The optimal storage moisture content of three species seeds were changed as storage temperature detecting in this study. The optimal seed moisture content of A. adsurgens and H. leave were 5.43% at -4℃, 1.24% at room temperature, 2.55% at 45℃and 2.92% at -4℃, 3.46% at room temperature and 45℃, respectively.3. Ultra-dry storage at room temperature is good for A. adsurgens, while storing at low temperature is better for germplasm conservation of H. leave.4. After being stored 12 months of ultra-dry seeds of H. leave and A. adsurgens under -4℃, 4℃, room temperature and 45℃, respectively, SOD, POD, and CAT activity of ultra-dry seeds was significantly higher than the control.Therefore, ultra-dry storage contributed to improve storability of seeds.5. E. dahuricus can be preserved at -4℃, 4℃and room temperature when its seed moisture content was below 3%6. The mechanism of seed aging and anti-aging under low temperature and high temperature was different. In low temperature, cell membrane kept a good integrity, the CAT activity was in normal status and SOD, POD as antioxidative system played an important role in mitigate the oxidative damage. In high temperature, cell membrane was subjected to aserious damage ,and CAT came into effect to mitigate the oxidative damage.7.GSH, as one of the non-enzymatic protection system, play an important protection during seed desiccation while this role decreased during seed storage. Enzyme protect system play an important role both in seed desiccation and storage.