脱水方式和时间对降香黄檀种子生理活性的影响OA

[Objective]Seeds of Dalbergia odorifera T.Chen are prone to viability loss during storage,and desiccation sensitivi-ty is a key limiting factor for their germplasm preservation.This study aimed to explore the effects of dehydration rate on seed viability,reveal the underlying physiological response mechanism,and determine key tolerance parameters,thereby providing a theoretical basis and technical support for the safe storage of D.odorifera seeds.[Methods]Using D.odorifera seeds as the experimental material,fast and slow dehydration treatments were implemented by drying the seeds with silica gel.At sched-uled intervals,measurements were taken of physiological and biochemical indicators,including relative water content,germina-tion rate,electrolyte leakage(expressed as electrical conductivity),malondialdehyde(MDA)content,and the activities of su-peroxide dismutase(SOD),peroxidase(POD),and catalase(CAT).The median lethal water content was calculated based on a germination rate-water content model.Correlation analysis was further employed to examine the relationships among the measured indices.[Results]The results demonstrated that the dehydration rate is a critical determinant of the preservation effica-cy of D.odorifera seeds.Slow dehydration more effectively maintained cellular membrane integrity compared to rapid dehydra-tion,as evidenced by a significantly lower final electrical conductivity(150.40 μS/(cm·g))and a significantly higher final ger-mination rate(67.78%,compared to 21.11%in the fast treatment).A significant positive correlation was identified between SOD activity and germination rate(r=0.586,P<0.01),highlighting the central role of SOD in the antioxidant defense sys-tem.Moreover,model analysis revealed a higher median lethal water content in slowly dehydrated seeds(10.4%)than in rap-idly dehydrated seeds(7.8%),suggesting that slow dehydration may enhance desiccation tolerance by triggering protective mechanisms at an earlier stage of hydration.[Conclusion]Based on the finding that D.odorifera seeds retained 67.78%germi-nation after slow dehydration to 9.12%moisture content,this study classified their storage behavior as intermediate.We recom-mended slow dehydration to a 10%～12%moisture content range followed by low-temperature moist storage for effective germ-plasm conservation.