人工老化对向日葵种子活力及生理特性的影响

[目的]研究人工老化对向日葵种子活力及生理特性的影响。[方法]以‘SunM 20’、‘民乐深紫葵’、‘大山葵花4’和‘吉葵24’4份向日葵种质为材料,研究了高温高湿人工老化（100%RH,45℃）处理不同时间（0、2、4、6、8、10d）对种子发芽率、发芽势、发芽指数、活力指数、过氧化物酶（POD）、超氧化物歧化酶（SOD）活性及丙二醛（MDA）含量的影响。[结果]随着向日葵种子老化时间的延长,发芽率、发芽势、发芽指数、活力指数、POD和SOD活性逐渐下降,MDA含量逐渐增加;不同种质的抗老化能力存在差异,其中‘SunM 20’比其他3份种质的抗老化能力强,在相同条件下,其种子活力和保护酶活性最高,MDA含量最低,并且在老化过程中,其种子活力变化及保护酶活性变化最慢。[结论]老化过程中保护酶POD、SOD活性的显著降低可能是导致种子活力下降的主要原因,而少量MDA的逐渐积累促进了种子的老化。

Effects of Sunflower Artificial Aging on Seed Vigor and Physiological Characteristics

[Objective] The aim was to study the effects of sunflower artificial aging on seed vigor and physiological characteristics.[Method]The varieties of seed germination capacity,vigor of germination,germination index,vigor index,peroxidase (POD) activity,superoxide dismutase (SOD) activity and malondialdehyde (MDA) content for four sunflower germplasms Such as 'SunM 20','Deep Purple Minle','Da San Kui Hua 4' and 'Ji Kui 24' were studied under high temperature and high humidity conditions(100% RH,45 ℃) for different days(0,2,4,6,8,10 d).[Result]The result showed that the germination capacity,vigor of germination,germination index,vigor index,POD activity,SOD activity declined gradually with the increase of seed aging days,whereas MDA content enhanced by degrees; The differences of resistance to artifical aging existed among the four accessions,'SunM 20' was the most resistant one,and exhibited the strongest seed vigor,highest activities of two protective enzyme(POD,SOD) and lowest content of MDA at the uniform condition,moreover,the seed vigor and protective enzyme activities of 'SunM 20' changed slowest among the four materials during the aging process. [Conclusion]The distinct reduction of POD,SOD activities maybe the main reasons for the decrease of sunflower seed vigor at the artificial aging,and the gradual accumulation of a few MDA accelerated seeds aging.