珍稀濒危种-斧形沙芥种子发育过程中脱水耐性的研究

he relationship between the desiccation tolerance of Pugionium dolabratum Maxin seeds and the antioxidant system was analyzed. P.dolabratum Maxin seeds during the development were dehydrated, and the change of moisture contents, germination rate and relevant index to antioxidant system were measured. The results showed that: From 40 days to 60 days after flowering (DAF), the moisture content of P.dolabratum Maxin seeds decreased gradually, but the dry weight increased. At 50 DAF, the seeds could germinate and the germination rate was 20%; Dehydration enhanced the germination rate, when the moisture content of seeds decreased to 12% and 5% with silica gel dehydration, the germination rate was up to 55% and 42% respectively. The activity of peroxidase (POD) decreased gradually during the development of P.dolabratum Maxin seeds, but the activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and lipoxidase (LOX) increased. With the increase of the DAF in the dehydration process, the activity of POD decreased gradually, while the activity of CAT and LOX increased, but the activity of SOD decreased first and then increased. With the increase of the DAF, the content of malondialdehyde (MDA) and O-2 generation rate in P.dolabratum Maxin seeds with dehydration and no dehydration increased, but the increased in 50 and 60 DAF seeds during the dehydration process were less than 40 DAF. The P.dolabratum Maxin seeds have acquired desiccation tolerance at 50 DAF, and the desiccation tolerance more than P.cornutum seeds.