Studies On The Physiological And Biochemical Mechanism And Differential Expression Of Genes Of Ultradried Seeds

At present, the genebank is the optimum to conserve germplasm resource, but it needed much fund to build it ,and it needed technique to safeguard it .so a new Technology would be found to conserve germplasm resource in poor area.Many results had showed that ultra-dry technology could increased storaged life with ultra-dry seeds at room temperature.But it has many differents in optimum moisture content and mechanism ,especial it had not been found to research mechanism with molecular methods .Working on seeds of Pea(Pesum sativum L),rice(Oryza sativa L) and maize(Zea may L),the effect of longevity was analyzed .Through the testing of the physiological and biochemical mechanism ,heat-stable protein and reversed levelof RNA.So as to provide scientific and theoretical basis for conserving germplasm resource.The rsearch results showed as following: 1. The germination test was done after ultra-dring of pea seeds. When moisture contents of pea was lowed to 5%, dry weight of root and vigor index of seeds compared with CK have significantly difference at 0.05 level, These showed that the pea seeds were not suited to ultra-dry storage. After ultra-dry seeds were conserved, SOD, CAT and POD of seeds were tested ,the results showed activities of SOD did not obvious correlated with the germination percentage and vigor index,but activities of POD and CAT positively correlated with the germination percentage and vigor index, especlly the activities of CAT .The content of malondialdehyde (MDA) of seeds after aged 6 months were tested , and the results showed that the contents of MDA of moisture contents of seeds (8% and 5%)were obvious lower than the others,and the changes of electrical conductivity of pea also got the same results, so they indicated that velum of seeds were kept preferably.New heat-stable protein was not found in the ultra-dried seeds, but contents of heat-stable proteins increased in seeds with moisture content of 5% and 8%,and the content of them still higher then others levels when they were aged for 6 months.2. Seed germination parameters and vigor index of different kinds of rice seeds stored for eight years at room temperature were investigated. Results showed that the optimum moisture content of Indica rice seeds stored in Beijing were 5.5% - 6.0%, but for Japonica rice seeds were 6.5% -7.0%. The optimum moisture content were 4.5%or so, 5.5% -6.0% for Indica rice seeds and Japonica rice seeds stored in Nanchang.It indicated that the level of the optimum moisture content of Japonica rice seeds...