Approach To Physiological Mechanism Of Vegetable Seed Longevity

In this experiment, three varieties of green onions (Zhangqiu green onion, Northeast green onion, local green onion) and three varieties of eggplant (eggplant 1, eggplant 2, eggplant 3) were used as materials. Multinomial physiological and biochemical indexes, including germination rate, the relative conductivity, dehydrogenase activity, soluble sugar content, soluble protein content and starch content, MDA content, SOD activity, POD activity, changes of POD, ETS Isozyme～spectrum, were analyzed respectively. A series of physiological and biochemical changes (seed vitality, storage substance, membrane lipid peroxidation and membrane permeability) in the course of being stored were studied in a systematic way. the results showed that:Seed vitality : the germination rate of green onion seed reduced from 86% to 27%, but the germination rate of eggplant seed was 93% to 75%. Totally, with the stored time prolongs, both green onions and eggplant seed germination rate showed decreasing trend, but Green onion seed germination rate has dropped faster.Relative conductivity: Seeds relative conductivity of the Green onion increased from 0.9 to 1.6 during storage, but that of eggplant increased from 0.3 to 0.5 in the same condition. In a word, with the prolonging of storage time, the relative conductivity of Green onion seeds and eggplant seeds showed upward trend after being stored in a long time, but relative conductivity of seed of Green Green onion was increased faster.Dehydrogenase activity: Dehydrogenase activity of Green onion seeds reduced from 0.57 to 0.16 when tested in the OD485nm during storage, and activity of eggplant seed reduced from 0.83 to 0.59. All in all, with the prolonging of storage time, the dehydrogenase activity of Green onion seeds and eggplant seeds showed increasing trend, but activity of seed of Green onion was increased faster. Seed storage substance: With the storage time prolongs, soluble sugar content, starch content, soluble protein content of Green onion seeds and eggplant seeds showed downward trend, but Green onion seeds decreased faster.Membrane lipid peroxidation: With the storage time prolongs, changes of MDA content of green onions and eggplant seed showed upward trend, but the content of MDA of Green onion seeds increased faster; SOD activity, POD activity of those seeds showed a downward trend, but Green onion Seeds drop faster.The study on Isozyme-spectrum of seeds showed that the peroxidase isozyme spectrum band reduced, also, activity of Isozyme-spectrum in both green onion and eggplant were weakened gradually. With the seeds viability loss, band B could be seen in the peroxidase isozyme-spectrum; Band B,C,D,F and G could not be seen in the Esterase Isozyme-spectrum, so these bands could be seen as key bands of aging. Band F in the peroxidase isozyme-spectrum and band B in the Esterase Isozyme-spectrum of eggplant are key bands of aging.The result of multiple comparion showed that: the difference of relative conductivity between green onion and eggplant variatise are significant. It is no significant difference in physiological and biochemical indicators of green onion varietes, but the differences of those indicators between green onion and eggplant are extreme significantPrincipal component analysis showed that the correlation between physiological and biochemical indicators are significantly different. The dehydrogenase activity, soluble sugar content, soluble protein content and starch content, the activity of SOD, POD activity were positively correlated to the viability of seed; MDA, and the relative conductivity of the seed were negatively correlated to the viability.