The Mechanism And Effects Of Seeds Treatment On Seed Vigor And Seedling Growth In Eggplant

Seed aging is an ubiquitous phenomena,in eggplant seed vigor decreases after aging, resulting in negative effects on its industry. In this experiment three different aged seeds including low, middle-low and middle levels were obtained through artificial aging technology. In order to get the best combinations enhanced seed vigor, the L9(34) orthogonal design treatment was applied to screen aged seeds by 11 different treatments. These best combinations selected were used to treat the seeds with different levels of seeds vigor, from which the physiological and biochemical indices of seeds were studied and its mechanism was analyzed. The effects of seeds treatment on seedling growth and cold resistance in eggplant were also investigated by treating the non-artificial aged seeds with the best combinations selected, which is useful for eggplant production and genetic resources conservation . The results are as follows:1) The seed vigor index, germination index, germination percentage, and germination potential in eggplant decreased gradually with the increase in the number of days of aging, with similar downward trend. Three different types of seeds including low, middle-low and middle vigor levels were obtained by aging 8,14 and 20 days respectively.2) The seeds vigor was increased by 11 different treatments of GA, 6-BA, AsA, PEG, KH₂PO₄, CaCl₂, SA, CTS, SNP, low temperature, hydration-dehydrationm. The best combination of each treatment was given through physiological and biochemical, ntuitionistic and variance analysis, among which GA was the best one with vigor index 2.44 times (aging treatment 8d), 2.70 times (aging treatment 14d) and 2.77 times (aging treatment 20d) higher than that of contrast, followed by 6-BA. The best combination conditions of GA were temperature of 25℃, time of 24h, and the concentration of 500mg/l; The best combination conditions of 6-BA were temperature of 15℃, time of 18h, and the concentration of 25mg/l; There were significant differences in vigor index between additional 9 treatments and contrast.3) By treating the different vigor levels of seeds with 11 different methods, the seed dehydrogenase activity, SOD activity, POD activity, CAT activity, soluble protein content, and starch content were significantly increased, the extract relative electrical conductivity, MDA content in seeds was significantly decreased. There were negative correlations between the vigor index and the MDA content, and relative electrical conductivity. The activity index was significantly correlated with the MDA content at 0.01 level, were positively correlated with CAT, POD, SOD, dehydrogenase activity and vigor index, and was significantly correlated with CAT activity at 0.01 level, was significantly correlated with SOD activity at 0.05 level. The activity index was also significantly correlated with starch content, soluble protein content at 0.01 level, in which the most relevant between the soluble protein content and the vitality index was observed. The above characteristics could explain the mechanism why seed vigor increases.4) The strong seedling index and the quality of seedlings were improved by treating eggplant seeds. Specifically, it increased the SOD activity, POD activity, CAT activity, soluble protein content in leaves, lowered MDA content and relative electrical conductivity in leaves, improved the cold tolerance of eggplant seedlings in some aspects.