Effect Of Temperature On Seed Germination And Physiological Character Of Different Maize Hybrid

For systematic and comprehensive study on variation of physiology and biochemistry values affected by temperature of maize at seed germination stage, a research was conducted by changing temperature gradient from high to low with main cultivars of Liaoning province, which concentrated on physiology and biochemistry values affected by temperature, for example, seed germination related values and change regularity of conductivity et al., to make sure physiology and biochemistry mechanism of temperature sensitivity of maize and find the best model for every variety, who got the higher physiology and biochemistry values under which exactly temperature. The purpose of this research was promote seeds germination and improved seed germinate condition and cultivation management at seedling stage, which provided the theory basis for temperature-resistant disaster and physiology and biochemistry breeding. As maize production, this experiment was beneficial to finding the proper temperature for protecting the seedlings and maize growing through the season, selecting varieties suited to local conditions and extension for farmers.The results showed that physiology values of different cultivars was showed one single peak curve with temperature increased, which peak at 33℃, Dongdan 90 was proved to be a low temperature sensitive variety, however, the change regularity of seed germination values of cultivars was no significant under other temperature conditions. As a result, further investigation of low temperature tolerant varieties, high temperature tolerant varieties and high temperature sensitive varieties was required.The result of cluster analysis showed that Dongdan 90 was low temperature sensitive variety, Liaodan 177 and Liaodan 145 were low temperature mid-sensitive varieties, Liaodan 565, Liaodan 527, Liaodan 526, Liaodan121, Shenyu 21, Zhengdan 958 and Dondan 60 were low temperature tolerant varieties. The sowing date could be calculated by different temperature tolerant varieties in agricultural production. The low temperature tolerant varieties should be sowing early, which could increase growth and development period and yield potential. Tieyan120, Dongdan60, Liaodan 177, Zhengdan 958 and Shenyu 21 were high temperature mid-sensitive varieties, Liaodan 565, Liaodan 527, Liaodan 526, Liaodan 121 were high temperature tolerant varieties under high temperature condition. As a result of above, Liaodan 565, Liaodan527, Liaodan526 and Liaodan 121 were low and high temperature tolerant varieties, which proved that that varieties had a broad adaptation and sowing date. Dongdan 90 was low temperature sensitive variety, it should be sowing delayed.On the basis of experiment results above, Contrastive Studies on seed conductivity, praline, MDA and soluble sugar of Liaodan 565, Liaodan 177 and Dongdan 90 under low temperature stress were conducted, the results showed that damage degree were decreased under low temperature stress condition by cold resistant physiological regulation by themselves of low temperature tolerant variety and little tolerant variety, which low temperature tolerant variety appeared more sensitively. However, the function effect of cold resistant physiological regulation was no apparent of low temperature sensitive variety.