Heilongjiang Province’s Main Maize Varieties Bud Seedling Low Temperature Resistant Capability To Compare

Maize(Zea mays L.) originated from subtropical region and as a thermophilic crop, it requires a high temperature condition. Located in the northern temperature zone, Heilongjiang is the biggest province of maize production and exporter in China. The maize production in Heilongjiang affects not only the development of economy and society of the province, but also the overall maize industry of China. Chilling-injury during the maize growing is main natural disasters and limiting factor of maize high yield. Therefore, the study on chilling damage is of theoretical value and practical significance for maize.This test is to heilongjiang province’s main20corn varieties as material, around the special geographical location and climate conditions of heilongjiang province, selects the heilongjiang province’s main corn varieties to low temperature stress processing, determination of germination rate under low temperature stress, seedling stage determination of the change of net photosynthetic rate, conductivity, low temperature resistant varieties screening, provide the basis for farmers choose low temperature resistant varieties, come to the conclusion of farmers’ production, income and efficiency has important significance.Low temperature resistant sort of20varieties, provide the basis for farmers choose low temperature resistant varieties.The major results were as followed.1.The seed-germination percentage to decrease in low temperature stress. A degree greater germination percentage is smaller.2. Conductivity and MDA were increase in low temperature stress.Pn was decrease. The temperature is lower the scope which increases or reduces to be bigger.3. The degree of low temperature stress were positive correlation during bud or seedling stage. Correlation coefficient is R=0.67. Heilongjiang introduced.cultivation variety of corn varieties of cold resistance differences. Through bud seedling stage of clustering analysis,20varieties are divided into three types, their single1, four varieties of resistance to low temperature type; Ken single10,4varieties for middle type; Single6grams, suijiang jade14,12varieties for sensitive type.4. The membrane system of maize leaves was injured under chilling stress, and the injury was weakest in the seedlings with strong cold-resistance. Both of the plasmalemma permeability and the MDA content were increasing under each low-temperature treatment, but the increasing amplitude of variety (Qingdan1) with the strong cold-resistance was lowest.