Evaluation Of Cold Resistance And Response Of Cucumber Seedlings To Chilling Stress

Cucumber of wild species originated in the Himalayan foothills, after long-term acclimation, now has become one of the main vegetables widely cultivated throughout the world, and is a kind of extremely important cultural value of vegetable crops in China. Cucumber not only widely cultivated in open field, the main vegetable crop is cultivated in greenhouse, China’s demand for a huge amount of cucumber. Cucumber is a thermophilic crops, greenhouse cucumber generally has some problems in winter:the long-term low temperature and short critical low temperature, these will make cucumber physiological disorders,"melon" serious, crop is reduced, caused a large number of dead plants phenomenon or even. So the cucumber cold resistance identification and Screening low temperature resistance ability is especially important. This study collects60cucumber cultivars of3leaf stage as the experimental material, processing8day of day/night temperature of12℃/6℃, the light intensity under the7000lx, Determinate the morphological index, physiological and biochemical index related to cold resistance, and analyze the cold resistant difference of60cucumber accessions using morphological, physiological and biochemical Index, while using SSR markers means clustering the60cucumber materials. Through a comparative analysis of different morphological, physiological indexes of clustering and UPGMA clustering map, the main results are the following:1. Different varieties of Cucumber Seedlings shows differently in low temperature resistance performance, the60cucumber accessions can be divided into three categories through the use of chilling injury index:cold sensitive, weak cold resistance and high cold resistance; from the electrical conductivity, stem diameter, free water, free water and bound water ratio indicators: From the electrical conductivity, stem diameter, free water, free water and bound water ratio shows:with the increase of cold resistant ability, the index value decreased; From the bound water, leaf area, plant height index shows:with the increase of cold resistant ability, the index value increased.2. By clustering the morphological, physiological and biochemical indexes, morphological and physiological and biochemical indexes, analysis the three clustering results, the best way to evaluate the cold resistant of cucumber cultivars is to clustering morphological index.3. Through the analysis of SSR molecular marker clustering results with the best clusteringevaluation results are basically the same, but the performance of certain differences in some breeds.4. The comprehensive evaluation results, evaluation of cold resistant of cucumber should be mainly based on the chilling injury index and morphological clustering evaluation, supplemented by SSR molecular marker analysis is more accurate.