Study On The Chilling Tolerance Of Kidney Bean Seedlings

The chilling tolerance of 32 genotypes of kidney bean(Phaseolus vulgaris L ) seedlings was identified by the indexes including electrolytic leakage of leaves and roots , chilling injury index under the low temperature to choose the higher chilling tolerance of kidney beans. Then the two kinds of kidney bean seedlings having a obviously difference in chilling tolerance made as materials were caused under low temperature in order to study the changes of growth, physiology characteristic and characteristic of photosynthesis and chlorophyll a fluorescence under low temperature stress. The physiological mechanism of the chilling tolerance of kidney beans was studied. The main results were as follows:The chilling tolerance of 32 genotype kidney bean seedlings of high , middle and low chilling tolerance has been grouped by cluster analysis; the result also showed that the chilling injury index had highly significant correlation with leaves and roots electrolytic leakage . The chilling tolerance of the kidney bean seedlings could be properly identified by electrolytic leakage of leaves and roots and chilling injury index of leaves.The two kind of kidney bean seedlings having a obviously difference in chilling tolerance made as materials were stressed under low temperature at 5℃in order to study the changes of of kidney bean seedlings. The results were as follows:'Chao-ji-jiu-li-bai'has a better chilling tolerance than that of'Da-jiang-106-jia-dou-wang'.Under low temperature stress,The chilling injury index of leaves. and electrolytic leakage of leaves and roots of the former were distinctly lower than that of the latter; The chilling injury index of leaves. and electrolytic leakage of leaves and roots of the former were distinctly lower than that of the latter; The relative water content ,the ratio of bound water to free water, chlorophyll content and root activity were distinctly higher than that of the latter.The main causes of the higher is that the leaves could maintain stronger SOD,POD,CAT activity and Vc content and lower MDA content and higher soluble protein content...