Studies On Drought Resistance Physiological Characters And Anatomy Of Different Mung Bean Mutants

The drought resistance physiological characters and anatomy of four varieties of Mung Bean with different drought resistance (including three mutants 172-3(strong resistance), 159-1 (moderate resistance) 145 - l(weak resistance) and their original cultivars zhonglvNo.2(non-drought-resistance)) were studied in the different growing stage and under different water stress. The purpose was to ascertain the mechanism of drought resistance. The experimental results showed :(1) in different growing stage, effect of different water stress on the characters of the varieties of Mung Bean with different drought resistance was various. The most effect was on plant height No. Of joints of the main stem. No.of branches per plant, No.of pods per plant and the yield per plant in seedling stage; In blooming and podding stage, the most effect was No.of pods per plant, No. of grains of per pod and the yield per plant; The more sensitive characters to water stress were pod length ,pod path. No. of pods per plant, 100-grains weight and the yield per plant in grouting stage. (2)In different growing stage ,the physiological and biochemical indexes of the varieties of Mung Bean with different, drought resistance were affected to different degree under different water stress . Most physiological and biochemical indexes were related to the drought - resistance properties of Mung Bean, only few of which were not in some growing stage. (3)From the studies for morphological and anatomical structure of four varieties of Mung Bean, the results were as follows: Compared with weak drought-resistance varieties ,the strong drought-resistance varieties of Mung Bean were characterized as that the number of vessel of xylem in the root was more and the root system had higher dry matter content ;The vascular bundle in the stem arranged more closely and the number of vessel of that is more; The cells of the cortex were bigger and the cortex was thicker; The content of tannin of ergiastic substance in the parenchyma cell of centex pith was more; The ratio of palisade tissue to spongy tissue in the leaf was higher; The midrid and the radius of vessel of vascular bundle in midrib were larger. (4)When studying the drought resistance of Mung Bean we should take from comprehensive factors from whole growing stage such as the characteristics of the morphological and anatomical structure , physiological and biochemical indexes and the final perform of the yield into consideration.