Study on Adaptability of Leguminous Crops to Stress Factors in Acid Soil

Xia Longfei; L Jiao; Zhao Zunkang; Li Xiaofeng; Wang Yongxiong

doi:10.14083/j.issn.1001-4942.2015.04.017

Abstract：Hydroponic experiments were conducted to study the response of three leguminous crops to the stresses of low pH, low phosphorus and high concentrations of Al3+and Mn2+.The plant growth, related en-zyme activities, nutrient absorption, organic acid secretion and their differences between the three leguminous crops were analyzed.The results were as follows.The biomass decreased significantly and the H+-ATPase activity in root tips increased significantly in the three leguminous crops under the low pH (4.5 and 5.5) con-dition;and the effects of low pH stress on the three leguminous crops showed the order of sweet clover>alfalfa>soybean.Low phosphorus (0.05, 0.10 mmol/L) stress significantly decreased the biomass and P accumu-lation in plants but increased the H+-ATPase activity in root tips;in which, alfalfa was more sensitive to low phosphorus, while sweet clover had the highest adaptability.After Al3+(3~10 μmol/L) treatment, the root tips of alfalfa and sweet clover could be dyed purple by hematoxylin, and the color of alfalfa was deeper.How-ever, the root tips of soybean could not be dyed obviously.After treated with 30μmol/L Al3+, the citric acid was secreted by the root tips of soybean.The effects of Mn2+(50, 100μmol/L MnSO4 ) on biomass and Mn2+accumulation in plants were in the order of soybean >alfalfa>sweet clover.The comprehensive adaptability of the three crops to the four stresses of acid soil were evaluated by assignment method, and the results showed that soybean had the best comprehensive adaptability, and then sweet clover;alfalfa had the worst comprehen-sive adaptability.