模拟酸雨对黑木相思幼苗生长与生理特性的影响OA

In order to study response mechanism of Acacia melanoxylon seedlings under acid rain stress,taking half-year-old A.melanoxylon seedlings as experimental materials,single factor test design was used to set treat-ments with different pH levels(5.6,5.0,4.0 and 3.0),with clear water treatment as control(CK).Changes of growth and physiological indexes of A.melanoxylon seedlings were compared.Results showed that compared with CK treatment,simulated acid rain treatments had no significant effects on ground diameter increment,total biomass and physiological indexes of seedlings in range of pH value from 4.0 to 5.6.Plant height increment,ground diameter increment,total biomass,soluble protein content and superoxide dismutase activity of seed-lings were the highest when pH value was 4.0,among which plant height increment was extremely significant higher than that of CK treatment.Contents of photosynthetic pigments were the highest under CK treatment.Un-der pH 3.0 treatment,plant height increment,ground diameter increment,soluble protein content and contents of photosynthetic pigments of seedlings were the lowest,which were significant or extremely significant lower than those of CK treatment.Results of membership function analysis showed that comprehensive performance of seedlings was the best when pH value was 4.0,and comprehensive performance was the worst when pH value was 3.0.A.melanoxylon seedlings had strong tolerance to acid rain and could grow well in acid rain environ-ment with pH≥4.0,which could be popularized and planted in acid rain prone areas with pH≥4.0.