[Indices selection and comprehensive evaluation of salinity tolerance for peanut varieties]

A total of two hundred peanut varieties (lines) were exposed to different salt concentrations under pot cultivation, to evaluate salinity tolerance by indices such as emergence, morphology and biomass accumulation from emergence to seedling stage. The results showed that, as the salinity concentration increased, the emergence time was prolonged, plant morphology establishment was inhibited seriously, and biomass accumulation was reduced. The optimal concentration for evaluating salinity tolerance was 0.30%-0.45%. Ten indices were contributed to the mean membership function value by the membership function analysis. According to the correlation coefficient between indices and the mean membership function value, plant fresh mass, shoot fresh mass, root fresh mass, root dry mass, plant height and stem height could be the first selected indices for evaluating salinity tolerance of peanut plant. Plant dry mass, shoot dry mass, taproot length and emergence speed could be the second selected indices to comprehensively evaluate salinity tolerance of peanut plant. The 200 varieties were divided into 4 groups at different salinity concentrations, i. e. high salinity tolerance, salinity tolerance, salinity sensitivity, and high salinity sensitivity. Number of salinity tolerant varieties was decreased with increasing salinity concentration while the salinity sensitive one was increased. Salinity tolerance of some varieties showed the similarity (tolerant or sensitive) under different salinity stresses. Some varieties showed different tolerance under different salinity stresses, i. e. tolerance at low salinity concentration while sensitivity at high salinity concentration.