Genetic analysis of Myanmar Vigna species in responses to salt stress at the seedling stage
Twelve (12) Vigna genotypes were investigated for the evaluation of their tolerance levels in responses to four concentrations of NaCl (0, 75, 150 and 225 mM) at seedling stage. In the investigation, salt stress inhibited almost all the growth parameters as well as relative water content; however, the degree of reduction was highly dependent on different genotypes and salinity levels. Generally, the control plants showed higher degree of all measured parameters than those of salt stress plants. Analysis of the heredity parameters based on the 12 investigated genotypes showed different genotypic variance of the salt tolerance index (STI) values. Salinity stress induced two new bands between 45 and 22 kDa, respectively, in salt tolerant genotypes. Furthermore, band intensity of the salt treated genotypes was higher than the control plants. Ward’s clustering technique was clearly divided into two clusters, A and B, according to their levels of salt tolerance. Considering their STI values of growth parameters, two genotypes V7 and V4 were identified as salt tolerant, whereas, V2, V6, V9, V8, V11 and V1 were recognized as salinity susceptible genotypes. These results suggest that, the genetically diverse
accessions resistant to salt stresses within the Vigna genotypes can be of considerable practical value for studying the mechanism of salt tolerance and for the provision of genetic resources for salinity breeding program.
Key words: Cluster analysis, heritability, salt tolerance, SDS-PAGE, Vigna.