Variation among Iranian alfalfa genotypes for absolute growth rates and salt stress tolerance indices

Abstract

In many parts of the world, one of the most important restricting factors in cropproduction is salinity stress. Screening and selecting tolerant genotypes based on morphological characteristics is one of the primary actions toward achieving salt tolerant varieties. In the present study, 20 genotypes of alfalfa, mostly from Iran, were evaluated in two separate experimentsin Agriculture Research Center of Safi Abad, Dezful, SW Iran, in 2014-2015. However highly significant variations were observed among genotypes in the both experiments, the results obtained from the first experiment (carried out within growth chamber) were more or less different from those obtained from the second one (carried out in a heated greenhouse) regarding to categorizing the genotypes as sensitive or tolerant. The results obtained from the growth chamber study illustrated that Nikshahri was the most tolerant genotype and Harpinger and Diablo-verde were the most sensitive ones. While in greenhouse experiment, the genotype Yazdi showed the highest tolerance and Bami showed the highest sensitivity to salt under moderate salinity stress environment. A similar trend was also found under severe salt stress conditions. Correlation analysis indicated highly significant relationships among the tolerance indices. In addition, principle component analysis revealed that the dimensions of data could be reduced to two components with explaining approximately the 99 percent of total variations among the genotypes.

Keywords

• Alfalfa
• Germination
• Salt stress
• Stress indices
• Variation