Selection of alfalfa (Medicago sativa L.) cultivars for drought stress tolerance through germination indices.

摘要

To select the most tolerant alfalfa genotypes to drought stress, an experiment was performed in a factorial scheme in a completely randomized design (CRD) with three replications. The cultivar and salinity stress factors comprised 20 cultivars and four levels of drought stress (control, -3, -6 and -9 bar) with PEG 6000, respectively. Results indicated that a significant decrease was observed in all traits in stress conditions. The Bami Garmsiri cultivar showed the highest germination percentage, germination rate, radicle length, seedling length and seed vigour traits in drought conditions. Results of the cluster analysis using the data for all measured traits and drought levels clustered cultivars into three groups. The first cluster included four of the cultivars KFA₁, KFA₄, KFA₁₁ and KFA₁₆, the second cluster included eight cultivars KFA₂, KFA₃, KFA₅, KFA₆, KFA₇, KFA₉, KFA₁₂ and KFA₁₅ and the third cluster included eight cultivars KFA₈, KFA₁₀, KFA₁₃, KFA₁₄, KFA₁₇, Yazdi Garmsiri, Nikshahri Garmsiri and Bami Garmsiri. Cultivars in the third cluster were found to be tolerant, while the second ones were sensitive and cultivars in the first cluster semi-sensitive to drought. Bami Garmsiri the most tolerant cultivar was found to drought. They will be used in large field trials to confirm their tolerance to drought waiting creation of new hybrid varieties.