Biochemical characteristics of red bean (Phaseolus vulgaris L.) genotypes as affected by seed pre-treatment with growth regulators .

In order to investigate the effect of seed pretreatment with growth regulators on biochemical characteristics of red bean genotypes, a factorial experiment was carried out in a randomized complete block design with three replications. In this research, seed pretreatment with growth regulators namely salicylic acid (SA) and naphthalene acetic acid (NAA) were applied at four levels including P0: control (pretreated with distilled water); P1: pretreated with NAA hormone (0.5 mM/lit); P2: pretreated with SA hormone (0.7 mM/lit); P3:  pretreated with combination of NAA hormones (0.5 and 0.7 mM/lit) and two genotypes of red beans (KS31169 and D81083). The ANOVA results showed that the simple effects and the interactive effects of genotypes × priming with growth regulators on all traits were significant except the relative chlorophyll content. The results of mean comparison for the interactive effect of genotypes and priming with growth regulators showed that application of SA increased the amount of chlorophyll a in D81083 genotype. The highest rate of chlorophyll b and total chlorophyll belonged to D81083 genotype with application of NAA. The rates of flavonoids and carotenoids decreased by using growth regulators, therefore the highest rates of these traits were observed in control × D81083 genotype. Seed priming with combined treatments (NAA+SA) led to the highest stability of cytoplasmic membrane in KS31169 genotype. In general, the results of the present study indicated that the use of growth regulators as seed pretreatment will increase the main pigments of photosynthesis and cytoplasmic membrane stability.