Genetic Variability for Antioxidant Activity and Total Phenolic Content in Four Major Pulse crops

Abstract

Total phenolic content and antioxidant activity were evaluated in 139 diverse genotypes of four pulse crops including 54 genotypes of chickpea (Cicer arietinum), 37 lentil (Lens culinaris), 21 pigeonpea (Cajanus cajan), and 26 blackgram (Vigna mungo). Results indicate significant genotypic variation (p < 0.01) for total phenolic content (TPC) as well as antioxidant activity (AOA). Amongst the four major pulse crops tested, maximum mean phenolic content was recorded in blackgram genotypes (7.01mg GAE/g), followed by lentil (3.46mg GAE/g), pigeonpea (3.32mg GAE/g) and chickpea (2.30mg GAE/g). In general, the Mediterranean landraces of lentil had higher phenolic content as compared to the other lentil varieties and breeding lines. Amongst the chickpea genotypes the phenolic content ranged from 0.40 to 5.63mg GAE/g and comparatively higher value for phenolic content was recorded in desi types (2.67mg GAE/g) as compared to the Kabuli types (1.05mg GAE/g). The antioxidant activity (AOA) was assayed in mature dry seeds utilizing DPPH (2,2-Diphenyl-1-picryl hydrazyl) radical scavenging assay which ranged from 1.73 to 19.14µmole Trolox/g tissue. As observed for TPC, highest AOA was also recorded in blackgram genotypes (19.14µmole Trolox/g tissue), followed by pigeonpea (2.72µmole Trolox/g tissue), chickpea (2.05µmole Trolox/g tissue) and lentil (1.73µmole Trolox/g tissue). Highly significant genotypic as well as phenotypic correlation (p<0.01) was recorded between phenolic content and antioxidant activity in chickpea, lentil as well as blackgram (rG values ranging from 0.268 to 0.850 and rP from 0.253 to 0.817), however, surprisingly the values were non-significant in case of pigeonpea. Strongest genotypic correlation was recorded in chickpea (rG=0.850), followed by lentil (rG =0.744), and blackgram (rG =0.268). High broad-sense heritability (h2bs) (0.89 to 0.97) for phenol content was recorded which indicates that substantial portion of total variation for phenolic content is due to genetic effects.