Physiological efficiencies in 186 peanut cultivars of various botanical groups

Abstract

Peanut is a major oilseeds crop of India with its largest area in the world, but its productivity is less than the world average. Though India has released a number of peanut cultivars, studies on the physiological efficiencies of such varieties are scarce. In this study, we tried to elucidate the physiological basis, net photosynthesis (PN), transpiration (E), stomatal conductance (gs), chlorophyll fluorescence (Fv/Fm), SPAD chlorophyll meter reading (SCMR), chlorophyll (chl) contents in leaf at 60-65 days of crop and pod and haulm yields at harvest in 186 peanut cultivars during Kharif season. The average and range of PN were 19.8 and 11.4-31.4 µ mol m-2s-1, gs 0.25 and 0.11-0.45 m s-1, E 6.84 and 3.96-11.61 m mol m-2s-1, SCMR 34.0 and 20.3-44.1, total chl 7.79 and 3.07-15 mg g-1 leaves, Fv/Fm 0.846 and 0.802-0.887, pod yield 179 and 68-309 g m-2 and haulm yield 464 and 144-884 g m-2 and a number of superior cultivars identified. The pod yield was strongly correlated with SCMR, chl and carotenoid contents, haulm yield and pods plant-1, but weakly associated with PN, gs, and Fv/Fm. The PN correlated with gs and E, however, SCMR was the single best parameter. The Spanish and Virginia bunch groups showed most desirable physiological traits. The cultivars TPG 41, Chintamani, M 37, GG 8, GG 13, Kadiri 7 and M 522 showed superior physiological traits for their cultivation.