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 (<em>P</em>_N), transpiration (<em>E</em>), stomatal conductance (<em>g</em>_s), chlorophyll fluorescence (F_v/F_m), 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 <em>Kharif </em>season. The average and range of <em>P</em>_Nwere 19.8 and 11.4-31.4 µ mol m^-2s^-1, <em>g</em>_s 0.25 and 0.11-0.45 m s^-1, <em>E</em> 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^-1leaves, F_v/F_m0.846 and 0.802-0.887, pod yield 179 and 68-309 g m^-2 and haulm yield 464 and 144-884 g m^-2and 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 <em>P</em>_N, <em>g</em>_s, and F_v/F_m. The <em>P</em>_N correlated with <em>g</em>_s and <em>E</em>, however, SCMR was the single best parameter<em>. </em>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.