Exploitation of heterosis in okra (Abelmoschus Esculentus (L.) Moench)

Abstract

Okra (Abelmoschus esculentus (L.) Moench), being an often cross-pollinated crop, responds well to heterosis breeding. Exploitation of heterosis is primarily dependent on the screening and selection of available germplasm that could be produced by better combinations of important agronomic characters. Ten elite, optimally divergent and nearly homozygous lines of okra namely P1(IC282248), P2(IC27826-A), P3(IC29119-B), P4(IC31398-A), P5(IC45732), P6(IC89819), P7(IC89976), P8(IC90107), P9(IC99716) and P10(IC111443) selected from the germplasm were crossed in all possible combinations excluding reciprocals during summer 2009. The resultant 45 F1s along with their 10 parents and one commercial check (Mahyco Hybrid No.10) were evaluated in a randomized block design with three replications during mid kharif (July - October), 2009 at the Vegetable Research Station, Hyderabad, Andhra Pradesh, India.  Heterosis over mid parent, better parent and standard check were studied for 17 quantitative characters pertaining to pod yield and its associated characters. For total yield per plant, the crosses as a whole manifested 7.17% and -15.22% average and standard heterosis, respectively. For marketable yield per plant, the crosses as a group manifested 6.77% and -22.64% average and standard heterosis, respectively. The crosses C16(P2×P9) and C4(P1×P5) manifested significantly negative commercial heterosis for days to 50% flowering (-5.13%) and first flowering and fruiting nodes (-16.55%), respectively indicating their earliness. Highest heterobeltiosis of 38.87% for total yield per plant and 37.95% for marketable yield per plant was manifested by the cross C23(P3×P9). The extent of standard heterosis for total yield per plant (9.32%) and marketable yield per plant (-6.69%) appears to be sufficient for exploitation of heterosis commercially. The crosses C42(P7×P10), C31(P5×P6) and C35(P5×P10) were statistically on par with the standard check in their mean performance and are as promising as that of the standard check (Mahyco Hybrid No. 10).