Estimates of heterosis, inbreeding depression and transgressive segregation in rice (Oryza sativa L.) under sodic soil

Abstract

Abstract The present investigation was carried out at the Main Experimental Station of Acharya Narendra Deva University of Agriculture & Technology, Narendra Nagar (Kumarganj), Ayodhya (U.P.) India. A field experiment was conducted by using a line x tester set of 63 F1s and 63 F2s derived by crossing 21 rice genotypes/varieties as lines (females) with three testers (males) viz., Narendra Usar Dhan 3, CSR 23 and IR 28 with 2 check varieties (Jaya and CSR 43) of rice (Oryza sativa L.) in randomized complete block design with three replications to work out the heterosis, transgressive segregantion and inbreeding depression effects for various attributes under the sodic soil condition. Among these, top 5 F1s viz., NDRK 5037 x Narendra Usar Dhan 3, NDRK 5062 x IR 28, NDRK 5062 x CSR 23, NDRK 5037 x CSR 23 and NDRK 5040 x Narendra Usar Dhan 3were showed significant positive standard heterosis for grain yield per plant over SV1 and SV2, respectively. All of the above mentioned crosses had highly significant inbreeding depression for grain yield per plant in F2 generation. Inspite of grain yield of these F1s had significant heterosis and inbreeding depression for some of the other yield contributing characters also. This study indicated the presence of non additive gene action in the inheritance of grain yield per plant and some of the other yield contributing characters. Tolerant breeding populations showed similar banding pattern whereas susceptible exhibited similar banding pattern but possesses wide variations between tolerant and susceptible. At 35 kDa the medium to dark bands were present in parents, F1s, F2s, transgressive segregants and checks while in highly inbreeding depressed cross combinations, variable range of the bands were observed viz., absence of bands, light, medium and dark bands. Our data ofer a valuable resource for advancing the understanding and facilitating the utilization of additive and non-additive information for rice improvement.