Heterobeltiosis and Economic Heterosis for Grain Yield Related Traits of Boro Rice (Oryza sativa L.)

Abstract

Rice is a staple food for more than half of the world’s population and to increase the yield potential of rice would be a key factor for mitigating global demands of about 810 million tons of rice by 2025. To exploit the economic importance of heterosis, quantitative valuation was carried out in a randomized complete block design with three replications for 16 agronomic traits of 5x5 half diallel populations during boro season of 2017-2018. Diallel populations were generated by using five selected parents (P₁: BRRI dhan28, P₂: BRRI dhan74, P₃: BINA dhan10, P₄: IR59418-7B-21-3 and P₅: BRRI dhan67) where, P₁ was considered as standard check to estimate the economic heterosis. Analysis of variance revealed highly significant variability among the genotypes for most of the traits except grain length and length-breadth ratio. The results showed that none of the hybrid combination performed better for all the traits over the three types of heterosis. The highest relative heterosis was recorded in P₃×P₄ followed by P₄×P₅ for grain yield plant^-1, filled grains panicle^-1, effective tillers plant^-1. Majority of the cross combinations (>60%) revealed highly significant positive heterosis for grain yield plant^-1 over mid parent. Heterobeltiosis for grain yield plant^-1 was observed significant for 50% cross combinations and could be utilized in hybrid breeding. Whereas, more than 70% crosses exhibited undesirable negative standard heterosis for grain yield plant^-1. Only two cross combinations (P₃×P₅ and P₃×P₄) among ten revealed significant positive economic heterosis for grain yield plant^-1 and those could be exploited in rice breeding.

Int. J. Appl. Sci. Biotechnol. Vol 9(1): 45-53