Assessment of genetic components and heterotic potential for panicle and yield related traits in rice (Oryza sativa L.)

Rice (Oryza sativa L.) is the staple food crop and it is cultivated under diverse ecological conditions. Understanding genetic effects and identifying superior hybrids are important steps in rice breeding to enhance yield. Six parents with varying numbers of grains per panicle were subjected to full diallel mating. Hayman's graphical approach was applied to compute various genetic parameters and better parental, mid parental and standard heterosis for panicle and yield related traits. The results revealed that, grain yield per plant and panicle related traits were governed by both additive and non-additive effects but the additive component was predominant for the number of filled grains per panicle and non-additive for grain yield per plant. The number of spikelets per panicle, the number of filled grains per panicle and the number of primary branches per panicle were mainly governed by recessive alleles present in the parents. The overdominance effect was found in the number of productive tillers, flag leaf area, panicle length, the number of primary branches per panicle, length of primary branches, thousand grain weight and grain yield per plant. The Vr-Wr graph depicted that the number of spikelets per panicle, the number of filled grains per panicle and the number of secondary branches per panicle were governed by partial dominance and grain yield per plant had over dominance effect and the low grain number parents, IET 28835 and ADT (R) 48 possessed more number of dominant alleles than other parents for all these traits. The promising cross combination BPT 5204 × CB12132 and its reciprocal hybrid exhibited high mid parental and standard heterosis for important panicle traits were adjudged as promising hybrids.