Identification of superior haplotypes for CCD8 regulating tiller number and grain yield in rice

Rice is one of the major food crops of the world. In the present day of increasing population there is an urgent need to increase the rice grain production. Yield is a complex trait and is mainly orchestrated by plant architecture. In the present study, a diverse set of 100 accessions from the 3K RG panel were evaluated for Carotenoid cleavage dioxygenase 8 (CCD8) loci which plays a role in altering tiller number which ultimately governs the crop yield. A normal phenotypic distribution for total tiller numbers and number of productive tillers was observed for the set of 100 accessions used in the study. Five non synonymous SNPs were present for CCD8 loci for the 100 rice 3K accessions in this study. Haplotype analysis was carried out using five non synonymous SNPs to understand the genetic diversity of the population and of which two significant SNPs in the positions 31223371 and 31223383 grouped the accessions into two haplotype H1 and H2 with the allelic combination of GC and AT respectively. Haplotype group H1 with 89 accessions and H2 with 8 accessions were formed. Among the two haplotype groups, H2 had the maximum mean value for both tiller number and productive tiller number indicating the superiority of the H2 allelic combination over H1. Hence H2 is considered as a superior haplotype that can be potentially explored for allele mining and can be used in future crop improvement programs.