Detection of rice grain length genes in the second-generation population using morphological and molecular markers

Grain length is one of the most important characteristics in rice breeding, which affects the yield and quality of the grain. In this study, the genetic diversity of grain length and width and 1000 seed weight were evaluated in the F2 population resulting from the crossing of L44 line (maternal parent) and IR-229R genotype (paternal parent). Also, molecular markers correlated with grain length were used to identify genotypes with longer grain length in the F2 population. The results of the evaluation of morphological traits showed that the average length of rice grain in the second generation L44 × IR-229R population is 11.16 mm, which is close to the average grain length in the mother genotype L44 (11 mm). Also, 10 genotypes showed longer seed length than the paternal parent, and among these genotypes, 6 genotypes (numbers 8, 10, 76, 82, 91 and 96) had greater seed width and 1000 seed weight than the population average. In the molecular evaluation, it was found that primers RM488 and RM234 (correlated with rice grain length on chromosome 1 and 7, respectively) showed polymorphism between parent’s genotypes. In examining the grain length trait with markers RM488 and RM234, genotypes 76, 82, 91 and 101 with grain length of 12.96, 12.66, 12.79 and 12.53 mm respectively were identified as long seed genotypes.