Genetic Variation of Some Agronomic Characteristics and Grain Quality Traits of Rice Mutant Genotypes

Mutagenesis techniques are used for induce genetic diversity  in many crop plants and several desire mutant lines have been developed by mutagenesis. So, this study was conducted with the aim of evaluating agronomic traits and yield comparison of rice mutant genotypes.

41 mutant genotypes, resulted from chemical mutation of Hashemi local rice variety, with control cultivars Hashemi, Anam, TH2 and Gilaneh was studied in an augmented design based on a randomized complete block design with 4 replications, at the Rice Research Institute of Iran, Rasht, in 2019.In this study, agronomic and qualitative characteristics including flowering time, plant height, number of fertile tillers, panicle length, number of filled grains, number of unfilled grains, 100-grain weight, milling recovery, amylose content, mean gelatinization temperature and grain yield were assessed in all genotypes.

Based on the results, there were considerable variations among genotypes in terms of flowering time (days to 50% of flowering), plant height, panicle length, grain yield, milling recovery and amylose content, and the differences among genotypes and as well as differences among genotypes with controls in all cases were significant (p≤0.05). Number of days from planting to flowering was less than 83 days in 33% of genotypes. Also, in 43% of lines, plant height was less than 130 cm and 30% of genotypes had yields higher than 5 t/ha. Results showed that mutant genotypes EM4-233 and EM4-233 had highest yields (more than 6 t/ha) and were superior to other genotypes. Cluster analysis by Ward method divided genotypes to four groups.

Regarding earliness, grain quality, yield traits and other desirable agronomic characteristics, mutant genotypes EM4-83, EM4-233, EM4-29, EM4-106 and EM4-294 were selected as superior genotypes.