BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF SOME ADVANCED MUTANT RICE (Oryza sativa) LINES OF BINA

Abstract

Rice (Oryza sativa) is one of the oldest cereal grains in the world and the main staple food of Bangladesh. In rice, amylose and protein are the main biochemical factors in selection and breeding of good eating quality varieties. A total of 12 rice genotypes [10 advanced mutant lines, 1 released mega variety (BRRI dhan49) and 1 landrace (Luxmidigha)] was incorporated in this study to assess their amylose and protein content as well as their genetic diversity relationship. Among the genotypes, Magic-86 was highest in amylose content (25.6%). The second and third highest amylose content were RM-40(C)-4-2-8 (25.1%) and Magic-10 (24.4%), respectively. Amylose of other genotypes ranged from 23.9 to 20.3%. SSB-3 was found to be the highest in protein content (8.86%) whereas Magic-86 (8.78%) and Luxmidigha (8.73%) were the second and third highest, respectively. Protein content of other genotypes were ranged from 8.50 to 5.04%. The highest gene diversity (0.81) was observed in RM519 and the lowest (0.28) was in RM111. The PIC values ranged from 0.24 to 0.78. The highest Nei’s genetic distance value 0.87 was found in RM-16(N)-10 vs RM-40(C)-4-2-8 and the lowest value 0.18 was found in LD-200-1-3-3-8 vs LD-200-1-3-2-4. A dendogram was constructed based on Nei’s similarity coefficient using UPGMA method to group the selected genotypes and observe relationship among them. Six major clusters were built at 0.7 cut off similarity coefficient. The highest number of genotypes was observed in cluster-6 (4 genotypes) and the lowest in cluster-1, cluster-2 and cluster-4 (each contained 1 genotype). Cluster-3 and cluster-5 contained 3 and 2 genotypes, respectively. The genotypes showing diverse ranges of amylose and protein content tended to cluster together in the dendogram with some exceptions. These findings may play potential role for the selection of parents or lines in future breeding program to develop better quality rice varieties for Bangladesh.