analysis of the physicochemical properties and grain yield of some rice promising lines from multiple crosses

grain quality currently represents a major problem in high yielding rice production in iran and many other rice producing areas of the world. quality assessment of rice involves the function of sensory tests and physicochemical determinations based on the chemical composition, cooking quality, gelatinization temperature and physical properties of cooked rice. these research genetic materials were 28 f4 favorable lines derived from the screening 126 f3 lines by multiple crosses with acceptability phenotype and superior yield. lines, parental and controls varieties to assess the physiochemical properties such as the milling, grain length before cooking, grain length after cocking, elongation after cooking, gelatinization temperature, gel consistency, amylase content and aromatic were used. cluster analysis has shown that domsiah, sangtarom and shastak of local check varieties located as first group, neda and ghaem in the second group, fajr in third group and nemat in fourth group. lines of gf//gs-03-1, gd//gs-03-1-23, gf//gn-03-1-34, gd//gs-03-2-16, gf//gn-03-2-24, gf//gn-03-2-18 and gf//gs-03-3 due to suitable characterization and high purity (87.5%) are introduced as promising lines. correlation coefficients of quality trait show that significant and positive correlation for grain length before cook and grain length after cook (r=0.70) and grain yield (r=0.50), grain length after cook with elongation after cooking (r=0.64), gt with grain yield (r=0.35)