ESTIMATION OF STANDARD HETEROSIS AND GRAIN QUALITY OF RICE HYBRIDS (Oryza saliva L) CULTIVATED IN BANGLADESH

Abstract

Six hybrids and two modem check varieties of rice (Oryw sa:iva L.) were evaluated to estimates standard heterosis of important yield contributing traits, to asses genetic variation among the grain characters, to study the grain appearance and milling quality and to determine cooking and eating characters of grain at the central research farm of Sher-e-Bangla Agricultural University. Uhaka, during the period of January 2006 to June 2006. All the hybrids were superior to best yielding check BRRI dhan29 in mean performance with respect to grain yield per plant, grain weight per meter square, 1000-grain weight and harvest index and all the 6 hybrids were superior to check BRRI dhan28 with respect to number of filled spikelets, grain yield per plant, grain weight per meter square. 1000-grain weight and harvest index. Positive and significant standard heterosis over BRRI dhan28 was observed in three hybrids for days to 50% flowering, five hybrids for days to maturity & grain yield per plant. four hybrids for panicle length, two hybrids for total spikelets per particle, biological yield, all hybrids for grain yield per square meter, harvest index and 1000-grain weight. Positive and significant standard heterosis over BRRI dhan29 was observed in four hybrids for days to maturity, harvest index and grain yield per square meter, all the hybrids for grain yield per plant and 1000-grain weight. All the hybrids showed higher grain yield per hectare (6.15 t/ha to 7.45 t/ha) than both the cheeks (5.50 VIta to 6.00 t/ha) on per square meter harvest basis. In general, yield was strongly and positively related to 1000-grain weight, grain yield per plant and harvest index. Highly significant variation was observed among the genotypes for hulling percentage, milling outturn, percent head rice recovery, grain length, grain breadth, L/B ratio of grain, breadth before cooking, breadth after cooking, alkali spreading value, cooking time, elongation index, volume expansion, water absorption, amylose content and protein content. Maximum hybrids showed higher hulling percent, and milling percent than checks. Most of the hybrids showed lower head rice recovery than the check BRRI dhan28 but higher the check BRRI dhan29. Two hybrids (Sonarbangla-1 & ileera) had long slender grains, three (Richer. A loran & Jagoron) belonged to medium slender grains and one hybrid (BRRI hybrid dhanl) belonged to long bold. Superior cooking performance over BRRI dhan29 was observed in all the hybrids for length of cooked rice elongation, kernel elongation ratio, kernel elongation index and one hybrid for volume expansion. Superior cooking performance over BRRI dhan28 was observed in two hybrids for length of cooked rice elongation, volume expansion & kernel elongation index, all the hybrids for kernel elongation ratio, three hybrids for water uptake. Protein content ranged from 7.80 to 10.00. All hybrids showed translucent grains. Maximum hybrids showed intermediate GT and intermediate amylase content. Among the hybrids A loran gave highest yield (7.45 t/ha) and BRRI hybrid dhanl gave lowest yield (6.15 t/ha). All the hybrids were identified having acceptable grain quality but overall performance in relation to cooking and eating point of view Sonarbangla-1 and BRRI hybrid dhan I performed better.