Heterosis breeding in rice (Oryza sativa L.).

摘要: Studies conducted at the International Rice Research Institute (IRRI) during 1980 and 1981 have shown up to 73% heterosis, 59% heterobeltiosis 34% standard heterosis for yield in rice. The latter was estimated comparison commercial varieties: IR36 IR42 (yield 4–5 t/ha wet season trials 7–8 dry trials). Generally speaking, absolute lower extent of higher than with some exception. Yields 5.9 (22% heterosis) 10.4 (34% were obtained. Most hybrids performed better while both seasons. Hybrids showed lodging resistance although they 5–10 cm taller. F1 had significant positive correlations parental traits viz., (r = 0.446), tillering 0.746), height 0.810) flowering 0.843). Selection parents among elite breeding lines on basis their per se performance, diverse origin insects diseases should give heterotic combination. Yield advantage due primarily increase number spikelets unit area even though tiller reduced. Grain weight either same or slightly higher. High yielding also total matter harvest index. For utilization rice, effective male sterility fertility restoration systems are available 45% natural outcrossing sterile has been observed. Consequently, rice hybrid successfully developed used China. Prospects developing varieties elsewhere appear bright especially countries that organized seed production, certification distribution programs where can be produced a reasonable cost.