【摘要】 水稻亚种间杂种与亚种内杂种及亲本品系相比较,表现结实率偏低、生育期偏长、植株偏高、较易落粒,但穗大粒多、分蘖力较强。供试组合中农艺性状的广泛变异为利用其有利优势提供了选择的余地。亚种间组合的亲子相关分析表明,杂种F₁的株高、生育期、落粒性、百粒重、每穗颖花数及有效分蘖数均与中亲值有显著相关。为了获得理想的籼粳杂种,要选择矮秆基因互为等位,感光性、感温性、落粒性互补的品种作亲本。为最大限度地提高产量潜力,亚种间F₁必须具有高而稳定的结实率,并将良好的水稻株型与有利优势结合起来。更多还原

【Abstract】 Compared with intrasubspecific hybrids and their parental lines, intersubspeeific （Indica-Japonica） hybrids （F₁s） in rice showed lower spikelet fertility, later maturity, higher stature and easier seed shedding, with desirable heteroses of larger and more spikelets and higher potentiality for tillering. The variation of various characters in the tested crosses made it possible to select the heterotic hybrid possessing the desirable characters. Parent- offspring correlations were significant for plant height, growth duration, seed shedding, 100-grain weight, spikelet number and effective panicle number in intersubspeeific combinations. To breed the desireble intersubspecific hybrid, the two parents selected should have an allelism for semidwarf gene and compensation for photosensitivity, thermosensitivity and seed shedding. High and stable spikelet fertility of the F₁ （intersubspecific compatibilty） and ideal plant type combined with desireble heteroses are necessary to maximize the yield potential.更多还原