【摘要】 改良水稻雄性不育系的柱头外露率对于提高杂交水稻制种产量具有重要意义。本研究结果表明:柱头外露率属数量性状,各世代均呈连续性变异;该性状不存在细胞质遗传现象,但不育性可能对该性状有增进效应;在控制该性状的各基因效应中,以显性最为重要,其次为加性,上位性的影响较小;各组合柱头外露率的广义遗传力均较高,为0.90左右,狭义遗传力为0.50左右;柱头外露率与柱头长、粒长、柱头角及子房长呈显著的正相关,与粒宽呈显著的负相关;各花器性状对柱头外露率直接效应的大小依次为:柱头角、子房长、柱头长、粒长、粒宽;F₃系统均值与 F₂个体值之间存在着显著的相关和回归。综合该性状的各遗传参数来推断,在变异的杂种群体中选出高柱头外露率的品系是有可能的,且在较晚世代选择才能奏效。更多还原

【Abstract】 The stigma extrusion is very important for increasing yield of hybridrice and seed set of conventional varieties.The results obtained in mystudy are as follows:1.Stigma extrusion was of quantitative inheritance,and variationsin stigma exsertion was continued in each generation.2.There was no occurrence of cytoplasmic inheritance in stigma ex-trusion,but the“WA”type male sterility influenced the rate of stigmaexsertion.3.Among the genic effects dominant effect was the major one in-fluencing stigma extrusion,and then was additive effect.Epistasis effectwas slight.4.All the combinations had higher heritability in the broad sensein stigma extrusion（about 0.90）,but those in the narrow sense was only-0.50 or so.5.Stigma extrusion was positively correlated with stigma length,spikelet length,stigma angle and ovary length,and was negatively cor-related with spikelet width.6.The direct effects of floral characteristics on stigma extrusion indescending sequence were:stigma angle,ovary length,stigma length,spikelet length and spikelet width.7.Significant correlations were found between F₂ and F₃ plants.Based on the above results,it would be much possible to breed higherstigma extrusion varieties,and selection would be taken in later genera-tions.The genetic advance of stigma length and spikelet length were gre-ater than other floral characteristics,更多还原