【摘要】 为提高水稻的异交率,于1983—1984年调查分析了435份国内外栽培稻种的柱头外露性.结果表明、不同类型和产地的栽培稻种间柱头外露率存在较大的差异.依其平均数,外露率的高低,籼稻高于粳稻(1983年和1984年的观察品种分别为19.85％、5.91％和19.34％、7.61％);陆稻高于水稻(18.76％、11.24％和30.52％、5.34％);云南高原粳高于太湖粳(25.2％,3.25％). 影响柱头外露的主要性状有三类,即柱头特性、小穗特性和开颖角.前两者包括开花时柱头的向外弯曲程度,雌蕊总长,柱头分枝数,小穗长、宽、厚、长宽比等.稃毛和芒长可以作为反映柱头外露性的间接指标.不同类型和产地的栽培稻种柱头外露率的差异以及影响柱头外露的主要性状表明,柱头外露率的高低与稻种的起源和进化之间表现为平行关系.更多还原

【Abstract】 In order to increase outcrossing in rice, Oryza sativa L., the variation in stigma exsertion of 435 cultivars from home and abroad was analysed daring 1983-1984.The results showed that the percentage of exserted stigma ( PES ) at anthesis varied widely in rice cultivars of different types and different origin, according to the PES, indica rice is higher than japonica rice (19.85%, 5.91% in 1983 and 19.34%, 7.61% in 1984 ),upland rice higher than lowland rice (18.76%, 11.24% in 1983 and 30.52%, 5.34% in 1984 ) , and japonica rice from Yunnan plateau higher than japonica rice from Taihu valley ( 25.20%, 3.25% ) .The characters contributing to the exsertion may be divided into three types, stigmatic characteristics, spikelet characteristics and the angle of floret openning. The first two consists of stigma curving outward, pistil length and width and the L/W ratio.Glume pubescence and awn length may be used as indirect indexes of stigma exsertion.Differences in percent exserted stigma among different types and homes and characters contributing exsertion of stigma indicate that there is a parallel relationship between stigma exsertion and the origin and evolution of cultivated rice.更多还原