Abstract: The 545-angustifoliate material(545AL), originated from a radiation mutation of Fu 54-needle material, was used to study the genetics of leaf width. The characters of 545AL were 69.8±5.0 cm in plant height, 18.8±1.6 cm and 0.87±0.07 cm in flag leaf length and width, and 13.7±0. 23 g in 1000-grain weight. 545AL always segregates,namely every angustifoliate plant always segregates two type plants (the wide-leaf plants and the angusti foliate plants) with different segregation ratios. The wide-leaf plants derived from the angustifoliate plants would produce only wide-leaf plants in next generation with small variation of plant population. Crosses between 545AL and wide -leaf materials expressed wide leaf in F₁, F₂,without angustifol iate plants in F₂. Crosses between the 545-wide leaf material and wid e-leaf materials showed wide-leaf in F₁, and classic segregation in F₂. It suggested that the 545AL might be a new type of rice germplasm

Key words: rice, leaf characteristic, leaf width, heredity

摘要： 从桂朝2号辐射突变系辐54针叶中选出545窄叶株，其株高（69.8±5.0） cm，剑叶长（18.8±1.6）cm，剑叶宽（0.87±0.07）cm，千粒重（13.7±0.23）g，谷粒为麻壳，株叶型好，不早衰。经过5年的连续跟踪选择和初步的遗传测定，该窄叶材料始终处于分离状态，且分离呈规律性变化，即凡是窄叶株，下代就一定分离出宽叶株和窄叶株两种类型，分离比单株间存在差异；从窄叶株分离出来的宽叶株，下代仅出现一种类型，即宽叶株，群体间变异小。545窄叶与具有标记性状的稳定宽叶材料杂交，各组合F[sub]1[/sub]代都表现为宽叶；F[sub]2[/sub]代群体中没有窄叶株出现，表现为一极分离状态。545宽叶与标记性状的稳定宽叶材料杂交，各组合F[sub]1[/sub]代都表现为宽叶；F[sub]2[/sub]代群体中既有双亲叶型，也有中间叶型。

关键词: 水稻, 叶片特性, 叶片宽度, 遗传