Abstract: Panicle exsertion(PE) of the elongated uppermost internode stock of japonica rice was controlled by a recessive eui gene. PE of plant with eui gene was positively correlated with uppermost internode length and plant height. The interaction between the eui gene and wild abortive male sterile(WAMS)cytoplasm could eliminate partly the negative effect of WAMS cytoplasm on MS line's PE so that panicle enclosure in MS line disappeared.The eui gene has been introduced into, Zhenshan 97A by backcrossing, one new MS line Zhenchang A(B) without panicle enclosure has been bred first. The PE of Zhenchang A elongated to -1.8 cm, whereas the PE of the control Zhenshan 97A was -11.1 cm. Spikelets enclosed in leaf sheath in the new MS line was 0-7.5 and in the control was 37.0-49.0. The exserted stigma percentage of the new MS line was 8.5-14.8 higher than that of the control. The yield of hybrid seed production using the new MS line without applying gibberellic acid would be as high as that using the control applying gibberellic acid. The combining ability of Zhenchang A was the same as Zhenshan 97A. The procedure of improvement of WAMS lines was discussed.

Key words: Rice male sterile line, Panicle exsertion, Panicle enclosure, eui gone, Inheritance

摘要： 粳型水稻长节间种质的穗伸出度受1对eui隐性基因控制，带有eui基因的植株，其穗伸出度与最上一节间长度和株高之间呈极显著正相关，eui基因与野败不育胞质之间的互作效应可以部分地抑制野败胞质对穗伸出度的负效应，导致不育系基本上不再出现包颈现象。通过回交将eui基因导人珍汕97A，首次育成不包颈的野败不育系珍长A、B。珍长A穗伸出度为-1.8 cm． 对照珍汕97A为-11.1 cm；剑叶叶鞘内的颖花数为0～7.5朵． 而对照为37.0～49.0朵；柱头外露率比对照高8.5～14.8个百分点，不喷赤霉素就能达到目前大田制种的异交率水平。初步测定珍长A的配合力与对照相同。并对野败不育系的改良工作进行了讨论。

关键词: 水稻, 穗伸出度, 遗传, 不育系