水稻雌性不育材料FS－1胚囊败育的细胞学观察

以水稻雌性不育材料FS－1为试验材料，采用石蜡连续切片技术对FS－1及其亲本藤坂5号幼穗发育中期的胚囊进行观察。结果表明：（1）亲本的胚囊都能正常发育分化，成为功能健全的雌配子体，而FS－1的胚囊却普通发生败育，在胚囊原来的区域充满了胚囊残迹和解体的珠心细胞。（2）败育基本上发生在功能大孢子发生期，近合点端的大孢子和珠孔端的三个大孢子都发生解体，实验中未发现二核，四核或八核的败育胚囊，我们初步认为，FS－1胚囊败育发生在功能大孢发生期。

A comparatively histological observation on the megagametophytic abortion of female-sterile rice FS-1 and its maternal parent Fujisaka 5]

A female-sterile rice FS-1, derived from the progeny of a backcross of F1 of Fujisaka 5 (Oryza sativa subsp. japonica, FJ) and Tjina (Oryza sativa subsp. indica) with FJ were used for histological study of megagametophytic abortion. FS-1 has a very low spikelet fertility (about 3%) and was regarded to have no true embryo sac. Paraffin sectioning was adopted to study the megagametophytic development of FS-1 compared with its maternal parent FJ. The materials were cultivated in field condition in Tsukuba, Japan and sampled at the middle stage of the panicle development. The results obtained were as follows: (1) FJ showed a normal megagametophytic development and resulted into a mature megagamete while most of the embryo sac of FS-1 underwent megaspore abortion. The remains of the embryo sac and the degenerated surrounding cells filled up the space where the normal embryo sac was expected to exist. (2) Abortion took place when the functional megaspore was being formed. Both the three nonfunctional megaspores near the micropyle and the functional megaspore farthest from the micropylar end were degenerated. No two-nucleus, four-nucleus and eight-nucleus embryo sac were found in the present study. It is concluded tentatively that the megagametophytic abortion of FS-1 occurred when the functional megaspore was being formed.