同源四倍体水稻成熟胚囊的结构及异常现象

应用整体染色透明激光扫描共聚焦显微术（WCLSM），对包括籼稻、粳稻及爪哇稻在内的13份同源四倍体水稻的成熟胚囊结构进行了观察。同源四倍体水稻多数子房（平均6290%）胚囊结构正常，与二倍体的正常蓼型的相似，一些子房（平均3710%）胚囊结构出现异常，异常包括雌性生殖单位退化、极核异常、胚囊退化、卵器退化、异常小胚囊和“双套结构”胚囊等6类。这些异常胚囊都可能影响受精，从而导致结实率降低。不同类型的同源四倍体水稻间异常结构胚囊的频率差异极显著。籼稻与粳稻比较，总的趋势是粳稻异常胚囊的频率高于籼稻，其中粳稻平均为2566%，籼稻平均为1934%。同一品种内异常类型的频率也存在明显的差异，显示异常结构胚囊的形成可能与品种的基因型有密切关系。

Structure of Mature Embryo Sac and Its Abnormal Phenomena in Autotetraploid Rice

The structure of mature embryo sacs of 13 pieces of autotetraploid rice, including indica, japonica and javanica, was studied by using the techniques of whole-mount stain-clearing laser scanning confocal microscopy(WCLSM). The majority of ovaries with normal polygonum embryo sac were found in each autotetraploid rice. Some ovaries in each were charactered by abnormal embryo sac. Six types of abnormal embryo sacs were observed, which included: (1) the embryo sac with no female germ unit; (2) the embryo sac with polar nuclei in abnormal position or number; (3) embryo sac degeneration; (4) the embryo sac without egg apparatus; (5) small embryo sac in size; (6) double set of embryo sac. The percentage of abnormal embryo sac in japonica, being 25.66% in average, was higher than that in indica, 19.34% in average. The percentage of each kind of abnormal embryo sac was significantly different in each variety, suggesting that the abnormal phenomena were related possibly to the genotype of variety.