CYTOMORPHOLOGICAL RESEARCH ON ANTHER DEVELOPMENT OF SEVERAL MALE-STERILE LINES IN BRASSICA NAPUS L.

The studies on the anther ontogeny of six cytoplasmic malesterile lines and one genic male-sterile line with comparision of one fertile line in Brassica napus seems to he indicated that these male sterile materials may be divided into three types:1. It was regarded as the same type in Xiangai A, Po-aA, Shan 2A and 75-3A. The inhibition of their anther development occurred at the stage of chearsporial cell. The anther consisted of the parenchyma and the vascular All tissue. of them had no differentiation of microsporangium.2. Ogu-nap AⅠ and Ogu-AⅡ were similar in anther ontogeny. The inhibition of their anther development occurred at the stage of tetrad and uninucleic pollen. It was difficult that the microspores were released from tetrad. After some microspores were released, they began to gradual vacuolation and stopped the cell division with rudimental exine. The tapetum started to vaeuolation and radial enlangment during meiosis. The traces of tapetum were still found in mature anther. The vascular bundle had poorly differentiated and the varied number in different anther. The endothecial cell failed to elongate radially with no fibrous band on their radial walls. Additionlly, there were a lot of other abnormal phenomena.3. Yi-3A belongs to genic male-sterile line The abnormality of anther development commenced at the stage of pollen mother cell (PMC). The abnormal expressions were PMCs death, anomalous meiosis and the failure of meiosis. The microspore's analogue which were formed by PMCs started gradually vaculation in cytoplasm and deformation in nuclei with the exine of no development. During late period of anther ontogeny, there were a lot of ball-shaped granules in the anther chamber It was sugguested that they might be Ubish bodies. The endothecial cells and parenchyma cells with fibrous band on radial walls were not significant as normal ones. The remnaint of tapetum persisted up to anthesis.