ISHS Acta Horticulturae 402: International Symposium on Cultivar Improvement of Horticultural Crops. Part 1: Vegetable Crops
STUDY ON MORPHOCYTOLOGY OF MICROSPOROGENESIS IN MALE STERILE LINE OF RADIFH (RAPHANUS SATIVUS L.) |
| Authors: | S. Yiwen, Z. Shangyi, Z. Yanjun, Z. Tongdu, H. Qiwei, S. Huilian, A. Zhenqin, L. Fengqing |
| Abstract:
In order to know the characters of abortion and its occurring stage during microsporogenesis of the radish male sterile line, the anthers and microspores in different developmental stage, that is, microspore mother cell stage, early uninucleate stage, two-cell pollen stage, three-cell pollen stage, of the male sterile line 64A and its maintainer 64B were compared and studied by optic microscopy. The mature anthers of two lines have also been observed with scaning electron microscopy. Some of the nonsynchronous phenomena of microsporogenesis of the male sterile line 64A are similar to the fertile line 64B. Under optic microscope, the appearance of vacuoles in cytoplasm of the early uninuvleate microspore is a sign of the beginning red in microspores, such as the cytoplasm became light staining and shrinking, the nucleoplasm was getting pale and even only the condensed nucleolus left, and the exine was not getting to further thicken. In this case whole uninucleate microspore always discontinued to develop. These microspores showed with irregular shape, various size, and increasing disintegration, these abnormal microspores and the degenerated tapetum cells stuck togather to form a lump in the anther chamber, and eventually vanished. Consequently the anthers of male sterile line were empty at the flowering period. During the antherdevelopment, tapetum abortion often occurred. The serious vacuolation of cytoplasm of tapetum cells resulted in their hypertrophy. The collapse of tapetum, however, were delayed. The cells of tapetum adhered with each other and then broke down in situ. By the scanning electron microscopy no pollen grains have been seen in the anthers of male sterile line. The wall of endothecium cells was not thickened and kept in characters of parenchymal cells. As a result of the regular and tight arrangment of endothecium cells, the endothecium was endowed with a rather smooth surface. These results show that there are many of significantly morphological differences of anthers and pollens during microsporogenesis in radish between the male sterile line 64A and the ferile line 64B. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
