不结球白菜Ogura雄性不育花器官形态及败育细胞学的研究

Morphological Studies on Flower Organ of Ogura Cytoplasmic Male Sterile and Its Cytological Characterization of Abortion in Brassica rapa ssp.chinensis

对不结球白菜细胞质雄性不育系S2108A和Y3611A及其相应的保持系S2108B和Y3611B进行了花器官形态比较和花药发育细胞学观察,结果表明:两套不育系和保持系之间在花器官的多个性状上差异极显著,而两个不育系S2108A和Y3611A之间除花蕾大小、雌蕊长和花瓣长有差异外,其他均不显著,说明从不同不育源转育来的两个不育系在花器官外形上差异不大;两个不育系花药败育表现均起始于四分体时期,且由于绒毡层的液泡化和径向膨大,挤压四分体小孢子导致败育,表明败育与绒毡层的不正常发育有关。此外,与Y3611A不同,在不育系S2108A中还存在另一种败育形式,绒毡层细胞壁发生融合,成为紧贴药室壁的类似于变形型绒毡层的周原质团,部分细胞质流入药室腔,包裹粘连四分体小孢子,成为染色很深的不连续团块状物,花药败育;两不育系花药发育存在花粉囊数目的变异,且花粉囊发育时期不同步,个别花粉囊较正常花粉囊发育推迟,在不育系Y3611A中还有巨型花粉囊的现象。

The morphologic comparison of flower organ and anatomical observations were conducted on male sterile lines S2108A and Y3611A and their maintainer lines S2108B and Y3611B in Brassica rapa ssp. chinensis. The results showed that there were significant differences in several characters of blossom organ between two set of male sterile lines and their maintainer lines, while between the two male sterile lines S2108A and Y3611A, the difference was not found except in the length of flower bud pistil and length of petal, suggesting that no significant difference in blossom morphology between the two male sterile lines transferred from different origin. The anther abortion of the two male sterile lines started from tetrad period,that due to taptum＇s vacuole changing and radial expandation,extrusion tetrad microspore and result in fail development,indicating the anther abortion had relationship with taptum abnormally development. Moreover, different from Y3611A, there is another anther abortion style in S2108A,taptum cell wall is fused,turn into periplasmodium like amoeboid tapetum cling to powder chamber wall, part of cytoplasm afflux into powder chamber, wrap and conglutinate tetrad microspore, the anther abortion. The number of clinandrium of the two male sterile lines is different,and development period of elinandrium is asynchrony,some clinandrium is late. In addition,huge clinandrium is found in the line of Y3611A.