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

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 clinandrium is asynchrony,some clinandrium is late.In addition,huge clinandrium is found in the line of Y3611A.