A Comparative Study On The Anther Abortionof Male Sterility Lines In Rapeseed (Brassica Napus L)

There are many lines of sterile rspeseed(Brassica napus L) e.g naturalcytoplasmic male sterility line, double-family genic male sterility line, synthetictransgenic male sterility line and chemical induced male sterility line. Systematicresearch on the growth of stamens and pistils, cytological anatomy characteristics, thecontent changes of soluble protein and RNA and free UMP, and the changes ofribonuclease(RNase) vitality in their anther abortion process will help us findrapeseed sterility causes, which is of great theoretic and practical insignificance.Based on cytoplasmic male sterility line 392A, chemical induced male sterilityline 392BS and maintainer line 392B, dominant double-family genic male sterilityline 629AB, recessive double-family genic male sterility line 86AB, and transgenicmale sterility line Xiang 15A and fertility Xiang 15, we have made a comparativestudy on buds and the growth of stamens and pistils, cytological anatomycharacteristics of anther abortion, the changes of RNase vitality in their antherabortion process, and the content of RNA, UMP and soluble protein change patternsand the findings are:1. After a comparative study on the growth of stamens and pistils, and the budgrowth patterns of male sterility line and fertility line of the above five rapeseed,we find that in different growth periods, sterility line in single buds and stamensare lighter than fertility line while sterility line in pistils is heavier thanproductivity line. There is great difference in the weight of buds and stamens andpistils of the five sterility and fertility lines. Therefore pistils play a veryimportant role in stamen abortion process of male sterility of rapeseed (brassicanapus).2. We have made cytological investigation on the bud growth process of 392A,629A and 86A. After paraffin-embedded section and microphotograph on buds atdifferent growth periods, we find that the abortion of the stamens of 86A takes place in spore producing time and the abortion of the stamen of 629A takes placein pollen female cell reduction division. Whether 392A stamen sterilizes dependson the changes of temperature. When it is lower than 10℃in bud growth, thestamens are generally normal; otherwise, they will not differentiate to producespore cell or clinandriums. There is a synchronic phenomenon in the abortion ofthe stamens of 86A and 392A.3. With the stamens in different growth periods, through separating them by hand,we have tested the quantity changes of soluble protein in the abortion process ofthe five sterility lines and their respective fertility lines. The result shows that theprotein quantity of the sterility line is less than that of the fertility line. It isfound by the t-test that the stamen content difference of the soluble proteinbetween 392BS and 392B, Xiang 15A and Xiang 15, 86A and 86 B, 629 A and629B is significant.4. After testing the content changes of RNA and free UMP with buds at differentgrowth periods, we find that the RNA content of buds in sterility line is lower thanthat in fertility line, but it has more free UMP than the latter. It is also found thatthe content difference of the buds' RNA and free UMP in the five sterility linesand their respective fertility lines is significant. The content difference of thebuds' RNA in the same pair of sterility line and fertility line at different growthperiods is significant. Except 329BS and fertility line 392B, there is greatdifference in the UMP content in the other four pairs in both sterility line andfertility line.5. With the stamens in different growth periods, through separating them by hand,we test the RNase vitality in their stamen abortion process of the five sterilitylines and their respective fertility line. We find that with buds at different growthperiods, the RNase vitality of the stamens in sterility line is markedly higher thanthat of the fertility line. It is found that there is great difference in the stamenRNase vitality in the five sterility lines and their respective fertility line. It is alsofound that there is great difference in the stamen RNase vitality in one pair ofsterility lines and its respective fertility line at different growth period. And RNase vitality changes coincide with the abortion periods of the anthers.6. Thus, RNase vitality is negative linear-related with the RNA content, single budweight, and single bud stamens and pistil weight of rapeseed. RNase vitality isalso closely related with the sterile degree of the sterility line. The higher thesterile degree of the sterility line, the stronger the RNase vitality of the stamens.