【作者】 苟晓松；

【导师】 李旭锋；

【作者基本信息】 四川大学 ， 遗传学， 2003， 硕士

【摘要】 Ad-6是由四川大学植物遗传研究室李旭锋通过蓝花子与甘蓝型油菜远缘杂交选育出来的油菜萝卜胞质不育系（OguCMS）恢复源，是恢复系的中间材料，它的外观农艺性状与甘蓝型油菜有很大的差别。为了选育出农艺性状象甘蓝型油菜，进而采用Ad-6和甘蓝型油菜OguCMS杂交，拟将Ad-6所含的OguCMS恢复基因转移到甘蓝型油菜中。本论文对Ad-6和甘蓝型油菜OguCMS杂交的后代的性状特征，组织培养及细胞遗传学行为进行了系统研究，取得了下列结果。 1．Ad-6和甘蓝型油菜OguCMS杂交的后代的性状特征 Ad-6基本上已趋于稳定，结实性较好，但其经济性状和农艺性状特征与甘蓝型油菜有很大的差别。Ad-6和甘蓝型油菜OguCMS测交的后代恢复株的结实性仍较差；恢复株自交、测交及天然授粉后代结实率都有所提高，并且其后代的性状有恢复为甘蓝型油菜的趋势。恢复株自交后代可育株再与不育株连续测交，后代仍然有分离，主要在花色及育性的分离上表现较明显。从这些分离后代中有可能选育出农艺性状特征接近于甘蓝型油菜且育性较好的恢复株。 2．测交后代F₄（TC₁）的组织培养 Ad-6向甘蓝型油菜转移恢复基因的过程中，往往会出现结实率低且发育不完全的后代种子，为了保存种质，扩大后代群体，必须对其进行快繁。我们的研究结果表明，MS培养基添加1.0mg／L6-BA+0.1mg／LNAA+5mg／LAgNO₃对诱导丛尘芽有较好的效果，而1／2MS培养基则有很好的生根能力，MS培养基添加0.5mg／L6-BA+0.1mg／LNAA+0.25mg／LGA3+0.1mg／L2、4-D诱导愈伤组织的效果最好。由于此培养丛配方适合于恢复株自交及测交后代的所有植株，因此，此培养丛配方的建立，为恢复源的进一步选育打下了良好的丛础。3.恢复株自交及测交后代的细胞遗传学行为（l）F;（TC.）的体细胞染色体数目及减数分裂行为 F4(TC户植株的体细胞染色体数目为Zn二36一39，其中Zn=37所占比例高。F;（TC!）花粉母细胞减数分裂行为较异常，在终变期及中期I有单价体、二价体及多价体，还有染色体桥存在;后期H还观察到三极分裂、不正常的四极分裂现象及乱分裂现象;在四分饱子形成过程中观察统计，发现其异常抱子率较高，但主要以三分袍子和异常的四分袍子为主;减数分裂过程能够完成。（2）F:（TC，）的体细胞染色体数目及减数分裂行为 对FS（TC:）随机取46株幼苗的嫩叶所做的研究表明，其体细胞染色体数目为Zn=35一38，其中还是Zn二37所占比例最高，但Zn=38所占比例增加了，说明选育出Zn=38的恢复株是有可能的。其减数分裂行为趋于正常，在终变期及中期I单价体和多价体的出现频率大大降低，反而二价体的比例较高，且多数为环状的;但在后期I仍然有落后染色体出现;未见多级分裂现象;在四分体时期，主要以四分饱子为主。（3）TC’的体细胞染色体数目及减数分裂行为 TC’的体细胞染色体数目在所取的株系中只有Zn二37和Zn二38两种，其减数分裂行为绝大部分趋于正常，在终变期及中期I，其二价体分别达到16.94和17.35;但在中期I及后期I、H均有落后染色体存在，且落后数目不等;另外在后期还观察到染色体桥及染色体粘连现象出现;在四分体时期，异常袍子较少，有少量的三分袍子。（4）TC”花粉母细胞减数分裂行为 TC”花粉母细胞的减数分裂行为仍然是异常，TC’，终变期及中期I染色体配对行为中，二价体已经占有很高的比例，最高的为19个二价体，但仍有少量的三价体和四价体出现。TC”后期I及后期11落后现象仍然严重，而后期H出现二极分裂现象。更多还原

【Abstract】 Ad-6s which were selected by Li Xufeng through distant crossing between B. napus and R. Sativus var. raphanistroides could restore B. napus OguCMS. It is a middle material. Its appearance agriculture characteristics was different from the B. napus L. To select like B. napus L. in agriculture characteristics, restored gene in Ad-6 was going to be transferred from Ad-6 to Brassica napus L. OguCMS by test crossing betweed Ad-6 and Brassica napus L. OguCMS. This thesis reported the studies on the morphological characteristics, tissue culture and cytogenetic behaviors of progenies of Ad-6 and B. napus L. The results were as follows:1. The morphological characteristics of the progenies of crossing between Ad-6 and B. napus L.Most of Ad-6s were stable. The setting percentage of Ad-6 was high. But the economic and morphological characteristics of it were not similar to those of B. napus L. The setting percentage of the progenies of restorer by test crossing between Ad-6 and B. napus L. OguCMS was low. The setting pecentage of the successive autocopulation and test cross which were restored and the progenies of natural crossing were improved. At the same time, the morpha of these progenies were similar to thoseof B. napus L.. When the restorer from autocopulation were test-crossed with OguCMS, their progenies still sepregated, maily in the flower color and fertility complicatedly. From these progenies, it is possible to select the restorer which is not only similar to B. napus L. in agricultural character but also can set the good seed.2. Tissue culture study on the test-crossing progenies of the restoring F4 (TC1)During the process of transforming the restoring gene from Ad-6 to B. napus L., it was accompanied with the poor seed set and incompletely developed seed set. In order to preserve the restoring resource, we regenerated the plant by inducing the polygemmic. The results showed that the medium MS+1.0mg/L 6-BA+0. 1mg/L NAA+5mg/LAgNO3 had the best effect to induce the polygemmic. The best root-inducing medium was 1/2MS. And the medium added 0. 5mg/L 6-BA+O. Img/L NAA+0. 25mg/L 2, 4-D had the best result to induce the callus. These mediums were suitable to priserve the selfs and test-crossed restorer and to increase the restoring population. Then it gave the basis to select the restorer further.3. The cytogenetic characteristic of progenies of selfs and test-crossing(1)the somatic chromosomal number and the miosis behavior of F4 (TC1) The somatic chromosomal number of F4 (TC1) was 2n=36-39, but 2n=37 was the high frequent. The miosis behaviors of F4 (TC1) were abnormal. There were univalents and bivalents and mutivalents in diakinasis and metaphase I , and there were chromosomal bridges. In anaphas II, tripolar segregation, abnormal pentpolar segregation and mutipolar segregation were found. In terad period, we found high frequent abnormal spores, most of which were triads and abnormal pentads. Finally the miosis could be finished.(2) the somatic chromosomal number and the miosis behavior of F5 (TC1) We randomly selected fresh leaves from 46 strain seedling to count the somatic chromosomal number. The results showed that the chromosomal number was 2n=35-38, but the 2n=37 was still the most high frequent, and the 2n=38 was added frequent. It is still possible to select the 2n=38 plants in selfs. Its miosis behaviors tended towards normal. In diakinasis and metaphase I , the frequent of univalents and mutivalents decreased complicately, but bivalents were the high frequent, most, of which were ring-shaped. There were lagging chromosomes in anaphas I . Mutipolar segregation was not observed in anaphas II. In quadrant period, mailly there were tetraspores. (3)the somatic chromosomal number and the miosis behavior of TC’The somatic chromosomal number of TC’ in selected strain were 2n=37 and 2n=38. But their miosis behaviors were normal mostly. In diakinasis and metaphase I , the numbers of bivalents were 16.94 and 17.35 respectively. But there were lagging chromosomes in metaphase I and ana更多还原