【作者】 俞斌；

【导师】 杨光圣；

【作者基本信息】 华中农业大学 ， 作物遗传育种， 2009， 博士

【摘要】 油菜是我国重要的油料作物和经济作物,我国常年种植面积超过一亿亩,年产油菜籽达1100万吨,种植面积和产量均占世界的三分之一,是世界上最大的油菜种植国和生产国(Zhou and Fu,2007)。因此利用各种生物技术手段,对油菜的主要性状进行进行遗传改良,增强其产量、品质及抗病虫害等能力,提高育种水平,对于发展我国油菜生产具有重要意义。甘蓝型油菜是常异花授粉的多倍体作物,在通过不同常规选择方法所获得的品种(品系)内可能存在不同程度的遗传变异。油菜小孢子培养是20世纪80年代发展起来的一项重要的生物技术,通过小孢子培养可以迅速获得基因型纯合的材料,因此研究利用该技术对不同来源的甘蓝型油菜品种(系)进行小孢子培养所获得DH群体的遗传变异特点,对于进一步改良这些油菜品种具有重要指导意义。菌核病位居我国油菜三大病害之首,主要发生在油菜的主产区长江流域,一般年份能造成10%的产量损失,重病年份可以使油菜产量减少80%。多年来,国内外在该病害的发生和流行规律及预测预报等方面做了大量的研究工作,在药剂和农业栽培措施防治等方面取得了一定的成绩,但仍未从根本上改变油菜菌核病严重危害的局面,因此,选育和利用抗(耐)病品种,作为最经济有效的方式,越来越受到人们的重视。在本试验中,以三个不同来源的波里马恢复系ZS4R、7-5和P24为供体,构建了3个DH群体。以7-5和P24 DH群体,及雷伟侠构建的包含有144个DH系的650 DH群体为材料,考查主要的农艺性状和品质性状,来探索常规品种(系)小孢子培养后代的遗传变异规律,以期为育种选择及小孢子培养技术的进一步应用提供参考。并以ZS4R、7-5、P24和650 DH群体为材料,选择抗(耐)菌核病恢复系,以期直接应用于育种工作。主要结果如下:1.对ZS4R、7-5和P24进行了小孢子培养,得到了分别包含有101、356和421个DH系的3个DH群体。2.在7-5和P24 DH群体中,所有的农艺性状和品质性状都产生了较大的分离,可以从中选择性状更优的DH系用于育种。3.7-5、P24 DH群体与650 DH群体相比,农艺性状和品质性状的变异系数没有显著的差异。4.在7-5、P24和650 DH群体中,角果长度和硫甙含量都出现了偏分离的现象,说明小孢子培养过程存在配子选择机制。5.对ZS4R、7-5、P24和650 DH群体的苗期菌核病抗性考查发现,四个DH群体苗期菌核病抗性平均水平呈现偏分离,ZS4R、7-5和P24 DH群体平均抗性强于各自的供体亲本,650 DH群体平均抗性偏向于高抗亲本。6.对ZS4R、7-5、P24和650 DH群体进行抗(耐)菌核病恢复系的选育过程中,对苗期和成株期菌核病抗性进行了相关分析,发现苗期抗性和成株期抗性相关系数极低。7.经过3年的选择鉴定,并配合以分子标记技术鉴定DH系间的遗传距离,最终在ZS4R、7-5、P24和650 DH群体中选到了10个菌核病抗性显著增强的优良DH恢复系,并应用于育种工作。本研究结果表明,常规育种方法所获得的油菜品种(系)的小孢子培养后代存在着丰富的遗传变异,且对其进行进一步的选择是有效的。更多还原

【Abstract】 Rapeseed is an important oil crop and economic crop in China. China is the the biggest rapeseed planting country and the largest producer in the world. The year sown area surpasses 7 million hectares, the annual production of rapeseed amounts to 11 milliom tons, and either the planting area or the output occupies 1/3 of the world (Zhou and Fu, 2007). Therefore it is significant to using biotechnologies to raise the breeding level and improve the main traits of rapeseed, such as yield, quality and disease resistance.Brassica napus is an often cross-pollinated polyploid crop. There are possibly genetic variations in varieties which were breeded with traditional selecting. Microspore culture is an important biotechnology which was firstly reported successed in Brassica napus in the 1980s (Litcher, 1982). Homozygous materials could be obtained by using this method. It is significant for improving varieties to study the genetic variations of DH populations which were constructed from different varieties by using microspore culture.Sclerotinia stem rot is one of the most devastating diseases of rapeseed in China, and it is mainly occurred in the Yangtze River basin. It has been reported that Sclerotinia stem rot can cause up to 80% yield loss on rapeseed in severe incidences in China. There are a lot of researches about Sclerotinia stem rot’s occurrence, regularity of epidemic and forecast forecast, and some progresses have acquired to prevent the disease by medicament and agricultural cultivation. But it still hadn’t changed severely impair condition of Sclerotinia stem rot. Therefore breeding and application of S. Sclerotiorum resistant cultivar was regarded as the most ecomomic and efficiecy way to resolve the problem.In this research, three doubled haploid (DH) populations were generated from three B. napus polima cytoplasmic male sterility (pol CMS) restorers "ZS4R", "7-5" and "P24". And another "650" DH population included 144 DH lines was also used. Main agronomic traits and quality traits of "7-5", "P24" and "650" DH populations were evaluated to explore genetic variation regularity of descendant of microspore culture. On the other hand, "ZS4R", "7-5", "P24" and "650" DH populations were used to select Sclerotinia stem rot resistant DH restorer lines. Main results of the study are as follows:1. By application of microspore culture, "ZS4R", "7-5" and "P24" DH populations consisting of 101, 356 and 421 DH lines, respectively, were generated.2. There are abundant variation among all the agronomic traits and quality traits in the 7-5, P24 and 650 DH populations.3. There is no significant difference among the coefficient of variation of same trait in the 7-5, P24 and 650 DH populations.4. The silique length and glucosinolate content are distorted segregation. Segregation distortion may indicate that preferential gametic selection occurred during the development of the DH lines.5. The results of assessment of seedling resistance to Sclerotinia stem rot showed that the average Sclerotinia stem rot resistance of the four DH populations is distorted segregation. The average resistance of "ZS4R", "7-5" and "P24" DH populations is better than the donors, and the average resistance of "650" DH population lean to the higher resistant parent.6. Correlation coefficient of seedling stage resistance to adult stage resistance is very low.7. Ten elite DH lines with partial resistance to Sclerotinia stem rot were chosen within three years’ selection and have been used in hybrid breeding.This study revealed that there is abundant genetic variation in DH populations generated from the varieties (lines) breeded by traditional methods and it is efficient to do the selecting in the DH populations.更多还原