【作者】 常建军；

【导师】 胡胜武；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2008， 硕士

【摘要】 油菜存在显著的杂种优势。目前,雄性不育是利用油菜杂种优势的主要途径之一。我国目前大面积推广的油菜杂交种品种细胞质类型单一,遗传基础狭窄,存在病、虫为害的潜在风险。因此,不育细胞质多样化研究是当前油菜育种的重要基础工作之一。本课题组从大白菜中成功转育出了一种细胞质雄性不育——改良型Ogu CMS油菜。本研究以改良型Ogu CMS油菜、原始Ogu CMS油菜及其保持系为材料,对恢保关系、雄性败育的细胞学特征以及育性相关基因的分子特征进行了对比研究,结果表明:1.改良型Ogu CMS材料克服了原始Ogu CMS材料的黄化缺绿现象,叶色正常,植株健壮;花瓣不皱缩,蜜腺发育正常;保持了Ogu CMS材料的雄蕊败育彻底的特征,综合性状优于原始Ogu CMS材料。2.以国内外103个油菜品种(系)对改良型Ogu CMS材料和原始Ogu CMS材料进行恢保关系测定,结果显示,改良型Ogu CMS材料和原始Ogu CMS材料的恢保关系相同,所有供试材料均为二者的保持系。3.常规压片和石蜡切片试验表明,原始Ogu CMS材料的主要败育时期是从四分体到小孢子单核期,属于小孢子败育型;改良型Ogu CMS材料的主要败育时期比原始Ogu CMS材料的晚,特征也存在明显差异,属于单核花粉败育型。败育的花粉囊的绒毡层出现加厚和液泡化或延迟分化,说明花药的败育可能与绒毡层细胞不适时解体并过度生长有关。总之,改良型Ogu CMS材料和原始Ogu CMS材料的相似点是二者都不能形成正常可育的花粉粒,败育彻底,对于杂种优势的利用很有价值。4.育性相关基因的分子特征对比研究表明,改良型Ogu CMS材料和原始Ogu CMS材料具有Ogu系统特异基因orf138的特征片段,同时具有Nap系统特异基因orf222的特征片段。说明改良型Ogu CMS材料与原始Ogu CMS材料部分同源,也和Nap CMS材料部分同源。以上结果说明,改良型Ogu CMS油菜雄蕊败育彻底,克服了原始Ogu CMS油菜的黄化缺绿现象;和原始Ogu CMS油菜具有相同的恢保关系;改良型Ogu CMS油菜同时具有Ogu系统特异基因orf138和Nap系统特异基因orf222的特征片段。寻找改良型Ogu CMS油菜的恢复系,和揭示改良型Ogu CMS油菜雄性败育的分子机理将是下一步工作的重点。第一部分研究结果对于油菜及其他芸薹属植物杂种优势利用具有一定的参考价值。本论文第二部分研究用6个细胞质雄性不育系与5个恢复系配置30个杂交组合。对这30个杂交组合的16个农艺性状进行了两年重复鉴定。应用灰色关联分析法对这30个杂交组合进行综合评价,结果表明:在30个油菜杂交组合中,有8个属于一等组合,15个二等组合,7个三等组合;在亲本方面,以L451和L89作母本较好,以L161、秦油3号作父本较好,杂交后代均有不同程度的杂交优势,其中L89×L161的杂交优势最高,L161可作为亲和力较高的自交系。因此第二部分研究对油菜杂交组合的选取和亲本的选择选配将提供一定的参考价值。更多还原

【Abstract】 A lot of experiments revealed that there exists a significant heterosis for rapeseed (Brassica napus L.). At present, Cytoplasmic male sterility has been one of main approachs to utilize heterosis in rapeseed. However, majority rapeseed hybrids in China employed Pol CMS (Shaan 2A CMS), which will result in a narrow genetic base, and has vulnerability to disease, insects, and other hazards. Therefore, discovery and characterization of novel male sterile cytoplasm is the base for rapeseed breeding. We have transfered a sterile CMS from Chinese cabbage and breeded a new CMS system, named improved Ogu CMS.The morphology, restoring and maintaining relationship, the cytological characters of anther abortion and molecular character of the improved Ogu CMS and orginal Ogu CMS were compared in this investigation, the main results obtained are as follows:1、Morphological observation showed that the improved Ogu CMS line grows strong,has normal nectary, not wrinkled petals. In all, it has overcomed etiolation of the original Ogu CMS line. Stamen of the improved Ogu CMS line aborted completely .2、Analysis of the restoring and maintaining relationship between the improved Ogu CMS line and the original Ogu CMS line by 104 rapeseed breeding lines from China and abroad indicated that all the materials are the maintaining line for both the improved Ogu CMS and the original Ogu CMS, So, discovery of restorer is still main task for the improved Ogu CMS line before it could be used in repaseed breeing programme.3、Traditional squash and paraffin section experiment showed that anthor abortion of the original Ogu CMS line starts from the tetrad to the microspore uninucleate stage, which belongs to the type of microspores abortion; The abortion of the improved Ogu CMS line starts later than origal Ogu CMS line,which belongs to the type of single nucleus pollen abortion.The tapetums of the abortion anther appear thickening and vacuoling, or delay such as polarization phenomenona. The abortion of anthers may be caused by the breakdown of tapetal cells or the excessive growth. In short, the improved Ogu CMS line and original Ogu CMS line can not form the normal fertile pollen.4、Molecular characters of the improved Ogu CMS line and the original Ogu CMS line by gene-specific PCR tests showed that the improved Ogu CMS line could amplify both Ogu CMS system specific gene-orf138 and the Nap CMS system specific gene-orf222. In one word, The improved Ogu CMS line has the genetic component of the original Ogu CMS and Nap CMS.In summary, the improved Ogu CMS stamen abort thoroughly, and it overcomes lacking green phenomenon of the orginal Ogu CMS; The improved Ogu CMS has the same restoring and maintaining relationship with the orginal Ogu CMS; The improved Ogu CMS has both Ogu system specific gene-orf138 and the Nap system specific gene-orf222. Searching the restoring line for the improved Ogu CMS and revealing the molecular mechanism of the improved Ogu CMS will be the tasks for the next step. This findings will have relevance for the heterosis utilization in Brassica napus and other related Brassica crops.In the second part of this paper,six male-sterile lines carrying the widely used Shaan2A cytoplasm were crossed with five restorer lines to produce 30 F1 hybrids. These 30 hybrids were evaluated for sixteen agronomical traits at Yangling, Shaanxi province in Northwest China for two years. Grey relational analysis showed that,among 30 hybrid combinations,eight were grouped as the best group,fifteen the second group and seven the third group. Among 30 hybrids, L89×L161 was the best one. As for the parent lines, L451 and L89 were identified as the best female parents, L161 and Qinyou 3 as the best male parents. Therefore, this research will provide some reference to the hybrid and parent selection in rapeseed breeding programme.更多还原