【作者】 朱家立；

【导师】 孟金陵；

【作者基本信息】 华中农业大学 ， 作物遗传育种， 2010， 硕士

【摘要】 甘蓝型油菜(B.napus, AnAnCnCn)作为世界上重要的油料作物和能源作物之一日益受到广泛的重视。虽然种植面积一直名列前茅,但是由于其驯化历史较短和遗传基础相对狭窄,杂种优势的利用徘徊不前。本实验室通过将来源于埃塞俄比亚芥(B. carinata, BcBcCcCc)的Cc基因组和来源于白菜型油菜(B. rapa, ArAr)的Ar基因组部分替换常规甘蓝型油菜的An和Cn基因组,创建出ArCc外源含量在30-50%左右的第一代新型甘蓝型油菜,其与常规甘蓝型油菜配制的杂种表现出很强的杂种优势并且发现存在随着外源含量的提高杂种优势逐渐变强的规律。随后进一步通过种间杂交、遗传重组和分子标记辅助选择等技术手段构建出第二代新型甘蓝型油菜,其农艺性状得到改良,ArCc外源含量提高到40-80%。通过两年的产量试验发现第二代新型甘蓝型油菜与国内核不育系配制的杂种在种子产量和农艺性状上都表现出较强的杂种优势。在上述研究成果的基础上,本论文中我们将第二代新型甘蓝型油菜与来自德国的4个甘蓝型油菜不育系配制杂种,在连续两年的产量试验中发现杂种不管是在田间的农艺性状上,还是在种子产量和生物重等产量性状上都表现出很强的杂种优势。大约有50%的杂种在种子产量上表现出超标优势且全部的杂种表现出超亲优势,其中MSL101C’×M5R059这个杂种在两年的田间试验中种子产量性状上都排名第一,甚至和对照达到了1%的极显著水平。除了每角果粒数以外,其他农艺性状都表现出超标优势：株高上新型甘蓝型油菜和冬性不育系MSL012C’配制的杂种表现最优,平均为129.93 cm；杂种在主花序长度上大都集中在50-65 cm之间,杂种MSL012C’×DH23最长；角果长度(10个)则明显地体现出冬性不育系配制的杂种比春性不育系配制的杂种有更强的优势,平均长4 cm左右；而千粒重方面除了MSL522C×m5R156外,其他杂种和对照相比都存在一定的超标优势,主要表现为种子大且饱满,另外优良杂种的经济系数也和对照的商业杂种不相上下。通过近红外光谱仪对品质性状的测量,希望通过分子标记辅助选择等技术手段降低硫甙的含量,从而为将来的应用奠定基础。另外对第二代新型甘蓝型油菜和德国不育系配制的杂种小区产量和ArCc外源含量进行相关性分析,进一步证实随着ArCc外源含量的增加,亚基因组杂种优势更加明显这个规律。与此同时第二代新型甘蓝型油菜株系还作为轮回亲本与来自德国、澳大利亚等不同国家的材料回交,以便扩宽种质资源从而进一步地开拓新型甘蓝型油菜亚基因组间的杂种优势。新型甘蓝型油菜里的芥酸含量变异很大,幅度在0-60%之间,而芥酸作为一种长链脂肪酸,在芸薹属作物的种子中主要以22碳的形式存在。1995年通过将玉米转座子插入到拟南芥FAE1中使其突变,导致芥酸含量下降并认为FAE1是控制芥酸合成过程中的一个关键基因。后来随着一系列研究结果的报道,发现此基因在常规甘蓝型油菜中存在2个拷贝,分别位于A8染色体和C3染色体上并且这2个拷贝的FAE1基因恰好位于2个芥酸主效QTL的峰值处。本论文将测序后的不同芥酸含量的新型甘蓝型油菜FAE1序列与高芥酸的常规甘蓝型油菜宁油7号FAE1序列进行比对,发现高芥酸的新型甘蓝型油菜与高芥酸的常规甘蓝型油菜之间没有区别,低芥酸的新型甘蓝型油菜与低芥酸的常规甘蓝型油菜之间没有区别,而不同芥酸含量的新型甘蓝型油菜之间则存在SNP位点的差异,该结果一定程度上为进一步开拓新型甘蓝型油菜亚基因组杂种优势奠定基础。更多还原

【Abstract】 As one of edible oil crops and raw materials for biodiesel in the world, B.napus is taken account of importance increasingly. Although the planting area is leading all the time, due to its limited historical domestication and narrow genetic foundation, the utilization of heterosis is stagnant. We replaced the An and Cn genome in traditional B. napus by introgressing Ar genome from B. rapa (ArAr) and Cc genome from B. carinata (BcBcCcCc) partially and led to develop the first new type B.napus whose ArCc exogenous content is 30-50%, and strong heterosis were exhibited in the hybrids resulted from the the first new type B.napus and the traditional B.napus. Also we found the law that as the exogenous content improved, the heterosis is stronger. Later we continued to use interspecific hybridization, genetic recombination, molecular assisted markers and other techniques to develop the second new type B.napus with improved agronomic traits and higher introgressed subgenomic component. The intersubgenomic hybrids resulted from the second new type B.napus and domestic nucleic male sterile lines exhibited great heterosis in seed yield and agronomic traits.Based on the above achievements, we crossed the second new type B.napus with four German male sterile lines in this study. In consecutive two-year field experiment, strong heterosis was found not only in agronomic traits but also in yield traits related to seed yield and biomass. Almost one half of the hybrids showed over check heterosis and all of them showed over parental heterosis, while the MSL101C’×m5R059 hybrid ranked first both in two years for seed yield, even achieving the 1% significant level as for control. Apart from the trait for seeds per pod, other traits exhibited over control heterosis in some sense:the hybrids made from new type B.napus with winter male sterile line MSL012C’ perform better with an average value of 129.93 cm for plant height; the main inflorescence length for hybrids focused on 50-65 cm and the hybrid MSL012C’×DH23 was the longest; there’s an obvious gap in the hybrids resulted from winter male sterile lines or spring male sterile lines for ten-pod length, while the former is 4 cm longer than the latter; all the hybrids exhibited over control heterosis for thousand-seed weight because the seeds were large and full excluding MSL522C×m5R156, and the economic coefficient for elite hybrids is equal to commercial control. For the quality traits which were measured by near-infrared reflectance spectroscopy, we hoped to use molecular assisted selections to reduce the glucosinolate content in order to lay the foundations for application in the future. In addition, we used the correlation analysis to confirm that as the ArCc exogenous content improved, the subgenomic heterosis is more obvious. At the same time, the second new type B.napus was used as recurrent parents to backcross with the materials from different countries, such as Germany and Australia in order to broaden the germplasm resource and extend the subgenomic heterosis in new type B.napus.The erucic acid in the new type B.napus differs from 0-60%, which belongs to long-chain fatty acid and exists in the seeds of Brassica species with twenty-two carbon. In 1995, James inserted maize transposon into Arabidopsis FAE1 to make it mutate and found the erucic acid content reduced, finally supposed that FAE1 is a key gene to control erucic acid synthesis. As lots of research results released, FAE1 has two copies in chromosome A8 and chromosome C3 in traditional B.napus, and the two copies located in the peak of two major QTL. According to the alignment about FAE1 between different erucic acid content new type B.napus and high erucic acid traditional B.napus cultivar Ningyou 7 after sequencing, we find there is no difference in high erucic acid new type B.napus and high erucic acid traditional B.napus, and there is no difference in low erucic acid new type B.napus and low erucic acid traditional B.napus, but there is SNP polymorphism in different erucic acid content new type B.napus.This result can lay the foundation for broadening the subgenomic heterosis in new type B.napus to some extent.更多还原