【作者】 刘艳；

【导师】 牟同敏；

【作者基本信息】 华中农业大学 ， 作物遗传育种， 2010， 硕士

【摘要】 水稻白叶枯病是水稻生产上危害较大的病害之一,我国每年均有不同程度的发生,水稻发病时,可使产量下降、米质变差。螟虫(包括稻纵卷叶螟、二化螟和三化螟)是危害我国水稻生产的主要害虫,我国年发生面积约1,500万公顷,防治面积达到3,800万公顷,由螟虫引发的年经济损失合计约为160亿元。运用转基因和分子标记辅助选择技术改良杂交水稻亲本的抗病虫性,选育和推广抗病虫杂交组合是最经济环保的方法。由恢复系先恢207配制的杂交水稻组合金优207和T优207是目前长江中下游稻区的主栽晚籼稻组合,年推广面积在60多万公顷以上,但是易感白叶枯病和螟虫。本研究的目的是运用分子标记辅助选择技术,把广谱抗白叶枯病的基因Xa7和Xa21、螟虫抗性基因cry1C*转移到先恢207中,以培育抗白叶枯病或抗螟虫的水稻新恢复系,提高杂交晚籼稻的抗病虫性。研究结果主要有：1)运用分子标记辅助选择,通过1次杂交,3-4次回交和3-4次自交,分别将Xa7、Xa21和cry1C*基因转入到水稻恢复系先恢207中,培育出基因型纯合和抗性稳定,并且与受体亲本先恢207农艺性状接近的分别含有Xa7、Xa21、cry1C和同时含有Xa7和Xa21双基因的新株系各2个。2)使用13个白叶枯病菌株(PX061、PXO99、ZHE173、GD1358、YN1、YN7、YN11、YN18、YN24、FuJ、ScYc6、HeN11和GD414)对育成的携有Xa7、Xa21抗性基因的株系进行田间人工接种抗性鉴定和抗谱分析。结果表明,携有单个Xa7或Xa21基因的新株系的抗性和抗谱均比受体亲本先恢207有明显的提高,同时携有Xa7和Xa21双基因的两个株系,除了中感PX099外,对其它菌株的抗性均比单基因株系的抗性有了进一步改善,说明基因聚合具有累加效应。同时,也进一步证明Xa7和Xa21为广谱高效的白叶枯病抗性基因。3)对以高感白叶枯病的川农1A为母本、育成株系为父本配制的6个杂交组合进行13个白叶枯病菌株的接种鉴定结果表明,杂交组合的白叶枯病抗性明显提高。杂交种的绝对病斑长度比父本(改良株系)的病斑要长一些,但是对多数菌株的抗性水平都接近父本的抗性水平,表明本研究所用的白叶枯病抗性基因Xa7和Xa21表现显性或部分显性。4)对携有cry1C*基因的两个新株系以及与川农1A所配杂交组合和对照材料进行了自然条件下的螟虫抗性鉴定。结果表明,受体亲本先恢207受稻纵卷叶螟危害的卷叶指数是9.9%,而新株系和杂交种并没有稻纵卷叶螟的危害,抗性达到100%。5)根据8个新株系和所配杂交种的主要农艺性状的表现和稻米品质的表现以及其配合力分析的结果,可知新株系的主要农艺性状和稻米品质与受体亲本先恢207相差不大,不过在同一遗传背景下,同一性状在不同株系中的一般配合力效应值都存在着明显差异。其中新株系TMQ91431 (cry1C*)的10个农艺性状与先恢207没有显著差异,但具有较高的一般配合力和特殊配合力效应,TMQ91436 (Xa7)的一般配合力表现较好,TMQ91435 (Xa7)和TMQ91438 (Xa7, Xa21)的特殊配合力表现较好。新株系所配杂交种除个别组合相对对照金优207减产外,其余基本都增产,并且在个别农艺性状上具有较高的特殊配合力效应,中9A/TMQ91432千粒重特殊配合力效应值最大,金23A/TMQ91434单株产量特殊配合力效应值最大。6)根据产量竞争优势分析结果可知,产量竞争优势最强的三个组合分别为C815S/TMQ91431(20%)、中9A/TMQ91431(18.03%)和川农1A/TMQ91431(17.3%),均为抗螟虫的组合。更多还原

【Abstract】 Rice bacterial blight (BB) is one of the most destructive diseases in rice production in China. It can threaten the rice production, yield stability and quality in epidemic years. Stemborers and leaffolders are two groups of Lepidopteran insects that cause severe damage to rice production. The economic losses caused by these insects could account for 16 billions of yuan in China. The incorporation of resistance genes into cultivars by transgenic method and Molecular marker-assisted selection (MAS) is the most economic and effective method to control diseases and insects. Xianhui207 is an elite indica restorer line of hybrid rice, but it is highly susceptible to BB and lepidopteran insects.The objective of this study was to improve the BB resistance and lepidopteran insects resistance of Xianhui207 by MAS and backcrossing methods. Two BB resistant genes, Xa7 and Xa21, and one lepidopteran insects resistance cry1C* were used as target genes. Main research results are as follows:1. The BB resistance genes Xa7, Xa21 and the insect resistance gene cry1C* were introgressed into Xinhui207 through MAS and backcrossing methods. Through selection we obtained near-isogenic lines (NIL) containing single resistance gene Xa7, Xa21, cry1C* or double resistance genes (Xa7, Xa21) whose agronomic traits were similar to original Xianhui207’s.2. Thirteen Xoo strains (PXO61, PXO99, ZHE173, GD1358, YN1, YN7, YN11, YN18, YN24, FuJ, ScYc6, HeNll and GD414), were used for identifying BB resistance of Xianhui207 and six NIL carrying Xa21 and Xa7 gene and donor parents under the field condition. The results showed that the new lines carrying Xa21 or Xa7 showed significantly higher resistance to BB than original Xianhui207. And the BB resistance of new lines carrying double resistance genes (Xa7+Xa21) were improved more. So Xa21 and Xa7 displayed high broad-spectrum resistance to Xoo races.3. Original Xianhui207, six new lines carrying Xa21 and Xa7 genes and a CMS line, Chuannongl A, were crossed. Thirteen Xoo strains were also used for identifying the BB resistance of seven F1 hybrids. The result showed that the BB resistance of new six F1 hybrids were improved significantly. So it is effective to improve the BB resistance of hybrid rice by improving the BB resistance of restorer lines.4. Two new lines carrying cry1C* gene and a CMS line, Chuannong1A were crossed. Under the field condition without pesticide-applying, the new lines and their F1 hybrids showed high insect-resistance.5. The results of combining ability analysis and grain quality analysis showed that the main agronomic traits and the grain quality of improved lines were similar to original Xianhui207’s. Among the 10 agronomic traits of eight new lines, TMQ91431 had the high general combining ability (GCA) effect and specific combining ability (SCA) effect. TMQ91436 had the high GCA. TMQ91435 and TMQ91438 had the high SCA. Among the 54 F1 hybrids, the grain yield of most F1 hybrids were higher than Jinyou207 (CK). Zhong9A/TMQ91432 had the highest SCA effect in 1000-grain weight, and Jin23A/TMQ91434 had the best SCA effect in grain yield.6. The competitive heterosis of yied in 48 F1 hybrids showed that the highest competitive yield heterosis values of C815S/TMQ91431, Zhong9A/TMQ91431 and Chuannong1A/TMQ91431 over CK hybrid Jinyou207, were 20%,18.03% and 17.30%, respectively. These three combinations were resistant to Lepidopteran insects.更多还原