分子标记辅助选育水稻抗白叶枯病和稻瘟病多基因聚合恢复系

利用分子标记辅助选择和田间鉴定选择相结合的方法, 将三黄占2号的抗稻瘟病主基因Pi-GD-1(t)、Pi-GD-2(t)和主效QTL GLP8-6(t) (分别简称G1、G2和G8)及抗白叶枯病基因Xa23导入到明恢86、蜀恢527和浙恢7954等3个骨干中籼恢复系, 通过复交进行基因聚合, 获得5个带有抗稻瘟病兼抗白叶枯病的双基因或多基因聚合系明恢86-G1-G2-Xa23、蜀恢527-G2-Xa23、明浙-G2-G8-Xa23-1、明浙-G2-G8-Xa23-2和明浙-G1-G2-G8-Xa23。以上5个抗病基因聚合改良系对稻瘟病的抗谱与抗源品种相仿或更宽, 改良系和与不育系II-32A配制的测交种对白叶枯病菌的抗谱与供体亲本IRBB23一致, 测交种在不接种白叶枯病菌条件下的产量和结实率与原来的恢复系及相应杂交种相仿, 但在接种条件下带有Xa23基因的恢复系及测交种的结实率、千粒重和产量明显优于原来的恢复系及相应杂交种。研究表明, 抗稻瘟病基因和抗白叶枯基因Xa23在不同恢复系背景下的抗性表达完全, 对恢复系稻瘟病以及白叶枯病改良的效果明显。对分子标记复交改良恢复系的抗病性进行了讨论。     

培育水稻恢复系抗稻褐飞虱基因导入系和聚合系

稻褐飞虱是水稻的主要虫害之一,培育优良的抗性基因聚合系对于防治稻褐飞虱具有重要的意义.本研究通过回交、分子标记辅助选择和接虫鉴定三者相结合的办法,将抗稻褐飞虱基因Bph3和Bph24(t)分别导入主栽杂交水稻恢复系广恢998、9311、R15、明恢63、R29中,最终获得遗传稳定的Bph3导入系32份和Bph24(t)...     

节水抗旱稻恢复系的抗褐飞虱分子标记辅助选育及抗性评价

褐飞虱是水稻的主要害虫之一,利用水稻抗褐飞虱基因培育抗虫品种是目前公认最经济有效、环境友好的策略。本研究利用水稻功能基因组已克隆的抗褐飞虱基因,通过分子标记辅助选择和常规回交育种相结合的方法,将抗褐飞虱基因Bph6、Bph9、Bph14和Bph15单独和聚合导入到节水抗旱稻恢复系旱恢3号,获得了一系列含有单基因、双基因、三基因和四基因的改良系。采用标准苗期集团筛选法进行褐飞虱抗性鉴定,评价这些基因在旱恢3号背景下的效应及相互作用。表明单基因改良系中, Bph9的抗性最强,且Bph9 Bph6 Bph15 Bph14;在聚合改良系中,抗性均优于单基因改良系,四基因聚合改良系的抗性最强,不同基因型组合的抗性效应是Bph6+Bph9+Bph14+Bph15Bph6+Bph9 Bph6+Bph9+Bph14 Bph6+Bph9+Bph15 Bph6+Bph14+Bph15 Bph9+Bph14+Bph15 Bph14+Bph15。在自然条件下,改良系与旱恢3号在株高、有效穗和千粒重等农艺性状上差异不显著,其他性状与旱恢3号相仿或略差。本试验表明单独和聚合导入Bph6、Bph9、Bph14和Bph15基因能显著提高节水抗旱稻恢复系的褐飞虱抗性,这4个基因的加性效应明显,可为今后节水抗旱稻抗褐飞虱育种提供理论依据和材料基础。     

聚合稻瘟病、白叶枯病和褐飞虱抗性基因的三系恢复系改良效果的评价

结合分子标记辅助轮回选择和田间鉴定的方法, 将三黄占2号的抗稻瘟病基因Pi-GD-1(t)和Pi-GD-2(t)(分别简称G1和G2)、CBB23中的抗白叶枯病基因Xa23 (简称X)和IR65482-7-216-1-2-B(简称IR65482)的抗褐飞虱基因Bph18(t) (简称B)导入温恢845、温恢117和温恢143等3个中籼恢复系,获得了8个兼抗稻瘟病和褐飞虱聚合系,温恢845-G1-G2-B-4、温恢845-G1-G2-B-5、温恢117-G1-G2-X-B-3、温恢143-G1-G2-B-3、温恢143-G2-X-B-9、温恢143-G2-X-B-10、温恢143-G1-G2-B-11和温恢143-G1-G2-B-37。这些聚合系及其与不育系五丰A的测交种,对稻瘟病和褐飞虱的抗性水平接近或略低于稻瘟病抗性亲本三黄占2号和稻飞虱抗性亲本IR65482。部分改良恢复系如温恢117-G1-G2-X-B-3、温恢143-G2-X-B-9和温恢143-G2-X-B-10及其测交种对白叶枯病表现为抗病或中抗。改良恢复系及其测交种在正常条件下的农艺性状与原始恢复系及其测交种相仿或更优,具有生产应用价值。研究结果表明,Xa23在不同恢复系背景下抗性表达完全,而Pi-GD-1(t)、Pi-GD-2(t)和Bph18(t)对稻瘟病和褐飞虱抗性的改良效果与恢复系的遗传背景有关。     

应用分子标记辅助选育抗褐飞虱水稻恢复系

稻褐飞虱是中国长江中下游及南方各省稻区中稻晚熟品种及晚稻品种的主要害虫。培育抗性水稻新品种是防治稻褐飞虱最经济有效的方法。本试验采用分子标记辅助选择和田间接虫鉴定的方法,将Bph14和Bph15基因分别导入到自选恢复系赣恢2688、赣恢4864和中组14中,最终获得遗传稳定的改良恢复系R1、R2和R3。分子标记检测表明三个改良恢复系都携带纯合的抗褐飞虱基因Bph14和Bph15;人工接虫鉴定结果显示,三个改良恢复系R1、R2和R3皆高抗褐飞虱;改良恢复系与4个不育系配制的组合之间抗性存在差异;农艺性状分析显示,株高、穗长、单株有效穗数、每穗实粒数、千粒重、结实率以及单穗重共7个农艺性状与受体恢复系差异不显著。证明本研究已成功获得了抗褐飞虱的改良恢复系R1、R2和R3,为选育抗褐飞虱杂交稻提供了重要的育种材料。     

抗褐飞虱基因Bph14和Bph15杂交稻的分子标记辅助选育与抗性评价

为科学评价抗褐飞虱基因Bph14和Bph15在杂交稻抗性改良中的育种利用价值,本研究通过分子标记辅助选择,获得恢复系桂339的抗褐飞虱近等基因系,并观察近等基因系与不育系良丰A配组的表现。结果表明分子标记辅助选择能够提高Bph14和Bph15的育种改良利用效率。恢复系桂339的抗褐飞虱近等基因系及其与良丰A所配的杂交组合,在苗期鉴定中,只有带有双抗基因的等基因系达到中抗水平,平均抗性指数为4.30,其余近等基因系和相应的组合均感虫,平均抗性指数介于7.43和8.57之间,但在大田种植中与对照相比,除桂339(Bph14)外,均表现出明显的褐飞虱抗性,说明苗期人工接种鉴定与成株期田间抗性表现相结合可更加客观地评价抗褐飞虱基因Bph14和Bph15的遗传改良效应。     

标记辅助培育水稻抗稻褐飞虱和稻白叶枯病基因聚合系

稻白叶枯病和稻褐飞虱是水稻的主要病虫害,利用优良的抗性基因培育抗性基因聚合系对于防治稻白叶枯病和稻褐飞虱具有重要意义。本研究通过回交与分子标记辅助选择相结合的方法,将抗稻白叶枯病基因Xa23和抗稻褐飞虱基因Bph3分别导入主栽杂交水稻品种的保持系先B、天B、盟B、龙特甫B和桂B中。结果表明,获得稳定的单抗性基因导入系1436份和双抗性基因聚合系144份。人工接种鉴定结果显示,Xa23导入系和Xa23Bph3聚合系对抗稻白叶枯水平达到中抗和接近高抗的水平(1.1～3.0级),Bph3导入系和Xa23Bph3聚合系抗褐飞虱水平达中抗到抗的级别(3.2～4.0级)。农艺性状分析显示多数抗性基因聚合系的株高、剑叶长宽度、每穗粒数、结实率、千粒重等主要农艺性状与受体差异不显著,只有少数聚合系有1～2个性状的差异。SSR标记分析表明抗性基因聚合系的遗传背景回复率达89.6%～97.8%,等位性位点纯合度达95.6%～99.9%。初步证明本研究已成功地获得抗稻白叶枯病和稻褐飞虱基因的聚合系,这些抗性改良保持系具有良好的应用前景,并为建立完善的分子设计育种平台提供了重要育种材料基础。     

利用分子标记辅助选择改良杂交水稻的褐飞虱和稻瘟病抗性

稻瘟病和褐飞虱目前是我国水稻产区最重要的病虫害。汕优63曾经是我国种植面积最大的杂交水稻组合,然而其易感白叶枯病、稻瘟病、褐飞虱和品质等问题导致其近年来在生产上基本没有了面积。本试验利用分子标记辅助选择将水稻抗褐飞虱基因Bph14、Bph15同时导入到汕优63的亲本明恢63和珍汕97B中,以改良汕优63的褐飞虱抗性;同时将抗稻瘟病基因Pi1、Pi2导入到已改良的珍汕97B中,使后者同时获得褐飞虱和稻瘟病抗性。褐飞虱苗期鉴定结果表明:改良的杂交稻(聚合Bph14,Bph15或单基因)的褐飞虱抗性较对照(汕优63)显著提高;穗颈瘟田间自然发病结果也表明:聚合Pi1、Pi2的杂交稻发病率仅为约6%,明显低于对照汕优63(约90%)。田间农艺性状考察也表明改良型杂交稻的主要农艺性状与对照基本一致,产量高于对照或与对照相仿。这些改良组合可以为进一步培育绿色超级稻提供中间材料。     

不同Xa21转基因杂交稻组合的大田试验与分析

在北京、四川和江苏等地对Xa21转基因杂交稻进行了大田释放实验. 分别对转基因纯合的3个恢复系明恢63-Xa21、盐恢559-Xa21和C418-Xa21与各种不育系配组的23个杂交组合进行了抗性和农艺性状分析. 在不同的杂合遗传背景下转基因Xa21稳定遗传和高效表达, 所有杂交组合均具有对白叶枯病的广谱抗性. 转基因恢复系配制的杂交组合与     

分子标记辅助选择抗褐飞虱基因改良桂农占的BPH抗性

本研究通过分子标记辅助选择和连续回交的方法将来源于栽培稻的抗褐飞虱基因Bph3、来源于野生稻的抗褐飞虱基因Bph14和Bph15分别转入到华南高产水稻品种桂农占中,在BC3F3获得了含单个抗性基因的稳定株系和含Bph14和Bph15的稳定株系,其遗传背景与桂农占相似达95%以上。这些株系苗期对褐飞虱的抗性评价表明,在含单个抗性基因的株系中,含Bph3的株系抗性水平最高,含Bph14的最低,而含Bph14和Bph15的株系抗性水平高于含单个基因的株系。对农艺性状的调查发现,含抗性基因的株系与桂农占在抽穗期方面表现出显著差异。在单株产量方面,含抗褐飞虱基因的株系与桂农占没有显著差异。研究结果可为培育抗褐飞虱基因高产水稻品种提供材料。     

Introgression of bacterial blight resistance genes Xa7, Xa21, Xa22 and Xa23 into hybrid rice restorer lines by molecular marker-assisted selection

Four bacterial blight (BB) resistance genes, Xa7, Xa21, Xa22 and Xa23, were introgressed into an elite hybrid rice restorer line Huahui 1035, by marker-assisted selection (MAS). Ten promising BB resistant lines identified by MAS approach in Huahui 1035 restorer background and their respective F₁ hybrids with a cytoplasmic male sterile line i.e. Jinke 1A, three BB resistant gene donors and their recurrent parent were evaluated for BB resistance by inoculating them with eleven representative races of Xanthomonas oryzae pv. oryzae (Xoo) in China. Further, the ten marker assisted selection of BB (MAS-BB) resistant restorer lines and their F₁ hybrids were also characterized for agro-morphological traits and grain yield. Results revealed that restorer lines with Xa23 introgression i.e. HBQ809 and HBQ810 were found to be resistant to all eleven Chinese representative Xoo races, showing broad spectrum resistance to BB. However, the lines possessing Xa7 or Xa7+Xa21 were resistant to ten out of eleven Xoo races. While restorer lines with Xa21 were resistant to nine out of eleven Xoo races. Interestingly, the F₁ hybrids with Xa23, Xa7 or Xa7+Xa21 were resistant to two severe epidemic Xoo races of China. Restorer lines i.e. HBQ807 and HBQ808 possessing Xa22 were only resistant to six or five out of inoculated eleven Xoo races. Lesion length comparisons between restorer lines and their F₁ hybrids for the above four BB resistance genes showed them to be dominant in heterozygote genotype. Three promising high yielding F₁ hybrids with BB resistance were identified for immediate exploitation for hybrid rice production in China.     

Pyramiding of Xa7 and Xa21 for the improvement of disease resistance to bacterial blight in hybrid rice

‘Minghui 63’ is a restorer line widely used in hybrid rice production in China for the last two decades. This line and its derived hybrids, including ‘Shanyou 63’, are susceptible to bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo). To improve the bacterial blight resistance of hybrid rice, two resistance genes Xa21 and Xa7, have been introgressed into ‘Minghui 63’ by marker‐assisted selection and conventional backcrossing, respectively. The single resistance gene‐introgressed lines, Minghui 63 (Xa21) and Minghui 63 (Xa7) had higher levels of resistance to bacterial blight than their derived hybrids, Shanyou 63 (Xa21) or Shanyou 63 (Xa7). Both Xa21 and Xa7 showed incomplete dominance in the heterozygous background of rice hybrids by infection with GX325 and KS‐1‐21. The improved restorer lines, with the homozygous genotypes, Xa21Xa21 or Xa7Xa7, were more resistant than their hybrids with the heterozygous genotypes Xa21xa21 or Xa7xa7. To further enhance the bacterial blight resistance of ‘Minghui 63’ and its hybrids, Xa21 and Xa7 were pyramided into the same background using molecular marker‐aided selection. The restorer lines developed with the resistance genes Xa21 and Xa7, and their derived hybrids were evaluated for resistance after inoculation with 10 isolates of pathogens from China, Japan and the Philippines, and showed a higher level of resistance to BB than the restorer lines and derived hybrids having only one of the resistance genes. The pyramided double resistance lines and their derived hybrids have the same high level of resistance to BB. These results clearly indicate that pyramiding of dominant genes is a useful approach for improving BB resistance in hybrid rice.     

Pyramiding of insect- and disease-resistance genes into an elite indica, cytoplasm male sterile restorer line of rice,'Minghui 63'

The wild‐rice‐derived dominant gene Xa21 conferring multi‐race resistance to bacterial blight and a fused Bt gene cry1Ab/cry1Ac conferring resistance to lepidopteran insects were individually introduced into the same genetic background of an elite indica cytoplasm male sterile (CMS) restorer line ‘Minghui 63′. The line showed the desirable insect‐ and disease‐resistant phenotypes. To maximize the effect, the two genes were also pyramided into the same recipient plant of ‘Minghui 63’ by marker‐assisted selection. After being subjected to natural infestation of leaf‐folders and yellow stem borers and inoculation of Xoo strain mixtures, the pyramiding line and its derived hybrids showed high levels of resistance against both insect damage and disease. Furthermore, data from field trials demonstrated that the hybrids made by crossing this pyramiding line with the CMS lines ‘Zhenshan 97A’ and ‘Maxie A’ retained a similar level of yield under conditions without chemical spray, indicating that the pyramiding genes have a yield‐stabilizing effect on the recipient line and its hybrids.     

分子标记辅助选择Xa23基因培育杂交稻抗白叶枯病恢复系

水稻抗白叶枯病新基因Xa23抗谱广、抗性强,被定位在第11染色体上。以携带抗白叶枯病基因Xa23的抗病品系CBB23为抗源,以优良杂交稻亲本9311和1826为受体材料,采用杂交和复交,在分离群体中利用与Xa23紧密连锁的EST标记C189进行分子标记辅助选择,通过苗期分子标记检测和成株期农艺性状选择,获得160份目标基因纯合且农艺性状稳定的株系。使用鉴别菌系P6,采用人工剪叶接种法,在苗期和孕穗期对21份重点株系进行了抗性鉴定,所有株系在苗期和孕穗期都表现抗病。同时对3个不育系与其中5个株系配制的15个杂交组合进行了抗性鉴定,所有组合在苗期表现抗或中抗,在孕穗期表现抗。对其中6个杂交组合进行了品比试验,2个组合产量略低于对照两优培九,其余4个组合的产量均高于两优培九,用于测配的3个株系C6201、C6271和C6351有望作为杂交稻恢复系在生产中应用。研究表明在育种进程中利用与Xa23基因紧密连锁的分子标记C189开展抗白叶枯病分子标记辅助育种是一种有效的途径。     

水稻抗纹枯病导入系的构建及抗病位点的初步定位

以我国目前生产中广泛应用的杂交稻恢复系蜀恢527和明恢86为轮回亲本, 以江西丝苗为供体亲本配制BC₂F₂混合群体。通过逐代人工接种筛选, 获得49个BC₂F₄抗病导入系。对抗病选择导入系进行基因型分析, 利用基于遗传搭车原理的卡方检验对等位基因导入频率的偏离进行检测, 共检测到12个显著位点, 2个群体定位的QTL各有1个在以往不同群体中也能被检测到。主要农艺性状分析表明, 非接种条件下, 选择导入系群体的抽穗期、株高和千粒重等与轮回亲本无显著差异;在接种的条件下, 在2个试验地点中, 分别有6个和2个蜀恢527和明恢86背景的株系抗病性显著高于轮回亲本, 产量与轮回亲本无显著差异。上述结果为水稻抗纹枯病分子育种提供了有用的信息和中间材料。