抗白叶枯病杂交水稻的分子标记辅助育种

应用分子标记辅助回交,育成了带广谱抗白叶枯病基因[i]Xa-21[/i]的两个杂交水稻恢复系R8006和R1176,所配的杂交水稻组合中优6号、中优1176在中国南方稻区及多个省级区试中表现抗病、优质、高产,具有较广的商业开发潜力。     

分子标记辅助选择创制抗白背飞虱水稻恢复系

 将分子标记辅助选择技术与传统育种的杂交、回交方法及白背飞虱频发区大田自然诱发抗虫鉴定相结合,创制了米质优、配合力好且具有水稻白背飞虱拒食抗性主效QTL位点qSI4 的新恢复系材料3份(R38、R46和R58)。室内抗性鉴定结果表明,新创制的恢复系材料的白背飞虱抗性与抗源春江06的抗性水平相当,具有较强的白背飞虱抗性。这些新恢复系通过与不同遗传背景的不育系进行杂交配组,经过田间测产和室内米质鉴定、评比,筛选出一批集抗性好、米质优、产量高等优良性状于一体的杂交水稻新组合。     

转Cry30Fa1基因抗褐飞虱水稻的获得及鉴定

将编码高效杀褐飞虱蛋白的苏云金芽胞杆菌基因Cry30Fa1密码子改造后,通过农杆菌介导法转入蜀恢818(R818),并最终获得46个转基因植株。通过定量PCR及Western Blot鉴定了Cry30Fa1在转录水平和蛋白水平的表达,并通过分子检测固定稳定表达的抗性基因,并结合传统育种系谱法选择具有优良农艺性状株系。对选育的株系在室内和大田环境下进行了抗虫性鉴定,选育的R818-Cry30Fal株系抗性明显优于亲本材料并达到抗的水平;在单株抗虫试验中,观察到了转基因株系对褐飞虱具有致死作用。说明转入Cry30Fa1基因使水稻产生了对褐飞虱抗性。培育出了具有抗褐飞虱蛋白的新型恢复系R818-Cry30Fal,为三系杂交育种提供了新的抗性材料并丰富了抗褐飞虱水稻种质资源。     

杂交水稻及其亲本抗细菌性条斑病的研究初报

水稻细菌性条斑病（以下简称细条病）在热带和中国南方已上升为一种主要病害。为探讨杂交水稻及其亲本对该病的抗性规律，笔者在国际水稻所曾用Ｘａｎｔｈｏｍｏｎａｓ ｃａｍｐｅｓｔｒｉｓＰＶ．ｏｒｙｚｉｃｏｌａ的两个菌株（９３和３３５号）喷雾接种于五个杂交组合及其亲本上。结果表明，杂交水稻对细条病表现出不同程度的抗病反应，其抗性值接近双亲平均值，且属水平抗性。杂种一 代的抗性在很大程度上决定于恢复杂的抗性水平。     

水稻Pi9基因序列标记的开发及其抗瘟育种应用

利用广谱抗稻瘟病基因Pi9的3'UTR序列设计特异DNA标记pi9utr,通过分子标记辅助选择和连续回交育种实践,改良7份籼稻亲本(316B、金23B、R207、R228、R288、R389、明恢86)的稻瘟病抗性。结果表明:pi9utr是一个高效显性分子标记,除R207外,在其余6份受体亲本与Pi9供体亲本75-1-127间均存在明显而稳定的多态;在室内接种后的316B×75-1-127 BC4F1群体和R288×775-1-127 BC6F1群体中随机取样,进行稻瘟病抗性表型和基因型鉴定及Pi9基因表达分析,证明pi9utr对两个组合回交后代个体的抗病性辅助选择效率均为100%,且在所有抗病单株中均能检测到Pi9基因的高效表达,在所有感病单株中均没有检测到Pi9基因的表达。利用pi9utr在回交世代中的连续辅助选择,获得了3个组合的BC4F1及3个组合的BC6F2代群体,为选育抗稻瘟病新品种打下了基础。     

Analysis of Blast Resistance Genes and Neck Blast Resistance of japonica Rice Varieties/Lines Recently Developed in Jiangsu Province

【Objective】Evaluating the breeding potential of the known blast resistance (R) genes harbored in rice varieties is one of prerequisites for developing rice blast resistant varieties and R genes-based control of the disease epidemic.【Method】A total of 195 new japonica varieties/lines from Jiangsu Province were genotyped using functional markers corresponding to 14 rice blast R gene loci. In order to identify gene or gene combination with breeding potential against neck-blast, 158 japonica rice varieties were then artificially inoculated with blast strains as well as 17 advanced backcrossing lines containing Pigm gene in two different genetic backgrounds at booting stage. 【Result】Most varieties carried 2 to 5 R genes, and none of new varieties contained Pigm; the distribution frequencies of Pib, Pita and Pikh were relatively high and all exceeded 45%, the rest 10 genes were under 30%; Pid3, Pid2, Pia and Pb1 had apparently higher frequency in lines from regional tests than that in authorized and released varieties. Three genes with effects ordered as Pia > Pi3/5/i > Pita significantly contributed to neck-blast resistance, and significantly positive interaction effects were found between Pia and Pita, and between Pi3/5/i and Pita. Combination effect of Pia+Pita was significantly higher than that of Pi3/5/i+Pita, and the varieties harboring Pia+Pita reached resistant or highly resistant levels. The resistance of 17 advanced backcrossing lines carrying Pigm was all significantly improved as compared with corresponding controls, and all reached resistant level or even higher. 【Conclusion】 The results suggested that Pigm and the combination of Pia+Pita have critically important breeding potential in japonica rice breeding against neck blast in Jiangsu Province.     

中国常用水稻保持系及恢复系开花灌浆期耐热性评价

 以我国常用的15个水稻保持系和26个丰产性较好的恢复系为材料,于主茎见穗当天起连续15 d进行高温胁迫处理（9:00-15:00,39~43  ℃）,研究花期高温胁迫对水稻保持系和恢复系结实特性的影响。结果表明,根据高温胁迫指数,可把水稻品种分为热钝感型、耐热型、不耐热型和热敏感型等4个类型。其中,水稻保持系K22B、博白B和V20B为热钝感型材料,Ⅱ 32B、中浙B和中9B为热敏感型材料;水稻恢复系明恢63耐热性最强,其次为R207和P929,P62 2 2、R8006 和P51等耐热性最弱。进一步分析表明,高温胁迫指数与水稻在自然条件下结实率、空壳率和秕谷率之间相关不显著,但与胁迫环境下结实率和空壳率的相关性均达极显著水平。花期高温胁迫致使水稻保持系和恢复系结实率下降,空壳率大幅度上升。     

2009年宁德市晚稻新品种引种初报

为了筛选适宜宁德市种植的高产优质晚稻新品种,2009年晚季引进特优716、中优85、中浙优1号、宜优673、Ⅱ优810、闽优3301和两优816共7个杂交水稻新品种进行比较试验,结果表明,中优85增产显著,表现产量高、适应性强、综合性状好,适合当地种植,可在当地示范推广。     

Thermal Resistance of Common Rice Maintainer and Restorer Lines to High Temperature During Flowering and Early Grain Filling Stages

Fifteen common rice maintainer lines and 26 high-yielding restorer lines were used to evaluate their thermal resistance and fertility during flowering and early grain filling stages.The rice plants were subjected to high temperature stress(39-43 ℃) for 1-15 d from main stem flowering.Based on the heat stress index,they were divided into thermal resistant lines,semi-thermal resistant lines,semi-thermal sensitive lines and thermal sensitive lines.Therefore,the maintainer lines K22B,Bobai B and V20B belonged to thermal resistant lines,whereas II-32B,Zhongzhe B and Zhong 9B belonged to thermal sensitive lines.For rice restorer lines,Minghui 63 had the highest thermal resistance,followed by R207,P32,P929,and the lowest thermal resistant lines P62-2-2,R8006 and P51.The correlation analysis indicated that the heat stress index was significantly correlated with seed-setting rate and abortive grain rate under heat stress,but not under natural conditions.This indicated that heat stress occurred during flowering and early grain filling stages mainly decreased the seedsetting rate and significantly increased the abortive grain rate in both rice maintainer and restorer lines.     

分子标记辅助选择改良三系杂交稻恢复系R225稻瘟病抗性

稻瘟病是水稻的主要病害,培育抗稻瘟病品种是防治稻瘟病的有效途径。本研究通过分子标记辅助选择与杂交育种相结合的方式,将稻瘟病抗性基因Pi1、Pi2和Pi9导入到三系杂交稻恢复系R225。对BC3F3代材料进行苗期和成熟期稻瘟病抗性鉴定,携带1个或2个抗性基因的目标株系抗性达到中抗以上水平,稻瘟病抗性显著高于各自的轮回亲本。SSR标记分析表明,改良株系的遗传背景回复率达到86.1%~95.3%。通过标记辅助选择获得的改良材料为三系杂交稻恢复系的培育提供了稻瘟病抗性亲本。     

抗稻瘟病基因Pi9的STS连锁标记开发及在分子标记辅助育种中的应用

 利用带有广谱抗稻瘟病基因Pi9的籼稻品系75 1 127作为抗病基因供体亲本,用于扬稻6号和R6547抗病性的回交育种。通过比较75 1 127、扬稻6号和日本晴的Pi9基因位点的DNA序列,开发出了与Pi9基因紧密连锁的共显性STS（序列标记位点）标记PB9 1,用于Pi9基因的分子标记辅助选择。结合田间农艺性状选择和分子标记辅助选择,培育出8个Pi9基因纯合的回交后代株系。其中,具有扬稻6号和R6547遗传背景的株系各4个。经湖北恩施和宜昌的病圃鉴定,携带有抗病基因株系的稻瘟病抗性水平较受体品种扬稻6号和R6547有不同程度的提高。具有R6547遗传背景的株系08C893配制的杂交组合在上述病区的抗性表现也明显优于对照品种扬两优6号。上述结果说明,共显性标记PB9 1在Pi9抗稻瘟病基因分子标记辅助育种中具有应用价值,并且Pi9基因作为稻瘟病抗源之一可以在湖北稻区进行有效利用。     

采用分子标记技术育成优质抗病杂交稻新组合中优218

中优218是用中国水稻研究所采用分子标记辅助育种技术培育的含白叶枯病抗性基因Xa21的恢复系中恢218,与印水型高异交率优质不育系中9A组配出的中晚兼用型杂交稻新组合.该组合连续多年参加国家南方稻区区试、江西省区试和各地的试种示范,表现高产稳产,米质优,抗至中抗稻瘟病,抗白叶枯病,适应性广,制种产量高,于2003年3月通过江西省品种审定.     

籼型水稻中稻瘟病抗性基因分布及抗性研究

稻瘟病严重威胁着水稻的安全生产。目前,培育抗性品种是控制稻瘟病危害最经济有效的途径之一。本研究利用11个主效稻瘟病抗性(R)基因(Pi2、Piz-t、Pi9、Pi54、Pik-m、Pid3、Pib、Pit、Pi5、Ptr和Pita)的分子标记对48个常规稻、15个不育系和129个杂交稻进行了检测。结果表明,在常规稻中,Ptr和Pi5的分布频率均为35.42%,Pib、Pi2、Piz-t、Pit的分布频率介于20.0%~30.0%之间,其余均在15%以下;在不育系中,Pita的分布频率为40.0%,其余均在20%以下;杂交稻中,Pita、Pib、Pi54、Ptr和Pi5的分布频率在40.31%~55.04%之间,其余均在20%以下;Pita在各个品系中均广泛存在,频率介于35.42%~51.16%。田间抗性评价表明,R基因较多的品种具有较高的抗性。综上所述,在参试的水稻材料中,不育系中存在抗性基因较少,所有类型材料中广谱抗性基因分布较少,抗性基因聚合可以有效提高稻瘟病田间抗性。     

Recent Advances in Development of Herbicide Resistant Transgenic Hybrid Rice in China

In addition to weed control in direct seeding field of hybrid rice, herbicide resistance genes were used by Chinese scientists to increase and identify the purity of hybrid seeds, and to realize the mechanization of hybrid seed production. The elite restorer lines, such as Minghui 63, R752, T461, R402, D68 and E32 were transformed directly with herbicide resistance genes, in which D68 and E32 are restorer lines of two-line system and the others are of three-line system. Because almost all of important restorer lines are indica varieties and are recalcitrant in transformation, many herbicide resistant near-isogenic restorer lines were developed by sexual hybridization of indica and japonica varieties and backcross with indica restorer lines later, such as Ce 64, Minghui 63, Teqing, Milyang 46, R402 and 9311, in which 9311 is a restorer line of two-line system. The elite photoperiod-sensitive/thermo-sensitive genic male sterile lines, such as Pei'ai 64S, P88S, 4008S and 7001S, were transformed with herbicide resistance genes. A few herbicide resistant male sterile lines were developed through sexual hybridization and subsequently systemic selection, such as Bar1259S, Bar2172S, 05Z221A and 05Z227A. With the employment of herbicide resistant male sterile lines or herbicide resistant restorer lines, a few herbicide resistant hybrid rice combinations were developed, such as Xiang 125S/Bar 68-1 and Pei'ai 64S/Bar 9311. Based on herbicide resistance, the research was marching on to investigate the parental lines of hybrid rice with insect resistance, drought tolerance, etc.     

Strategy for Use of Rice Blast Resistance Genes in Rice Molecular Breeding

Rice blast is one of the most destructive diseases affecting rice production worldwide. The development and rational use of resistant varieties has been the most effective and economical measure to control blast. In this review, we summarized the cloning and utilization of rice blast resistance genes, such as Pi1, Pi2, Pi9, Pi54, Pigm and Piz-t. We concluded that three main problems in the current breeding of rice blast resistance are: availability of few R(resistance) genes that confer resistance to both seedling and panicle blast, the resistance effect of pyramided lines is not the result of a simple accumulation of resistance spectrum, and only a few R genes have been successfully used for molecular breeding. Therefore, novel utilization strategies for rice blast R genes in molecular breeding were proposed, such as accurately understanding the utilization of R genes in main modern rice varieties, creating a core resistant germplasm with excellent comprehensive traits, screening and utilizing broadspectrum and durable resistance gene combinations. Lastly, the trends and possible development direction of blast resistance improvement were also discussed, including new genes regulating resistance identified via GWAS(genome-wide association study) and improving rice blast resistance using genetic editing.     

Improvement of bacterial blight resistance of hybrid rice in China using the Xa23 gene derived from wild rice (Oryza rufipogon)

A novel bacterial blight (BB) resistance gene, Xa23, identified from Oryza rufipogon was introgressed into three popular restorer lines (Minghui63, YR293 and Y1671) for wild abortive cytoplasmic male sterility by marker-assisted backcross breeding approach in combination with artificial inoculation and stringent phenotypic selections. The three derived BB resistant restorer lines (Minghui63-Xa23, YR293-Xa23 and Y1671-Xa23) and their hybrid combinations with Zhenshan97A (Shanyou63-Xa23), NongfengA (Fengyou293-Xa23) and Zhong9A (Zhongyou1671-Xa23) demonstrated similar BB resistance spectrum as the donor parent, CBB23 (B). The newly developed BB resistant restorers and their derived hybrids were identical to their respective original versions for agronomic traits especially under disease free condition. However, under severe disease condition, the three BB resistant restorer lines exhibited significantly higher grain weight and spikelet fertility as compared to the respective original restorer lines thus further resulting in BB resistant hybrids with significantly higher grain yields than their respective popular original hybrids. The results indicated that the Xa23 gene could completely express its dominant broad spectrum resistance in different backgrounds of both restorer and male sterile lines across different growth stages, suggesting its immense breeding value in BB resistance improvement for hybrid rice. Moreover, a reasonable utilization and deployment of Xa23 gene for efficient control of BB disease in hybrid rice production was recommended.     

Race Specificity of Major Rice Blast Resistance Genes to Magnaporthe grisea Isolates Collected from indica Rice in Guangdong, China

Race-specific resistance and field resistance of 30 rice blast resistance monogenic lines dedved from different resources were evaluated. The spectra of resistance to 163 Magnaporthe grisea isolates collected from indica rice in Guangdong Province, China ranged from 0.6% to 89.6%. Most of the monogenic lines showed a narrow resistance spectrum and high susceptibility in rice blast area, whereas the lines with Pikh and Pi1(t) had the broad resistance spectra of 89.6% and 82.2% respectively, showing a high and stable blast resistance in fields. According to the cluster analysis of specific resistance to 163 blast isolates tested, the 30 monogenic lines were divided into 15 groups, and based on the principal factor analysis, nine kinds of race-specific resistance were identified. Pik, Piz5, Pi9 and Pish can be used as candidate resistance genes for rice breeding since their specific resistance differed from those of the backbone parents in Guangdong, China. Gene pyramiding of Pikh [or Pi1(t)], Pi9 (or Piz5) and Pish (or Pita2) will be effective to obtain broad-spectrum blast resistance in rice breeding program in Guangdong, China. The strategies for studying and application of rice blast resistance genes were discussed.     

优质抗稻瘟病水稻恢复系成恢177的选育与利用

成恢177系四川省农科院作物研究所用籼型恢复系绵恢502与美国光身稻Lemont杂交，后代通过花药培养和病圃稻瘟病抗性鉴定选育而成的优质、抗稻瘟病、高配合力、强恢复力水稻恢复系。成恢177已配组出川香优2号、冈优177、中优177和D优177等4个组合通过国家或省级品种审定，也作为稻瘟病抗性资源在杂交水稻育种中应用。     

优质高产杂交早稻金优1176的选育与应用

金优1176是湖北省咸宁市农科所用金23A与早灿恢复系1176配组面成的籼型杂交早稻新组合。该组合具有米质较优、产量高、制种易获高产等特点，于2002年2月通过湖北省农作物品种审定委员会审定。介绍了其选育过程、特征特性、栽培及制种技术要点。     

转几丁质酶-葡聚糖酶基因水稻稻瘟病抗谱分析

用来源于云南各地属于24个稻瘟病菌（[i]Magnaporthe grisea[/i]）生理小种的33个菌株,对受体品种南29及其4个转几丁质酶 β-1,3-葡聚糖酶串联基因水稻T5代品系进行了温室接种鉴定。结果表明,不能侵染受体品种南29 的13个菌株也不能侵染转基因品系,可侵染受体品种南29 的20个菌株一般不能侵染转基因品系,转基因水稻对稻瘟病菌抗性范围较受体对照扩大,证明转几丁质酶 葡聚糖酶基因水稻对稻瘟病具有一定的广谱抗性;诱发条件下,转基因品系大田叶瘟病情指数为0～1级,穗瘟发病率为0.3%～10.23%,抗性较受体对照大幅度提高,表明这些品系在稻瘟病抗病育种中是有应用潜力的。