Molecular approaches in identifying leaf rust resistance genes in Russian wheat varieties

Russian soft wheat varieties are screened with the use of molecular markers of Lr genes. A low genetic diversity is found among leaf rust resistant varieties, in which genes Lr9 and Lr19 dominate. There are no highly effective genes Lr25, Lr29, and Lr39(41) and adult plant resistance genes Lr37 and Lr21 in the studied varieties. Among genes with limited effectiveness, the most prevalent are genes Lr10 and Lr26, respectively in 45 and 10% of the varieties.     

Seedling and adult plant resistance to leaf rust in 46 Chinese bread wheat landraces and 39 wheat lines with known Lr genes

Wheat leaf rust,caused by Puccinia triticina(Pt),is an important foliar disease that has an important influence on wheat yield.The most economic,safe and effective way to control the disease is growing resistant cultivars.In the present study,a total of 46 wheat landraces and 34 wheat lines with known Lr(leaf rust resistance)genes were inoculated with 16Pt pathotypes for postulating seedling resistance gene(s)in the greenhouse.These cultivars and five wheat differential lines with adult plant resistance(APR)genes(Lr12,Lr22b,Lr34,Lr35 and Lr37)were also evaluated for identification of slow rusting resistance in the field trials in Baoding,Hebei Province of China in the 2014–2015 and 2015–2016 cropping seasons.Furthermore,10 functional molecular markers closely linked to 10 known Lr genes were used to detect all the wheat genotypes.Results showed that most of the landraces were susceptible to most of the Pt pathotypes at seedling stage.Nonetheless,Lr1 was detected only in Hongtangliangmai.The field experimental test of the two environments showed that 38 landraces showed slow rusting resistance.Seven cultivars possessed Lr34 but none of the landraces contained Lr37 and Lr46.Lr genes namely,Lr9,Lr19,Lr24,Lr28,Lr29,Lr47,Lr51 and Lr53 were effective at the whole plant stage.Lr18,Lr36 and Lr45 had lost resistance to part of pathotypes at the seedling stage but showed high resistance at the adult plant stage.Lr34 as a slowing rusting gene showed good resistance in the field.Four race-specific APR genes Lr12,Lr13,Lr35 and Lr37 conferred good resistance in the field experiments.Seven race-specific genes,Lr2b,Lr2c,Lr11,Lr16,Lr26,Lr33 and LrB had lost resistance.The 38 landraces showed slow rusting resistance to wheat leaf rust can be used as resistance resources for wheat resistance breeding in China.     

Donors of spring common wheat resistance to leaf rust and powdery mildew with genetic material of the species Aegilops speltoides L., Aegilops triuncialis L., and Triticum kiharae Dorof. et Migusch

Spring wheat donors obtained by the wide hybridization method with several leaf rust and powdery mildew resistance genes effective for the Non-Chernozem Zone of the Russian Federation have been identified. The presence of effective genes of resistance to leaf rust (Lr37, Lr39, Lr46, Lr50) and powdery mildew (Pm2, Pm13) that can be used in breeding for immunity with STS and SSR markers has been established.     

粗山羊草苗期抗叶锈性鉴定及抗叶锈基因推导

普通小麦D基因组的供体材料粗山羊草含有丰富的抗叶锈病基因资源,而且具有较好的农艺性状,在抗病育种中具有重要的应用价值。本研究旨在了解粗山羊草的抗叶锈性以及准确了解其中所含抗叶锈基因。选取25株小麦叶锈菌株对6个粗山羊草品系进行抗叶锈性离体鉴定,筛选出4个在苗期对22个和23个菌株表现中到高抗的品系。试验选用18个不同毒力类型的小麦叶锈菌株和44个已知的抗叶锈单基因品系对其进行了抗叶锈基因推导,推导出粗山羊草4254-Y206可能含有Lr1,Lr10和Lr29或其他未用于本次研究的抗叶锈基因;4255-Y212可能含有Lr10和Lr29抗叶锈基因或其他未用于本次研究的抗叶锈基因;Y192可能含有Lr41抗叶锈基因或其他未用于本次研究的抗叶锈基因;Y201可能含有其他未用于本次研究的抗叶锈基因。     

Identification of leaf rust resistance genes in common wheat varieties from China and foreign countries

Wheat leaf rust, triggered by Puccinia triticina Eriks(Pt), is among the most important diseases of wheat worldwide. Deploying resistant varieties against leaf rust is the most effective, environmentally-friendly and economic way to control the disease. In the present study, 66 wheat varieties form China and foreign countries were tested with 17 Pt races for gene postulation during the seedling stage in the greenhouse. All the varieties were also planted to identify slow rusting responses to leaf rust at the adult plant stage in Baoding and Zhoukou field trials during the 2016/2017 to 2017/2018 cropping seasons. Moreover, 12 closely linked molecular markers to known leaf rust resistance(Lr) genes were used for assessing all the varieties. The results of both gene postulation and molecular marker identification showed that a total of eight Lr genes, Lr1, Lr10, Lr17, Lr20, Lr26, Lr34, Lr37 and Lr46, either singly or in combination were detected in 32 varieties. Known Lr genes were not identified in the remaining 34 varieties. Seventeen varieties were found to have slow rusting resistance. The resistance sources identified in this study can be used as resources for resistance against leaf rust in wheat breeding programs in China and the respective foreign countries.     

2009年河北省小麦叶锈菌群体EST-SSR遗传多样性分析

通过对小麦叶锈菌群体毒性多态性和EST-SSR多态性分析,为河北省小麦抗病品种的培育和合理利用提供依据。利用34个小麦抗叶锈近等(单)基因系和21对EST-SSR引物对河北省唐山、秦皇岛、沧州、保定、石家庄、邢台和邯郸的30个单孢子分离纯化小麦叶锈菌株进行毒性和DNA多态性分析。结果表明:30株小麦叶锈菌菌株间毒性相似性较高,相似系数为0.70~1.00,分子遗传多态性的相似系数为0.80~1.00。部分地理来源相同的菌株聚在同一亚组,表明小麦叶锈菌株地理来源与毒性多态性和遗传多态性有一定的相关性,但毒性多态性和SSR分子多态性相关性不明显。     

中国小麦叶锈菌群体的毒性基因分析

 1986-1991年间，利用已知抗叶锈病基因的小麦近等基因系（或单基因系）作鉴别寄主，首次采用毒性基因频率、毒性因子（FV）、毒性值（VV）和Shannon-Wiener多样性指数等反映群体水平的参数，对我国小麦叶锈菌的毒性基因结构、频率、时间动态、空间格局及不同生理小种毒性基因的异质性等进行了比较分析。结果表明，毒性基因 V2a、V9、V15、V19、V24、V28、V29的出现频率较低（小于30%），其对应的抗性基因为目前我国小麦叶锈菌的有效抗病基因；V1、V3ka、V10、V26的频率处于升高的趋势，V2a、V15的频率有下降的趋势；不同地区叶锈菌群体的毒性因子、毒性值和毒性基因组合的多样性明显不同，我国和北美的叶锈菌至少存在4-5个毒性基因的差异；不同生理小种的毒性基因结构差异显著，叶中3号不具备V26基因，叶中34号不具有V1、V14a、V17和V27基因，而叶中4号携带有这些毒性基因。文中还对利用近等基因系作鉴别寄主的优点进行了讨论。     

Genetic diversity analysis and GWAS reveal the adaptive loci of milling and appearance quality of japonica rice (Oryza sativa L.) in Northeast China

Milling and appearance quality are important contributors to rice grain quality. Abundant genetic diversity and a suitable environment are crucial for rice improvement. In this study, we investigated the milling and appearance quality-related traits in a panel of 200 japonica rice cultivars selected from Liaoning, Jilin and Heilongjiang provinces in Northeast China. Pedigree assessment and genetic diversity analysis indicated that cultivars from Jilin harbored the highest genetic diversity among the three geographic regions. An evaluation of grain quality indicated that cultivars from Liaoning showed superior milling quality, whereas cultivars from Heilongjiang tended to exhibit superior appearance quality. Single- and multi-locus genome-wide association studies (GWAS) were conducted to identify loci associated with milling and appearance quality-related traits. Ninety-nine significant single-nucleotide polymorphisms (SNPs) were detected. Three common SNPs were detected using the mixed linear model (MLM), mrMLM, and FASTmrMLM methods. Linkage disequilibrium decay was estimated and indicated three candidate regions (qBRR-1, qBRR-9 and qDEC-3) for further candidate gene analysis. More than 300 genes were located in these candidate regions. Gene Ontology (GO) analysis was performed to discover the potential candidate genes. Genetic diversity analysis of the candidate regions revealed that qBRR-9 may have been subject to strong selection during breeding. These results provide information that will be valuable for the improvement of grain quality in rice breeding.     

458份小麦品种(系)抗病性状功能基因的KASP标记检测

[目的]研究不同小麦品种(系)抗病性状功能基因的分布状态,分析小麦品种(系)的抗病功能基因,为小麦抗病育种提供理论依据.[方法]利用KASP技术通过1个抗白粉病分子标记(Pm21)、1个抗条锈病分子标记(Yr15)和2个抗叶锈病分子标记(Lr14、Lr68),检测458份小麦品种(系).[结果]筛选出携带Pm21标记材...     

21个小麦品种(系)抗叶锈性基因推导

选用１７个小麦叶锈菌菌系对１９９９扑河北省使用的２１个小麦品种（系）进行了抗叶锈性基因的推导。通过与２１个抗叶锈单基因系的反应型比较,鉴定出Ｌｒ１、Ｌｒ１４ａ、Ｌｒ２６和Ｌｒ３７等４个抗叶锈基因。８９０４含有Ｌｒ１;５１０８和４１８５可能含有Ｌｒ１或含与Ｌｒ１不同的抗性基因;中麦９号含有Ｌｒ１４ａ及其它抗性基因;８４２５１、邯郸４５６４、７１－３、梁麦２、７１１８－８、８５９－３４、８５９－３９和矮三共８个品种（系）含有Ｌｒ２６抗性基因;２６３１、北农８、鲁麦２３、高优５０３、９７－１１、益麦１含有与供试的已知基因不同的抗性基因;冀麦３８、京３８和３１８１没有鉴定出抗叶锈基因。     

Population genetic structure of Sitobion miscanthi in China

The wheat aphid, Sitobion miscanthi, is one of the most destructive pests of wheat plants in the temperate regions of China. Little is known about the genetic structure evolution of the different geographic populations of S. miscanthi with its migration. In this study, we investigated the population genetic structure and demographic history of S. miscanthi by analysing 18 geographical populations across China using one mitochondrial gene, COI; one nuclear gene, EF-1α; and two endosymbiont Buchne...     

山东省小麦叶锈菌群体毒性研究

[目的]为小麦抗病品种的培育和合理利用提供依据。[方法]以小麦抗叶锈近等（单）基因系及已知基因的品系作为鉴别寄主,对2008年采集自山东省的62株叶锈菌菌株标样进行测定,计算其毒性频率。[结果]62株菌株共划分为35个致病类型,其中THSS、PHSS、THQS、THTS、FHSS、PHQT和THTT为优势致病类型,其出现频率分别为9.7%、6.5%、6.5%、6.5%、6.5%、4.8%、4.8%;根据小麦叶锈菌群体毒性基因频率,可确定抗叶锈基因Lr9、Lr19、Lr24、Lr30、Lr36、Lr39、Lr42、Lr21＋39、Lr45和Lr47为目前山东省有效抗病基因（组合）。[结论]该研究为山东省小麦叶锈病的有效控制提供了参考。     

Postulation of seedling leaf rust resistance genes in 84 Chinese winter wheat cultivars

Wheat leaf rust(caused by Puccinia triticina) is one of the most important fungal diseases in China. There are tens of winter wheat cultivars which are approved to be released by the government at a national level and more than 100 wheat cultivars at the provincial level. But there is no information about leaf rust(Lr) genes in these cultivars, which makes it difficult for farmers and breeders to select which cultivars they should plant in their fields and use in their breeding programs. The objective of this paper was to identify the leaf rust resistant genes at seedling stage present in the 84 commercial wheat cultivars from China that have been released in the past few years. A set of 20 near isogenic lines with Thatcher background and 6 lines with known Lr genes were used to test the virulence of 12 races of P. triticina(Pt). By comparing the infection types(ITs) produced on the 84 cultivars by the 12 Pt races with the ITs on the differential sets, the Lr genes were postulated. In addition, 8 molecular markers of Lr genes such as Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr26 and Lr29, which are closely linked to or co-segregated with the Lr gene, were used for further validation of the genes in the 84 Chinese winter wheat cultivars. Twelve Lr genes, including Lr1, Lr3,(Lr3bg),(Lr3ka), Lr11, Lr13, Lr14 a, Lr16, Lr26, Lr27, Lr30 and Lr31 were postulated to be present either singly or in combinations in these Chinese wheat cultivars. Lr3 and Lr26 were detected most often in the tested cultivars, with frequencies of 51.2 and 38.1%, respectively. No wheat Lr genes were detected in 16 cultivars, and 4 cultivars may carry unknown Lr genes other than those used in this study. Lr9, Lr20, Lr21, Lr24, Lr25 and Lr29 were not present in any of the 84 tested accessions.     

河北省21个小麦品种抗叶锈基因的推导

选用了18个小麦叶锈菌菌系对河北省的21个小麦品种(系)进行了抗性基因推导。通过与31个抗叶锈的单基因系的反应作比较,在河北省的品种中鉴定出Lr1,Lr3,Lr3Bg,Lr18,Lr26和Lr30共6个抗性基因。冀麦15有Lr3,冀麦3号有Lr3Bg;有8个品种有3个基因,其中7个品种例如冀麦23等,有Lr3,Lr3Bg 和Lr26,另一品种冀麦20有Lr18,Lr26和Lr30。有两个品系88-5424和84—5103有4个基因;前者有Lr1,Lr18,Lr26和Lr30,后者有Lr3,Lr3Bg,Lr18和Lr26。冀麦26和冬协4号有与供试的已知基因不同的基因;在丰抗8号等3个品种中没有鉴定出抗性基因。Lr26最为普遍,在13个品种中存在。     

已知Lr基因小麦在叶锈菌侵染过程中PO活性及其同工酶的变化

利用２个近等基因系ＴｃＬｒ３和ＴｃＬｒ２６及３个小麦品种洛夫林１０＜Ｌｔ２６＞、阿芙乐尔＜Ｌｒ３＋Ｌｒ２６＞、和洛夫林１３＜Ｌｒ３＋Ｌｒ２６＞分别与２个毒力不同的叶锈菌（Ｐｕｃｃｉｎｉａｒｅｃｏｎｄｉｔａｆ．ｓｐ．ｔｒｉｔｉｃｉ）小种１０—２和冀７７—１，组合成亲和程度不同的品种—小种组合。对侵柒过程中过氧化物酶（ＰＯ）活性及其同工酶谱的变化进行了研究。结果表明，ＴｃＬｒ３与小种互作过程中ＰＯ活性变化是单峰曲线特征，峰值出现在接种后３６ｈ，同时在ＰＯ同工酶谱的变化中表现出ｐ１６．３，６．８处的酶带活性增强，而ＴｃＬｒ２６和其他含Ｌｒ２６的各品种与小种互作过程中ＰＯ活性变化均呈双峰曲线特征，峰Ⅰ，Ⅱ分别出现在接种后３６ｈ和８４ｈ，同时在ｐｏ同工酶谱变化中也有特征性表现。     

小麦品种‘武农148’和‘西农928’的抗叶锈病基因分析

本研究选用9个小麦叶锈菌菌系接种36个已知基因载体品种(系)、‘武农148’和‘西农928’进行抗叶锈基因苗期推导分析,在2014—2015和2015—2016连续两年两点对其进行成株抗叶锈性鉴定并结合苗期抗叶锈基因推导与系谱分析;利用9个与已知抗病基因紧密连锁的特异性标记进行标记检测,从而得出供试材料的抗性和携带的抗病基因。结果表明,‘西农928’中可能携带抗病基因Lr30、Lr42和携带有未知微效抗病基因,所检测的2个品种均不含抗病基因Lr1、Lr9、Lr10、Lr19、Lr20、Lr24、Lr26、Lr34和Lr46。针对西农928中含有的抗叶锈病基因,可作为小麦抗锈病育种中的抗源材料。     

30个重要小麦生产品种抗叶锈性基因分析

【目的】小麦叶锈病是影响中国小麦产量的重要病害之一,培育持久抗病品种可以经济、有效地控制该病害。论文通过基因推导结合系谱分析、分子标记及成株抗病鉴定对小麦生产品种中抗病基因进行鉴定,从而确定小麦品种中所携带的抗病基因。【方法】选用18个小麦叶锈菌菌系(PHGQ、THJT、PHJT、KHJS、PHJS、THTT?、KHHT、FHRT、FHJQ、PHTT、THTT?、PHTT、FHTR、FHHT?、FHHT?、TGGT、FHTT、FGMT)接种36个已知抗叶锈病基因载体品种和中国的30个小麦生产品种进行苗期抗叶锈病基因推导,进一步利用9个与已知抗病基因紧密连锁的特异性标记进行标记检测,同时系谱分析法确定供试小麦品种中所携带的已知抗叶锈病基因。为了鉴定小麦品种的成株抗性基因,在2014—2015和2015—2016年度将30个小麦品种、慢锈对照品种SAAR和感病对照品种郑州5389种植于河北农业大学小麦试验田和河南周口黄泛区农场试验田,田间用混合生理小种(FHRT、THTT、THJT)接种进行成株抗叶锈性鉴定,进一步运用软件IBM SPSS Statistics 19.0进行方差分析(ANOVA),根据苗期与成株期的侵染型排除具有主效抗性基因的品种,将田间最终严重度(当达到发病高峰时调查的严重度为最终严重度,final disease severity,FDS)明显小于或与慢锈对照SAAR无显著差异的作为慢锈品种,从而筛选出表现慢锈的小麦品种。【结果】基因推导、系谱分析结合标记检测结果表明,30个小麦生产品种中有4个品种(鄂恩5号、鄂麦14、陕229和西农979)含有抗病基因Lr1,10个品种(鄂恩1号、鄂恩5号、鄂恩6号、贵农16、陕225、陕354、陕715、陕合6号、陕麦509和陕农7859)携带有抗病基因Lr26,2个品种(陕225和小偃81)经分子标记检测含有慢锈抗病基因Lr46,另外还有3个品种(西农979、陕229和贵农16)可能含有基因Lr13,所有供试品种均不含Lr9、Lr10、Lr19、Lr20、Lr24和Lr34抗病基因。根据2年2点的田间抗叶锈病鉴定筛选出18个表现慢锈的品种,且方差分析结果表明各品种间和地点间差异均极显著,年份间差异显著,品种与地点间、品种与年份间差异均极显著,而品种与重复间和重复间均不显著,这表明小麦叶锈病抗性的表达受基因型和环境互作共同影响。【结论】30个小麦品种中共检测到Lr1、Lr26、Lr13和Lr46等4个抗叶锈病基因,其中Lr46为成株抗病基因,通过田间抗性鉴定共检测出18个品种可能携带成株慢锈基因,所有慢锈材料中可能含有未知成株抗叶锈病基因,需要进一步进行遗传鉴定。     

Socio-Economic and Scientific Impact Created by Whitefly-Transmitted,Plant-Virus Disease Resistant Tomato Varieties in Southern India

Research carried out to assess the impact of open-pollinated Tomato leaf curl virus (ToLCV)-resistant tomatoes and hybrids on the livelihoods of resource-poor farmers in Southern India is described and discussed. Three high-yielding ToLCV-resistant tomato varieties were developed initially using conventional breeding and screening techniques involving inoculation by ToLCV-viruliferous whitefly, Bemisia tabaci. In 2003 and 2004, respectively, these varieties were released officially by the Karnataka State Seed Committee and the Indian Ministry of Agriculture through notification in the Gazette of India. From 2003 to 2005, eleven seed companies bought breeder seed of the ToLCV-resistant varieties and used them to begin breeding F₁ hybrids from them. Socio-economic studies carried out to assess the benefits obtained from growing the ToLCV-resistant varieties found that farmers could gain up to 10 times the profit by growing the ToLCV-resistant varieties compared to the pre-existing ToLCV-susceptible varieties. Adoption of ToLCV-resistant tomatoes was also associated with reduced pesticide use. Extra income from tomato sales was prioritised by farmers to pay for children's education, better nutrition and medicines. In a joint effort with the commercial seed sector in India, a promotional field day was organised in 2007. As well as the three ToLCV-resistant varieties, 62 ToLCV-resistant hybrid tomatoes were exhibited during a farmer-field day by 17 commercial seed companies and several public institutes. Tomatoes with ToLCV-resistance are now grown widely in South India and seeds of the three open-pollinated varieties have been distributed to more than 12 countries. In 2007, a conservative estimate of the financial-benefit to cost of the research ratio was already more than 837:1.     

Genetic Structure and Eco-Geographical Differentiation of Cultivated Keng Rice (Oryza sativa L. subsp. japonica) in China Revealed by Microsatellites

China is one of the largest centers of genetic diversity of Oryza sativa L. and is the original centers of Oryza sativa L. subspecies japonica. Using a genetically representative core collection of 1 442 rice landraces of japonica in China, the genetic structure, differentiation, and geographic diversity were analyzed. The model-based structure analysis on varieties within three ecotypes revealed 16 eco-geographical types, which are partially accorded with some of the ecological zones in China. The differentiation of eco-geographical types contributed to the local ecological adaption and physical isolation, and maybe could be used to develop the heterotic groups of japonica. To facilitate the identification of different ecotypes and eco-geographical types, we provided the SSR character alleles of each ecotype or geographical eco-group and a rapid discriminated method based on these character alleles. Lastly, investigation on genetic diversity, genetic differentiation indicated that southwest region of China, including south of Yunnan Province, northwest of Guangxi Zhuang Autonomous Region, and southwest of Guizhou Province, possessed the highest genetic diversity and all the necessary conditions as a center of genetic diversity and should be the center of genetic diversity of rice landraces of japonica in China.     

23份中国小麦微核心种质抗叶锈性评价

【目的】探测23份微核心种质材料的抗叶锈性和可能携带的抗叶锈基因。【方法】选取12个具有鉴别能力的小麦叶锈菌生理小种对23份微核心种质进行了苗期和成株期的抗性鉴定以及基因推导,同时结合使用已经报道的能够用于抗病基因分子鉴定的分子标记对其进行进一步抗叶锈基因的分子检测。【结果】这些品种中除中国春表现感病外,其余22份种质均表现出较强的抗性。火球、老齐麦、凤麦11、山红麦、红和尚头、府麦、尕老汉和郑引4号含Lr34和未知抗性基因,中国春含Lr34,碱麦和小佛手含Lr1和Lr34,同家坝小麦和红花麦含Lr34和Lr32,克丰3号含有Lr10、Lr34、Lr16和Lr32,Atlas66含有Lr1、Lr2c和Lr32,烟农15含Lr1,可能含有Lr17,白条鱼含Lr26、Lr16、Lr42和LrZH84,木宗卓嘎含Lr26,可能含Lr14a,金黄麦含Lr1、Lr34和Lr32,云麦34含Lr26、Lr37和LrZH84,可能含有Lr15,百农3217含Lr1和Lr16,白朗灰麦和山麦可能含有未知抗叶锈基因。【结论】这些小麦微核心种质中含有比较丰富的抗叶锈基因,具有较好的抗叶锈性,是抗叶锈育种的重要资源。