小麦品系19HRWSN-76的抗叶锈性研究

小麦叶锈病是影响小麦产量的最主要病害之一,CIMMYT品系19HRWSN-76高抗小麦叶锈病,以该品系与感病品系郑州5389杂交得到F2群体,利用叶锈菌生理小种FHJP对F2群体接菌鉴定,结果显示群体的抗感比例符合3∶1的理论比值,推测19HR WSN-76的抗叶锈性由一对显型基因控制,暂命名为Lr HR76。利用分子标记技术和分离群体分组分析法对F2群体进行分子标记检测,位于3DL的SSR标记barc71与该抗病基因连锁,遗传距离为3.0 c M。     

小麦Hussar衍生品系抗叶锈病基因分析

以抗叶锈病小麦品系Hussar的衍生品系H103P为抗病亲本,郑州5389为感病亲本杂交得到的234个F4家系群体为材料,进行抗叶锈病基因定位分析。利用带有不同毒力的16个叶锈菌生理小种进行苗期抗叶锈性鉴定,结果表明周麦22及携带Lr13、Lr23和Lr16单基因的载体品种对16个叶锈菌生理小种均表现感病,H103P对除PHKT外的所有小种表现抗病,表明H103P抗叶锈性与携带Lr13、Lr23和Lr16单基因的载体品种不同。利用5种强毒力混合菌种(THTT、PHTT~((2))、FHJS~((2))、PHKS、PHTT~((1)))进行田间抗叶锈性鉴定,结果表明H103P、SAAR、周麦22以及Lr13载体品种田间表现均为高抗,234个F4家系群体抗性呈连续性分布,在田间表现出良好的成株期抗性。抗叶锈病基因定位分析结果表明,在小麦品系H103P中定位到1个位于小麦2BS染色体上的抗叶锈病基因,暂命名为LrHu。利用含有Lr13的特异性引物对H103P和郑州5389的扩增产物进行特异性酶切,结果发现小麦品系H103P含有抗叶锈病基因Lr13。小麦抗叶锈病基因LrHu与Lr13的关系还需...     

8个小麦育种亲本抗叶锈基因分析

选取19个小麦叶锈菌生理小种对8个小麦育种亲本进行成株期和苗期抗叶锈病鉴定及基因推导,同时利用与24个抗叶锈基因紧密连锁或共分离的31个分子标记进行分子检测。推测出L83#-5与L83#-6含有Lr1,可能含有Lr2c和Lr42;L/PL2003-1含有Lr1,可能含有Lr2c、Lr28和Lr42;贵农13号可能含有Lr28;92R137可能含有Lr2c和Lr28;L201含有Lr1,可能含有Lr2c、Lr16和Lr28;TM可能含有Lr41和其他抗叶锈基因。研究结果表明,测试的8个小麦育种亲本中TM的抗叶锈性最好,具有很好的抗叶锈病应用潜力,可作为小麦抗叶锈病育种的重要抗源。     

山东省12个主栽小麦品种(系)抗叶锈性分析

本研究旨在明确山东省12个小麦主栽品种(系)抗叶锈性及抗叶锈基因,为小麦品种推广与合理布局、叶锈病防治及抗病育种提供依据。利用2015年采自山东省的5个小麦叶锈菌流行小种的混合小种对这些材料进行苗期抗性鉴定,然后选用15个小麦叶锈菌生理小种对这些品种(系)进行苗期基因推导,并利用与24个小麦抗叶锈基因紧密连锁(或共分离)的30个分子标记对其进行抗叶锈基因分子检测。结果显示,山东省12个主栽小麦品种(系)苗期对该省2015年的5个小麦叶锈菌混合流行小种均表现高度感病。通过基因推导与分子检测发现,济南17含有Lr16,矮抗58和山农20含有Lr26,其余济麦系列、烟农系列、良星系列等9个品种(系)均未检测到所供试标记片段。此外,本研究还对山东省3个非主栽品种进行了检测,结果发现,中麦175含有抗叶锈基因Lr1和Lr37,含有成株抗性基因;皖麦38只检测到Lr26,济麦20未检测到所供试标记片段。综合以上结果,山东省主栽小麦品种(系)所含抗叶锈基因丰富度较低,尤其不含有对我国小麦叶锈菌流行小种有效的抗锈基因,应该引起高度重视,今后育种工作应注重引入其他抗叶锈基因,提高抗叶锈性。     

河南省16个主栽小麦品种抗叶锈基因分析

为了明确河南省小麦品种的抗叶锈性及抗叶锈基因的分布,为小麦品种推广与合理布局、叶锈病防治及抗病育种提供依据,本研究利用2015年采自河南省的5个小麦叶锈菌流行小种混合菌株,对近几年河南省16个主栽小麦品种进行了苗期抗性鉴定,然后选用12个小麦叶锈菌生理小种对这些品种进行苗期基因推导,同时利用与24个小麦抗叶锈基因紧密连锁(或共分离)的30个分子标记对该16个品种进行了抗叶锈基因分子检测。结果显示,供试品种苗期对小麦叶锈菌混合流行小种均表现高度感病;基因推导与分子检测结果表明,供试品种可能含有Lr1、Lr16、Lr26和Lr30这4个抗叶锈基因,其中先麦8号含有Lr1和Lr26;郑麦366和郑麦9023含有Lr1;西农979和怀川916含有Lr16;中麦895、偃展4110、郑麦7698、平安8号、众麦1号、周麦16、衡观35和矮抗58含有Lr26;周麦22中含有Lr26,还可能含有Lr1和Lr30;豫麦49-198和洛麦23可能含有本研究中检测以外的其他抗叶锈基因。因此,河南省主栽小麦品种的抗叶锈基因丰富度较低,今后育种工作应注重引入其他抗叶锈性基因,提高抗叶锈性,有效控制小麦叶锈病。     

新疆的小麦品种（系）苗期和成株期抗叶锈性鉴定

对来自新疆的104个小麦品种、高代品系及35个含有已知抗叶锈基因载体品种,在苗期接种12个中国小麦叶锈菌生理小种进行抗叶锈基因推导分析和分子检测;2007-2008年和2008-2009年连续2年度对这些材料进行成株抗叶锈性鉴定并筛选慢叶锈性品种。研究结果显示,在41个品种中共鉴定出6个已知抗叶锈基因Lr26、Lr34、Lr50、Lr3ka、Lr1和Lr14a,其中Lr26存在于21个品种中,Lr34在17个品种被发现,Lr1和Lr14a分别存在于3个品种中,还有2个品种携带Lr3ka以及1个品种携带Lr50。2年田间抗叶锈性鉴定筛选出7个慢叶锈性品种,可用于小麦抗病育种。     

182份黄淮海麦区小麦品种（系）苗期抗叶锈病基因分析

利用KHST、FHKT和FHJT②3个小麦叶锈菌混合菌株对182份小麦品种(系)进行苗期抗叶锈鉴定,对筛选出的抗性品种利用15个小麦叶锈菌生理小种进行基因推导,结合与20个抗叶锈基因连锁的25个分子标记进行抗叶锈基因分析。182份小麦品种(系)中,14个品种(泰科麦5303、驻麦305、豫圣麦118、存麦18号、轩麦6号、农丰川、丹麦118、郑麦103、郑麦119、赛德麦5号、郑麦369、许科918、豫麦668和AF116-120)表现抗性,其余品种(系)均表现高感;基因推导结果显示,驻麦305、存麦18号、农丰川、郑麦119、赛德麦5号、郑麦369、许科918含有抗叶锈基因Lr33+34;郑麦103含有抗叶锈基因Lr10和Lr33+34;AF116-120含有抗叶锈基因Lr10、Lr16、Lr20和Lr33+34;泰科麦5303、豫圣麦118、丹麦118和豫麦668可能含有其他抗叶锈基因;分子检测结果显示,农川丰、轩麦6号、郑麦103和许科918含有抗叶锈基因Lr1和Lr26;泰科麦5303、豫圣麦118、郑麦119和郑麦369含有抗叶锈基因Lr1;驻麦305、存麦18号和豫麦668含有抗叶锈基因Lr26;AF116-120含有抗叶锈基因Lr1和Lr2c;丹麦118含有抗叶锈基因Lr26和Lr37。所检测小麦品种含抗叶锈基因丰富度低,缺乏有效抗叶锈基因。182份黄淮海麦区小麦品种对小麦叶锈菌的抗病性及抗性品种中抗性基因组成的分析,可以为该地区小麦品种推广、合理布局及叶锈病防治与抗病育种提供科学依据。     

小麦品种莱州137抗叶锈性鉴定及基因检测

摘要：小麦叶锈病是小麦生产中的重要病害,培育持久抗叶锈性品种可以有效、经济地控制该病害。本文通过基因推导、分子检测结合系谱分析成株抗性鉴定对小麦重要生产品种中抗病基因进行分析,从而确定小麦品种中所携带的抗病基因。本试验用20个不同毒力的叶锈菌菌系、36个已知抗叶锈基因载体品种以及感病对照品种郑州5389对供试品种莱州137进行苗期抗叶锈病基因推导分析,并分别用12个与抗叶锈病基因连锁的分子标记进行目的基因的分子检测,同时利用系谱分析法来验证莱州137所携带的已知抗叶锈病基因;在2014-2015年度和2015-2016年度将莱州137、慢锈性对照品种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,用田间混合生理小种（FHRT、THTT、THJT）接种进行成株期抗病性鉴定。结果表明,通过苗期基因推导分析,莱州137对小种FGBQ、PGJQ、TGTT、THSM、PHGM、PHST、FHJS、FHGQ、FNTQ、PRSQ和KHGQ表现抗病,而Lr26对FGBQ、PGJQ和TGTT高抗,Lr10和Lr14b分别对小种THSM、PHGM和PHST、PHGM、THTT表现高抗,同时系谱分析和分子检测也验证已知抗叶锈基因Lr26和Lr10,因此在供试品种莱州137中鉴定出Lr26、Lr10、Lr14b以及未知的抗叶锈病基因;根据2年2点的田间抗叶锈病鉴定,莱州137表现出成株抗性特点,且经分子标记检测该品种中未含有Lr34和Lr46,故小麦品种莱州137中含有未知的成株抗叶锈性基因,可作为新的小麦叶锈病抗源加以利用。     

两系杂交小麦恢复系MR168抗条锈病基因遗传分析及分子标记定位

小麦条锈病是影响杂交小麦普及推广的重要因素。文章利用基因推导法和SSR分子标记技术,研究了温光型两系杂交小麦恢复系MR168的抗条锈性遗传规律及其控制基因染色体位置。结果表明,MR168对CY29、CY31、CY32、CY33等条锈菌生理小种表现高抗至免疫;对SY95-71/MR168杂交组合的正反交F1、BC1、F2和F3群体分单株接种鉴定显示,MR168对CY32号小种的抗性受1对显性核基因控制,该抗病基因来源于春小麦品种辽春10号。利用集群分离分析法(Bulked segregant analysis,BSA)和简单重复序列(Simple sequence repeat,SSR)分子标记分析抗病亲本MR168、感病亲本SY95-71及183个F2代单株,发现了与MR168抗条锈病基因连锁的5个微卫星标记Xgwm273、Xgwm18、Xbarc187、Xwmc269、Xwmc406,并将该基因初步定位在1BS着丝粒附近,暂命名为YrMR168;构建了包含YrMR168的SSR标记遗传图谱,距离YrMR168最近的两个微卫星位点是Xgwm18和Xbarc187,遗传距离分别为1.9 cM和2.4 cM,这两个微卫星标记可用于杂交小麦抗条锈病分子标记辅助育种。     

普通小麦品种农大399抗白粉病基因SSR和AFLP-SCAR分子标记

小麦白粉病是由布氏禾白粉菌(Blumeria graminis f.sp.tritici)引起,在小麦生产上发生最广泛的世界性病害之一。普通小麦品种农大399(系谱为Torino/2*2552//9516/3/5*石4185)是利用"滚动式加代回交转育"育成的高产、抗白粉病新品种。利用农大399和高感白粉病小麦品种石4185进行杂交,获得农大399/石4185的F1、F2分离群体和F2:3家系。对F1、F2分离群体和F2:3家系进行了苗期抗白粉病鉴定和遗传分析,结果表明:农大399对白粉菌生理小种E09的抗性受l对显性基因控制,暂命名为MlND399。通过BSA和分子标记分析,获得了与MlND399连锁的1个SSR标记Xcfd81和2个AFLP-SCAR标记SCAR203和SCAR112。其中MlND399与Xcfd81的遗传距离为0.2 cM,与SCAR203的遗传距离为1.0 cM,与SCAR112的遗传距离为1.2 cM。根据SSR标记在中国春缺体-四体、双端体和缺失系中的定位结果,将MlND399定位在小麦染色体臂5DSBin 0.67～0.78区间上。根据对抗白粉病基因的染色体定位结果,推测MlND399是Pm2基因。这些与MlND399连锁分子标记为利用农大399的抗白粉病基因进行抗病基因聚合和分子标记辅助选择育种奠定了基础。     

Identification of microsatellite markers linked to leaf rust resistance gene <Emphasis Type="Italic">Lr25</Emphasis> in wheat

The leaf rust resistance gene Lr25, transferred from Secale cereale L. into wheat and located on chromosome 4B, imparts resistance to all pathotypes of leaf rust in South-East Asia. In an F₂-derived F₃ population, created by crossing TcLr25 that carries the gene Lr25 for leaf rust resistance with leaf rust-susceptible parent Agra Local, three microsatellite markers located on the long arm of chromosome 4B were found to be linked to the Lr25 locus. The donor parent TcLr25 is a near-isogenic line derived from the variety Thatcher. The most virulent pathotype of leaf rust in the South-East Asian region, designated 77–5 (121R63-1), was used for challenging the population under artificially controlled conditions. The marker Xgwm251 behaved as a co-dominant marker placed 3.8 cM away from the Lr25 locus on 4BL. Two null allele markers, Xgwm538 and Xgwm6, in the same linkage group were located at a distance of 3.8 cM and 16.2 cM from the Lr25 locus, respectively. The genetic sequence of Xgwm251, Lr25, Xgwm538, and Xgwm6 covered a total length of 20 cM on 4BL. The markers were validated for their specificity to Lr25 resistance in a set of 43 wheat genetic stocks representing 43 other Lr genes.     

Marker-assisted selection for leaf rust resistance genes Lr19 and Lr24 in wheat (Triticum aestivum L.)

Leaf rust caused by Puccinia recondita f.sp. tritici is a wheat disease of worldwide importance. Wheat genotypes known to carry specific rust resistance genes and segregating lines that originated from various cross combinations and derived from distinct F2 lineage, so as to represent a diverse genetic background, were included in the present study for validation of molecular markers for Lr19 and Lr24. STS markers detected the presence of the leaf rust resistance gene Lr19 in a Thatcher NIL (Tc*Lrl9) and Inia66//CMH81A575 and of the gene Lr24 in the genotypes Arkan, Blue Boy II, Agent and CI 17907. Validation of molecular markers for Lr19 and Lr24 in parental lines, followed by successful detection of these genes in F3 lines from various cross combinations, was carried out. The molecular test corresponded well with the host-pathogen interaction test response of these lines.     

Genetics of durable resistance to leaf rust and stripe rust of an Indian wheat cultivar HD2009

The Indian bread wheat cultivar HD2009 has maintained its partial resistance to leaf rust and stripe rust in India since its release in 1976. To examine the nature, number and mode of inheritance of its genes for partial leaf rust and stripe rust resistance, this cultivar was crossed with cultivar WL711, which is susceptible to leaf rust and stripe rust. The F1, F2, F3 and F5 generations from this cross were assessed separately for adult plant disease severity under artificial epidemic of race 77-5 of leaf rust and race 46S119 of stripe rust. Segregation for rust reaction in the F2, F3 and F5 generations indicated that resistance to each of these rust diseases is based on 2 genes, each with additive effects. Although the leaf rust resistance of HD2009 is similar in expression to that conferred by the gene Lr34, but unlike the wheats carrying this gene, cultivar HD2009 did not show leaf tip necrosis, a morphological marker believed to be tightly linked to the leaf rust resistance gene Lr34. Thus, the non-hypersensitive resistance of HD2009 was ascribed to genes other than Lr34.     

Microsatellite mapping of adult-plant leaf rust resistance gene <Emphasis Type="Italic">Lr22a</Emphasis> in wheat

This study was conducted to identify microsatellite markers (SSR) linked to the adult-plant leaf rust resistance gene Lr22a and examine their cross-applicability for marker-assisted selection in different genetic backgrounds. Lr22a was previously introgressed from Aegilops tauschii Coss. to wheat (Triticum aestivum L.) and located to chromosome 2DS. Comparing SSR alleles from the donor of Lr22a to two backcross lines and their recurrent parents showed that between two and five SSR markers were co-introgressed with Lr22a and the size range of the Ae. tauschii introgression was 9-20 cM. An F(2) population from the cross of 98B34-T4B x 98B26-N1C01 confirmed linkage between the introgressed markers and Lr22a on chromosome 2DS. The closest marker, GWM296, was 2.9 cM from Lr22a. One hundred and eighteen cultivars and breeding lines of different geographical origins were tested with GWM296. In total 14 alleles were amplified, however, only those lines predicted or known to carry Lr22a had the unique Ae. tauschii allele at GWM296 with fragments of 121 and 131 bp. Thus, GWM296 is useful for selecting Lr22a in diverse genetic backgrounds. Genotypes carrying Lr22a showed strong resistance to leaf rust in the field from 2002 to 2006. Lr22a is an ideal candidate to be included in a stack of leaf rust resistance genes because of its strong adult-plant resistance, low frequency of commercial deployment, and the availability of a unique marker.     

Identification of molecular markers for the detection of the yellow rust resistance gene Yr17 in wheat

The Yr17 gene, which is present in many European wheat cultivars, displays yellow rust resistance at the seedling stage. The gene introduced into chromosome 2A from Aegilops ventricosa was previously found to be closely linked (0.5 cM) to leaf and stem rust resistance genes Lr37 and Sr38, respectively. The objective of this study was to identify molecular markers linked to the Yr17 gene. We screened with RAPD primers, for polymorphism, the DNAs of cv. Thatcher and the leaf rust-resistant near-isogenic line (NIL) RL 6081 of cv. Thatcher carrying the Lr37 gene. Using a F2 progeny of the cross between VPM1 (resistant) and Thésée (susceptible), the RAPD marker OP-Y15580 was found to be closely linked to the Yr17 gene. We converted the OP- Y15580 RAPD marker into a sequence characterized amplified region (SCAR). This SCAR marker (SC-Y15) was linked at 0.8 ± 0.7 cM to the Yr17 resistance gene. We tested the SC-Y15 marker over a survey of 37 wheat cultivars in order to verify its consistency in different genetic backgrounds and to explain the resistance of some cultivars against yellow rust. Moreover, we showed that the Xpsr150-2Mv locus marker of Lr gene described by Bonhomme et al. [6] which possesses A. ventricosa introgression on the 2A chromosome was also closely linked to the Yr17 gene. Both the SCAR SC-Y15 and Xpsr150-2Mv markers should be used in breeding programmes in order to detect the cluster of the three genes Yr17, Lr37 and Sr38 in cross progenies. This revised version was published online in June 2006 with corrections to the Cover Date.     

Molecular markers for four leaf rust resistance genes introgressed into wheat from wild relatives.

Near-isolines carrying four different genes for resistance to leaf rust were used to find linked molecular markers for these genes. Clones used to detect polymorphism were selected on the basis of the reported chromosomal location of the resistance genes. Both Lophopyron-derived resistance genes, Lr19 and Lr24, cosegregated with eight molecular markers assigned to chromosomes 7DL and 3DL, respectively. One clone cosegregated with Lr9 and two closely linked RFLP markers were found for Lr32, mapping at 3.3 +/- 2.6 and 6.9 +/- 3.6 cM from the resistance gene. The Lophopyron-chromatin segment in isolines carrying chromosomes 7E (Lr19) and 3E (Lr24) replaced a large portion of chromosome 7D and the distal portion of chromosome 3D, respectively. Clones assigned to these chromosomes on the basis of aneuploid analysis hybridized to 7E and 3E segments, thus confirming cytological results that these introgressed segments represent homoeologous chromosomes. The linked RFLP markers could be used to identify the resistance genes and generate new combinations in breeding populations, especially in the absence of disease in the environment or when virulence is lacking.     

High-resolution mapping of the leaf rust disease resistance gene <Emphasis Type="Italic">Lr1</Emphasis> in wheat and characterization of BAC clones from the <Emphasis Type="Italic">Lr1</Emphasis> locus

Leaf rust is the most common disease in wheat production. There are more than 45 specific resistance genes described and used in wheat breeding to control epidemics of leaf rust, but none of them has been cloned. The leaf rust disease resistance gene 1 ( Lr1) is a good model gene for isolation by map-based cloning because it is a single, dominant gene which is located in the distal region of chromosome 5DL of wheat. As the first step towards the isolation of this gene we constructed a high-resolution genetic map in the region of the Lr1 locus by saturation mapping of two large segregating F(2) populations (Thatcher Lr1 x Thatcher, Thatcher Lr1 x Frisal). The resistance gene Lr1 was delimited in a 0.16-cM region between the RFLP markers ABC718 and PSR567 (0.12 cM from ABC718 and 0.04 cM from PSR567). A genomic BAC library of Aegilops tauschii (D genome) was screened using the RFLP markers ABC718 and PSR567. Five positive BAC clones were identified by ABC718 and four clones by PSR567. Two NBS-LRR type of resistance gene analogs, which encode proteins highly homologous to the bacterial blight disease resistance protein Xa1 of rice, were identified on BAC clones isolated with PSR567. Polymorphic BAC end probes were isolated from both ends of a 105-kb large BAC clone identified by ABC718. The end probes were mapped at the same locus as ABC718, and no recombination event was found within 105 kb around ABC718 in our analysis of more than 4,000 gametes.     

Identification and molecular tagging of a gene from PI 289824 conferring resistance to leaf rust (Puccinia triticina) in wheat

Host-plant resistance is the most economically viable and environmentally responsible method of control for Puccinia triticina, the causal agent of leaf rust in wheat (Triticum aestivum L.). The identification and utilization of new resistance sources is critical to the continued development of improved cultivars as shifts in pathogen races cause the effectiveness of widely deployed genes to be short lived. The objectives of this research were to identify and tag new leaf rust resistance genes. Forty landraces from Afghanistan and Iran were obtained from the National Plant Germplasm System and evaluated under field conditions at two locations in Texas. PI 289824, a landrace from Iran, was highly resistant under field infection. Further evaluation revealed that PI 289824 is highly resistant to a broad spectrum of leaf rust races, including the currently prevalent races of leaf rust in the Great Plains area of the USA. Eight F₁ plants, 176 F₂ individuals and 139 F_2:3 families of a cross between PI 289824 and T112 (susceptible) were evaluated for resistance to leaf rust at the seedling stage. Genetic analysis indicated resistance in PI 289824 is controlled by a single dominant gene. The AFLP analyses resulted in the identification of a marker (P39 M48-367) linked to resistance. The diagnostic AFLP band was sequenced and that sequence information was used to develop an STS marker (TXW₂₀₀) linked to the gene at a distance of 2.3 cM. The addition of microsatellite markers allowed the gene to be mapped to the short arm of Chromosome 5B. The only resistance gene to be assigned to Chr 5BS is Lr52. The Lr52 gene was reported to be 16.5 cM distal to Xgwm443 while the gene in PI 289824 mapped 16.7 cM proximal to Xgwm443. Allelism tests are needed to determine the relationship between the gene in PI 289824 and Lr52. If the reported map positions are correct, the gene in PI 289824 is unique.     

Molecular mapping of leaf rust resistance gene Lr15 in hexaploid wheat

Leaf rust is a widespread and commonly occurring rust disease of wheat. Genetic resistance is the most economical method of reducing losses due to leaf rust. Lr15 has been shown to be present on wheat chromosome 2D and is reported to be a seedling resistance gene. However, tightly linked markers associated with Lr15 have not been reported to date. To identify molecular markers linked to Lr15, an F₂ mapping population of Thatcher × Thatcher-Lr15 was generated. Available wheat simple sequence repeat markers were utilized in parental screening and polymorphic markers were used to analyze the entire population of 221 plants. Phenotypic evaluations of the F₂-derived F₃ progenies with Puccinia triticina Eriks. pathotype 162A (93R15) confirmed the monogenic inheritance of Lr15. The linkage group representing chromosome 2DS was constructed at LOD 4.0 which revealed the closest flanking markers Xgwm4562 and Xgwm102 at a distance of 3.1 and 9.3 cM, respectively. Furthermore, utilization of these flanking markers in combination has successfully identified wheat lines with or without Lr15. These markers could potentially be useful in gene pyramiding with other genes to enhance rust resistance in wheat.