小麦黑胚病种子带菌的光镜和扫描电镜观察

 检测表明京双16、聊89-1、聊89-2、聊91-1、聊91B18-27-1及鲁麦12 6个小麦品种(品系)的黑胚病病粒率为7.6%~45.7%,病情指数为3.2%~13.5%,以聊89-1最轻,鲁麦12最重。借助光学显微镜和扫描电子显微镜对6个品种(品系)的黑胚种子和健康胚种子进行了比较观察,证实了黑胚种子胚中链格孢菌(Alternaria)的存在,此外,亦观察到了黑胚种子寄藏有类似于长蠕孢属(Helminthosporium)、枝孢属(Cladosporium)等真菌的菌体。     

河南省小麦黑胚病菌的分离鉴定及致病性测定

 为明确我国小麦主产区河南省小麦黑胚病菌的主要类群,为该病的防治工作提供理论依据,对河南省不同地区种植的50个小麦品种(系)的黑胚籽粒进行了分离鉴定和致病型测定。鉴定结果表明：河南省小麦黑胚籽粒病原分离物包括链格孢(Alternaria alternate)、麦根腐蠕孢（Bipolaris sorokiniana）、细极链格孢(A. tenuissima)和小麦链格孢（A. triticina）,平均分离频率分别为63.0%、18.0%、12.2%和6.8%,不同品种小麦黑胚籽粒各种病原菌分离频率有一定差异。扬花后10 d利用孢子悬浮液接种进行分离物的致病性测定,结果表明链格孢(A.alternate)和麦根腐蠕孢（B. sorokiniana）致病力较强。结合分离频率和致病性测定结果,确定链格孢(A. alternate)是河南省小麦黑胚病的优势病原菌。     

小麦黑胚病与种子千粒重的关系

小麦黑胚病与种子千粒重的关系田世发朱之（河北农业大学农学院植保系保定０７１００１）小麦黑胚病在河北省北部春麦区普遍发生。几年来，作者收集张家口崇礼县不同海拔的小麦品种和张家口坝下所肥、水试验地的小麦叶枯病、黑胚病种子，于室内调查其黑胚病病粒率和黑胚...     

小麦黑胚病发生规律及防治措施初探

经过2000～2002年对小麦黑胚病发生规律的调查研究,初步了解到春性强的早熟小麦品种易感小麦黑胚病,小麦灌浆至成熟期降水多是该病发生的重要条件。防治上应以选育、选用抗病品种为前提,加强小麦健身抗病栽培,灌浆盛期施药的综合措施。     

小麦黑胚病种子菌的光镜和扫描电镜观察

检测表明京双１６、聊８９－２,聊９１－１,聊９１Ｂ１８－２７－１及鲁麦１２６个小麦品种（品系）的黑胚病病粒率为７．６％￣４５．７％,病情指数为３．２％￣１３．５％,以聊８９－１最轻,鲁麦１２最重。借助光学显微镜和扫描电子显微镜对６个品种（品纱）的黑胚种子和健康胚种子进行了比较观察,证实了黑胚种子胚中链格孢菌的存在,此外,亦观察到黑胚种子寄藏有类似于长蠕孢属,枝孢属等真菌的菌体。     

河西走廊麦类作物新发生的几种真菌病害

麦类(小麦、大麦、燕麦)是甘肃河西走廊主要的栽培作物,播种面积约占粮食作物的60％左右,1959年《甘肃省农作物病虫杂草调查汇编》曾记载麦类病害11种,1983年甘农大魏勇良报道22种,我们通过5年调查,又发现以下省内未正式报道过的真菌病害: 一、小麦假黑斑病 (一)症状:感病麦粒轻微变色,胚部呈褐色,有的种胚末端皱缩,容易与小麦黑胚病(Drechslera sorokiniana)混淆。病种子播种后一般能发芽出苗,但幼苗细弱,长势缓慢。     

15%敌力脱乳油防治小麦黑胚病效果显著

近年来 ,小麦黑胚病在我国主要麦区发生严重 ,造成小麦籽粒黑胚 ,严重影响小麦品质 ,并降低出苗率。为防治小麦黑胚病 ,我们在小麦生长中、后期 ,对当地两个主栽小麦品种 4 5 89和 5 316进行了不同药剂防治试验。供试药剂有 2 5 %敌力脱乳油 (ｐｒｏｐｉｃｏｎａｚｏｌ)33ｍｌ/667ｍ2 ,瑞士诺华公司生产 ;15 %粉锈宁可湿性粉剂 70 ｇ/667ｍ2 ,江苏桥头农药厂生产 ;70 %代森锰锌可湿性粉剂 80 0倍液 ,江苏利民化工有限公司生产 ;70 %甲基托布津可湿性粉剂 70ｇ/667ｍ2 ,日本曹达株式会社生产 ;5 0 %多菌灵可湿性粉剂10 0 ｇ/667ｍ2 ,江苏吴县…     

13种杀菌剂对小麦黑胚病的防治效果

在田间测定了13种杀菌剂对小麦黑胚病的防治效果.结果表明,13种杀菌剂对小麦黑胚病均有一定的防效,防效为34.8％～67.7％.其中7.5％氟环唑乳油50 g/hm2、50％嘧菌环胺水分散粒剂 375 g/hm2、56％嘧菌·百菌清悬浮剂330 g/hm2、25％丙环唑乳油180 g/hm24个处理对小麦黑胚病有较好的防治效果,防效均达到60％以上,可在生产中推广应用.     

小麦种子黑胚对幼苗生长的影响

小麦种子黑胚对幼苗生长的影响刘红彦，马奇祥，张忠山，何家泌（河南省农科院植保所郑州４５０００２）王胜亮，刘顺通，韩桂仲（河南省洛阳市农科所）小麦种子黑胚病（黑点病）［Ｂｉｐｏｌａｒｉｓｓｏｒｏｋｉｎｉａｎａ（Ｓａｃｃ．）〕近年河南省在一些感病小麦品种...     

新疆春小麦黑胚发生与产量及加工品质之间的关系

通过多点分析春小麦加工品质、产量表现和小麦黑胚发生的特点,发现干旱区春小麦黑胚发生率受环境的影响比较大,同一品种在不同地区表现结果不同,同时小麦的籽粒加工品质和产量也受环境条件的影响.小麦抽穗至成熟期间低温、多雨的环境条件有利于小麦黑胚病的发生,也有利于产量的提高,但这种环境条件不利于优良品质的形成.黑胚率高的小麦千粒重和容重较高,降落数值较小,发芽的可能性增大,籽粒蛋白质含量较低,面团流变学特性较差,小麦总体加工品质变差.     

Main effects, epistasis, and environmental interactions of quantitative trait Loci for fusarium head blight resistance in a recombinant inbred population

ABSTRACT Chinese Spring Sumai 3 chromosome 7A disomic substitution line (CS-SM3-7ADS) is highly resistant to Fusarium head blight (FHB), and an F(7) population of recombinant inbred lines derived from the cross CS-SM3-7ADS x Annong 8455 was evaluated for resistance to FHB to investigate main effects, epistasis, and environmental interactions of quantitative trait loci (QTLs) for FHB resistance. A molecular linkage map consists of 501 simple sequence repeat and amplified fragment length polymorphism markers. A total of 10 QTLs were identified with significant main effects on the FHB resistance using MapQTL and QTLMapper software. Among them, CS-SM3-7ADS carries FHB-resistance alleles at five QTLs on chromosomes 2D, 3B, 4D, and 6A. One QTL on 3BS had the largest effect and explained 30.2% of the phenotypic variance. Susceptible QTLs were detected on chromosomes 1A, 1D, 4A, and 4B. A QTL for enhanced FHB resistance was not detected on chromosome 7A of CS-SM3-7ADS; therefore, the increased FHB resistance in CS-SM3-7ADS was not due to any major FHB-resistance QTL on 7A of Sumai 3, but more likely was due to removal of susceptible alleles of QTLs on 7A of Chinese Spring. QTLMapper detected nine pairs of additive-additive interactions at 17 loci that explained 26% phenotypic variance. QTL-environment interactions explained 49% of phenotypic variation, indicating that the environments significantly affected the expression of the QTLs, especially these epistasis QTLs. Adding FHB-enhancing QTLs or removal of susceptible QTLs both may significantly enhance the degree of wheat resistance to FHB in a wheat cultivar.     

环介导等温扩增技术快速检测麦根腐平脐蠕孢

 为建立麦根腐平脐蠕孢简单快速的分子检测方法,基于环介导等温扩增(Loop-mediated isothermal amplification, LAMP)技术,以核糖体DNA的ITS为靶标序列,设计和筛选出一组麦根腐平脐蠕孢的特异性引物,成功开发可快速准确检测麦根腐平脐蠕孢的LAMP方法。甜菜碱作用测试显示LAMP体系中是否添加甜菜碱对扩增结果无明显影响;特异性测试显示该LAMP方法能够从14种植物病原菌中特异地检测出麦根腐平脐蠕孢;灵敏度测试显示该LAMP方法的检测极限为10^-3 ng·μL^-1,是常规PCR检测方法灵敏度的100倍;通用性测试显示该LAMP方法能够准确检测洛阳、安阳、开封和邯郸等不同地理来源的麦根腐平脐蠕孢菌株;发病组织检测显示该LAMP方法能够准确地从人工接种的小麦发病组织中检测出麦根腐平脐蠕孢,检出时间为侵染12 h及以上。这些研究结果表明所建立的麦根腐平脐蠕孢LAMP检测方法特异性好、灵敏度高、适用性强,可用于小麦根腐病的早期快速诊断。     

Identification and Mapping of Quantitative Trait Loci Conditioning Resistance to Southern Leaf Blight of Maize Caused by Cochliobolus heterostrophus Race O

ABSTRACT A random set of recombinant inbred (RI) lines (F2:7) derived from the cross of the inbred lines Mo17 (resistant) and B73 (susceptible) were evaluated for resistance to southern leaf blight (SLB) caused by Cochliobolus heterostrophus race O. The RI lines were genotyped at a total of 234 simple sequence repeat, restriction fragment length polymorphism, or isozyme loci. Field plots of the RI lines were inoculated artificially with an aggressive isolate of C. heterostrophus race O in each of two growing seasons in North Carolina. Lines were rated for percent SLB severity two (1996) or three (1995) times during the grain-filling period. Data also were converted to area under the disease progress curve (AUDPC) and analyzed using the composite interval mapping option of the PLABQTL program. When means of disease ratings over years were fitted to models, a total of 11 quantitative trait loci (QTLs) were found to condition resistance to SLB, depending upon which disease ratings were used in the analyses. When the AUDPC data were combined and analyzed over environments, seven QTLs, on chromosomes 1, 2, 3, 4, 7, and 10 were found to come from the resistant parent Mo17. An additional QTL for resistance on chromosome 1 came from the susceptible parent B73. The eight identified QTLs accounted for 46% of the phenotypic variation for resistance. QTL x environment interactions often were highly significant but, with one exception, were the result of differences in the magnitude of QTL effects between years and not due to changes in direction of effects. QTLs on the long arm of chromosome 1 and chromosomes 2 and 3 had the largest effects, were the most consistently detected, and accounted for most of the phenotypic variance. No significant additive x additive epistatic effects were detected. These data support earlier reports of the polygenic inheritance of resistance to SLB of maize.     

福建省丙环唑不同敏感性玉米小斑病菌的遗传多样性和致病性

 利用菌丝生长法、ISSR分子标记和分生孢子悬浮液喷雾接种法,探讨了福建省玉米小斑病菌对丙环唑的敏感性以及不同敏感性病菌群体的遗传多样性和致病性。敏感性测定结果表明,福建省玉米小斑病菌对丙环唑产生了抗药性,抗药性菌株的抗性倍数达到2.1~9.4倍。筛选获得的10条ISSR引物对55个菌株共检测出153个位点,其中多态性位点百分比高达93.46%。在敏感型、中间型和抗药型群体中多态性位点百分比分别为77.12%、69.93%和81.70%,在抗药型群体中,等位基因观测值、等位基因有效值、Nei’s遗传多样性指数和Shannon’s信息指数均高于敏感型群体,表明玉米小斑病菌抗药型群体的遗传多样性最丰富。聚类分析结果表明,病菌群体遗传多样性与抗药性水平和地理来源均有较高的相关性。致病性测定表明,丙环唑不同敏感性病菌群体对11个鲜食玉米品种均具有较强的致病性,但是,在9个玉米品种上,敏感型群体中强致病力菌株出现频率明显低于抗药型群体。研究结果为深入研究玉米小斑病菌群体遗传结构及其田间抗药性监测提供了理论基础。     

Quantitative trait loci for Fusarium head blight resistance in a recombinant inbred population of Wangshuibai/Wheaton

Use of diverse sources of Fusarium head blight (FHB)-resistant germplasm in breeding may significantly improve wheat resistance to FHB. Wangshuibai is an FHB-resistant Chinese landrace unrelated to cv. Sumai 3, the most commonly used FHB-resistant source. In all, 139 F(6) recombinant inbred lines were developed from a cross between Wangshuibai and an FHB-susceptible cultivar, Wheaton, to map quantitative trait loci (QTL) for wheat resistance to initial infection (type I resistance), spread of FHB symptoms within a spike (type II resistance), and deoxynivalenol (DON) accumulation (type III resistance) in infected grain. The experiments were conducted in a greenhouse at Manhattan, KS from 2003 to 2005. More than 1,300 simple-sequence repeat and amplified fragment length polymorphism markers were analyzed in this population. Five QTL for type I resistance were detected on chromosomes 3AS, 3BS, 4B, 5AS, and 5DL after spray inoculation; seven QTL for type II resistance were identified on chromosomes 1A, 3BS, 3DL, 5AS, 5DL, and 7AL after point inoculation; and seven QTL for type III resistance were detected on chromosomes 1A, 1BL, 3BS, 5AS, 5DL, and 7AL with the data from both inoculation methods. These QTL jointly explained up to 31.7, 64, and 52.8% of the phenotypic variation for the three types of FHB resistance, respectively. The narrow-sense heritabilities were low for type I resistance (0.37 to 0.41) but moderately high for type II resistance (0.45 to 0.61) and type III resistance (0.44 to 0.67). The QTL on the distal end of 3BS, 5AS, and 5DL contributed to all three types of resistance. Two QTL, on 7AL and 1A, as well as one QTL near the centromere of 3BS (3BSc), showed effects on both type II and type III resistance. Selection for type II resistance may simultaneously improve type I and type III resistance as well. The QTL for FHB resistance identified in Wangshuibai have potential to be used to pyramid FHB-resistance QTL from different sources.     

甜玉米小斑病抗性的遗传分析与主效QTL定位

为培育抗病品种,利用抗小斑病甜玉米自交系T14和感小斑病自交系T18为亲本配制杂交组合,对玉米抗小斑病性状进行遗传分析和抗病基因分子标记定位,用主基因＋多基因混合遗传模型和P₁、P₂、F₁、B₁、B₂、F₂ 6世代联合分析的方法对单位叶面积病斑数量进行遗传分析,并应用复合区间作图法检测抗小斑病QTL。结果表明,单位叶面积病斑数量受2对加性-显性-上位性主基因控制,自交系T14的抗病性在各个分离世代都以主基因遗传为主。在第4染色体上检测到4个相互连锁的小斑病抗性QTL,解释表型变异的7.7%、30.9%、14.8%和11.5%;在第6染色体上定位了1个抗病QTL,可解释表型变异的37.7%。检测到的小斑病抗性主效QTL位于第4和第6染色体的特征与2对主基因的遗传模型相吻合。     

Quantitative trait loci for adult-plant resistance to Mycosphaerella graminicola in two winter wheat populations

Septoria tritici blotch (STB) is one of the most important leaf spot diseases in wheat worldwide. The goal of this study was to detect chromosomal regions for adult-plant resistance in large winter wheat populations to STB. Inoculation by two isolates with virulence to Stb6 and Stb15, both present in the parents, was performed and STB severity was visually scored plotwise as percent coverage of flag leaves with pycnidia-bearing lesions. 'Florett'/'Biscay' and 'Tuareg'/'Biscay', each comprising a cross of a resistant and a susceptible cultivar, with population sizes of 316 and 269 F(7:8) recombinant inbred lines, respectively, were phenotyped across four and five environments and mapped with amplified fragment length polymorphism, diversity array technology, and simple sequence repeat markers covering polymorphic regions of ≈1,340 centimorgans. Phenotypic data revealed significant (P < 0.01) genotypic differentiation for STB, heading date, and plant height. Entry-mean heritabilities (h(2)) for STB were 0.73 for 'Florett'/'Biscay' and 0.38 for 'Tuareg'/'Biscay'. All correlations between STB and heading date as well as between STB and plant height were low (r = -0.13 to -0.20). In quantitative trait loci (QTL) analysis, nine and six QTL were found for STB ratings explaining, together, 55 and 51% of phenotypic variation in 'Florett'/'Biscay' and 'Tuareg'/'Biscay', respectively. Genotype-environment and QTL-environment interactions had a large impact. Two major QTL were detected consistently across environments on chromosomes 3B and 6D from 'Florett' and chromosomes 4B and 6B from 'Tuareg', each explaining 12 to 17% of normalized adjusted phenotypic variance. These results indicate that adult-plant resistance to STB in both mapping populations was of a quantitative nature.     

The effect of homoeologous group 7 chromosomes upon adult plant resistance of wheat to yellow rust (Puccinia striiformis)

Aneuploid and intervarietal chromosome substitution lines of wheat ev. Chinese Spring were used to study the effects of homoeologous chromosomes 7A, 7B and 7D upon adult plant resistance to yellow rust ( Puccinia striiformis). Chromosomes 7B and 7D carry factors upon their short arms which interact to influence resistance. The results can be explained if there is a single locus determining resistance upon the short arms of chromosomes 7B and 7D. These loci may be homoeo-allelic; however, no evidence was found for a corresponding locus upon the short arm of chromosome 7A. Three homologous variants of the factor on 7D^S were found but no variation was found for the factor on 7B^S.     

Genome-wide association study for spot blotch resistance in Afghan wheat germplasm

Spot blotch (SB), caused by Bipolaris sorokiniana, is a devastating disease of wheat globally, especially in South Asia and South America. Understanding the genetics of resistance to SB is important for developing breeding strategies to improve resistance. A panel of 301 genotypes from Afghanistan was phenotyped over two crop seasons using a mixture of virulent B. sorokiniana isolates and genotyped using DArTSeq to obtain genome-wide markers. Fifty genotypes (16.6%) showed disease scores less than the resistant control. Principal component analysis using the genotypic data clustered the genotypes into five different groups. Among models used for genome-wide association mapping, the multilocus mixed model, and fixed and random model circulating probability unification algorithms were most effective in identifying significant marker-trait associations (MTA). Twenty-five MTAs at p ≤ .001 were identified on chromosomes 1A, 1B, 1D, 2B, 2D, 3A, 3B, 4A, 5A, 5B, 6A, 7A, and 7D, indicating the quantitative nature of resistance to SB. Phenotypic variation explained by these markers ranged from 2.0% to 17.7%, and genomic regions on the chromosomes 1D, 2D, 3A, 3B, 4A, 5A, and 5B coincided with loci identified in previous studies. Three single nucleotide polymorphism (SNP) markers on chromosomes 1B (SNP 1113207) and 5A (SNPs 5411867 and 998276) were significant in both crop seasons as well as in the combined analysis across seasons. Marker 5411867 is close to Vrn-A1, shown to be associated with SB in previous studies. Furthermore, among known SB resistance genes, Sb2 on chromosome 5B was predicted to be significant in this panel.     

Association mapping of quantitative resistance to Phaeosphaeria nodorum in spring wheat landraces from the USDA National Small Grains Collection

Stagonospora nodorum blotch (SNB), caused by Phaeosphaeria nodorum, is a destructive disease of wheat (Triticum aestivum) found throughout the United States. Host resistance is the only economically feasible option for managing the disease; however, few SNB-resistant wheat cultivars are known to exist. In this study, we report findings from an association mapping (AM) of resistance to P. nodorum in 567 spring wheat landraces of diverse geographic origin. The accessions were evaluated for seedling resistance to P. nodorum in a greenhouse. Phenotypic data and 625 polymorphic diversity array technology (DArT) markers have been used for linkage disequilibrium (LD) and association analyses. The results showed that seven DArT markers on five chromosomes (2D, 3B, 5B, 6A, and 7A) were significantly associated with resistance to P. nodorum. Genetic regions on 2D, 3B, and 5B correspond to previously mapped quantitative trait loci (QTL) conferring resistance to P. nodorum whereas the remaining QTL appeared to be novel. These results demonstrate that the use of AM is an effective method for identifying new genomic regions associated with resistance to P. nodorum in spring wheat landraces. Additionally, the novel resistance found in this study could be useful in wheat breeding aimed at controlling SNB.