小麦抗赤霉病研究现状与展望

小麦是我国最重要的口粮作物之一。在小麦生产所面临的各种病害中,赤霉病的发生具有愈来愈严重的趋势,引起小麦产业界的高度关注。近几十年来,科研人员在小麦抗赤霉病遗传育种以及防控技术领域进行了持续不懈的努力,在赤霉病病原菌致病基因、小麦赤霉病抗性基因定位、克隆及功能研究以及抗赤霉病分子育种等方面取得了重大进展。本文主要从赤霉病抗性基因资源的发掘和鉴定、不同抗源遗传基础解析、小麦赤霉病抗性基因、抗赤霉病分子标记辅助选择育种与基因聚合以及小麦抗赤霉病基因的克隆和功能研究等方面进行了综述,分析了目前小麦抗赤霉病研究中存在的问题,并提出应加强基因克隆、功能分子标记开发以及应用单体型辅助选择(HAS)和标记组辅助选择(MSAS)等小麦抗赤霉病研究的相关建议。     

小麦抗条锈病基因定位及分子标记研究进展

本文综述了小麦抗条锈病基因染色体定位及抗条锈病基因分子标记的研究进展,并对几种分子标记技术的应用潜力作了比较分析,特别是对ＳＳＲ、ＩＳＳＲ、ＡＦＬＰ等新型分子标记在小麦遗传育种中的应用前景作了初步探讨。     

PCR-RAPD分子生物学技术及其在植物抗病性研究中的应用

PCR—RAPD技术是一种高效的基因组DNA多态性分析技术,能够在对生物细胞或组织中DNA遗传多样性、亲缘关系及系统进化分子标记检测的同时进行基因定位与遗传作图。本综述了PCR—RAPD技术的基本原理和应用范围,以及近年来在植物抗感病品种(品系)间亲缘远近关系分析、植物抗病性遗传基因的DNA分子标记与检测、植物抗病基因的标记和定位、植物抗病基因的分离与克隆、植物抗病育种的分子标记辅助选择与检测等植物抗病性分子机制研究方面的应用,并对该技术所存在的问题及应用前景进行了探讨。     

DNA分子标记在果树遗传育种研究中的应用

DNA分子标记是随着分子生物学技术的发展出现的一类重要的遗传标记,近年来发展非常迅速,已在果树遗传育种研究的各个方面得到广泛的应用。介绍了几种DNA分子标记技术的原理,综述了DNA分子标记在果树种质资源研究、分子遗传图谱构建、基因定位、分子辅助选择等方面的应用,并对其在果树上的应用前景和存在问题进行了评述。     

分子标记技术的发展及应用

介绍了几种应用前景较广的分子标记,如基于DNA杂交技术的分子标记:限制性片段长度多态性(RFLP)和DNA可变串联重复数标记(VNRT);基于PCR技术的分子标记:随机扩增多态性 DNA(RAPD)、酶切扩增多态性(CAPS)、扩增片段长度多态性(AFLP)、微卫星DNA(SSR)和DNA单链构象多态性(SSCP);以及新兴的第3代分子标记,即基于DNA芯片技术的分子标记:单核苷酸多态性(SNP)等。分别阐述了它们的原理、方法步骤与优缺点、应用注意事项和适用范围,同时概述了它们在生物学研究中的应用和进展。     

小麦抗白粉病基因定位与分子标记

对小麦抗白粉病基因的遗传定位与分子标记进行了综述,介绍了小麦抗白粉病的遗传,并对今后的研究方向进行了讨论。     

分子标记技术在蝇类研究中的应用

DNA分子标记作为新发展起来的一种遗传标记形式,凭借其可靠有效等优点,在动植物研究中的应用已越来越广泛。本文主要综述了DNA分子标记技术的发展及其在蝇类研究应用的进展,并对有关问题进行了初步讨论和展望。     

我国科学家发现抗小麦条锈病新基因

经过4年多的研究，巾国农业科学院作物科学研究所的一个课题组人工合成了小麦新种质CI108．发现其含有一个抗条锈病新基凼YrC108．并利州分子标记对该基因进行了染色体定位．该成果不仅为抗条锈病小麦育种提供了新抗源。而且为高效分子育种提供了选择标记。[第一段]     

小麦抗白粉病基因Pm21的分子鉴定和标记辅助选择

利用小麦抗白粉病基因Ｐｍ２１的ＲＡＰＤ标记、ＳＣＡＲ标记和荧光源位杂交技术对小麦抗病育种材料中的抗白粉病Ｐｍ２１基因进行了分子鉴定和标记辅助选择。     

小麦秆锈抗性遗传及抗性基因研究进展

目前国际上已发现近80个小麦抗秆锈基因,其中45个抗秆锈基因已被正式定名,58个抗秆锈基因已定位在小麦特定染色体上,其中12个基因被标记。本文对小麦抗秆锈病基因抗源、抗秆锈性遗传、分子标记研究现状及存在问题加以综述,并对抗秆锈分子遗传前景进行展望。     

小麦条锈菌国际鉴别寄主Vilmorin23的抗条锈病基因YrV23微卫星标记

Vilmorin23是小麦条锈菌国际鉴别寄主和国际上重要抗源材料。采用SSR技术,利用由Vilmorin23为基因供体转育而成的小麦抗条锈近等基因系Taichung29*6/YrV23,选用YrV23所在2B染色体上的55对SSR引物,对Taichung29*6/ YrV23及其轮回亲本Taichung29和抗性基因供体Vilmorin23的基因组DNA进行PCR扩增和聚丙烯酰胺凝胶电泳分析。结果显示,引物Xwmc356在近等基因系与轮回亲本间扩增出特异性DNA片段,经F₂代群体150个抗、感单株检测证实,该片段位点与抗条锈病基因YrV23有连锁关系,遗传距离为9.4 cM。Xwmc356可作为抗条锈基因YrV23的SSR标记。      

黄淮麦区小麦品种(系)中Yr26基因的SSR检测

选用与Yr26紧密连锁的SSR标记Xgwm11和Xgwm18结合田间抗性鉴定,对239份黄淮麦区小麦品种(系)进行检测,以明确Yr26基因在黄淮麦区小麦品种资源中的分布.结果表明:共有35份品种(系)含有与Yr26紧密连锁的SSR标记Xgwm18或Xgwm11的特征带,占检测样本的14.6%.在这35份材料中,31份田间抗性鉴定表现免疫至中抗,4份表现中感.分子标记检测与田间抗病性检测吻合度较好,该标记可以用于Yr26基因的分子标记辅助选择.综合分子标记和田间鉴定,31份小麦(系)含有Yr26基因,占102份抗病材料的30.39%.     

小麦条锈菌大片段基因组DNA的提取方法研究

由条锈菌Puccinia striiformis引致的小麦条锈病是小麦最重要的病害之一。由于其活体寄生的特点,对小麦条锈菌的遗传学和分子生物学研究十分有限,大片段核DNA的提取研究还未见报道。高分子量基因组DNA是开展大片段基因组文库构建、基因组分析以及基因组重建的重要基础,通过系统建立和优化小麦条锈菌大片段基因组DNA的分离方法,成功获得分子量大于1Mb高质量的病菌基因组DNA。     

Isolation of microsatellite and RAPD markers flanking the Yr15 gene of wheat using NILs and bulked segregant analysis.

Microsatellite and random amplified polymorphic DNA (RAPD) primers were used to identify molecular markers linked to the Yr15 gene which confer resistance to stripe rust (Puccina striiformis Westend) in wheat. By using near isogenic lines (NILs) for the Yr15 gene and a F2 mapping population derived from crosses of these lines and phenotyped for resistance, we identified one microsatellite marker (GWM33) and one RAPD marker (OPA19(800)) linked to Yr15. Then, bulked segregant analysis was used in addition to the NILs to identify RAPD markers linked to the target gene. Using this approach, two RAPD markers linked to Yr15 were identified, one in coupling (UBC199(700)) and one in repulsion phase (UBC212(1200)). After MAPMAKER linkage analysis on the F2 population, the two closest markers were shown to be linked to Yr15 within a distance of about 12 cM. The recombination rates were recalculated using the maximum likelihood technique to take into account putative escaped individuals from the stripe rust resistance test and obtain unbiased distance estimates. As a result of this study, the stripe rust resistance gene Yr15 is surrounded by two flanking PCR markers, UBC199(700) and GWM33, at about 5 cM from each side.     

Evaluation of Pakistan wheat germplasms for stripe rust resistance using molecular markers

Wheat production in Pakistan is seriously constrained due to rust diseases and stripe rust (yellow) caused by Puccinia striiformis f. sp. tritici, which could limit yields. Thus development and cultivation of genetically diverse and resistant varieties is the most sustainable solution to overcome these diseases. The first objective of the present study was to evaluate 100 Pakistan wheat cultivars that have been grown over the past 60 years. These cultivars were inoculated at the seedling stage with two virulent stripe rust isolates from the United States and two from Pakistan. None of the wheat cultivars were resistant to all tested stripe rust isolates, and 16% of cultivars were susceptible to the four isolates at the seedling stage. The data indicated that none of the Pakistan wheat cultivars contained either Yr5 or Yr15 genes that were considered to be effective against most P. striiformis f. sp. tritici isolates from around the world. Several Pakistan wheat cultivars may have gene Yr10, which is effective against isolate PST-127 but ineffective against PST-116. It is also possible that these cultivars may have other previously unidentified genes or gene combinations. The second objective was to evaluate the 100 Pakistan wheat cultivars for stripe rust resistance during natural epidemics in Pakistan and Washington State, USA. It was found that a higher frequency of resistance was present under field conditions compared with greenhouse conditions. Thirty genotypes (30% of germplasms) were found to have a potentially high temperature adult plant (HTAP) resistance. The third objective was to determine the genetic diversity in Pakistan wheat germplasms using molecular markers. This study was based on DNA fingerprinting using resistance gene analog polymorphism (RGAP) marker analysis. The highest polymorphism detected with RGAP primer pairs was 40%, 50% and 57% with a mean polymorphism of 36%. A total of 22 RGAP markers were obtained in this study. RGAP, simple sequence repeat (SSR) and sequence tagged site (STS) markers were used to determine the presence and absence of some important stripe rust resistance genes, such as Yr5, Yr8, Yr9, Yr15 and Yr18. Of the 60 cultivars analyzed, 17% of cultivars showed a RGAP marker band for Yr9 and 12% of cultivars exhibited the Yr18 marker band. No marker band was detected for Yr5, Yr8 and Yr15, indicating a likely absence of these genes in the tested Pakistan wheat cultivars. Cluster analysis based on molecular and stripe rust reaction data is useful in identifying considerable genetic diversity among Pakistan wheat cultivars. The resistant germplasms identified with 22 RGAP markers and from the resistance evaluations should be useful in developing new wheat cultivars with stripe rust resistance.     

小麦条锈菌分子生态学研究进展

小麦条锈病是危害最严重的小麦流行性病害之一,小麦条锈菌的生态学研究对制定合理的防治策略和抗锈育种具有重要意义.近十几年来,DNA分子标记技术被应用于小麦条锈菌的群体遗传学研究,推动了小麦条锈菌分子生态学研究的快速发展,为揭示小麦条锈菌的群体生态特性开辟了一个新的途径.本文系统介绍小麦条锈菌分子生态学研究的主要进展,并就我国当前研究的局限性和发展趋势进行了分析.     

Development of resistance gene analog polymorphism markers for the Yr9 gene resistance to wheat stripe rust.

The Yr9 gene, which confers resistance to stripe rust caused by Puccinia striiformis f.sp. tritici (P. s. tritici) and originated from rye, is present in many wheat cultivars. To develop molecular markers for Yr9, a Yr9 near-isogenic line, near-isogenic lines with nine other Yr genes, and the recurrent wheat parent 'Avocet Susceptible' were evaluated for resistance in the seedling stage to North American P s. tritici races under controlled temperature in the greenhouse. The resistance gene analog polymorphism (RGAP) technique was used to identify molecular markers for Yr9. The BC7:F, and BC7:F3 progeny, which were developed by backcrossing the Yr9 donor wheat cultivar Clement with 'Avocet Susceptible', were evaluated for resistance to stripe rust races. Genomic DNA was extracted from 203 BC7:F2 plants and used for cosegregation analysis. Of 16 RGAP markers confirmed by cosegregation analysis, 4 were coincident with Yr9 and 12 were closely linked to Yr9 with a genetic distance ranging from 1 to 18 cM. Analyses of nullitetrasomic 'Chinese Spring' lines with the codominant RGAP marker Xwgp13 confirmed that the markers and Yr9 were located on chromosome 1B. Six wheat cultivars reported to have 1B/1R wheat-rye translocations and, presumably, Yr9, and two rye cultivars were inoculated with four races of P. s. tritici and tested with 9 of the 16 RGAP markers. Results of these tests indicate that 'Clement', 'Aurora', 'Lovrin 10', 'Lovrin 13', and 'Riebesel 47/51' have Yr9 and that 'Weique' does not have Yr9. The genetic information and molecular markers obtained from this study should be useful in cloning Yr9, in identifying germplasm that may have Yr9, and in using marker-assisted selection for combining Yr9 with other stripe rust resistance genes.     

Mapping of stripe rust resistance gene in an <Emphasis Type="Italic">Aegilops caudata</Emphasis> introgression line in wheat and its genetic association with leaf rust resistance

A pair of stripe rust and leaf rust resistance genes was introgressed from Aegilops caudata, a nonprogenitor diploid species with the CC genome, to cultivated wheat. Inheritance and genetic mapping of stripe rust resistance gene in backcross-recombinant inbred line (BC-RIL) population derived from the cross of a wheat–Ae. caudata introgression line (IL) T291-2(pau16060) with wheat cv. PBW343 is reported here. Segregation of BC-RILs for stripe rust resistance depicted a single major gene conditioning adult plant resistance (APR) with stripe rust reaction varying from TR-20MS in resistant RILs signifying the presence of some minor genes as well. Genetic association with leaf rust resistance revealed that two genes are located at a recombination distance of 13%. IL T291-2 had earlier been reported to carry introgressions on wheat chromosomes 2D, 3D, 4D, 5D, 6D and 7D. Genetic mapping indicated the introgression of stripe rust resistance gene on wheat chromosome 5DS in the region carrying leaf rust resistance gene LrAc, but as an independent introgression. Simple sequence repeat (SSR) and sequence-tagged site (STS) markers designed from the survey sequence data of 5DS enriched the target region harbouring stripe and leaf rust resistance genes. Stripe rust resistance locus, temporarily designated as YrAc, mapped at the distal most end of 5DS linked with a group of four colocated SSRs and two resistance gene analogue (RGA)-STS markers at a distance of 5.3 cM. LrAc mapped at a distance of 9.0 cM from the YrAc and at 2.8 cM from RGA-STS marker Ta5DS_2737450, YrAc and LrAc appear to be the candidate genes for marker-assisted enrichment of the wheat gene pool for rust resistance.     

小麦抗条锈病基因YrCN19的诊断检测和遗传分析

用小麦条锈病抗性基因YrCN19的诊断标记Xgwm410对19个小麦品种或品系进行PCR筛选,其中川农19、新抗5号、爱民5号和爱民6号扩增出与条锈病抗性基因YrCN19共分离的特征片断,其大小为391个碱基,而在其他的小麦品种或品系中未能检测到该片断。系谱分析和抗性鉴定结果表明川农19、新抗5号、爱民5号和爱民6号含有小麦条锈病基因YrCN19。抗性遗传分析发现小麦条锈病抗性在川农19,新抗5号和爱民5号中的遗传符合单个显性基因的遗传规律(3抗:1感);杂交组合烟辐188/爱民6号的抗性遗传也符合单个显性基因的遗传规律,而另外一些杂交组合(如R25/爱民6号,鲁955159/爱民6号和苏3110/爱民6号)中的抗性分离则符合两对基因互补的遗传规律(9抗:7感)。本研究揭示了小麦条锈病抗性基因YrCN19在不同遗传背景和杂交组合的抗性表达和分离有差异,从而加速YrCN19在小麦抗条锈育种中的开发与利用。     

小麦抗条锈基因Yr69的连锁标记开发

抗条锈病基因Yr69对我国小麦条锈菌(Puccinia striiformis f.sp.tritici)小种具有广谱抗性,在小麦抗条锈病育种中具有重要价值.为提高分子标记辅助选择育种的效率,加快Yr69在小麦抗病育种中的应用,本研究利用条锈菌小种CYR34对包含340个小麦家系的'Taichung29/CH7086'...