中粱93447抗条锈病基因遗传分析和分子作图

 用小麦条锈菌生理小种对中梁93447与感病品种铭贤169的杂交后代F₁、F₂和F₃代进行苗期温室抗条锈性遗传分析,结果表明中梁93447对CYR30的抗病性由1对显性基因控制。用中梁93447×铭贤169 F₂代分离群体建立抗、感DNA池,在F₂代群体中通过SSR标记技术寻找与抗病基因连锁的分子标记,发现7个位于5BS上的标记Xwmc813、Xwmc740、Xgwm159、Xbarc4、Xwmc616、Xwmc363和Xbarc89与目的基因连锁,遗传距离分别为17、12.9、8.3、4.5、3.7、9.1和20.8cM。系谱分析及分子标记分析表明,该基因可能来自中间偃麦草,暂命名为YrZL93447。与已定位于5B染色体上的抗条锈病基因的比较研究表明,YrZL93447可能是1个新的抗条锈病基因。用SSR引物BARC4和WMC616检测43个黄淮麦区主栽品种,其中7%的黄淮麦区主栽品种具有与YrZL93447基因相同的标记位点。     

东农415稻瘟病抗性遗传分析及基因定位

 粳稻品种东农415自育成以来一直以其早熟、抗病、高产特性而著称,在黑龙江省稻瘟病高发区种植20多年均表现高抗稻瘟病。本研究利用158个采集于黑龙江省不同稻区的稻瘟病菌株对东农415进行接种鉴定,结果表明东农415对黑龙江省稻瘟病菌株有很强的抗性,抗谱高达89.2%。以东农415与丽江新团黑谷(LTH)杂交衍生的F₁和F₂群体为遗传分析试验材料,通过接种鉴定,发现东农415对稻瘟病菌株F-10-11的抗性由一个显性基因控制。进一步采用分子标记结合隐性群体分离分析法,以对菌株F-10-11极端感病的99个F₂单株为作图群体,将东农415的抗病基因定位在第2染色体,距离基因两侧标记RM5300和RM213的遗传距离分别为7.6和3.0 cM,暂命名为Pi-dn(t)。将Pi-dn(t)位点映射到水稻参考基因组图谱上,在抗病位点基因组区段内发现3个编码基因Os02g56010、Os02g55540和Os02g56400具有抗病基因结构域,可作为Pi-dn(t)的候选基因。     

西瓜抗小西葫芦黄花叶病毒基因的连锁分子标记研究

 小西葫芦黄花叶病毒中国株系(Zucchini yellow mosaic virus Chinese strain,ZYMV-CH)是危害我国西瓜的主要病毒。本实验以抗病毒病西瓜野生种质P.I.595203与感病的普通西瓜自交系98R为亲本,采用单粒传方式得到109个E代株系,分别对亲本、F₁及109个F₃代株系群体进行了苗期抗ZYMV-CH接种鉴定,通过F₃代群体的抗感分离情况,推测得到F₂代各单株的基因型,采用集团分离分析法(bulked segregant analysis,BSA)在F₂代建立抗感基因池,以亲本、F₁和抗感基因池为模板,对640条RAPD引物进行PCR扩增筛选,其中引物AK13在亲本、F₁和抗感基因池之间扩增出一条多态性片段(644bp),在F₂代群体上验证该多态性条带与ZYMV-CH的抗性基因呈现连锁关系,遗传连锁距离为8cM,定名为AK13_-644,该连锁标记在ZYMV-CH抗性转育后代自交系上得到了验证。最终将此RAPD标记成功转化成SCAR标记SCAK13_-644,该标记可以作为西瓜抗病毒病辅助选择的分子标记。     

大白菜抗芜菁花叶病毒基因EST-PCR-RFLP分子标记的研究

 本试验以高抗芜菁花叶病毒C₃株系(TuMV-C₃)的高代自交系A₁56-2和感病自交系P9805杂交后代的F₂代为群体,根据大白菜的抗性相关的表达序列标签(EST)设计引物,利用分离群体分群分析法(BSA),筛选出2个与TuMV-C₃株系抗病基因紧密连锁的EST-PCR-RFLP分子标记BS300及BS160,遗传距离均为6.5 cM,为大白菜分子辅助育种、抗病基因克隆以及研究抗病基因编码特性等奠定基础。     

水稻恢复系华占抗稻瘟病遗传分析及基因鉴定

 华占是近年来我国新选育的恢复系,广泛应用于杂交稻育种中,其配组的杂交稻组合对稻瘟病均表现出良好的抗性。本研究利用来源于华南稻区的62个稻瘟病菌株对恢复系华占、明恢63和广恢998进行抗病性鉴定,结果表明:华占对接种菌株的抗谱达到95.2%,对稻瘟病表现出广谱抗性。为进一步了解该恢复系所含的抗稻瘟病基因,以高感稻瘟病品种丽江新团黑谷为母本,以华占为父本,构建了丽江新团黑谷(LTH)/华占的F₂抗病遗传分析群体。利用对华南水稻品种具有致病谱较广的稻瘟病代表菌株GD00-193a对随机选择的1 000个来源于LTH/华占的F₂个体及其F₁个体进行抗病遗传分析,结果发现F₁个体表型全为抗病,1 000个F₂个体的抗/感比率符合3∶1的显性单基因分离比,说明华占至少含有一个显性抗稻瘟病基因。利用均匀分布于水稻12条染色体的250对SSR引物,通过分离群体分析结合隐性群体分析法将华占的一个抗稻瘟病基因定位于水稻第6染色体的Pi2/Pi9/Pi50区域。通过Pi2等位基因的测序分析,结果表明华占含有Pi2抗病基因。本试验结果为华占在杂交稻上的应用及其配组组合的品种布局提供重要依据。     

小簇麦易位系V9128-3抗条锈病基因的遗传分析和SSR分子标记

 用7个我国当前流行的条锈菌生理小种对V9128-3的抗条锈性进行了评价,表明本易位系对我国优势流行小种具有良好的抗病性。以Su-4对V9128-3与铭贤169配置的F₁、BC₁F₁、F₂及F₃代群体进行了遗传分析,并对其中1个F₂群体进行了SSR标记,再用BC₁F₁群体的部分单株和F₃家系进行连锁标记的初步验证。遗传分析表明了V9128-3对Su-4的抗病性由1对显性核基因独立控制,从219对SSR引物中筛选到2个位于2AL上的该基因YrHV(暂命名)两侧的标记Xgwm356和Xwmc658,遗传距离分别为8.5和5.6cM,所用部分BC₁F₁单株和F₃家系验证了该2个标记与YrHV连锁性。将此标记可用于小麦抗条锈病分子标记辅助育种。     

小麦抗白粉病基因Pm13及Pm4累加体的分子标记辅助选择

 利用Pm4的STS-PCR标记及Pm13的SCAR标记,检测含Pm4b的YW243与含Pm13抗性基因品系杂交的F₃代的抗感单株,初步筛选到累加了Pm4b及Pm13两个抗性基因的植株R1、R4;并分别对R1和R4自交后代(F₄代)的15个抗病单株进行跟踪检测,得到13株累加体,而另外2株仅具Pm4b基因。本研究说明分子标记是检测抗病基因累加体、辅助育种的有效手段。     

玉米抗青枯病基因的遗传分析

 本研究对2亲本1145和Y331、杂交F₁以及F₂群体进行玉米青枯病单一致病菌(肿囊腐霉菌)的接种鉴定,统计F₂群体中抗病、感病植株分离情况,并作了初步统计分析。结果表明:单一肿囊腐霉菌也能引起玉米青枯病;玉米对肿囊腐霉菌引起青枯病的抗性由显性单基因控制。     

番木瓜抗环斑病毒突变体抗性遗传及RAPD标记

 ⁶⁰Coγ-射线处理番木瓜种子,从诱变一代中筛选到1株耐环斑病毒(PRSV)的变异植株(M₁),其侧芽组培后代(VM₁)部分植株也表现出了耐病性,以VM₁为母本进行回交,人工接种病毒鉴定回交后代(BM₂)的抗病性,结果为:在出自部分回交果实的BM₂群体中,包含有对PRSV Ys和Vb株系具抗性的植株,抗感分离比为1:1,但未发现抗Sm株系的植株;BM₂抗病两性株自交或以其为母本进行回交,分别获得诱变第三代(M₃)及回交诱变第三代(BM₃),人工接种PRSVYs株系,结果表明,BM₃抗感分离比也为1:1,因而认为辐射处理突变产生了具PRSV株系专化性的显性抗病基因,命名为Rys;但M₃抗感分离比不符合显性单基因3:1理论值,认为是单倍体选择的结果。运用BSA法,在BM₂中寻找到一个与抗病性密切相关的RAPD标记,经在BM₂、M₃及BM₃抗感群体中检验,可作为抗病育种的辅助选择标记。Rys是番木瓜栽培种中发现的第一个抗PRSV基因。     

来自簇毛麦抗条锈病新基因的SSR标记

 用小麦条锈菌条中30号生理小种,对小麦抗病种质小麦-簇毛麦易位系V9128-1和铭贤169的杂交后代进行抗条锈性遗传分析,小麦-簇毛麦易位系V9128-1的抗病性符合1对显性抗条锈病基因控制。并根据F₂抗、感病单株分离比例组建抗感池,用SSR技术寻找与抗病基因连锁的分子标记。从121个SSR引物组合中筛选到2个与抗病基因YrV1(暂命名)紧密连锁的微卫星标记Xgwm566和Xgwm376,遗传距离分别为3.6和5.5cM;因此,该抗条锈病基因位于小麦3B染色体短臂上。这2个标记不仅能在小麦-簇毛麦易位系V9128-1中检测到,而且在抗病基因供体亲本簇毛麦中也能检测到。综合抗病基因来源和分子生物学试验结果,可以推断,YrV1很可能是1个来自簇毛麦并与已知抗条锈病基因不同的新基因。     

水稻抗穗瘟基因的分子定位

 本试验以中156和谷梅2号为亲本建立F₈重组自交系群体,应用稻瘟病菌株92-183对群体的叶瘟和穗瘟抗性表现进行了分析。结果表明,叶瘟和穗瘟抗性遗传控制机制存在明显差异。应用DNA标记将一个兼抗叶瘟和穗瘟的基因定位于水稻第6染色体,其抗性等位基因来源于谷梅2号。而且,该基因在病区表现出较强的效应。     

Molecular mapping of the crown rust resistance gene rpc1 in barley

ABSTRACT Crown rust of barley, caused by Puccinia coronata var. hordei, occurs sporadically and sometimes may cause yield and quality reductions in the Great Plains region of the United States and Canada. The incompletely dominant resistance allele Rpc1 confers resistance to P. coronata in barley. Two generations, F(2) and F(2:3), developed from a cross between the resistant line Hor2596 (CIho 1243) and the susceptible line Bowman (PI 483237), were used in this study. Bulked segregant analysis combined with random amplified polymorphic DNA (RAPD) primers were used to identify molecular markers linked to Rpc1. DNA genotypes produced by 500 RAPD primers, 200 microsatellites (SSRs), and 71 restriction fragment length polymorphism (RFLP) probes were applied to map Rpc1. Of these, 15 RAPD primers identified polymorphisms between resistant and susceptible bulks, and 62 SSR markers and 32 RFLP markers identified polymorphisms between the resistant and susceptible parents. The polymorphic markers were applied to 97 F(2) individuals and F(2:3) families. These markers identified 112 polymorphisms and were used for primary linkage mapping to Rpc1 using Map Manager QT. Two RFLP and five SSR markers spanning the centromere on chromosome 3H and one RAPD marker (OPO08-700) were linked with Rpc1 and, thus, used to construct a 30-centimorgan (cM) linkage map containing the Rpc1 locus. The genetic distance between Rpc1 and the closest marker, RAPD OPO08-700, was 2.5 cM. The linked markers will be useful for incorporating this crown rust resistance gene into barley breeding lines.     

Molecular mapping of the blast resistance genes Pi2-1 and Pi51(t) in the durably resistant rice 'Tianjingyeshengdao'

Tianjingyeshengdao' (TY) is a rice cultivar with durable resistance to populations of Magnaporthe oryzae (the causal agent of blast) in China. To understand the genetic basis of its resistance to blast, we developed a population of recombinant inbred lines from a cross between TY and the highly susceptible 'CO39' for gene mapping analysis. In total, 22 quantitative trait loci (QTLs) controlling rice blast resistance were identified on chromosomes 1, 3, 4, 5, 6, 9, 11, and 12 from the evaluation of four disease parameters in both greenhouse and blast nursery conditions. Among these QTLs, 19 were contributed by TY and three by CO39. Two QTL clusters on chromosome 6 and 12 were named Pi2-1 and Pi51(t), respectively. Pi2-1 was detected under both growth chamber and natural blast nursery conditions, and explained 31.24 to 59.73% of the phenotypic variation. Pi51(t) was only detected in the natural blast nursery and explained 3.67 to 10.37% of the phenotypic variation. Our results demonstrate that the durable resistance in TY is controlled by two major and seven minor genes. Identification of the markers linked to both Pi2-1 and Pi51(t) in this study should be useful for marker-aided selection in rice breeding programs as well as for molecular cloning of the identified resistance genes.     

Towards the isolation of resistance genes by transposon targeting in potato

A general strategy for the isolation of disease resistance genes is presented, employing a two-step approach of transposon targeting near genes of interest followed by transposon tagging. A library of transposon (Ac/Ds) transformants in a self fertile potato diploid are being mapped by deriving genomic DNA probes flanking the transposon containing T-DNA insertions with the inverse polymerase chain reaction and using these probes for RFLP analysis. We have produced a large number of transposon (Ac/Ds) transformants in a self fertile potato diploid. Genomic DNA probes, flanking the transposon containing T-DNA insertions, are produced by the inverse polymerase chain reaction (IPCR) and mapped by restriction fragment length polymorphism (RFLP) analysis in a segragating potato location. A transposon mapped close to a resistance gene can be recombined cis to the gene and used for efficient transposon targeting due to preferential transposition to linked sites.     

转基因水稻对稻瘟病的抗性研究

 采用苗期初筛、复筛、抗谱测定和田间自然诱发试验等不同鉴定方法,对经分子检测证明已整合有碱性几丁质酶基因和β-1,3-葡聚精酶基因的22个转化系的转基因水稻植株进行稻瘟病抗性鉴定研究,筛选出对稻瘟病的抗性比原种对照七丝软占有明显提高的一系列转基因水稻品系,其中表现高抗的有来自F4-9转化株系的7个品系。高抗材料的R7代品系,经室内抗谱测定及田间病圃试验结果,仍然表现高抗稻瘟病。本研究通过转基因技术,成功地将优质感病品种改良成高抗品系,研究结果证明了利用基因工程手段培育抗病水稻新品种是一个非常有希望的育种途径。     

Identification of a new resistance gene to a chinese blast fungus isolate in the Japanese rice cultivar aichi asahi

ABSTRACT Genetic analysis of the rice cultivar Aichi Asahi and some other Japanese cultivars for the high resistance to the blast fungus isolate CHNOS58-3-1 from China was performed. All the Japanese differential cultivars were resistant to the isolate except for 'Pi No. 4', which showed moderate resistance. Analysis of the F(2) population of a cross of the susceptible cultivar Reiho and the resistant cultivar Aichi Asahi indicated that the resistance of 'Aichi Asahi' to the isolate was conferred by one dominant gene. To identify the gene in other Japanese differential cultivars, AK lines, which were derived from a cross of 'Aichi Asahi' x 'K59' and assumed to harbor no known genes except for the new one, were used for the allelism tests. The new, completely dominant resistance gene was detected in 14 differential cultivars, but not in 'Pi No. 4', 'Yashiro-mochi', and 'K1', and was designated as Pi19(t). Pi19(t) was allelic or closely linked to Pita(2) on chromosome 12. Pi19(t) was extensively distributed among Japanese traditional local cultivars.     

Lr46: a gene conferring slow-rusting resistance to leaf rust in wheat

ABSTRACT Wheat (Triticum aestivum) cultivar Pavon 76 carries slow-rusting resistance to leaf rust that has remained effective in Mexico since its release in 1976. 'Pavon 76' was crossed with two leaf rust-susceptible wheat cultivars, Jupateco 73S and Avocet S, and between 118 and 148 individual F(2) plant-derived F(3) and F(5) lines were evaluated for adult-plant leaf rust resistance at two field sites in Mexico during different seasons. Evaluation of F(1) plants and parents indicated that the slow-rusting resistance was partially dominant. Segregation in the F(3) and F(5) indicated that the resistance was based on two genes with additive effects. Monosomic analysis was carried out to determine the chromosomal locations of the resistance genes. For this purpose, two or three backcross-derived cytogenetic populations were developed by crossing 'Pavon 76' with a monosomic series of adult-plant leaf rust-susceptible cultivar Lal-bahadur. Evaluation of such BC(2)F(3) and BC(3)F(3) lines from 16 confirmed 'Lalbahadur' monosomics indicated that one slow-rusting gene was located in chromosome 1B of 'Pavon 76'. This gene, designated as Lr46, is the second named gene involved in slow-rusting resistance to leaf rust in wheat.     

Tomato Breeding Lines Resistant and Tolerant to Tomato Yellow Leaf Curl Virus Issued from Lycopersicon hirsutum

ABSTRACT Two tomato yellow leaf curl virus (TYLCV)-resistant plants from accessions LA1777 and LA386 of the wild tomato species Lycopersicon hirsutum have been crossed. The resulting resistant F1 plants were crossed with the domesticated tomato L. esculentum, and a series of selfing was performed. At each generation, individuals were selected for resistance (no symptoms and undetectable viral DNA) and tolerance (no symptoms but with detectable viral DNA) following controlled massive and repeated inoculations with viruliferous whiteflies. A stable BC1F4 line (denominated 902) that does not segregate for resistance was obtained. This line does not support virus accumulation, even upon extensive whitefly-mediated inoculation of young seedlings, and does not need protection with nets or insecticides. Another stable BC1F4 line (denominated 908) was tolerant to the virus. Both lines have good horticultural characteristics and bear 80- to 120-g red fruits. Analysis of segregation of susceptibility, tolerance, and resistance during the BC1F1 to BC1F4 crosses indicated that tolerance is controlled by a dominant major gene and resistance by two to three additive recessive genes. The resistant and tolerant lines do not need to be protected by insecticides or nets.     

Development of Co-Dominant Amplified Polymorphic Sequence Markers in Rice that Flank the Magnaporthe grisea Resistance Gene Pi7(t) in Recombinant Inbred Line 29

ABSTRACT Pi7(t), a dominant blast resistance gene derived from the rice cultivar Moroberekan, confers complete resistance against the fungal pathogen Magnaporthe grisea. Pi7(t) previously was positioned on chromosome 11 by restriction fragment length polymorphism (RFLP) mapping of a recombinant inbred line population. One derivative of this population, recombinant inbred line (RIL)29, was designated as the representative line for Pi7(t). A segregating F2 population was created from RIL29 in order to determine the location of Pi7(t). The new mapping data indicate a position for Pi7(t) 30 centimorgans distal to the original location. Pi7(t) shares a common position with the previously mapped Pi1 M. grisea resistance gene. RIL29 carries DNA not derived from either parent used to create the RIL population at the newly assigned Pi7(t) locus. RFLP analysis has identified a possible donor source.     

已知抗瘟基因在黑龙江省寒地稻区的评价与利用

 利用12个日本鉴别品种、7个中国鉴别品种、24个抗稻瘟病单基因系及6个当地主栽品种,对2006年采自该省主要积温区不同水稻品种的178个稻瘟病菌株进行了致病性测定。结果表明：2006年黑龙江省稻瘟病菌生理小种划分为104个日本小种,077.7号生理小种比例最高为4.49%,017.1号、017.5号、037.5号生理小种出现频率为3.93%。就抗性基因而言,抗瘟基因Pi9(t)在全省抗谱为97.75%,是较好的抗源可以在全省内广泛利用;Piz-5、Pi12(t)抗瘟基因抗谱分别为78.09%和78.65%,根据品种种植区域可以有选择地利用。就品种而言,抗瘟基因Pi9(t)、Piz-5是空育131;Pi5(t)、Pita-2是垦稻10号;Pi9（t）、Pita是上育397;Piz-5、Pi12(t)是垦稻12号等品种抗瘟改良的有利基因;在研究中同时加强对稻瘟病菌种群的监测和新抗源的发掘,有针对性地向主栽品种导入新的抗性基因。