亚麻品系9801-1抗白粉病基因的RAPD标记

 F2 populations were obtained from the cross between 9801-1 and DIANE.Bulked segregate and RAPD analyses were employed to identify molecules linked to the resistance to powdery mildew.OPP02 amplified about 792 bp polymorphic band in all individuals from 9801-1 and resistant bulk,but absent in all individuals from DIANE and susceptible bulk.By further analysis in F2 segregating population,the polymorphic band was found to be cosegregated with the resistant gene possibly.The fragment was sequenced,     

梨抗黑星病AFLP标记筛选

 Pear scab caused by Venturia nashicola is one of the most destructive diseases of pears. Molecular markers linked to scab resistance gene is expected to be useful for improving pear. In this study, the F₁ population derived from the cross of ‘Huangguan’ and ‘Yali’ was analyzed genetically. The resistance of pear to scab was proved to be controlled by a single gene in a dominant manner. Bulked segregant analysis (BSA) was conducted to screen 64 fluorescent AFLP primer pairs. A marker designated as D3-365 was found to be linked to the resistant locus. Selective genotype linkage analysis showed that the genetic distance between the marker and the resistant locus was 14.9 cM.     

小麦-滨麦易位系M8657-1抗条锈病基因遗传分析和分子标记

 M8657-1, one of the wheat translocation lines derived from Leymus mollis Trin. Hara, is possessed of effective resistance at all stages to Su-ll and other dominant races of Puccinia striiformis f. sp. tritici in China. Seedlings of the parents, F₁, and F₂ progeny derived from the cross of M8657-1 (resistant) Mingxian169 (susceptible) were inoculated with Su-ll in greenhouse to identify and map the probable new stripe rust resistance gene. The results suggested that the stripe rust resistance in M8657-1 was conferred by a pair of recessive genes. Simple sequence repeat (SSR) technique was used to detect molecular marker associated with the resistance gene:208 pairs of wheat SSR primers were used to screen the two parents, as well as resistant and susceptible bulks and then three SSR markers were selected for genotyping the F₂ population. The geue, temporarily designated as YrLml, was found to be located on the chromosome 7DL and flanked by three SSR markers GDM67, WMC150 and WMC671, with the genetic distance of 5.0, 9.7 and 11.8cM, respectively.     

分子标记辅助选择小麦抗白粉病兼抗赤霉病聚合体

 Sumai 3, a wheat variety resistant to Fusarium head blight(FHB), was crossed with Neimai 9, a commercial wheat cultivar with the resistance to powdery mildew.The SCAR(sequence characterized amplified region) markers of powdery mildew resistance gene Pm21 and four SSR(simple sequence repeats)markers flanking the major FHB resistance QTL(Qfhs.ndsu-3BS) in Sumai 3 were used to detect the resistance loci by marker assisted selection(MAS) in the plants of the F₂ population.Identification of resistance to both powdery mildew and FHB in field showed that 12 plants resistant to both diseases were obtained.In addition, the agronomic traits of these plants were better than those of Sumai 3, and are perhaps the excellent parental materials for wheat breeding.     

普通小麦-华山新麦草易位系H9020-1-6-8-3抗条锈病基因的遗传分析和SSR标记

 It have proved that wheat translocation line H9020-1-6-8-3 derived from Psathyrostachys huashanica Keng is an important resistant resource to stripe rust.To confirm the existence of resistant genes,it was crossed with susceptible cultivar MingXian 169 as male and female parent,respectively.Seedlings of parents and F₂ progeny were tested for resistance to selected CY29 of races of Puccinia striiformis f.sp.tritici from China.H9020-1-6-8-3 had one dominant resistant gene which temporarily named YrHs,whatever it was male or female parent.By using BSA method,two markers,Xgwm261 and Xgwm455 located on 2DL were found.The distance to YrHs were 4.3 and 5.8 cM respectively.The result could be used in molecular-assisted breeding.     

小麦抗白粉病基因Pm6的微卫星标记鉴定

 Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is a prevalent disease worldwide. Breeding and planting resistance cultivars have been proved effective and environmental friendly for control of the disease. To develop easily used PCR-based markers in marker assisted selection (MAS) for Pm6, a dominant powdery mildew resistance gene in wheat, 25 microsatellite markers on chromosome 2BL in wheat were screened between susceptible parent Yumai13 and resistance parent Timgalen carrying Pm6. F₂ population derived from Yumai13 and Timgalen was further analyzed by the marker Xgwm501. The results indicated that Xgwm501 was a co-dominant marker linked to Pm6 gene at a distance of 14.8 cM. 29 Pm-carrying varieties were tested by the marker Xgwm501 and only those carrying Pm6 showed 117 bp resistance specific band. This marker is proved to have high practicability and can be used in MAS of Pm6 gene in wheat breeding programs.     

亚麻品系9801-1对白粉病的抗性遗传分析

 The genetics of resistance against powdery mildew in flax was analyzed. The F₁ plants from reciprocal cross of resistant materials 9801-1 and three susceptible cultivars ILONA, VENUS and DIANE were resistant to powdery mildew. The ratio of resistant and susceptible plants in F₂ generation fitted the excepted 3 to 1. It was postulated that 9801-1 carded a single dominant and resistant gene.     

黄瓜-酸黄瓜渐渗系霜霉病抗性及感病前后几种酶活性的变化

 Using resistant and susceptible cultivars as controls, the resistant evaluation to Pseudoperonospora cubensis was carried out in 12 introgression lines from wide cross between cucumber(Cucumis sativus L.) and sour cucumber(Cucumis hystrix Chakr.). Three enzyme activities including POD, SOD and PAL were analyzed before and 7 d after inoculation, and the POD isozyme was detected by polyacrylamide electrophoresis. The inoculation results showed that, of the 12 accessions, 3 were identified as high resistant, 5 were moderately resistant and 4 were moderately susceptible to downy mildew. The enzyme activities of POD, SOD and PAL were greatly increased in resistant accessions after inoculation. PAL enzyme activities showed close correlation with disease rating before or after inoculation, which implicated that PAL enzyme activity might be used to estimate the resistance to downy mildew. POD isozyme electrophoresis showed that the number and intensity for the bands of resistant lines were significantly increased more than those of susceptible lines after inoculation.     

应用基因芯片检测烟草脆裂病毒

 Total RNA in tulips was extracted by Trizol method. Primers were designed according to the sequences of Tobacco rattle virus and 18S rRNA gene of plant. The corresponding sections were amplified by RT-PCR and the PCR products were labeled by Cy3-dCTP. The probes of plant virus, 18S rRNA gene and comparisons were designed and immobilized on chips. Labeled PCR products were hybridized with the probes and the signals were scanned by scanner and analyzed by GenePix Pro 4.0 software. Tobacco rattle virus was detected from tulips which were imported from Holand. The accuracy and sensitivity of the plant virus gene chip were proved.     

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.     

Identification and Characterization of Random Amplified Polymorphic DNA Markers Linked to a Major Gene (Cr2) for Resistance to Cronartium ribicola in Pinus monticola

ABSTRACT DNA markers tightly linked to resistance (R) genes provide a very powerful tool for both marker-assisted selection in plant breeding and positional cloning of R genes. In the present study, a linkage of random amplified polymorphic DNA (RAPD) markers to the single dominant gene (Cr2) for resistance to white pine blister rust fungus (Cronartium ribicola) was investigated in western white pine (Pinus monticola). A mapping population of 128 individual megagametophytes was generated from seeds of a heterozygous resistant tree (Cr2/cr2), and the corresponding seedlings of each megagametophyte were subjected to the test of phenotype segregation by inoculation with C. ribicola. Bulked segregant analysis and haploid segregation analysis identified eight robust RAPD markers linked to Cr2. This constitutes the first Cr2 genetic linkage map spanning 84.7 cM with four markers only 3.2 cM from Cr2. One sequence (U256-1385) of these linked markers was significantly similar to the Ty3/gypsy-like long terminal direct repeats retrotransposons. Another marker, U570-843, had no significant similarity to any entry in either GenBank or the loblolly genomics data bank. As presumed that the average physical distance per centimorgan is about 10 Mb in P. monticola, it is probably unrealistic to use these DNA markers for positional cloning of the Cr2 gene.     

Identification of Random Amplified Polymorphic DNA Markers Linked to the Co-4 Resistance Gene to Colletotrichum lindemuthianum in Common Bean

ABSTRACT New cultivars of the common bean (Phaseolus vulgaris) with durable resistance to anthracnose can be developed by pyramiding major resistance genes using marker-assisted selection. To this end, it is necessary to identify sources of resistance and molecular markers tightly linked to the resistance genes. The objectives of this work were to study the inheritance of resistance to anthracnose in the cultivar TO (carrying the Co-4 gene), to identify random amplified polymorphic DNA (RAPD) markers linked to Co-4, and to introgress this gene in the cultivar Rudá. Populations F(1), F(2), F(2:3), BC(1)s, and BC(1)r from the cross Rudá x TO were inoculated with race 65 of Colletotrichum lindemuthianum, causal agent of bean anthracnose. The phenotypic ratios (resistant/susceptible) were 3:1 in the F(2) population, 1:1 in the BC(1)s, and 1:0 in the BC(1)r, confirming that resistance to anthracnose in the cultivar TO was monogenic and dominant. Six RAPD markers linked to the Co-4 gene were identified, four in the coupling phase: OPY20(830C) (0.0 centimorgan [cM]), OPC08(900C) (9.7 cM), OPI16(850C) (14.3 cM), and OPJ01(1,380C) (18.1 cM); and two in the repulsion phase: OPB03(1,800T) (3.7 cM) and OPA18(830T) (17.4 cM). OPY20(830C) and OPB03(1,800T), used in association as a codominant pair, allowed the identification of the three genotypic classes with a high degree of confidence. Marker OPY20(830C), which is tightly linked to Co-4, is being used to assist in breeding for resistance to anthracnose.     

Molecular mapping of rsp1, rsp2, and rsp3 genes conferring resistance to septoria speckled leaf blotch in barley

ABSTRACT Septoria speckled leaf blotch (SSLB) caused by Septoria passerinii is a common disease in barley. SSLB resistance genes Rsp1, Rsp2, and Rsp3 have previously been identified in the United States Department of Agriculture National Small Grains collection accessions CIho 14300, CIho 4780, and CIho 10644, respectively. Populations of 100 to 120 F(2) individuals were evaluated for SSLB resistance in the greenhouse. Inheritance was evaluated in F(2:3)-derived families in the field. Partial molecular maps for three Rsp genes were constructed on F(2) and F(2:3) families derived from crosses between Robust and the resistant accessions CIho 14300, CIho 4780, and CIho 10644. The resistant locus Rsp1 was mapped to the short arm of chromosome 3H with two flanking diversity arrays technology (DArT) markers, bPb-6978 (8.9 cM) and bPb-9945 (16.3 cM), and two random amplified polymorphic DNA (RAPD) markers, OPC2(441R) (3.0 cM) and UBC285(158R) (4.3 cM). The genes Rsp2 and Rsp3 were positioned on the short arm of barley chromosome 1H with two restriction fragment length polymorphism (RFLP), six DArT, and three RAPD markers. An RFLP marker, MWG938, and an RAPD marker, OPAH5(545C), were tightly associated with Rsp2 at a distance of 0 cM. Five DArT markers spanning the short arm of 1H surrounded Rsp3 at a distance of 2.3 and 5.8 cM, while two RAPD markers-OPBA12(314C) (2.4 cM) in coupling and OPB17(451R) (3.5 cM) in repulsion-flanked Rsp3. Molecular marker data associated with Rsp2 and Rsp3 indicated that the two genes are closely linked on chromosome 1HS. A total of 17 of 154 simple sequence repeats (SSRs) tested were associated with Rsp genes on chromosome 1H and 3H, and they were also integrated into genetic linkage maps of the three F(2) Robust populations. Knowledge about the map position of Rsp genes on barley chromosomes will be useful for breeding for SSLB resistance in barley and eventual gene cloning.     

一个与马铃薯青枯病抗性连锁的RAPD标记

 用原始栽培种Solanum phureja作为抗源构建了一个二倍体马铃薯作图群体,并且用于进行群分法(bulked segregant analysis,BSA)分析,以筛选检定马铃薯青枯病抗性的RAPD连锁标记。使用300个随机引物进行RAPD检测,发现引物OPG09可在抗感性DNA池之间产生960 bp的稳定的相斥型多态性产物。进一步分析分离群体并得到与抗性相连锁的标记OPG09₉₆₀。该标记已有效地应用于检测其它具相近遗传背景的二倍体群体的抗性。     

应用RAPD方法获得与番茄ToMV抗性基因Tm2nv连锁的分子标记

 运用RAPD技术,在番茄ToMV抗性基因Tm2^nv的F₂代群体中采用混合分组分析法(bulkedse gregant analysis,BSA)进行分子标记研究,找到了一个与Tm2^nv基因连锁的分子标记OPD20₁₇₀₀,其遗传距离为7.067cM,LOD值为16.768。     

应用RAPD方法获得与番茄ToMV抗性基因Tm2nv连锁的分子标记

运用 RAPD技术 ,在番茄 To MV抗性基因 Tm2 nv的 F2 代群体中采用混合分组分析法 ( bulkedsegregant analysis,BSA)进行分子标记研究 ,找到了一个与 Tm2 nv基因连锁的分子标记 OPD2 0 170 0 ,其遗传距离为 7.0 67c M,L OD值为 16.768     

一个新的与稻瘟病菌无毒基因AVR-Pikm紧密连锁的SCAR标记

 无毒基因是病原物中决定寄主抗病性表达的功能基因,其功能的丧失导致毒性小种的产生。本研究利用随机引物扩增DNA多态性技术,从稻瘟病菌菌株S1522中新筛选到1个与无毒基因AVR-Pik^m紧密连锁的DNA标记OPE12₁₄₀₀。根据OPE12₁₄₀₀的核苷酸序列,设计了1对含有17个核苷酸的特异性SCAR引物,并利用该引物对无毒表型亲本S1522和毒性表型亲本S159及其有性杂交后代的108个菌株进行了PCR扩增。结果表明:所有无毒表型的菌株均能特异性扩增出1条与OPE12₁₄₀₀大小相近的DNA片段,而毒性表型的菌株除2个重组体外,均不能扩增出此片段。根据计算,这一SCAR标记与目标无毒基因AVR-Pik^m之间的遗传距离为1.89 cM,与本研究小组先前报道的另一个标记OPO12₁₀₀₀位于目标基因的同一侧,但与OPO12₁₀₀₀相比,距目标基因近了2.86 cM。本标记的获得将有助于确定AVR-Pik^m在染色体上的位置,有助于确定用于进一步筛选位于相反一侧的连锁标记的重叠群区域。     

Generation and Molecular Mapping of a Sequence Characterized Amplified Region Marker Linked with the Bct Gene for Resistance to Beet curly top virus in Common Bean

ABSTRACT A random amplified polymorphic DNA (RAPD) marker directly linked (0.0 cM) with a resistance gene was identified in a snap bean recombinant inbred population (Moncayo x Primo) consisting of 94 F(5:7) recombinant inbred lines that had uniform segregation for disease reaction to Beet curly top virus (BCTV) across three field locations. Resistance was conditioned by a single dominant allele tentatively designated Bct. Seven hundred and fifty decamer primers were screened to obtain the linked RAPD marker that was then converted to a sequence characterized amplified region (SCAR) marker SAS8.1550. The SCAR mapped within a cluster of resistance genes on linkage group B7 of the core map. A survey of 103 BCTV-resistant and -susceptible snap and dry bean genotypes was conducted using SAS8.1550. Results showed that the SCAR would be highly useful for marker-assisted selection of Bct in snap and dry bean originating from the Andean gene pool. Marker-assisted selection for Bct will expedite the development of BCTV-resistant cultivars and minimize the need for cumbersome pathogen tests.     

玉米抗粗缩病遗传及分子标记研究

Maize rough dwarf disease caused by Rice black-streaked dwarf virus (RBSDV) is transmitted by planthopper in China. Identification and development of resistant hybrids are complicated because of the inconsistencies in viral disease pressure every year. Marker-assisted selection can provide means for main-taining virus resistance alleles even in the absence of disease. In this paper a F₂ segregation population was constructed to identity the molecular markers linked to the resistance gene using a cross between a resistant and a susceptible parents (Qi319×Ye107). Fifteen-day-old seedlings of F₂ population were exposed to small brown planthoppers carrying RBSDV for 3 days in specific inoculation chamber. The inoculated plants were transplanted to screenhouse after removing the insects completely. In plant maturity stage the disease resistance of all the individuals were visually assessed. The results showed that 17, 8, 11, 51 and 122 plants were scaled from 0-4 respectively, in which 0 means no symptoms and 4 represents highly susceptible. Chi-square test demonstrated that the segregation ratio of phenotype was 1∶15 (resistant: susceptible) or 1∶6∶9 (resistant∶moderate∶susceptible) in the F₂ population, indicating RBSDV resistance of maize was controlled by two recessive genes. The F₂ individuals DNA were extracted and 261 SSR (simple sequence repeat) primers derived from maize genome ten chromosomes were selected from maize GDB database to construct genetic linkage map. The linkage map consisted of 71 polymorphic SSR markers, spanning a genetic distance of 996.6 cM with an average interval of 14.0 cM between adjacent markers. The resistant and susceptible gene pools were set up for BSA (bulked segregant analysis) and 6 polymorphism markers were obtained with BSA-SSR method between the two pools. The F₂individuals were further analyzed with 6 polymorphism markers. Chi-square test showed that phi 051, umc1407 and umc1432, mapped on chromosome 7 and 10, exhibited segregation distortion significantly and very significantly in susceptible individuals. These three SSR markers were identified as potential markers linked to the resistant loci.