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1.
Summary The oat line Pc54 was found to be resistant to powdery mildew under both field and glasshouse conditions. The ratio of resistant to susceptible F2 and F2 progeny of a cross between a selection from the Pc54 line (Cc7422) and a susceptible cultivar (Selma) showed that, in addition to carrying the crown rust resistance gene Pc54 and the pg15 gene for stem rust resistance, the mildew resistance of the Pc54 line was conditioned by a single incompletely dominant gene along with additional factors which modified the expression of resistance. Previous results, that there was no linkage between genes Pc54 and Pg15, were confirmed. In addition, there was no evidence of linkage between the mildew resistance gene and gene Pc54. Evaluation of selections from within the Pc54 line showed that the expression of both stem rust and mildew resistance was modified by, or linked to, plant height. The effectiveness of genes Pc54 and Pg15, as measured by virulence frequencies, in central and eastern Europe is described. 相似文献
2.
A powdery mildew resistant double disomic wheat-rye substitution line carrying rye chromosomes 1R and 2R was crossed with
normal bread wheats. The F2 generation was analysed cytologically by C-banding. Wheat-rye chromosome translocations involving both rye chromosomes 1R
and 2R were frequent in F2. Lines with translocations of 1R and 2R were harvested separately. After four generations of selfing and selection for mildew
resistance and fertility, fully fertile resistant lines were selected and analysed cytologically. Lines with 1BL/1RS and 2BS/2RL
translocations were identified. The resistance on chromosome 1RS could not be shown to be different from control varieties
carrying the same rye segment, while the resistance on 2RL is much broader than the earlier known 2RL derived resistance in
the line Transec.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
V97‐3000 is a maturity group (MG) V soybean breeding line derived from SS 516 × V90‐2592 (Vance × V81‐1325) with high stachyose, small seed and powdery mildew resistance. A total of 53 F2:3 families were derived from a cross between V97‐3000 and a powdery mildew susceptible line V99‐5089. The 53 F2:3 families, each with 30 plants, were grown in the greenhouse for powdery mildew evaluation, and the corresponding 53 F2 plants were genotyped using simple sequence repeat (SSR) markers. Results showed that the 53 F2:3 families segregated in ratio of one resistant : two segregating : one susceptible (13 : 26 : 14) and the 26 segregating F2:3 families each exhibited a good fit to three resistant : one susceptible, indicating that resistance to powdery mildew is conditioned by a single dominant gene. The gene for powdery mildew resistance in V97‐3000 was mapped on chromosome 16 [linkage group (LG) J] flanked by Satt547 and Sat_396 on one side and Sat_393 on the other side with 3.8 cM and 3.9 cM distance, respectively. This study provides a new source of powdery mildew resistance and information of genetic location of the resistance gene and linked markers, which is useful for breeders selecting powdery mildew resistance through marker‐assisted selection (MAS) in soybean breeding programmes. 相似文献
4.
While studying powdery mildew resistance in a recombinant line (code 81882) derived from a Hordeum vulgare (cv. ‘Vada’) ×Hordeum bulbosum hybrid, a low infection type of resistance to leaf rust was observed. To determine the mode of inheritance of the leaf rust resistance and whether there was linkage between the two resistances, F2 and F3 progenies from crosses between 81882 and ‘Vada’ were inoculated with the leaf rust and powdery mildew pathogens. Southern blots were prepared using restricted DNA extracted from leaves of 82 F2 plants and four chromosome 2HS sequences were hybridized with the blots to define the length of the introgression. The leaf rust resistance appears to be inherited as a single dominant gene on chromosome 2HS, which co-segregates with the powdery mildew resistance. There was an almost complete association between the resistances and the respective molecular markers, but it is likely that the strong linkage results from the frequent inheritance of the introgressed H. bulbosum DNA as an intact segment of chromatin with only low levels of recombination within the segment. 相似文献
5.
In pea, a single recessive gene (er) on linkage group 6 confers resistance to powdery mildew caused by Erysiphe pisi. The present study aims to identify molecular markers linked to the er gene. Screening of the powdery mildew‐resistant cultivar ‘DMR11’ and its susceptible nearisogenic line for polymorphism revealed linkage of two RAPD primers (OPO‐02 and OPU‐17) to the er gene and a sequence characterized polymorphic region (SCAR) primer, ScOPD‐10650 with er in a population of 83 F2 plants in the order: OPU‐17 ‐ er ‐ ScOPD‐10650 ‐ OPO‐02. The markers ScOPD‐10650 and OPU‐17 being coupled with the allele causing resistance would substantially increase the efficiency of marker‐assisted selection in peabreeding for powdery mildew. 相似文献
6.
Summary Since June 1973 Pseudoperonospora cubensis (Berk & Curt) Rost., which causes downy mildew in cucumber, occurs in the Netherlands. The resistance against this disease appears to be based on one recessive gene in linkage with the dominant gene D for dull green fruit skin colour. It is demonstrated that this recessive gene is also linked with one of the genes for resistance to powdery mildew present in the variety Ashley.The powdery mildew resistant lines tested are also resistant against downy mildew, the linkage with the gene D having been broken.Stationed at Breeding Station Pannevis B.V., De Lier, the Netherlands. 相似文献
7.
A new powdery mildew resistance gene: Introgression from wild emmer into common wheat and RFLP-based mapping 总被引：28，自引：0，他引：28
An Israeli accession (TTD140) of wild emmer, Triticum turgidum var. dicoccoides, was found resistant to several races of powdery mildew. Inoculation of the chromosome-arm substitution lines (CASLs) of
TTD140, in the background of the Israeli common wheat cultivar ‘Bethlehem’ (BL), with five isolates of powdery mildew revealed
that only the line carrying the short arm of chromosome 2B of wild emmer (CASL 2BS) exhibited complete resistance to four
of the five isolates. To map and tag the powdery mildew resistance gene, 41 recombinant substitution lines, derived from a
cross between BL and CASL 2BS, were used to construct a linkage map at the gene region. The map, which encompasses 69.5 cM
of the distal region of chromosome arm 2BS, contains six RFLP markers, a morphological marker (glaucousness inhibitor, W1
I), and the powdery mildew resistance gene. Segregation ratios for resistance in F2 of BL × CASL 2BS and in the recombinant lines, combined with the susceptability of F1 progeny to all tested isolates, indicate that resistance is controlled by a single recessive allele. This alleleco-segregated
with a polymorphic locus detected by the DNA marker Xwg516, 49.4 cM from the terminal marker Xcdo456. The new powdery mildew resistance gene was designated Pm26.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
9.
One hundred and eighty six F1 plants from a ‘Regent’ × ‘RedGlobe’ cross were used to generate a partial linkage map with 139 microsatellite markers spanning all 19 chromosomes. Phenotypic scores for downy mildew, taken over two years, confirmed a major resistance QTL (Rpv3) against downy mildew in the interval VVIN16-cjvh to UDV108 on chromosome 18 of ‘Regent’. This locus explained up to 62 % of the phenotypic variance observed. Additionally a putative minor downy mildew resistance locus was observed on chromosome 1 in one season. A major resistance locus against powdery mildew (Ren3) was also identified on chromosome 15 of ‘Regent’ in the interval UDV116 to VChr15CenGen06. This study established the efficacy of and validated the ‘Regent’-derived downy and powdery mildew major resistance genes/QTL under South African conditions. Closely linked SSR markers for marker-assisted selection and gene pyramiding strategies were identified. 相似文献
10.
Xuefei Ning Xianlei Wang Xingwang Gao Ziqiang Zhang Lihu Zhang Weili Yan Guan Li 《Euphytica》2014,195(3):345-353
Powdery mildew caused by Podosphaera xanthii is a major disease in melon. Here we report two Px race 1 strains named Px1A and Px1B in Xinjiang, which have different pathogenicities. The more pathogenic Px1B made some powdery mildew resistant genes on linkage group V (LGV) lose their resistant traits. The inheritances of resistance to Px1A and Px1B in melon Edisto47 were studied using a BC1 population derived from a cross between the resistant genotype Edisto47 and the susceptible cultivar Queen. The resistance/susceptibility segregation ratios observed in the Px1A-inoculated BC1 population and the loci of polymorphic markers indicated that resistance to Px1A was controlled by two dominant genes. Quantitative trait locus analysis identified two loci mapped on LGII and LGV, respectively, for powdery mildew resistance. However, for resistance to Px1B, Edisto47 was found to bear one dominant gene. A genetic linkage map was constructed using the Px1B-inoculated BC1 population to map the resistant gene. Comparative genomic analyses revealed that the linkage map of Pm-Edisto47-1 was collinear with the corresponding genomic region of the melon chromosome 2. Genetic analysis showed that Pm-Edisto47-1 was located between simple sequence repeat (SSR) markers CMGA36 and SSR252089, at a genetic distance of 2.1 cM to both markers. Synteny analysis showed that two genes named MELO3C015353 and MELO3C015354 were predicted as candidates for Edisto47-1 in this region. 相似文献
11.
Nine populations of rye (Secale cereale L.; the cultivars ‘Kustro’, ‘Danko’ and ‘Carokurz’. a breeding population PA 14/75 and five Iranian primitive ryes) were tested with three or two pathotypes of powder)’ mildew (Erysiphe graminis DC. f. sp. secalis Marchal) to determine the frequencies of vertical resistances. Similarly, three populations of powder)’ mildew isolated from the above eultivars were tested with two rye pathodemes to estimate the frequencies of vertical virulences. Tests were carried out on leaf segments cultivated in vitro. To explain the pattern of the host-parasite interaction, a model with at least four resistance and virulence genes was required. In the rye populations the genotypes of most plants could be determined unambiguously whereas in the powdery mildew populations no unique classification of one-postule isolates was possible due to the limited number of rye differentials. Both the host and the pathogen populations were polymorphic for resistance and virulence, respectively. In all lye populations except PA 14/75 the resistance frequencies were low. In the mildew populations the virulence frequencies were high and complex races occurred rather frequently. The virulence frequencies were related to the resistance frequencies of the respective host population. Results were compared with mathematical host-parasite models accounting for gene-for-gene interaction and balancing natural selection. Observations agree well with theory. 相似文献
12.
B. Chaitieng A. Kaga O. K. Han X. W. Wang S. Wongkaew P. Laosuwan N. Tomooka D. A. Vaughan 《Plant Breeding》2002,121(6):521-525
Both restriction fragment length polymorphism (RFLP) and amplified fragment length polymorphism (AFLP) analyses were employed to map a new source of resistance to powdery mildew in mungbean. Disease scores of an F2 population derived from the cross between a moderately resistant breeding line VC1210A and a susceptible wild relative (Vigna radiata var. sublobata, accession TC1966) showed a continuous distribution and was treated as a quantitative trait. Although no significant quantitative trait loci (QTL) that can explain the variation was detected by QTL analysis based on the reconstructed RFLP linkage map, new marker loci associated with resistance were discovered by AFLP analysis. The RFLP loci detected by two of the cloned AFLP bands are associated with resistance and constitute a new linkage group. A major resistance quantitative trait locus was found on this linkage group that accounted for 64.9% of the variation in resistance to powdery mildew. One of the probes developed in this study has the potential to assist in breeding for powdery mildew resistance in mungbean. 相似文献
13.
Two unnecessary powdery mildew resistance genes in a synthetic rye population are neutral on fitness
A synthetic winter rye population was produced with two race-specific powdery mildew resistance genes, one dominant (Rm1) and the other (rm2) recessive, each at a frequency of about 0.50. The population was advanced by open-pollination in an isolated plot under mildew-free conditions for eight years. Samples of generations Syn-0 through Syn-7 were inoculated in the laboratory with two mildew isolates, one avirulent to either resistance gene, the other virulent to Rm1 and avirulent to rm2, to discriminate resistant and susceptible phenotypes. From the proportions of resistant plants, frequencies of Rm1 and rm2 were calculated and the fitness of carriers of resistance alleles was estimated in relation to carriers of susceptibility alleles at the two loci using continuous models and linear regression analyses. Frequencies of the two resistance genes oscillated only weakly over the eight generations. Coefficients of selection against Rm1-and rm2rm2 genotypes were –0.04 and –0.02, respectively, and not significantly different from zero. Thus the two resistance genes were selectively neutral. It is concluded that pyramiding of major powdery mildew resistance genes in rye varieties should not reduce their yield potential in the absence of mildew. 相似文献
14.
Shuiyang Yu Hai Long Hong Yang Jie Zhang Guangbing Deng Zhifen Pan Erliang Zhang Maoqun Yu 《Euphytica》2012,186(1):247-255
Powdery mildew (Pm), caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most serious diseases for common wheat in many regions around the world. Seeking for new resistance source
is urgently required to meet the challenge of the rapid loss of resistance due to the co-evolution of the pathogen’s virulence.
Wheat line 07jian126 (Triticum aestivum L.) is highly resistant to the Pm disease prevailing in Sichuan province of China. Previous study showed that a SSR marker
Xbarc183 was linked to the Pm resistance in 07jian126, which might be controlled by a single dominant gene, designated as Pm07J126. In this study, two additional F2 populations were used to confirm the linkage between Pm07J126 and Xbarc183. Furthermore, rye chromatin was detected in 07jian126 by molecular analysis of a rye-specific SCAR marker O5 which co-segregated with Pm07J126. This result indicated that Pm07J126 might originate from rye. The reaction patterns to 21 Bgt isolates and molecular marker analysis implied that Pm07J126 might be different from the known rye-derived Pm genes Pm7, Pm8, Pm17 and PmJZHM2RL. Chromosome observation, molecular marker, and A-PAGE analysis suggested that 07jian126 might be a rye introgression line
and neither contain 1RS translocation nor secalins gene. Consequently, 07jian126 could be considered as a valuable resource
for Pm resistance development of wheat. Besides, the molecular markers Xbarc183 and O5 are useful in marker-assisted selection of Pm07J126 in wheat breeding programs. 相似文献
15.
Molecular markers for the major apple powdery mildew resistance gene Pl1 were identified and are presently used in marker-assisted selection in apple breeding. However, the precise map position of the Pl1 gene in the apple genome was not known. The objectives of this investigation were the identification of the Malus linkage group (LG) carrying the Pl1 locus, mapping of the resistance gene by simple sequence repeat (SSR) markers, and the analysis of genetic associations between the Pl1 gene and the numerous NBS-LRR resistance gene candidates already mapped in the apple genome. A two-step linkage mapping was used, based on two different apple families. The identification of LG 12 carrying Pl1 was performed indirectly by mapping the SCAR marker AT20 in an apple progeny for which there was a core genetic map but no mildew data available. Then, the position of Pl1 on LG 12 was determined by SSR markers in a second population which has been scored for mildew over 6 years in a greenhouse and in the field. The SSR Hi07f01, previously mapped on LG 12 [Tree Genet. Genomes, 2 (2006), 202] cosegregated with AT20 and was closely linked (∼1 cM) to the Pl1 gene. The TIR-NBS-LRR resistance gene analogue 15G11 mapped by the SSCP technique was also closely linked to the Pl1 resistance locus and might be a candidate for Pl1 itself, a second powdery mildew major resistance gene ( Pld , [Theor. Appl. Genet., 110 (2004), 175]), or two scab resistance genes ( Vg , [IOBC/WPRS Bull., 23 (2000), 245]; Vb , [Genome, 49 (2006), 1238]) which all seem to be located in a common R gene cluster at the distal end of apple LG 12. 相似文献
16.
One of the most important diseases of barley (Hordeum vulgare) is powdery mildew, caused by Blumeria graminis f. sp. hordei. Spring barley line 173-1-2 was selected from a Moroccan landrace and revealed broad-spectrum resistance to powdery mildew. The objective of this study was to map and characterize the gene for seedling powdery mildew resistance in this line. After crossing with the susceptible cultivar ‘Manchuria’, genetic analysis of F2 and F3 families at the seedling stage revealed powdery mildew resistance in line 173-1-2 conditioned by a single recessive gene. Molecular analysis of non-segregating homozygous resistant and homozygous susceptible F2 plants conducted on the DArTseq platform (Diversity Arrays Technology Pty Ltd) identified significant markers which were converted to allele-specific PCR markers and tested among 94 F2 individuals. The new resistance gene was mapped on the long arm of chromosome 6H. No other powdery mildew recessive resistance gene has been located on 6H so far. Therefore, we concluded that the 173-1-2 barley line carries a novel recessive resistance gene designated as mlmr. 相似文献
17.
E. Kooistra 《Euphytica》1971,20(4):521-523
Summary The flesh of ripe cucumber fruits can show different colours, varying from intense or dingy white to yellow and orange. These colours appear to be governed by two genes, for which the symbols V and W are proposed. If both genes are recessive, an orange colour is produced; if both are dominant they give a dirty white colour. No linkage with the genes for mildew resistance could be demonstrated.A very strong linkage was observed between mildew resistance and a dull green exterior fruit colour governed by one gene for which the symbol D is proposed. 相似文献
18.
Elizabeth Keep 《Euphytica》1985,34(3):865-868
Summary In black currant progenies derived from parents heterozygous for resistance to American gooseberry mildew. Sphaerotheca mors-uvae (Schw.) Berk., and to gall mite, Cecidophyopsis ribis
Westw. (genes Sph
2from the Swedish cultivar Öjebyn and Ce from Ribes grossularia L., respectively), there is invariably a defieit of mildew resistant plants. Linkage in repulsion between Sph
2and Ce would account for the significantly greater deficit of mildew resistants in the gall mite resistant class. In contrast with published data for the mildew resistance gene Sph
3, there is no evidence of linkage of Sph
2with the leafing out gene Lf
1, suggesting that the gene order is Sph
2-Ce-Lf
1-Sph
3. 相似文献
19.
与大白菜抗霜霉病基因连锁的分子标记研究 总被引：3，自引：0，他引：3
【研究目的】 研究与大白菜抗霜霉病基因紧密连锁的DNA分子标记。【方法】利用高抗自交系‘660’和高感自交系‘654B’及其杂交F2群体162个单株为材料,采用构建抗、感病池,利用BSA法筛选了87对SSR引物,35对拟南芥抗霜霉病相关基因的特异引物,其中特异引物RPP13P2和RPP131-2R在抗感病亲本和抗感病池中扩增出一条多态性片段RPP13MK,利用这对引物对F2代单株构建的分享群体进行扩增,验证标记RPP13MK与目的基因的连锁关系,Mapmaker 3.0软件计算遗传距离。【结果】通过F2单株验证后证明RPP13MK与抗霜霉病基因紧密连锁,其遗传距离为5.6 cM。【结论】获得了一个与大白菜抗霜霉病基因紧密连锁的分子标记RPP13MK。 相似文献
20.
The availability of molecular markers linked to mildew resistance genes would enhance the efficiency of apple-breeding programmes. This investigation focuses on the identification of random amplified polymorphic DNA (RAPD) markers linked to the Pl1 gene for mildew resistance, which has introgressed from Malus robusta into cultivated apples. The RAPD marker technique was combined with a modified ‘bulked seg-regant analysis’ mapping strategy. About 850 random decamer primers used as single primers or in combinations were tested by PCR analysis on the basis of resistant and susceptible DNA pools. Selected primers producing RAPD fragments were applied in an additional selection step to M. robusta and genotypes representing intermediate breeding stages of the breeding population 93/9, for which a 1:1 segregation could be observed for the resistance trait. Seven RAPD markers, all representing introgressed DNA sequences from M. robusta, were identified and arranged with the Pl1 locus in a common linkage group. The two most tightly-linked RAPD markers, OPAT20450 and OPD21000 were mapped with a genetic distance of 4.5 and 5 cM, respectively, from the Pl1 gene. Both markers are suitable for marker-assisted selection in apple breeding. The polymorphic DNA fragment OPAT20450 was cloned and sequenced, and longer primers for the generation of a sequence-characterized amplified region (SCAR) marker have been constructed; this marker was easier to score than the original RAPD marker. 相似文献