首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 879 毫秒
1.
Rice blast caused by Pyricularia oryzae is a devastating disease worldwide. In Vietnam, rice blast is especially severe in the Red River Delta in the North. The genetic diversity of 114 P. oryzae isolates collected from rice in 2001 in the Red River Delta and nine additional Vietnamese P. oryzae isolates was analysed using Amplified Fragment Length Polymorphism (AFLP). DNA similarity and cluster analysis based on 160 polymorphic AFLP markers showed twelve different AFLP genetic groups among the 123 field isolates. Isolates collected from japonica hosts clustered separately from indica host isolates with at least 60% dissimilarity with little evidence for gene flow between the two populations. In the 2001 population originating from indica hosts, three genetic groups were predominant and represented 99% of the isolates sampled. One predominant clonal lineage represented 59% of the 2001 indica host population and was found in eleven provinces in the Red River Delta of North Vietnam. Significant genotype flow could be demonstrated between the indica population south of Red river and the indica population north of Red river. There was significant linkage disequilibrium between the AFLP loci within the indica population, indicating that this is not a random mating population. Pathogenicity tests of 25 isolates selected from the 12 AFLP groups on a set of 29 differential rice lines revealed two avirulent isolates and 23 pathotypes. Different combinations of known resistance genes were found to have potential for blast resistance breeding for North Vietnam. First two authors contributed equally  相似文献   

2.
The objective of this study was to determine whether genetically distinct groups of Puccinia triticina are present in four regions of the Russian Federation. Collections of P. triticina were obtained from the Central, North Caucasus, Volga and West Siberia regions from 2006 to 2010. Ninety‐nine single uredinial isolates were tested for virulence phenotype with 20 Thatcher near‐isogenic lines of wheat. Forty‐one virulence phenotypes were found in the four regions, with eight in common between the widely separated Central and West Siberia regions. A total of 72 isolates were tested for molecular genotype with 23 simple sequence repeat (SSR) primer pairs, and 66 isolates were used for further analysis after clone correction for virulence and molecular genotype. Analysis of variation showed no overall differentiation of SSR genotypes or virulence phenotypes based on region of origin. Linkage disequilibria for SSR genotypes were high across the entire population. The regional populations had higher than expected levels of allelic heterozygosity that indicated clonal reproduction. Based on cluster analysis of SSR genotypes there were two groups of P. triticina isolates that were widely distributed across Russia. The two SSR groups also differed significantly for virulence. Puccinia triticina may be dispersed from a common source of inoculum in the European or Caucasus regions of Russia. The Russian P. triticina populations were highly differentiated for SSR genotype from populations in Tajikistan, Kyrgyzstan, Uzbekistan, Armenia, Georgia and Azerbaijan and more similar to populations from southern Kazakhstan and northern Kazakhstan.  相似文献   

3.
The distribution of two races (1 and 2) of Phialophora gregata f. sp. adzukicola, the causal agent of brown stem rot of adzuki bean, was examined using a total of 483 isolates obtained from 39 fields in 19 locations on Hokkaido, Japan between 1997 and 1999. Race 1 was predominant (416 isolates or 86.1%) in the commercial fields tested. Race 2 was found in 25 fields (64.1%), including two fields of cultivar Kita-no-otome (resistant to race 1, but susceptible to race 2), indicating that race 2 was widely distributed in most of the production areas in Hokkaido. Using amplified fragment length polymorphisms (AFLP), a total of 67 polymorphic AFLP markers was recorded among 72 representative isolates (37 and 35 isolates of races 1 and 2, respectively), and 57 distinct haplotypes were detected. Cluster analysis revealed no close correlation between races and AFLP groups. Thus, no difference was observed between values of gene diversity in each race (0.253 and 0.284 in races 1 and 2, respectively), and the coefficient of gene differentiation was very low (G ST =0.015). Gene differentiation between both races by analysis of molecular variance was not significantly different from zero (Φ=−0.001; p=0.403). However, the results of gene differentiation among regional populations (G ST =0.290, Φ=0.292; p<0.001) are not necessarily consistent with the result that isolates from the same district were generally not tightly clustered. Received 15 April 2002/ Accepted in revised form 6 September 2002  相似文献   

4.
The genetic diversity and relationships of 48 Lolium temulentum accessions derived from eight countries (Morocco, Egypt, Tunisia, Italy, Ethiopia, Pakistan, Nepal and Japan) were analysed using seven microsatellite and 44 AFLP polymorphic loci to investigate the origin and distribution of genetic variation. Cluster analysis was performed using the unweighted pair-group method with arithmetic averages (UPGMA) based on the simple matching coefficient of similarity. Nei's gene diversity (h) and the coefficient of gene differentiation (Gst) were calculated. The results from microsatellite analysis indicated that accessions from the same country did not always cluster together, probably because of the limited number of loci used. In contrast, AFLP clearly separated clusters between countries and/or regions; Pakistan–Nepal complex, the Mediterranean region, Ethiopia and Japan. The h value was much higher for microsatellite than for AFLP analysis, indicating that microsatellites are the more variable markers. For AFLP analyses, h values were highest in accessions from Pakistan–Nepal complex, and from the Mediterranean region. These are in agreement with proposals that the origin of L. temulentum lies between the South-western Asia and the Mediterranean basin. The clear groupings of accessions from each country and/or region with high Gst (0.688) indicate that exchange of seeds between them is limited.  相似文献   

5.
Kolmer JA  Ordoñez ME 《Phytopathology》2007,97(9):1141-1149
ABSTRACT Isolates of Puccinia triticina collected from common wheat in the Central Asia countries of Kazakhstan, Uzbekistan, Tajikistan, and Kyrgyzstan and the Caucasus countries of Azerbaijan, Georgia, and Armenia were tested for virulence to 20 isolines of Thatcher wheat with different leaf rust resistance genes and molecular genotype at 23 simple sequence repeat (SSR) loci. After clone correction within each country, 99 isolates were analyzed for measures of population diversity, variation at single SSR loci, and for genetic differentiation of virulence phenotypes and SSR genotypes. Isolates from Central Asia and the Caucasus were also compared with 16 P. triticina isolates collected from common wheat in North America that were representative of the virulence and molecular variation in this region and two isolates collected from durum wheat in France and the United States. Populations from the Caucasus, Uzbekistan, Tajikistan, and Kyrgyzstan were not significantly (P > 0.05) differentiated for SSR variation with F(st) and R(st) statistics. Populations from the Caucasus, Uzbekistan, Tajikistan, and Kyrgyzstan were significantly (P < 0.05) differentiated from the populations in South and North Kazakhstan for SSR variation. All populations from Central Asia and the Caucasus were significantly differentiated from the North American isolates and isolates from durum wheat for SSR variation and virulence phenotypes. There was a correlation between virulence phenotype and SSR genotype among individual isolates and at the population level. Mountain barriers may account for the differentiation of P. triticina geographic populations in Central Asia and the Caucasus.  相似文献   

6.
Ninety-six isolates of sunflower Sclerotinia sclerotiorum (Lib.) de Bary from Inner Mongolia (IM) in China, from Canada and the United Kingdom (UK) were sampled to investigate the genetic diversity and structure using Sequence-Related Amplified Polymorphism. A total of 123 polymorphic bands were obtained, ranging in size from 100 to 500 base pairs. The five populations of S. sclerotiorum isolated from the three countries showed various levels of genetic variability. The percentage of polymorphic loci varied from 30.89% in the UK population to 97.56% in the Middle IM population. The values of Shannon index (i) varied from 0.1876 in the UK population to 0.5301 in the West IM population. The heterozygosity of the five geographic populations obtained by estimating allele frequency varied from 12.91% in the UK population to 35.44% in the West IM population. The genetic identity, as indicated by the Nei unbiased identity index, ranged from 0.9744 between populations from Canada and East IM to 0.6477 between populations from West IM and UK. UPGMA cluster analysis using Nei’s genetic distance gave distances ranging from 0.0259 to 0.4343. The rates of gene flow among five geographic populations ranged from 1.5406 between West IM and UK populations to 18.4149 between West IM and Middle IM populations. The four populations from West IM, Middle IM, East IM and Canada were clustered into one subgroup in which the isolates from West and Middle IM belonged to one population, whereas those from East IM and Canada essentially were another population. The isolates from the UK formed a population that was significantly distinct from other populations.  相似文献   

7.
Rwt4 (synonym of Rmg1), a temperature-insensitive gene for resistance to Avena isolates of Magnaporthe oryzae, was identified in wheat cultivar Norin 4 in a seedling assay. The significance of Rwt4 was evaluated using flag leaves of wheat cultivars. At high temperature, Norin 4 was completely resistant to Avena isolate Br58, while Chinese Spring, a noncarrier of Rwt4, was susceptible. Genetic analysis of F2 plants derived from Norin 4 × Chinese Spring indicated that the resistance of flag leaves of Norin 4 to the Avena isolate is conditioned by a single major gene. Segregation analysis of F3 seedlings derived from the F2 plants showed that the major gene is actually Rwt4. These results suggest that Rwt4 is effective against Avena isolates throughout the growth stages. Furthermore, screening of Pyricularia isolates from various hosts suggested that Panicum isolates are possible carriers of the corresponding avirulence gene, PWT4. Segregation analyses of F2 and F3 seedlings showed that Panicum isolates actually carry PWT4, and, therefore, that Rwt4 is also effective against Panicum isolates. On the other hand, none of the Oryza, Setaria, Triticum, and Lolium isolates tested was a carrier of PWT4. The significance of this finding is discussed from the viewpoint of epidemics of blast disease on wheat.  相似文献   

8.
In vitro detached leaf assays involving artificial inoculation of wounded and unwounded oat and wheat leaves were used to investigate the potential pathogenicity and aggressiveness of F. langsethiae, which was linked recently to the production of type A trichothecenes, HT-2 and T-2 in cereals in Europe. In the first two experiments, two assays compared disease development by F. langsethiae with known fusarium head blight pathogen species each used as a composited inoculum (mixture of isolates) at 10°C and 20°C and found all fungal species to be pathogenic to oat and wheat leaves in the wounded leaf assay. In the unwounded leaf assay, F. langsethiae was not pathogenic to wheat leaves. Furthermore, there were highly significant differences in the aggressiveness of pathogens as measured by lesion length (P < 0.001). In the second two experiments, pathogenicity of individual F. langsethiae isolates previously used in the composite inoculum was investigated on three oat and three wheat varieties. The wounded leaf assay showed that all isolates were pathogenic to all oat and wheat varieties but only pathogenic towards oat varieties in the unwounded assay. Highly significant differences (P < 0.001) in lesion length were found between cereal varieties as well as between isolates in the wounded assay. Significant differences in lesion lengths (P = 0.014) were also observed between isolates in the unwounded assay. Results from the detached leaf assays suggest that F. langsethiae is a pathogen of wheat and oats and may have developed some host preference towards oats.  相似文献   

9.
Dynamics of chromosomal ends during meiosis was examined using a tetrad F1 population derived from a cross between Setaria and Triticum isolates of Magnaporthe oryzae. Telomeric fragments were liberated by six restriction enzymes and detected with a telomere probe. Each fragment was assigned to one of the 14 chromosomal ends using chromosome-specific markers. Size shifts and non-Mendelian segregation (4:0, 3:1, 1:3, and 0:4) were frequently observed in these telomeric fragments and were considered to be caused by deletion, insertion, point mutation, and gene conversion. Similar results were obtained in another tetrad F1 population derived from a cross between Oryza and Triticum isolates. These results suggest that subtelomeric regions are unstable during meiosis and are prone to various rearrangements including gene conversion.  相似文献   

10.
Seventy three isolates of Pythium aphanidermatum obtained from cucumber from four different regions of Oman and 16 isolates of muskmelon from the Batinah region in Oman were characterized for aggressiveness, sensitivity to metalaxyl and genetic diversity using AFLP fingerprinting. Twenty isolates of P. aphanidermatum from diverse hosts from different countries were also included in the study. Most isolates from Oman were found to be aggressive on cucumber seedlings and all were highly sensitive to metalaxyl (EC50 < 0·80 µg mL?1). Isolates from cucumber and muskmelon were as aggressive as each other on both hosts (P > 0·05), which implies a lack of host specialization in P. aphanidermatum on these two hosts in Oman. AFLP analysis of all isolates using four primer–pair combinations resolved 152 bands, of which 61 (~40%) were polymorphic. Isolates of P. aphanidermatum from Oman and other countries exhibited high genetic similarity (mean = 94·1%) and produced 59 different AFLP profiles. Analysis of molecular variance indicated that most AFLP variation among populations of P. aphanidermatum in Oman was associated with geographical regions (FST = 0·118; P < 0·0001), not hosts (FST = –0·004; P = 0·4323). These data were supported by the high rate of recovery (24%) of identical phenotypes between cucumber and muskmelon fields in the same region as compared to the low recovery (10%) across regions in Oman, which suggests more frequent movement of Pythium inoculum among muskmelon and cucumber fields in the same region compared to movement across geographically separated regions. However, recovering clones among regions and different countries may imply circulation of Pythium inoculum via common sources in Oman and also intercontinental spread of isolates.  相似文献   

11.
To assess the genetic relationships of Botrytis cinerea populations in Almería (Spain), 44 isolates of B. cinerea, collected from six commercial greenhouses (subpopulations), were analysed by Random Amplified Polymorphic DNA (RAPD) and amplified-fragment length polymorphism (AFLP). Polymorphisms were more frequently detected per primer with AFLP than with RAPD (16 compared to 4). However, RAPD detected polymorphisms more frequently per loci than AFLP (56% compared to 32%). The analysis of population structure revealed that the genetic diversity within subpopulations (HS) accounted for 96% of the total genetic diversity (HT) , while genetic diversity among subpopulations represented only 4% of the total diversity, independently of whether they were analysed with RAPD or AFLP markers. The relative magnitude of gene differentiation between subpopulations (GST) and the estimate of the number of migrants per generation (Nm) averaged similar values when estimated with RAPD or AFLP markers (0.039 and 0.036, or 12.32 and 13.39, respectively). The results obtained in dendrograms were in accordance with the gene diversity analysis. However, the diversity of B. cinerea was higher when analysed by RAPD than with AFLP. In these cases, the isolates could not be grouped by greenhouse or fungicide resistance (except those sensitive to carbendazim and resistant to procymidone). Both the RAPD and AFLP technologies are suitable for studies of genetic structure of B. cinerea populations, although RAPD generated more polymorphisms per loci than AFLP, and provided a better explanation of the genetic relationships between isolates.  相似文献   

12.
The objective of the current study was to characterize Fusarium oxysporum f. sp. radicis-cucumerinum isolates from cucumbers in Turkey in terms of pathogenicity, vegetative compatibility and amplified fragment length polymorphism (AFLP) variation. In the 2007 and 2008 greenhouse cucumber-growing seasons, surveys were conducted in Adana, Antalya, Hatay and Mersin provinces of the Mediterranean region of Turkey. Forty-seven fungal isolates of F. oxysporum were recovered from diseased cucumber plants. The pathogenicity of each isolate was tested on cucumber seedlings at the one-true-leaf stage. Forty of the 47 isolates of F. oxysporum were virulent on cucumber seedlings. Based on disease symptoms, the differential effect of temperatures of 17°C and 29°C on disease development, and the virulence on cucumber seedlings, these 40 isolates were identified as F. oxysporum f. sp. radicis-cucumerinum. Nitrate non-utilizing mutants were generated on minimal medium containing 1.5% KClO3 and their phenotypes were determined. Mutants in different phenotypic classes were paired on minimal medium; of 40 F. oxysporum f. sp. radicis-cucumerinum isolates, thirty-eight were placed into VCG 0260. Remaining two strains were assigned to VCG 0261. The AFLP primers produced a total of 180 fragments between 200 and 500 bp in length for the 30 isolates tested. At a genetic similarity of 0.71, the UPGMA analysis separated the isolates into two distinct clusters. The first cluster, AFLP I, included 28 isolates, of which all belonged to VCG 0260. Two strains in the second AFLP cluster both belonged to VCG 0261.  相似文献   

13.
The population structure of Alternaria species associated with potato foliar diseases in China has not been previously examined thoroughly. Between 2010 and 2013, a total of 511 Alternaria isolates were obtained from diseased potato leaves sampled in 16 provinces, autonomous regions or municipalities of China. Based on morphological traits and molecular characteristics, all the isolates were identified as Alternaria tenuissima, A. alternata or A. solani. Of the three species, A. tenuissima was the most prevalent (75·5%), followed by A. alternata (18·6%) and A. solani (5·9%). Phylogenetic analysis based on sequences of the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) of representative Alternaria isolates showed that A. solani was distinct from the two small‐spored Alternaria species. Phylogenetic analysis of the partial coding sequence of the histone 3 gene divided the same collection of isolates into three main clades representing A. tenuissima, A. alternata and A. solani, respectively. The pathogenicity of the isolates on detached leaves of potato cv. Favorite did not differ significantly between the three species or between isolates from different geographical origins. The results indicate that the population structure of Alternaria species associated with potato foliar diseases differs from that reported previously in China. This is the first report of A. tenuissima causing potato foliar diseases in China.  相似文献   

14.
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive wheat diseases in China. Yunnan Province, located in south-western China, possesses unique features of geography, climate, wheat growth and stripe rust epidemics, different from main epidemic regions in China. The isolates of this pathogen were collected from nine counties in Yunnan Province during February to May of 2008. Used as a comparison, isolates were also collected from five counties of Gansu Province, the province important in inter-regional stripe rust epidemics in China. Amplified fragment length polymorphism (AFLP) method was applied to study the population genetics of the pathogen among different populations in these two provinces. Forty one AFLP genotypes were obtained from 150 isolates and the genotype qj3 showed the highest frequency in Yunnan Province. While 22 genotypes were detected from 40 isolates, no genotype showing as predominant was identified in Gansu Province. Genotypic diversity in Gansu Province was higher than that in Yunnan Province. A free recombination signature was detected in Gansu Province but not in Yunnan Province. We concluded that the population of P. striiformis in Yunnan Province can be considered as a clonal population.  相似文献   

15.
Stemphylium vesicarium (teleomorph: Pleospora herbarum) is the causal agent of brown spot disease in pear. The species is also able to cause disease in asparagus, onion and other crops. Saprophytic growth of the fungus on plant debris is common. The objective of this study was to investigate whether isolates of S. vesicarium from different hosts can be pathogenic to pear. More than hundred isolates of Stemphylium spp. were obtained from infected pear fruits, dead pear leaves, dead grass leaves present in pear orchard lawns as well as from necrotic leaf parts of asparagus and onion. Only isolates originating from pear orchards, including isolates from dead grass leaves, were pathogenic on pear leaves or fruits in bioassays. Non-pathogenic isolates were also present in pear orchards. Stemphylium vesicarium from asparagus or onion, with one exception, were not pathogenic to pear. Analysis of the genetic variation between isolates using Amplified Fragment Length Polymorphism (AFLP) showed significant concordance with host plants. Isolates from asparagus or onion belonged to clusters separate from the cluster with isolates from pear or grass leaves collected in pear orchards. Multilocus sequencing of a subset of isolates showed that such isolates were similar to S. vesicarium.  相似文献   

16.
Phaeomoniella chlamydospora, (Chaetothyriales, Herpotrichiellaceae) is one of the main causal agents of Petri disease and esca on grapevines. We have used AFLP markers to study the population genetic structure of 74 isolates collected at different spatial scales: 56 isolates originated from vines with esca disease sampled from four French vineyards (Poitou-Charentes, Aquitaine, Languedoc-Roussillon, Alsace); 18 isolates were collected from a single plot (Aquitaine vineyard). Significant linkage disequilibrium indicated that P. chlamydospora populations are not panmictic, whereas the level of haplotypic diversity observed, 72 single multilocus haplotypes identified in total among the 74 isolates analysed, suggest that reproduction in this species may not be strictly clonal. Clustering analyses suggests the presence of two genetically differentiated but sympatric clusters of isolates. The level of differentiation between the two clusters is high (F ST = 0.23) and significant at 13 out of the 21 loci analyzed. The most plausible explanation for this pattern of admixture is the coexistence in P. chlamydospora French populations of two predominant clonal lineages. Finally, the low level of spatial genetic differentiation in this study is consistent with the spread of this fungus through the transport of infected plant material by human activities.  相似文献   

17.
Dieback of European ash was first observed in Europe in the early 1990s. The disease is caused by the invasive ascomycete Hymenoscyphus fraxineus, proposed to originate from Far East Asia, where it has been considered a harmless saprotroph. This study investigates the occurrence of H. fraxineus in tissues of local ash species in the Russian Far East, and assesses its population‐specific genetic variation by ITS sequencing. Shoot dieback symptoms, characteristic of H. fraxineus infection on European ash, were common, but not abundant, on Fraxinus mandshurica and Fraxinus rhynchophylla trees in Far East Russia. High levels of pathogen DNA were associated with necrotic leaf tissues of these ash species, indicating that the local H. fraxineus population is pathogenic to their leaves. However, the low levels of H. fraxineus DNA detected in shoots with symptoms, the failure to isolate this fungus from such tissues, and the presence of other fungi with pathogenic potential in shoots with symptoms indicate that local H. fraxineus strains may not be responsible (or their role is negligible) for the observed ash shoot dieback symptoms in the region. Conspicuous differences in ITS rDNA sequences detected between H. fraxineus isolates from Russian Far East and European populations suggest that the current ash dieback epidemic in Europe might not directly originate from the Russian Far East. Revision of the herbarium material shows that the earliest specimen of H. fraxineus was collected in 1962 from the Russian Far East and the oldest H. fraxineus specimen of China was collected in 2004.  相似文献   

18.
We examined whether PWT4, an avirulence gene of Avena isolates of Magnaporthe oryzae toward wheat, corresponded to Rwt4, a resistance gene identified in wheat cultivar Norin 4, in a one-to-one manner. Twelve wheat cultivars were inoculated with 65X1, an F1 culture with PWT4 derived from a cross between an Avena isolate (Br58) and a Triticum isolate (Br48). Three wheat cultivars (Norin 26, Shin-chunaga, Cheyenne) were resistant and therefore selected as possible carriers of Rwt4. The three cultivars were then inoculated with a population derived from a backcross of 61M2 carrying PWT4 with Br48 carrying pwt4. Segregation analyses revealed that PWT4 operates against the three cultivars. If PWT4 corresponds to Rwt4 in a one-to-one manner, all three cultivars should carry Rwt4. To test if this is the case, the three cultivars were crossed with Chinese Spring (a noncarrier of Rwt4) and Norin 4. When F2 seedlings from Chinese Spring × Norin 26, Chinese Spring × Shin-chunaga, and Chinese Spring × Cheyenne were inoculated with 61M2, resistant and susceptible seedlings segregated in a 3 : 1 ratio. On the other hand, crosses between the three cultivars and Norin 4 yielded no susceptible F2 seedlings. These results indicate that all three cultivars carry Rwt4. Considering all results, we concluded that PWT4 corresponds to Rwt4 in a one-to-one manner. An inoculation test with Chinese Spring–Cheyenne chromosome substitution lines indicated that Rwt4 is located on chromosome 1D.  相似文献   

19.
The objective of this study was to determine whether genetically differentiated groups of Puccinia triticina are present in Europe. In total, 133 isolates of P. triticina collected from western Europe, central Europe and Turkey were tested for virulence on 20 lines of wheat with single leaf rust resistance genes, and for molecular genotypes with 23 simple sequence repeat (SSR) markers. After removal of isolates with identical virulence and SSR genotype within countries, 121 isolates were retained for further analysis. Isolates were grouped based on SSR genotypes using a Bayesian approach and a genetic distance method. Both methods optimally placed the isolates into eight European (EU) groups of P. triticina SSR genotypes. Seven of the groups had virulence characteristics of isolates collected from common hexaploid wheat, and one of the groups had virulence characteristics of isolates from tetraploid durum wheat. There was a significant correlation between the SSR genotypes and virulence phenotypes of the isolates. All EU groups had observed values of heterozygosity greater than expected and significant fixation values, which indicated the clonal reproduction of urediniospores in the overall population. Linkage disequilibria for SSR genotypes were high across the entire population and within countries. The overall values of RST and FST were lower when isolates were grouped by country, which indicated the migration of isolates within Europe. The European population of P. triticina had higher levels of genetic differentiation compared to other continental populations.  相似文献   

20.
A Japanese differential rice cultivar K60 was tested with 114 F1 cultures of Magnaporthe oryzae from a cross between isolates 84R-62B and Y93-245c-2. Segregation patterns of avirulence and virulence in the progeny suggested that avirulence on cv. K60 was controlled by a single gene derived from 84R-62B and tentatively named AvrK60. In the F1 population, AvrK60 cosegregated with avirulence gene AvrPik on a small 1.6-Mb chromosome of 84R-62B and with the 1.6-Mb chromosome itself. Therefore, we suggest that, along with AvrPik, AvrK60 is also located on the 1.6-Mb chromosome of 84R-62B.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号