جستجوی مقالات مرتبط با کلیدواژه "زنگ زرد" در نشریات گروه "بیوتکنولوژی و ژنتیک گیاهی"

Fungal diseases, especially leaf and stripe rusts are wheat yield reducing factors in Iran and the world. In this study, genetic diversity of 20 wheat varieties with different response to leaf and stripe rusts were studied using primers designed based on the conserved regions of plant disease resistance genes. The banding patterns of polymorphic markers were scored as dominant and number of amplified bands and percentage of polymorphism were determined. In addition, for each primer combination, polymorphic information content (PIC) and marker index (MI) were calculated. Out of the 11 used single primers and primer combinations, five primer combinations and a single primer produced scorable amplification. The maximum and minimum of PIC were observed for LLOOP-1 and H2016-H2020 primer combination with mean value of 0.50 and 0.28, respectively. The primer combinations of H2016-H1146 and H2016-H2020 with mean values of 4.80 and of 2.84, had minimum and maximum of MI, respectively. Cluster analysis based on Neighbor-Joining algorithm and evolutionary P-distance coefficient assigned the varieties into four groups which were in agreement with their response to yellow rust. In principal coordinate analysis, the scatter plot of varieties based on two first coordinates confirmed the groups obtained from cluster analysis.

Yellow or stripe rust caused by Puccinia striiformis f. sp. tritici, is the most important disease in terms of the amount of damages to wheat crop in the worldwide. The best method used to control this disease is the application of resistant cultivars. So, It is absolutely necessary for determine the virulence factors of stripe rust and evaluation of host resistance in different growing level. To study evaluation of resistance sources to stripe rust, twenty wheat genotypes were separately evaluated in the forms of randomized complete block design with three replications in the seedling stage under greenhouse condition with 20 races of stripe rust 6E158A, 230E158A, 198E150A, 134E150A, 6E150A, 166E150A, 198E130A, 166E158A, 70E0A, 6E16A, 102E134A, 6E134A, 6E130A, 6E150A, 6E6A, 70E50A, 6E18A, 134E22A, 166E254A and166E134A. The components of resistance including latent period and infection type were recorded under greenhouse condition. Results indicated genotypes were evaluated in terms of both traits were significant at 1% level. 30% genotypes (Mv17, M-85-7, Aflak, Morvarid, Sivand and Parsi) were completing resistant to all races studied. Probably, in resistant genotypes each of the resistance genes, Yr1, Yr3, Yr4, Yr5, Yr10, Yr15,Yr24 or the other unknown genes which are types of seedling resistance are either alone or in combination of one another cause strength in resistant genotypes. Resistant genotypes have seedling resistance genes, which could be used as resistance source in breeding programs.

Yellow، leaf and stem rusts are among the most devastating diseases of wheat in Iran and worldwide. The use of resistant cultivars is the most effective and economic approach to control these diseases. To date، a significant number of molecular markers linked to the resistance loci to these diseases have been identified. In this study، pre-released wheat lines of four major wheat climate zones of Iran were evaluated for the presence or absence of molecular markers linked to 11 resistance loci including Lr46/Yr29/Pm39، Lr34/Yr18/Pm38، Lr67/Yr46، Sr2/PBC، Sr24/Lr24، Sr26، Sr31/Yr9/Lr26، L21، Sr38/Yr17/Lr37، SrCad and Lr29. The results showed that Lr46/Yr29/Pm39، Lr34/Yr18/Pm38 and Lr67/Yr46 loci existed in four and five genotypes، respectively، while Sr31/Yr9/Lr26 and Sr38/Yr17/Lr37 loci existed only in one genotype. The remaining genotypes did not possess markers linked to resistance loci tested in this study. The results showed that the frequency of presence of these loci in pre-released lines is low and، thus، lines possessing the resistance loci should be incorporated in wheat breeding programs in order to increase the frequency of the resistance genes in new cultivars.

to study the inheritance of stripe rust resistance and to estimate the genetic components of resistance in wheat, F1, F2, BC1 and BC2 generations derived from crosses between two resistant cultivars and one susceptible cultivar (Bolani) along with parental lines were evaluated in a randomized complete block design (RCBD) with three replications in greenhouse. The plant materials were inoculated with pathotype 4E0A+ of stripe rust. In all plants, resistance components including latent period and infection type were recorded after appearance of pustules on leaves. Generation mean analysis revealed that additive, dominance and epistasis play major roles in increasing and decreasing of latent period and infection type, respectively. In spite of significant additive effect, dominance effect was more important in controlling these two characteristics. Broad sense heritability and narrow sense heritability estimates for latent period was 0.33 and 0.28 and for infection type was 0.42 and 0.39 respectively

In order to study the relationships among components of resistance to yellow rust (Puccinia striiformis f.sp. tritici), 47 wheat genotypes of national plant gene bank of Iran were assessed by 4 pathotypes of 6E6A+, 134E134A+, 134E142A+ and 6E4A+ at seedling stage. Correlation Analysis among components of resistance showed that association between latent period and pustule density was not influenced by the pathotype but relationship between latent period and pustule size was affected bythe pathotype of the pathogen. Principal component analysis based on components of resistance, for each pathotype separately, indicated that latent period have the largest effect on the variation of relating principal components. Principal component analysis based on components of resistance for all pathotypes showed that the first 4 components justified 81% of the total variation in the data. Coefficients of traits revealed that the first principal component indicates susceptibility to all pathotypes and the second principal component indicates specific resistance to pathotypes of 134E134A+ and 6E4A+ and sensitivity to pathotypes of 6E6A+ and 134E142A+. Studied genotypes were divided into two groups of resistant and susceptible by cluster analysis through UPGMA method based on principal components. The results of this investigation demonstrated that latent period could be a suitable replacement for other components of resistance to yellow rust in order to select superior genotypes.