جستجوی مقالات مرتبط با کلیدواژه « virulence » در نشریات گروه « بیوتکنولوژی و ژنتیک گیاهی »

Barley yellow rust is one of the important barley diseases in the world. However, the importance of this disease has recently increased in Iran. The main aim of the present study was to identify the sources of resistance to this disease in a collection of Iranian barley genotypes provided from the National Plant Gene Bank of Iran (NPGBI). For this purpose, a set of 128 accessions of the north and northwest regions of Iran were assessed in terms of resistance components such as disease severity, infection type and coefficient of infection under natural incidence of the disease in the field of Ardebil Research Station as a hotspot region for barley yellow rust during 2019-2022 cropping seasons. The results indicated a considerable genetic diversity among the tested genetic materials in response to this disease. A moderate correlation was observed between the evaluations of different years. The accessions were separated into five groups using cluster analysis, and the second group with 41 members with the lowest infection coefficient average was identified as the most resistant group. The results of this research showed the high capacity of the collection to identify sources of resistance to barley yellow rust disease. The identified resistant germplasm can be used in breeding programs for resistance to this disease.

Wheat powdery mildew caused by fungal pathogen Blumeria graminis f.sp. tritici is a destructive wheat disease, occurring in regions with cool and humid climates. In order to investigate the changes in pathogenicity of the disease and to identify the effective genetic source of resistance, a total of 29 wheat genotypes with different resistance major genes (Pm) were studied in two hotspots of Gorgan and Sari under natural incidence of the disease over 2015-2018. Resistance reaction of the genotypes was evaluated by disease development, disease severity and coefficient of infection. The results indicated that mean of coefficient of infection for Gorgan was larger than that for Sari in all three years of the study. The reaction of some genotypes showed apparent differences between the two regions during the years of study. The highest genetic distance was observed between Ralle (Pm3d) and Holger (Pm6). NK-747 (Pm6) and Maris Huntsman (Pm2+Pm6) as well as Amigo (Pm17) and Maris Huntsman (Pm2+Pm6) showed the highest genetic similarities to each other. A total of 65.78% of the data variation was justified by principal component analysis on the basis of the coefficient of infection. The genotypes Maris Dove (Mld+Pm2), Shamrock (with unknown Pm), Broom (Pm3d) and Axona (Pm2+Pm3d+Mld) expressed effective resistance over the years and locations. The total results of this research indicated variations in the virulence of wheat powdery mildew population during the years of the experiment. This finding emphasizes on the necessity of constant monitoring of the disease in the infected areas. The genes with effective resistance identified in this study could be used in resistance breeding to powdery mildew especially for Gorgan and Sari.