hoseinali fallahi

Wheat powdery mildew caused by the biotrophic fungus Blumeria graminis f. sp. tritici, is a serious threat to wheat production in many regions of the world. This disease can reduce the yield up to 45% and reduce the quality of the grains by affecting the flour protein. Due to the adoption of high-yield crop systems that require high use of nitrogen fertilizers and high irrigation, as well as due to climate changes towards milder winters and increased rainfall in wheat production areas, the importance of powdery mildew disease is also increasing. One of the most useful strategies to control powdery mildew disease is to identify the sources of resistance among germplasm, which is also known as the most economical method among farmers. This research was conducted to identify resistant genetic samples to powdery mildew in the bread wheat collection of the National Plant Gene Bank of Iran.

The plant materials of this research were 173 accessions of bread wheat from the collection of the National Plant Gene Bank of Iran received from different countries, which were investigated to identify the sources of resistance to powdery mildew under natural incidence conditions at the research stations of Gorgan and Sari as the disease hotspots during three crop years (2018-2021). A two-digit scoring system was used to evaluate the response of the genotypes to the disease, in which the first digit is measured based on the infection development in plant height and the second is measured based on the disease severity in terms of the infection percentage on flag leaf surface. Then, by combining these two criteria, disease development and disease severity, the infection coefficient was calculated and used for the statistical analysis. K-means cluster analysis was used to group the germplasm and determination function analysis based on principal components was used to confirm the cluster analysis results. The relationship between the reaction of accessions in different years and locations was also investigated using multidimensional scaling analysis, and then the stability of the studied accessions over the experimental years and locations was investigated using the Wricke’s equivalence stability criterion based on the infection coefficient.

The results of this experiment showed that the average coefficient of infection during the studied three crop years varied from 0.05 to 0.29 percentage in Sari station and from 0.25 to 0.29 percentage in Gorgan station. The studied genetic materials were separated into five groups using K-means cluster analysis, and the fourth group consisting of 68 accessions was identified as the most resistant group. Based on the results of this experiment, the accessions KC 5292 (Turkey) and KC 5824 (Austria) were identified as the resistant genotype, and the accessions KC 5389, KC 5579 and KC 5476 (Iran), KC 5772, KC 5773 and KC 5384 (Afghanistan), KC 5133 and KC 5147 (Portugal), KC 5715 (Japan) and KC 5801 (unknown origin) as the resistant to semi-resistant genotype, and had the most stable response to the disease in various environments.

The results of the current research showed that there is a suitable genetic capacity to identify sources of powdery mildew resistance in wheat genetic stocks. The superior and resistant genetic materials identified in this research can be used to improve resistance to powdery mildew in wheat in the future breeding programs.

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.

The most important cereal Barley and due to the high compatibility of different environments screw. In order to evaluate the agronomic morphophysiological trait of barley, 103 families F3 of a cross Becher × Kavir in randomized complete block design with three replications at the Agricultural Research Station of Gonbad kavus was cultured.The most important traits measured, grain yield, number of spike, number of grains per spike, biological yield, total weight and length spike Analysis of variance showed that all traits except plant height was a positive and significant. Results the comparison average showed the highest and least grain yield was related 87(8572.8) and 6(1946.3) families. The highest correlation coefficient was related to grain yield and biological yield (r=0.68**). Cluster analysis divided families into four groups that it of 55 families was the largest group. The highest grain yield (7187/05) and the total number of spikes (639/56) belong to the second group, as well as for grain weight (29/50) and number of grains per spike (44/08) highest the amount was in the first group. Stepwise regression analysis biological yield the first adjective, grain yield model and 0.470 of the changes to be justified. Path analysis showed that biological yield (1.016) highest strong and direct impact on yield. Identify the attributes and the relationship between them it is necessary to determine the selection criteria and can be effective in the selection of high yielding genotypes.

Irrigated barley is grown on about 50,000 hectares in the warm agro-climate zone in the south of Iran. The average grain yield of barley in these areas is 2,000 Kg/ha. Wide adaptability and high grain yield stability are important assets for barley varieties to be grown by farmers. Zahak barley cultivar was initially selected from international barley germplasm received from CYMMIT and based on its high grain yield and yield stability as well as its desirable agronomic characteristics in the experiments, which were conducted from 1996 to 2010, was released for growing in the warm agro-climate zone in the south of Iran. The average grain yield of Zahak is 4846 kg/ha that is 524 kg/ha higher than grain yield recorded for Nimrooz variety, a widely-grown barley variety in the warm regions of Iran. Zahak is six-rowed spring barley with a medium plant height (85-90 cm). The average of days from sowing to maturity for Zahak is 138 days but it has a longer grain filling period comparing to the older barley cultivars in southern parts of Iran such as Jonoob and Nimrooz. Possessing fertile florets at the lower spikelets of the mature spike is other important characteristic of Zahak. In addition, it exhibits lodging resistance, non-shattering rachis as well as semi-resistant infection responses to powdery mildew and spot blotch diseases in the most of warm agro-climate zone in the south of Iran.

This study was conducted to evaluate 13 promising triticale lines and cultivars based on yield traits, metabolizable energy and anti-nutritional compounds. The experiment was carried out using a RCB design with three replications at the Seed and Plant Improvement Institute, Karaj and Gonbad, during 2008-2009 cropping season. These genotypes were studied in the next year, at the Animal Science Research Institute for their metabolizable energy and anti-nutritional compounds traits. Analyses of variance indicated significant differences for grain filling period, thousand kernel weight, harvest index and plant height traits. According to the final results the experimental lines ET-85-9, ET-84-15, ET-79-3 and ET-79-4 were superior in metabolizable energy and cultivar Sanabad had the lowest arabinoxylane and the highest grain yield; therefore, these lines were advanced to the next year for further studies under on- farm conditions.