Race Analysis of Puccinia Striiformis f.sp. Tritici in Iran

Globally, wheat is an important crop; as a strategic plant it occupies the largest area of cultivation. Puccinia striiformis f.sp. tritici, known as yellow rust, caused the embrace damage and epidemic in Iran. Resistance cultivars are known to be the best way to control and prevent the spread of rust. This research studied the genetics of the pathogenicity of 26 isolates of stripe rust from different important wheat-growing areas in Iran; 56 differential and isogenic lines were used with a Bolani susceptible check, under greenhouse condition. Race 6E6A+,Yr27 from Neishabour (Eshgh Abad) and 7E22A+,Yr27 from Kermanshah were found to be less aggressive races in this research and races 206E182A+,Yr27 from Islam Abad, 207E190A+,Yr27 from Fars and race 231E150A+,Yr27 from Mashhad, with more than 19 known wheat genes, were the most aggressive races. Results of this research were that virulence was observed on plants with genes Yr1, Yr2, Yr3, Yr6, Yr7, Yr8, Yr9, Yr18, Yr21, Yr25, Yr26, Yr28, Yr29, Yr31, Yr32, YrSU, YrND, YrCV and YrA. No virulence was detected on plants with genes Yr4, Yr5, Yr10, Yr15, Yr24 and YrSP

Trends in important agronomic traits, grain yield and its components in bread wheat cultivars released in northern warm and humid climate of Iran, 1968–2018

Investigating the relationship between grain yield and main agronomic traits and understanding the trend of changes in traits during breeding history are important for breeding strategies. In order to determine the trend of changes in improved wheat cultivars and calculate the genetic gain of yield and related traits, 20 spring wheat cultivars released for the northern climate of the Iran during the years 1968 to 2018 were evaluated. Cultivars were cultivated in a randomized complete block design with three replications in Gorgan, Gonbad, Sari and Moghan in three consecutive years (2015–18). Morphological and phenological traits and grain yield and related traits were assessed in each year. Linear regression analysis between investigated characteristics and year of cultivar release showed that the grain yield, biological yield, harvest index, number of spikes per square meter, thousand-kernel weight and grain filling rate were significantly increased. No significant changes, however, were observed during breeding programs in maturity-related traits such as days to heading, days to anthesis, days to maturity, duration of grain filling, plant height, peduncle length, spike length and number of grains per spike. According to the positive and significant correlation between biomass, harvest index, number of spikes per square meter and thousand-kernel weight with grain yield, it seems that breeders in the northern climate of the country have been selected these traits to increase grain yield during the process of breeding cultivars

Evaluation of Grain Yield Stability in Some Selected Wheat Genotypes Using AMMI and GGE Biplot Methods

Wheat Triticum aestivum L. is one of the most important agricultural products, and meets the highest nutritional needs of humans in various countries. This study aims to evaluate the compatibility and stability of 25 wheat genotypes for two crop years in five regions (Karaj, Qazvin, Isfahan, Varamin and Damavand) in a randomized complete block design with three replications. The results of variance analysis in the additive main effects and multiplication interaction (AMMI) method showed that the effect of genotype and the genotype × environment interaction in the first, second, and mean two crop years had a significant difference at the level of one percent probability. Based on the results obtained from the first and second principal components, G8, G4 and G22 genotypes were identified as superior genotypes. Isfahan was an ideal environment for this study. The results obtained from the comparison of the Duncan method showed that G14, G12, and G1 genotypes had suitable ranks. Graphical analysis was used to study the genotypes of wheat and the environment, and the genotype × environment interaction. Based on the ranking genotypes in the first and second principal components and an average of two years, G2 and G21 genotypes were identified as high yielding, and G21 genotypes as stable. G18 and G23 genotypes were selected as the best genotypes in all three experimental periods, based on the multidimensional diagram. The results of the ideal genotype diagram were G12 and G21 genotypes; and based on the results of the ideal environment diagram, Damavand and Varamin environments were identified as ideal environments. AMM1 covered 69.6% and AMMI2 75.6% of the data variance in the first year of the experiment. In the second crop year, 78.1% of the total variance of the data was explained based on the AMMI1, and 71.1% based on the AMM2