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Introduction: Breeding experiments initiated with the examination of segregating generations serve as a significant source for creating genetic diversity, continuing with comparing genotypes in preliminary, advanced, and adaptability performance trials. Superior lines require further investigation under real farm conditions. Selected lines, along with common regional varieties, were assessed in performance comparison experiments, categorized as On-farm trials. These comparisons aim to evaluate new lines against traditional varieties concerning higher grain yield, disease resistance, early maturity, and lower water consumption outside of the research station areas. Additionally, conducting these trials on farmers' fields enhances the awareness of farmers, experts, and extension agents regarding the characteristics of new lines. Materials and methods: This study aimed to compare the agronomic and quality traits of three promising bread wheat lines (S-98-7, S-98- 11, and S-98-22) with the local control variety Merghan in the warm climates of Fasa and Darab during the cropping season 2022-2023. The seed rate was set at 400 seeds per square meter (equivalent to 180 kg per hectare) over 2000 square meters. Data on days to germination, spike emergence, physiological maturity, number of grains per spike, number of spikes per square meter, sensitive to shedding, plant height, lodging, grain yield, thousand-grain weight, and major plant diseases (yellow rust, stem rust, brown rust, septoria leaf blotch, and septoria strip blotch) were recorded. Quality traits related to baking (protein content, Zeleny mix volume, hardness index, wet gluten percentage, gluten index, SDS sedimentation, and hectoliter weight) were analyzed to examine the nutritional value. Results: Results indicated no significant differences in the number of days to physiological maturity among the tested genotypes. Based on the results from Darab, Fasa, and the average of both experiments, Line S-98-22 yielded the highest grain production (10,006; 9,880; and 9,943 kg per hectare, respectively) compared to the control yield (Darab: 9,947 kg per hectare, Fasa: 8,571 kg per hectare, and average of both regions: 9,259 kg per hectare). Observations in both regions indicated no lodging or the presence of leaf blotch diseases (septoria leaf blotch, bacterial strip blotch, yellow rust, brown rust, and stem rust), with only 5% yellow rust reported in the control variety in the Fasa trial and 5% lodging in the control variety in the Darab trial. Ultimately, the Selection Index of Ideal Genotype Index (SIIG) identified Line S98-22 as the best line based on the evaluated traits across both regions. Regarding quality traits, Line S-98-22 exhibited the highest wet gluten, gluten index, protein content, and suitable Zeleny volume, indicating the best baking quality. Other genotypes also fell within the range of desirable baking quality genotypes. Conclusion: Given its favorable agronomic traits, including high grain yield and drought stress tolerance at the end of the season, along with quality characteristics, Line S-98-22 can be introduced as a new bread wheat variety for warm and dry regions. [ABSTRACT FROM AUTHOR]

Introduction One of the effective strategies to control wheat diseases is to use a mixture of varieties. Basically, varieties with good and similar agricultural traits, but different in diseases resistance should be used. It is common to use a mixture of cultivars, when the high-yielding cultivar is sensitive and the lowyielding cultivar is resistant, so that their mixture has an acceptable efficiency. The mixture of cultivars is defined as a mixture of different cultivars that are similar enough to grow together, but differ in many traits such as disease resistance. The mixture of cultivars does not completely stop the disease, instead it reduces the disease progression rate by eliminating a large number of pathogen spores in each reproductive cycle. The aim of this research was to investigate the effect of mixed cultivation of three cultivars, Kohdasht, Moghan and Morvarid, in controlling four diseases, powdery mildew, tan spot, stripe rust and leaf rust. Materials and methods To investigate the effect of the mixture of cultivars in control of wheat leaf diseases, a research was performed in a randomized complete block design with 12 treatments and four replications in the Gorgan Agricultural Research Station, Gorgan, Iran. The studied cultivars included three cultivars, Kohdasht, Moghan, and Maorvarid, and the evaluated diseases were four leaf diseases including powdery mildew, tan spot, stripe (yallow) rust, and leaf (brown) rust. Powdery mildew and tan spot were measured based on contamination rate using the Sari and Prescott scale, and atripe and leaf rusts were measured based on the disease type and severity. Final disease severity and standardized area under disease progression curve (SAUDPC) were evaluated for all four diseases. Research findings The results of the statistical analysis of data revealed that there was a very significant statistical difference (P<0.01) between experimental treatments for the final disease severity and SAUDPC of all four diseases. The results of comparison of means for powdery mildew showed that all treatments had a final disease severity higher than 30% and lower than 45%. Therefore, none of the treatments could reduce the severity of this disease. However, in term of stripe rust, the resistance of Kohdasht and Morvarid cultivars and their mixtures was clearly observed. For tan spot, the lowest final severity of disease was recorded in Morvarid and 1:1 mixture of Kohdasht-Moghan, and the other mixtures of Kohdasht-Moghan could not significantly reduce the severity of this disease. In term of leaf rust, the lowest final severity of the disease was observed in Morvarid and Moghan cultivars with a density of 150 seeds per m², and the highest final severity in Kohdast cultivar. Conclusion In this research, the effect of the mixture of cultivars in the control of wheat leaf diseases was investigated. In the case of powdery mildew, all treatments had a final severity of the disease higher than 30% and lower than 45%, and therefore, there is no proper efficiency in any of the treatments to reduce the severity of this disease. For yellow rust disease, the resistance of Kohdasht (treatment No. 1) and Marwarid (treatment No. 3) cultivars and their seed mixture (treatment No. 10) was clearly observed. In term of tan spot disease, the lowest final severity of the disease was observed in two treatments, Morvarid cultivar (treatment No. 3) and 1:1 mixture of Kohdasht and Mughan cultivars treatment No. 4), and the other proportions of the seed mixture of Kohdasht and Moghan varieties could not properly control the disease. In the case of brown rust disease, the lowest final intensity of the disease was observed in two treatments, Morvarid (treatment No. 3) and Moghan (treatment No. 12) with a density of 150 seeds per m², and the highest severity of this disease was observed in the treatments belonging to Kohdasht variety. [ABSTRACT FROM AUTHOR]

Kalhaydari is a tall, drought-tolerant and rain-fed cultivar which has been a dominant rain-fed cultivar in Fars and Kohgelouyeh and Boyerahmad provinces for a long time (more than 70 years). However, this superior cultivar is susceptible to yellow rust, caused by Puccinia striiformis f. sp. tritici. Yellow rust causes a severe damage to this cultivar in high rainfall years. The aim of the present study was to transfer two seedling resistance genes (Yr5 and Yr15) and two adult plant resistance genes (Yr18 and Yr29) from standard lines to this cultivar using marker assisted backcrossing. In four separate breeding projects, Kalhaydari was crossed with four donor parents including Yr5/6*Avocet'S', Yr15/6*Avocet'S', Lalbahadur/Pavon and Opata 85 to transfer Yr5, Yr15, Yr18 and Yr29 genes, respectively. The first generation (F1) was backcrossed with Kalhaydari (BC1F1). In the offspring, selection for desirable genotypes was performed using markers assisted selection. Then, offspring carrying the favorable genes were entered the second backcross. The third backcross was performed using the same method. After a few more backcrosses and a selfing generation four yellow rust-resistant lines with the same genetic background, Kalhaydari cultivar, will be created. Durable resistance can be achieved using genes pyramiding. [ABSTRACT FROM AUTHOR]

Annual survey for monitoring of reaction of commercial wheat cultivars to stripe rust disease is very important after their introduction and extensive cultivation. The host materials surveyed included the standard differential cultivars for stripe rust along with 24 and three respectively commercial bread and durum wheat cultivars. This study was accomplished in selected wheat fields of six regions of Fars province including Zarghan, Marvdashat, Fassa, Mammassani, Darab and Eghlid during 2003- 2005 and in two stripe rust nurseries in Zarghan and Mammassani during 2003- 2013. The results showed that the resistance of 12 cultivars including Chamran, Shirodi, Shiraz, Darab 2, Falat, Star, kavir, Zarin, Shahriar, Alvand, Alemot and Bahar was overcome by stripe rust during or before the last decade. Yavarous and several recently introduced cultivars including Zareh, Mihan, Siravan, Chamran 2, Ophogh, Behrang and Shabrang have conferred moderately to intermediate resistance reaction to the disease. The cultivars Sivand, Parsi, Pishgham, Marvdasht and Aflak showed a range of moderately resistance to moderately susceptible reaction. The response of Pishtaz varied from moderately susceptible to resistance. Nicknejad has shown to have high level of resistance since its long time introduction. Decrease or changes in the resistance of some of the cultivars can be attributed to changes in stripe rust races, weather conditions and environmental factors. In this regard among the differential cultivars, virulence was almost present for Yr2, Yr6, Yr7, Yr9, Yr17, Yr25, Yr26, Yr27, YrA and YrSU. Current research indicates that annual survey on responses of commercial wheat cultivars to stripe rust together with monitoring of pathogen virulence factors in Fars province are very necessary. These information not only can effectively aid in giving on-time warning to replace susceptible cultivars and to use effective control measures to reduce the loss of the disease, but also can play an important role in short and long time wheat breeding programs. [ABSTRACT FROM AUTHOR]

Wheat rusts including stripe and stem rusts are the most important fungal diseases in the world and Iran as frequently causes natural epidemics and significant yield loses due to rapid development of new races in life cycle resulted from mutation or sexual recombination. In this research, distribution and genetic diversity of aecial infection on barberry bushes and their relation to wheat yellow rust was studied. A total of 95 samples of infected leaves to aecial stage on barberry bushes were collected from Borujerd, Dorud, Azna and Aligudarz regions. To identify the rust species, in vivo and in vitro pathogenicity test were conducted by artificial inoculation of wheat seedlings using collected aeciospores from each region. The results showed the production of urediniospores of P. striiformis f. sp. tritici (yellow rust) as well as P. graminis f. sp. tritici (black rust) in inoculated wheat seedlings. Molecular detection and sequencing of the rDNA regions of representative aecial isolates on Barberry were done. Genetic diversity of 134 aecial isolates was also studied by amplification of IGS1-rDNA region. The Results also confirmed the pathogenicity test and showed that barberry could be the aecial host of yellow and black rusts in Lorestan province. The IGS-rDNA amplification of aecial isolates from Azna and Aligudarz showed most a production of three bands with a frequency of 15 and 21 isolates respectively. In Dorud samples was with five bands (26 isolates) as well as in Broujerd samples with two bands (10 isolates) in which showed a genetic variation among aecial isolates collected from sampling regions in Lorestan province. [ABSTRACT FROM AUTHOR]