Wheat (Triticum sp. L.), as one of the first domesticated food crops, is the basic staple food for a large segment of population around the world. The crop though is susceptible to many fungal pathogens. Stripe rust is an important airborne disease caused by Puccinia striiformis (Pst) and is widespread wherever wheat is cultivated throughout the world, in temperate-cool and wet environments. The causal fungus of stripe rust or yellow rust is an obligate parasite that requires another living host to complete its life cycle. Pst includes five types of spores in the life cycle on two distinct hosts. Stripe rust is distinguished from other rusts by the dusty yellow lesions that grow systemically in the form of streaks between veins and on leaf sheaths. The importance and occurrence of stripe rust disease varies in cultivated wheat, depending on environmental conditions (moisture, temperature, and wind), inoculum levels and susceptible host varieties. Transcaucasia was previously thought to be the center of origin for the pathogen. However, new findings further underlined Himalayan and near-Himalayan regions as center of diversity and a more tenable center of origin for P. striiformis. Long-distance dispersal of stripe rust pathogen in the air and occasionally by human activities enables Pst to spread to new geographical areas. This disease affects quality and yield of wheat crop. Early seeding, foliar fungicide application and cultivation of resistant varieties are the main strategies for its control. The emergence of new races of Pst with high epidemic potential which can adapt to warmer temperatures has expanded virulence profiles. Subsequently, races are more aggressive than those previously characterized. These findings emphasize the need for more breeding efforts of resistant varieties and reinforcement of other management practices to prevent and overcome stripe rust epidemic around the world.

During the periodic purity checks of pathotypes 107-1(45R35=JCGPL) and 20(5R27=SGQPL) of Puccinia triticina in national repository at Shimla, India, mixtures of infection types were observed on the differential Lr3 and Lr15 , respectively. Single pustule isolations and further pure cultures in both the cases yielded new pathotypes designated as 57(45R39= KGTPL) and 20-2(57R27= SHKPL). Pathotype 57 was one step gain in virulence on Lr3 in 107-1 whereas 20-2 on Lr15 in mother culture of pathotype 20. The difference of virulence on one gene to each mother culture and their non occurrence in the field samples is indicative of mutation for virulence in situ . To ascertain the novelty of new pathotypes, detailed study on differentials, avirulence/virulence structure, DNA polymorphism using SSR markers, and other related information is presented in this publication. The new cultures are being maintained as PrtI 57 and PrtI 20-2 in the repository.

Stripe (Yellow) rust caused by Puccinia striiformis f.sp. tritici (Pst) is a crucial wheat disease causing severe damage to cultivated susceptible wheat varieties. The wheat yellow rust assessment was conducted during the primary rainy season of 2018/19 at Ada’a, Lume, and Gimbichu using the zigzag disease assessment method. Disease data, agro-ecological data, and other essential parameters were recorded. The disease was prevalent in all districts by diverse incidence and severity ranges. This implies that yellow rust is distributed wheat disease at all surveyed potential districts. The highest yellow rust prevalence, 62.5% was recorded at Gimbichu district; conversely, the lowest prevalence 31.25% was recorded at Ada’a district. The highest severity and incidence of yellow rust 60% and 100%, respectively, was recorded at Ada’a district with susceptible reaction. In comparison, the lowest severity and incidence (30% and 5%) respectively were recorded at Lume districts with moderate...

Yellow rust is caused by Puccinia striiformis f. sp. tritici, is one of the known pathogens of wheat. This rust usually occurs at early in the growth season of wheat, when temperature ranges between 2 and 15°C; but it may occur to a maximum temperature of 23°C. High humidity and rainfall are conducive for increasing the infection (disease) on both leaf blade and leaf sheath, even on spikes when the disease occurred as epidemic form. Stunted and weakened plants, shriveled grains, and fewer spikes are among the symptoms of the disease. Therefore the objective of this paper is to review Effect of yellow rust (puccinia striiformis.f.sp.tritici) on wheat production and their management options. Yellow rust yield losses can be 50%, but in severe situations 100% is vulnerable. In countries where wheat is grown in winters or at high altitudes, stripe rust is a common threat, but not more significant than wheat leaf rust and stem rust, which are continuous threats in all wheat-growing seasons up to maturity of the crops. Epidemics of yellow rust have become more frequent and widespread at higher altitudes in southeastern Ethiopia due to frequent production of mega cultivars, varietal susceptibility, expansion of wheat mono cropping, development and introduction of new virulent races and conducive environmental factors prevailing rust development. There are many methods of yellow rust (puccinia striiformis) management like bio control, chemical, cultural control and breeding for diseases resistance, among this, breeding resistant varieties is the most cost-effective method to control this rust. Fungicides are available but vary in ability to control this rust depending on their registration restrictions by state or national governments in addition they are not recommended more due environmentally unfavorable.

Hanzalová A., Bartoš P., Sumíková T. (2013): Physiological specialization of wheat leaf rust (Puccinia triticina Eriks.) in the Czech Republic in 2009–2011. Czech J. Genet. Plant Breed., 49: 103–108. In 2009–2011 virulence of the wheat leaf rust population was studied on Thatcher near isogenic lines with Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr11, Lr13, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. Samples of leaf rust were obtained in different parts of the Czech Republic. A total of 164 wheat leaf rust isolates were analysed. Resistance gene Lr9 was effective to 98% of all tested isolates. No virulence to Lr19 was found. Gene Lr24 was effective to 93% of isolates. A lower frequency of virulence to Lr2a, Lr2b and Lr28 was also observed. Recently registered cultivars were tested with six older and five most widespread leaf rust pathotypes at present. Winter wheat cultivars Carroll and Citrus were resistant to all tested older pathotypes at the seedling stage and they were also resi...