Wheat germplasm screening for stem rust resistance using conventional and molecular techniques

Abstract

Abstract:In Central Asia, stem rust (Puccinia graminis f.sp. tritici) causes considerable damage, especially during growing seasons with high rainfall. Ug99 is a race of stem rust that is virulent to the majority of wheat varieties. To develop disease-free germplasm, wheat material was screened using the predominant stem rust races of Kazakhstan and tested in two nurseries; CIMMYT-Turkey and the Plant Breeding Station at Njoro, Kenya. A total of 11 pathotypes of P. graminis f.sp. tritici were identified in Kazakhstan from the stem rust samples collected in [2008][2009]. In particular, pathotypes TDT/H, TPS/H, TTH/K, TKH/R, TKT/C and TFK/R were highly virulent. Of the 170 advanced lines of wheat, 21 CIMMYT lines resistant to 5 aggressive Kazakhstani pathotypes of P. graminis were identified. A high level of resistance was observed in 11 wheat cultivars and advanced lines: Taza, E-19, E-99, E-102, E-572, E-796, E-809 (Kazakhstan), Ekinchi (Azerbaijan), Dostlik, Ulugbek 600 (Uzbekistan) and Umanka (Russia). Based on data obtained from Turkey-CIMMYT and the Plant Breeding Station Njoro, Kenya nurseries, out of 13 tested entries, 6 wheat breeding lines which were resistant to both stem and yellow rust and 10 wheat lines which showed high and moderate levels of resistance to Ug99 were selected. Using the sequence tagged site (STS) molecular marker Sr24#12, associated with Sr24/Lr24, seven wheat entries resistant to stem rust were identified. These results will assist breeders in choosing parents for crossing in programmes aimed at developing varieties with desirable levels of stem rust resistance in Kazakhstan and they will also facilitate stacking the resistance genes into advanced breeding lines.

Characterization of Virulence and Diversity of Puccinia graminis f. sp. tritici on Wheat in Egypt

“…Rust diseases of wheat are still the most dangerous biotic stress that threatens wheat production in Egypt and many wheat-growing areas in the world (Kolmer, 2005;Wellings, 2011;Singh et al, 2011) and this is mainly due to the appearance of aggressive races of the pathogen (Singh et al, 2005). Wheat stem rust fungus could affect the entire wheat crop, especially during the early growth stages leading to the blocking of the vascular system hence stunting and lodging of weak stalks eventually causing yield losses of even 100% due to shriveled grain and damaged tillers (Boukhatem et al, 2002;Kokhmetova et al, 2011).…”

Screening of CIMMYT Wheat Genotypes to Stem Rust Disease under Field Conditions in Egypt غربلة التراکیب الوراثیة لقمح السیمیت ضد مرض صدأ الساق تحت ظروف الحقل فی مصر

“…Accordingly, several genotypes were previously assessed in different countries to reveal their reaction to wheat stem rust disease, under field conditions (Kokhmetova et al, 2011 andAbdelaal et al, 2018). Wheat genotypes produced by International Maize and Wheat Improvement Center (CIMMYT) were utilized by most countries to improve and obtain highly resistant cultivars to stem rust pathogen.…”

Effective and Ineffective of some Resistance Genes to Wheat Leaf, Stem and Yellow Rust Diseases in Egypt

“…Under Egyptian conditions, losses due leaf rust reached to more than 20% (Shahin &El-Orabey, 2016 andEl-Orabey et al, 2017). On the other hand, wheat stem rust can causes yield losses of up to 100 % due to damaged tillers and shriveled grains (Kokhmetova et al, 2011). In Egypt, yield losses due to stem rust ranged from 1.96 % to 8.21 % recorded on the Egyptian wheat cultivars (Ashmawy et al, 2013).…”