Identification of Pm24, Pm35 and Pm37 in thirteen Egyptian bread wheat cultivars using SSR markers

Abstract

Powdery mildew of wheat (Triticum spp.) caused by Blumeria graminis f.sp. tritici (DC) E.O. Speer Em. Marchal is one of the most important bread wheat diseases in Egypt. All the Egyptian common bread wheat cultivars are susceptible to that disease at seedling and adult stages. Breeding of resistant cultivars is the most economical and environmentally safe method to eliminate the disease and reduce crop losses. Combinations of two or more effective resistance genes may lead to better, more durable resistance to that disease. Eight Pm genes i.e. Pm2, Pm6, Pm12, Pm16, Pm24, Pm35, Pm36 and Pm37 out of 21 powdery mildew monogenic wheat lines (Pm) were resistant to 42 individual isolates of powdery mildew collected from different governorates in the Nile Delta area, Egypt, at seedling and adult stages. Only four DNA specific SSR markers (Xgwm337, Xcfd7 linked to Pm24, Pm35 and Xgwm332, Xwmc790) linked to Pm37 resistance genes were selected to detect these genes in 13 Egyptian common bread wheat cultivars. This study reveals the absence of Pm24, Pm35 and Pm37 in all the 13 Egyptian bread wheat cultivars. These results gave evidence that the Egyptian cultivars are not having resistance genes and need to further incorporate one, two or more resistant genes in a single genotype as all commercial cultivars defeated by the pathogen.

Novel genomic regions on chromosome 5B controlling wheat powdery mildew seedling resistance under Egyptian conditions

“…Moreover, most of the Egyptian genotypes were found to be moderately resistant or susceptible. The absence of immune Egyptian wheat genotypes was reported previously in most of the commercial cultivars ( Emara et al., 2016 ; Draz et al., 2019 ; Elsayed and Elkot, 2020 ; Draz et al., 2022 ). The 19 common resistant genotypes in both experiments were found to be moderately resistant to the studied Bgt isolates.…”

“…Unlike rust diseases in Egyptian wheat, little concern was drawn into the genetic control of PM resistance under Egyptian conditions. Some previous studies tested the presence of specific PM resistance genes in the Egyptian wheat germplasm without knocking into the new sources of genetic control ( Emara et al., 2016 ; Elsayed and Elkot, 2020 ; Draz et al., 2022 ). In this study, the association mapping of PM resistance was studied for the first time under Egyptian conditions.…”

“…Few efforts have been made to control such a serious disease in Egyptian fields. Some studies tested the presence of specific Pm genes in the Egyptian wheat germplasm ( Emara et al., 2016 ; Elsayed and Elkot, 2020 ; Draz et al., 2022 ). Others figured out the different Bgt isolates exist in the Egyptian Bgt populations ( El-Shamy et al., 2012 ; El-Shamy and Mohamed, 2022 ).…”

Deciphering field resistance to powdery mildew and yellow rust among popular cultivars of wheat and set of differential lines

“…markgrafii chromosome disomic addition lines (Niu et al 2018), Indian advanced wheat breeding material (Basandrai et al 2016;Sood et al 2020). Emara et al (2016) also observed that eight Pm genes i.e., Pm2, Pm6, Pm12, Pm16, Pm24, Pm35, Pm36 and Pm37 were resistant to 42 isolates of PM at seedling stage. Basandrai and Basandrai (2017) reviewed seedling resistant donors identified among Triticum spp.…”

Identification of the Resistance Gene Sr2 in some Egyptian Wheat Hybrids

“…The total DNA of Sr2, wheat cultivars, and their F1 populations were extracted from 200 mg of 10 days seedlings. The extraction method was carried out according to Emara et al (2016).…”