scholarly journals POWDERY MILDEW INFECTION ON SOME EGYPTIAN BREAD WHEAT CULTIVARS IN RELATION TO ENVIRONMENTAL CONDITIONS.

2012 ◽  
Vol 3 (4) ◽  
pp. 363-372
Author(s):  
M. El-Shamy ◽  
M. Sallam ◽  
H. Awad
Plant Disease ◽  
2005 ◽  
Vol 89 (5) ◽  
pp. 457-463 ◽  
Author(s):  
Z. L. Wang ◽  
L. H. Li ◽  
Z. H. He ◽  
X. Y. Duan ◽  
Y. L. Zhou ◽  
...  

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a widespread wheat disease in China. Identification of race-specific genes and adult plant resistance (APR) is of major importance in breeding for an efficient genetic control strategy. The objectives of this study were to (i) identify genes that confer seedling resistance to powdery mildew in Chinese bread wheat cultivars and introductions used by breeding programs in China and (ii) evaluate their APR in the field. The results showed that (i) 98 of 192 tested wheat cultivars and lines appear to have one or more resistance genes to powdery mildew; (ii) Pm8 and Pm4b are the most common resistance genes in Chinese wheat cultivars, whereas Pm8 and Pm3d are present most frequently in wheat cultivars introduced from CIMMYT, the United States, and European countries; (iii) genotypes carrying Pm1, Pm3e, Pm5, and Pm7 were susceptible, whereas those carrying Pm12, Pm16, and Pm20 were highly resistant to almost all isolates of B. graminis f. sp. tritici tested; and (iv) 22 genotypes expressed APR. Our data showed that the area under the disease progress curve, maximum disease severity on the penultimate leaf, and the disease index are good indicators of the degree of APR in the field. It may be a good choice to combine major resistance genes and APR genes in wheat breeding to obtain effective resistance to powdery mildew.


2016 ◽  
Vol 40 (3) ◽  
pp. 279-287 ◽  
Author(s):  
Hassan Mahmoud Emara ◽  
Ayman Feisal Omar ◽  
Moustafa Mahmoud El-Shamy ◽  
Mona Elsaid Mohamed

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.


Plant Disease ◽  
2018 ◽  
Vol 102 (2) ◽  
pp. 391-397 ◽  
Author(s):  
Abdelrazek Abdelrhim ◽  
Harby M. Abd-Alla ◽  
El-Sayed Abdou ◽  
Mamdoh E. Ismail ◽  
Christina Cowger

Powdery mildew, caused by Blumeria graminis (DC.) Speer f. sp. tritici (Em. Marchal), is a serious disease of wheat that can cause a large reduction in yield. In Egypt, high powdery mildew severity has been observed in the past few years on many commercial cultivars of both bread and durum wheat. Little information is available about virulence characteristics of the Egyptian B. graminis f. sp. tritici population in Egypt or the resistance of Egyptian wheat cultivars to powdery mildew. Virulence frequencies of a representative sample of the Egyptian B. graminis f. sp. tritici population were studied. Seven provinces were chosen to represent the country: two in Upper Egypt (Qena and Sohag), one in Middle Egypt (El Minia), and four in the north (Alexandria, Kafr Elsheikh, Dakahlia, and Sharqia). Ten isolates from each province (70 isolates total) were derived from single ascospores and used for this study. They were inoculated individually on 21 powdery mildew differential lines, each bearing a single resistance (Pm) gene. Also, the responses of 14 Egyptian bread wheat cultivars and 6 durum cultivars to each of the 70 isolates were evaluated individually. Among all tested Pm genes, only seven (Pm1b, Pm2, Pm21, Pm34, Pm36, Pm37, and Pm53) were effective against B. graminis f. sp. tritici isolates from all provinces. Several other genes were effective against most or all isolates from a majority of provinces. All tested bread wheat cultivars showed full susceptibility to all isolates, whereas two durum wheat cultivars, Beni-Suef-5 and Beni-Suef-6, had intermediate responses to a large percentage of the isolates, likely indicating partial resistance. To enhance mildew resistance in Egyptian wheat cultivars, it is recommended to use combinations of genes that are nationally effective or effective against multiple provincial B. graminis f. sp. tritici populations.


Hereditas ◽  
2007 ◽  
Vol 144 (3) ◽  
pp. 102-119 ◽  
Author(s):  
Shu-Chin Hysing ◽  
Arnulf Merker ◽  
Erland Liljeroth ◽  
Robert M. D. Koebner ◽  
Friedrich J. Zeller ◽  
...  

2014 ◽  
Vol 185 ◽  
pp. 24-33 ◽  
Author(s):  
Nimesha Fernando ◽  
Joe Panozzo ◽  
Michael Tausz ◽  
Robert M. Norton ◽  
Nathan Neumann ◽  
...  

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