Resistance spectra of wheat genotypes and virulence patterns of Mycosphaerella graminicola isolates in Iran

Abstract

Co-evolution of wheat and its devastating pathogen Mycosphaerella graminicola (anamorph Septoria tritici), the causal agent of septoria tritici blotch, a foliar disease of wheat, is suggested to occur in Fertile Crescent as their center of origin and, thus, interaction between pathogen virulence and host resistance is important subject to be addressed. We have investigated resistance spectra of 54 wheat genotypes including a set of differentials carrying known resistance genes and virulence patterns of 14 M. graminicola isolates at seedling stage under controlled environmental conditions. The isolates were collected in Iran from five provinces. Diversity in virulence and aggressiveness was observed among the isolates from four provinces. Isolates collected from Golestan province were virulent to all wheat genotypes from germplasm of Iran, while specific resistances were identified to the isolates from other provinces. Among wheat genotypes, cvs. Chamran, Morvarid and Hirmand had the greatest number of specific resistances as well as partial resistance. Wheat genotypes of the differential set also differed in their reactions to the isolates. Arina, Flame and TE 9111 were specifically resistant to the greatest number of isolates from different provinces. Most isolates were virulent to the other differentials such as cvs. Shafir, Estanzuela federal and Courtot indicating that extensive adaption of virulence to most of the known resistance genes (Stb) has occurred in these regions. The new sources of resistance to highly virulent isolates from Iran may also be utilized in wheat breeding programs to develop resistant cultivars against pathogen populations in other countries.

Effectiveness determination of wheat genotypes andStbresistance genes against IranianMycosphaerella graminicolaisolates

“…Among other wheat genotypes, 10 wheat genotypes, including Chamran, Morvarid, Arta, Hirmand, Marvdasht, Cross of Shahi, Tabasi, Tajan, Darab 2 and Boolani, were common in this research and the previous study of Abrinbana et al (2012) to which 19 new genotypes were added. Nineteen new M. graminicola isolates were studied which had been collected from three provinces (East Azarbaijan, Khuzestan and Fars) and were common with Abrinbana et al (2012) study.…”

“…SAS 9.1 for windows was used for data analysis. General resistance of wheat genotypes to the isolates and aggressiveness of the isolates on wheat genotypes were calculated by omitting data for specific interactions Chartrain, Brading, Widdowson et al 2004;Abrinbana et al 2012;Ghanei et al 2012). Means of transformed disease severity values of the wheat genotypes by each isolate were subjected to hierarchical cluster analysis using the average between-groups linkage and Euclidean distance in the SPSS 16.0 for windows.…”

“…In this research, Sullivan (carrying Stb1), Bulgaria 88 (carrying Stb1 and Stb6), Salamoni (carrying Stb13 and Stb14), Riband (carrying Stb15 or another gene) and M3 (carrying Stb16 and Stb17) were the new wheat differential cultivars used compared to the previous study of Abrinbana et al (2012). Among other wheat genotypes, 10 wheat genotypes, including Chamran, Morvarid, Arta, Hirmand, Marvdasht, Cross of Shahi, Tabasi, Tajan, Darab 2 and Boolani, were common in this research and the previous study of Abrinbana et al (2012) to which 19 new genotypes were added.…”

“…Hosseinnezhad et al isolate-specific interactions between Iranian tetraploid wheat landraces and M. graminicola isolates. Abrinbana et al (2012) determined virulence patterns of 14 M. graminicola isolates collected from different wheat-growing regions of Iran on 54 wheat genotypes including 13 wheat differential cultivars and 41 wheat genotypes from Iranian germplasm and identified new isolate-specific resistances between these isolates and Iranian germplasm. Also, they introduced cvs.…”

Response of selected winter wheat cultivars to inoculation with different Mycosphaerella graminicola isolates

“…It is, however, important that certain cultivars (e.g. Arina,Flame and TE 9111) were specifically resistant to the largest number of isolates collected in different regions (Abrinbana et al 2012). Also Chartrain et al (2004a) did not find resistance in Arina, carrying the genes Stb6 and Stb15 (Arraiano et al 2007), specific to any of the three fungal isolates used in the tests and no QTL controlling a major part of the Arina resistance was identified either, suggesting that its resistance may be dispersed and polygenic.…”