Effectiveness determination of wheat genotypes andStbresistance genes against IranianMycosphaerella graminicolaisolates

Abstract

Septoria tritici blotch (STB) caused by Mycosphaerella graminicola is a serious disease in some wheat-growing regions of Iran. Continuous monitoring of the fungus populations is indispensable to study the efficiency of known resistant cultivars and Stb genes. In this study, resistance of 49 wheat genotypes, including 20 wheat differential cultivars worldwide and 29 other wheat genotypes, were studied to 19 M. graminicola isolates. Among 931 genotype-isolate interactions, 224 isolate-specific resistances (26%) were observed by comparing the means of disease severity data using LSD 1% and LSD 5% . Iranian M. graminicola isolates showed new virulence patterns. All isolates were virulent to Stb2, Stb5, Stb6, Stb7, Stb13 and Stb14. Among wheat differentials, M3 was resistant to all isolates, indicating that it has gene(s) with the most efficiency against Iranian isolates. Among other genotypes, two genotypes were resistant to all isolates. This suggests that these genotypes have efficient resistance gene(s) to Iranian M. graminicola isolates and could be used as resistance sources to STB in Iran. They may be effective against other populations of M. graminicola worldwide.

Identification of New Sources of Resistance to Septoria Tritici Blotch Caused by Zymoseptoria tritici

“…Comparing to our previous studies and other reports elsewhere in the world (Eyal et al 1983;Chartrain et al 2004a;Abrinbana et al 2012;Ghaneie et al 2012;Hosseinnezhad et al 2014), the number of specific resistances identified in this study was considerable. Of 150 interactions, 78 isolate-specific interactions (52%) were identified, indicating that SHWs possessed many known or novel effective resistance genes.…”

“…; Hosseinnezhad et al. ), the number of specific resistances identified in this study was considerable. Of 150 interactions, 78 isolate‐specific interactions (52%) were identified, indicating that SHWs possessed many known or novel effective resistance genes.…”

“…, ; Hosseinnezhad et al. ). Our recent study showed that all isolates ( n = 19) of Z. tritici were virulent to Stb2 , Stb5 , Stb6 , Stb7 , Stb13 and Stb14 and the remaining Stb genes were not effective against the majority of the isolates, indicating that new sources of resistance are required to be integrated into the wheat breeding programme in Iran, which is the most practical and cheapest approach to control the disease.…”

“…Most importantly, fungicide efficacy towards STB is hampered by the development of fungicide resistant strains of the pathogen (Fraaije et al 2005). Furthermore, Iranian Z. tritici isolates have moderate to high genetic diversity and remarkably most of them are virulent on the majority of wheat differentials containing Stb genes (Abrinbana et al 2010Hosseinnezhad et al 2014). Our recent study showed that all isolates (n = 19) of Z. tritici were virulent to Stb2, Stb5, Stb6, Stb7, Stb13 and Stb14 and the remaining Stb genes were not effective against the majority of the isolates, indicating that new sources of resistance are required to be integrated into the wheat breeding programme in Iran, which is the most practical and cheapest approach to control the disease.…”

Genome-wide association mapping in wheat reveals novel QTLs and potential candidate genes involved in resistance to septoria tritici blotch

“…This genotype contains Stb16 and Stb17 (Tabib Ghaffary et al 2012;Mahboubi et al 2020). Therefore, it can be concluded that this gene still is effective against STB, which is consistent with previous (Hosseinnezhad et al 2014;Makhdoomi et al 2015). The resistant genotypes identi ed in this study are likely novel sources of resistance, which can be used in breeding programs for the development of modern wheat cultivars.…”