QTL mapping for field resistance to wheat blast in the Caninde#1/Alondra population

Xinyao He,Muhammad Rezaul Kabir,Md Babul Anwar,Eric Huttner,Firuz Odilbekov,Etienne Duveiller,Krishna K Roy,Aakash Chawade,Kaijie Xu,Felix Marza,Pawan K Singh

doi:10.1007/s00122-020-03624-x

Abstract

Key messageWheat blast resistance in Caninde#1 is controlled by a major QTL on 2NS/2AS translocation and multiple minor QTL in an additive mode.Wheat blast (WB) is a devastating disease in South America, and it recently also emerged in Bangladesh. Host resistance to WB has relied heavily on the 2NS/2AS translocation, but the responsible QTL has not been mapped and its phenotypic effects in different environments have not been reported. In the current study, a recombinant inbred line population with 298 progenies was generated, with the female and male parents being Caninde#1 (with 2NS) and Alondra (without 2NS), respectively. Phenotyping was carried out in two locations in Bolivia, namely Quirusillas and Okinawa, and one location in Bangladesh, Jashore, with two sowing dates in each of the two cropping seasons in each location, during the years 2017–2019. Genotyping was performed with the DArTseq® technology along with five previously reported STS markers in the 2NS region. QTL mapping identified a major and consistent QTL on 2NS/2AS region, explaining between 22.4 and 50.1% of the phenotypic variation in different environments. Additional QTL were detected on chromosomes 1AS, 2BL, 3AL, 4BS, 4DL and 7BS, all additive to the 2NS QTL and showing phenotypic effects less than 10%. Two codominant STS markers, WGGB156 and WGGB159, were linked proximally to the 2NS/2AS QTL with a genetic distance of 0.9 cM, being potentially useful in marker-assisted selection.

Highlights

Wheat blast (WB) is an emerging and devastating disease of wheat, caused by the fungus Magnaporthe oryzae pathotype Triticum (MoT), leading to yield losses of up to 100% and grain quality deterioration, greatly threatening food security in the epidemic regions (Kohli et al 2011; Cruz and Valent 2017)
Higher correlation coefficients were found among experiments in Bolivia, whereas lower correlation coefficients were observed among experiments in Bangladesh (Table 2)
This, along with the gain of virulence of newly emerged MoT isolates, could be the most important reasons explaining that early-suggested WB resistant lines turned out to be susceptible in later evaluations

Summary

Introduction

Wheat blast (WB) is an emerging and devastating disease of wheat, caused by the fungus Magnaporthe oryzae pathotype Triticum (MoT), leading to yield losses of up to 100% and grain quality deterioration, greatly threatening food security in the epidemic regions (Kohli et al 2011; Cruz and Valent 2017). This disease first appeared in 1985 in the Paraná state of Brazil and soon spread throughout many of the important wheat-producing areas in Brazil (lgarashi et al 1986; Goulart and Paiva 1990; Picinini and Fernandes 1990; Dos Anjos et al 1996). This disease might further spread to other major wheat production regions like USA, Ethiopia or Australia (Cao et al 2011; Maciel 2011; Cruz et al 2016a)

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