Identification of the Powdery Mildew Resistance in Chinese Wheat Cultivar Heng 4568 and its Evaluation in Marker-Assisted Selection.

Huiming Gao,Fuyi Luo,Pengfei Ai,Xiaozhe Xu,Pengtao Ma,Peng Guo

doi:10.3389/fgene.2022.819844

Huiming Gao, Fuyi Luo + Show 4 more

Open Access

https://doi.org/10.3389/fgene.2022.819844

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Abstract

Powdery mildew induced by Blumeria graminis f. sp. Tritici (Bgt) has a devastating impact on global wheat yield and quality. Host resistance is the most effective and economical means to control this disease. In this study, Heng 4568, an elite wheat cultivar, shows high resistance to 12 Bgt isolates from different regions in China at the seedling stage. Genetic analysis demonstrates that the powdery mildew resistance in Heng 4568 is conferred by a single dominant locus, temporarily designated PmH4568. Furthermore, PmH4568 is mapped to the reported Pm2 interval on chromosome 5DS with five Pm2 linked markers and flanked by the markers Bwm20 and Bwm21 with a genetic distance of 0.3 and 0.6 cM, respectively. To further investigate the relationship between PmH4568 and Pm2, the diagnostic marker Pm2b-map-3 of Pm2 is used to genotype the F2:3 population derived from the cross Heng 4568 × Daimai 2173. Notably, there is no recombination found, indicating that PmH4568 is also probably a Pm2 allele. In addition, five closely linked markers as well as one diagnostic marker are successfully developed and tested in 16 wheat cultivars from different agro-ecological areas in China, which have potential applications in molecular breeding by marker-assisted selection.

Highlights

Wheat powdery mildew incited by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt) is a foliar disease worldwide (Wu et al, 2019)
Wheat cultivar Daimai 2173 served as a susceptible parent that was crossed with Heng 4568 to produce F1 hybrids, F2 population, and F2:3 families for genetic analysis and molecular mapping of the powdery mildew resistance (Pm) gene(s) in Heng 4568
Heng 4568 was highly resistant to 12 Bgt isolates with the infection types (IT) 0–2, whereas Daimai 2173 and susceptible control Huixianhong were all highly susceptible to all the tested Bgt isolates (Table 1)

Summary

Introduction

Wheat powdery mildew incited by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt) is a foliar disease worldwide (Wu et al, 2019). The rapid spread of powdery mildew will cause severe wheat yield losses in a short time, especially in the winter wheat-growing regions with high inputs of irrigation and fertilizers (Luo et al, 2009; Hao et al, 2014). In China alone, the area of winter wheat affected annually by powdery mildew has exceeded 6 mha during recent decades, causing 300,000 tons of crop loss each year (http://cb.natesc.gov.cn/sites/cb/). With the climate getting warmer, the epidemics of wheat powdery mildew in China are growing more severe, which will always be a serious threat to national food security. Given the significant yield-limiting effects of powdery mildew, the research and exploration of effective prevention and control technology has become urgent in wheat production. Chemical control, biological control, and cultivation of disease-resistant varieties are common means.

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