Genome-Wide Association Analysis of Fusarium Head Blight Resistance in Chinese Elite Wheat Lines.

Zhanwang Zhu,Chunbao Gao,Weiwei Zhu,Jindong Liu,Yike Liu,Lijun Yang,Hanwen Tong,Ling Chen,Wei Zhang,Luping Fu,Awais Rasheed,Zhonghu He,Yuanfeng Hao,Xianchun Xia,Junhui Li

doi:10.3389/fpls.2020.00206

Abstract

Fusarium head blight (FHB) is a devastating wheat disease worldwide. To decipher the genetic architecture of FHB resistance in Chinese germplasm, a Wheat Association Panel for Scab Research (WAPS) consisting of 240 leading Chinese wheat cultivars and elite lines was genotyped using the 90K single nucleotide polymorphism (SNP) arrays. The FHB response was evaluated in the field nurseries in Wuhan in Hubei Province over four consecutive years from 2014 to 2017. Five quantitative trait loci (QTL) were consistently identified on chromosome arms 1AS, 2DL, 5AS, 5AL, and 7DS using a mixed linear model (MLM), explaining 5.6, 10.3, 5.7, 5.4, and 5.6% of phenotypic variation, respectively. The QTL on 5AS, 5AL, and 7DS QTL are probably novel. The allelic frequency analysis indicated that cultivars from the Middle and Lower Yangtze River Valleys harbored more favorable alleles and were therefore more resistant than those from other regions. To facilitate in-house germplasm screening and marker-assisted selection (MAS), SNP-derived PCR markers were developed for the QTL regions on 1AS, 5AS, and 5AL QTL. In addition to the above five QTL, the WAPS population had a very low frequency of Fhb1, confirming that the gene is not widely used in Chinese wheat breeding programs. The resistant lines and molecular markers developed in this study are resources and information for enhancing FHB resistance in breeding populations by marker-assisted recurrent selection and gene stacking.

Highlights

Fusarium head blight, caused mainly by the fungus Fusarium graminearum Schwabe, is a devastating disease of wheat worldwide, in warm and humid regions (Bai et al, 2018)
Heritability of Fusarium head blight (FHB) indices across the 4 years was 0.63, indicating that the FHB response of the Wheat Association Panel for Scab Research (WAPS) population was mainly controlled by genetic factors
Cultivars from Jiangsu and Hubei, in the Middle and Lower Yangtze River Valleys, had the highest levels of FHB resistance, whereas cultivars from other provinces tended to be more susceptible, those from Shandong, Henan, and Hebei in the Yellow and Huai River Valleys (Zone II) where almost one-half of the total Chinese wheat crop is produced. This geographical differentiation for FHB resistance agrees with the prevalence of FHB

Summary

Introduction

Fusarium head blight, caused mainly by the fungus Fusarium graminearum Schwabe, is a devastating disease of wheat worldwide, in warm and humid regions (Bai et al, 2018). Resistance to FHB is a typical quantitative trait and the infection process is complicated. Plant morphological and phenological traits and their growing environments all affect FHB infection (Bai et al, 2018). Buerstmayr et al (2019) summarized the influence of plant height, AE and heading date/flowering time on FHB response. Taller plant height and higher AE contribute to FHB resistance. Different heading date/flowering time results in differences in weather conditions during disease infection and development, but the differences vary depending on specific environments and could lead to either positive, negative or no correlation to FHB responses. Due to the close correlation between morphological traits and FHB resistance, it is critical to include these traits in FHB resistance studies

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Conclusion