Resistance of the Wheat Cultivar ‘Renan’ to Septoria Leaf Blotch Explained by a Combination of Strain Specific and Strain Non-Specific QTL Mapped on an Ultra-Dense Genetic Map

Genes

Romain Valade¹  Pierre Sourdille²  Christophe Bergez³  Thierry C. Marcel³  Murielle Cuenin³  Sandrine Gélisse³  Camilla Langlands-Perry³  Safa Ben Krima³ 

[1] ARVALIS Institut du Végétal, 91720 Boigneville, France;Université Clermont–Auvergne, INRAE, UMR GDEC, 63000 Clermont-Ferrand, France;Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France;

关键词: bread wheat;    Septoria tritici blotch;    quantitative trait loci;    Stb20q;    strain specificity;    resistance durability;   

DOI  :  10.3390/genes13010100

来源: DOAJ

【 摘 要 】

Quantitative resistance is considered more durable than qualitative resistance as it does not involve major resistance genes that can be easily overcome by pathogen populations, but rather a combination of genes with a lower individual effect. This durability means that quantitative resistance could be an interesting tool for breeding crops that would not systematically require phytosanitary products. Quantitative resistance has yet to reveal all of its intricacies. Here, we delve into the case of the wheat/Septoria tritici blotch (STB) pathosystem. Using a population resulting from a cross between French cultivar Renan, generally resistant to STB, and Chinese Spring, a cultivar susceptible to the disease, we built an ultra-dense genetic map that carries 148,820 single nucleotide polymorphism (SNP) markers. Phenotyping the interaction was done with two different Zymoseptoria tritici strains with contrasted pathogenicities on Renan. A linkage analysis led to the detection of three quantitative trait loci (QTL) related to resistance in Renan. These QTL, on chromosomes 7B, 1D, and 5D, present with an interesting diversity as that on 7B was detected with both fungal strains, while those on 1D and 5D were strain-specific. The resistance on 7B was located in the region of Stb8 and the resistance on 1D colocalized with Stb19. However, the resistance on 5D was new, so further designated Stb20q. Several wall-associated kinases (WAK), nucleotide-binding and leucine-rich repeats (NB-LRR) type, and kinase domain carrying genes were present in the QTL regions, and some of them were expressed during the infection. These results advocate for a role of Stb genes in quantitative resistance and for resistance in the wheat/STB pathosystem being as a whole quantitative and polygenic.

【 授权许可】

Unknown