Genetic mapping of adult-plant resistance genes to powdery mildew in triticale

Mateusz Dyda,Mirosław Tyrka,Marcin Rapacz,Maria Wędzony,Gabriela Gołębiowska

doi:10.1007/s13353-021-00664-x

Abstract

Triticale is a cereal of high economic importance; however, along with the increase in the area of this cereal, it is more often infected by the fungal pathogen Blumeria graminis, which causes powdery mildew. The rapid development of molecular biology techniques, in particular methods based on molecular markers may be an important tool used in modern plant breeding. Development of genetic maps, location of the QTLs defining the region of the genome associated with resistance and selection of markers linked to particular trait can be used to select resistant genotypes as well as to pyramidize several resistance genes in one variety. In this paper, we present a new, high-density genetic map of triticale doubled haploids (DH) population “Grenado” × “Zorro” composed of DArT, silicoDArT, and SNP markers. Composite interval mapping method was used to detect eight QTL regions associated with the area under disease progress curve (AUDPC) and 15 regions with the average value of powdery mildew infection (avPM) based on observation conducted in 3-year period in three different locations across the Poland. Two regions on rye chromosome 4R, and single loci on 5R and 6R were reported for the first time as regions associated with powdery mildew resistance. Among all QTLs, 14 candidate genes were identified coded cyclin-dependent kinase, serine/threonine-protein kinase-like protein as well as AMEIOTIC 1 homolog DYAD-like protein, DETOXIFICATION 16-like protein, and putative disease resistance protein RGA3. Three of identified candidate genes were found among newly described QTL regions associated with powdery mildew resistance in triticale.

Highlights

Triticale is a human-made wheatrye hybrid commercialized in the late 1960s (Ammar et al 2004)
We present a new, high-density genetic map of triticale doubled haploids (DH) population “Grenado” × “Zorro” composed of diversity arrays technology (DArT), silicoDArT, and single nucleotide polymorphism (SNP) markers
Composite interval mapping method was used to detect eight quantitative trait loci (QTL) regions associated with the area under disease progress curve (AUDPC) and 15 regions with the average value of powdery mildew infection based on observation conducted in 3-year period in three different locations across the Poland

Summary

Introduction

Triticale (xTriticosecale Wittm.) is a human-made wheatrye hybrid commercialized in the late 1960s (Ammar et al 2004). Hexaploid triticale (2n = 6x = 42, AABBRR) accumulates important traits determined by wheat (A and B) and rye (R) genomes Triticale has raised its economic importance mainly in Europe. Poland with triticale cultivation area of 1.3 million ha contribute to 1/3 of world production and remains the top producer of this crop (Faostat 2020). The epidemic appearance of powdery mildew on triticale has been observed in several European countries, including Belgium, France, Germany, and Poland as well (Walker et al 2011). The cultivation of triticale varieties resistant to pathogenic fungi offers the most economical and environmentally friendly alternative to chemical protection. 50 loci with more than 78 genes/alleles associated with powdery mildew resistance have been identified on 18 chromosomes of bread wheat and its relatives (Yang et al 2017) and only 8 resistance genes have been identified in rye

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