Molecular mapping of Rym17, a dominant and rym18 a recessive barley yellow mosaic virus (BaYMV) resistance genes derived from Hordeum vulgare L.

Abstract

PK23-2, a line of six-rowed barley (Hordeum vulgare L.) originating from Pakistan, has resistance to Japanese strains I and III of the barley yellow mosaic virus (BaYMV). To identify the source of resistance in this line, reciprocal crosses were made between the susceptible cultivar Daisen-gold and PK23-2. Genetic analyses in the F(1) generation, F(2) generation, and a doubled haploid population (DH45) derived from the F(1) revealed that PK23-2 harbors one dominant and one recessive resistance genes. A linkage map was constructed using 61 lines of DH45 and 127 DNA markers; this map covered 1268.8 cM in 10 linkage groups. One QTL having a LOD score of 4.07 and explaining 26.8% of the phenotypic variance explained (PVE) for resistance to BaYMV was detected at DNA marker ABG070 on chromosome 3H. Another QTL having a LOD score of 3.53 and PVE of 27.2% was located at marker Bmag0490 on chromosome 4H. The resistance gene on chromosome 3H, here named Rym17, showed dominant inheritance, whereas the gene on chromosome 4H, here named rym18, showed recessive inheritance in F(1) populations derived from crosses between several resistant lines of DH45 and Daisen-gold. The BaYMV recessive resistance genes rym1, rym3, and rym5, found in Japanese barley germplasm, were not allelic to rym18. These results revealed that PK23-2 harbors two previously unidentified resistance genes, Rym17 on 3H and rym18 on 4H; Rym17 is the first dominant BaYMV resistance gene to be identified in primary gene pool. These new genes, particularly dominant Rym17, represent a potentially valuable genetic resource against BaYMV disease.

Bulked segregant RNA-sequencing (BSR-seq) identified a novel rare allele of eIF4E effective against multiple isolates of BaYMV/BaMMV

“…The genetic mapping against the barley yellow mosaic disease had identified 18 resistance genes (designated as rym1 to rym18) that are attributed to at least nine discrete loci on the barley genome (Kai et al 2012;Ordon et al 2005). Fifteen of these 18 genes encode for a recessive resistance, while the other three genes/alleles are inherited in a dominant manner, including two derived from Hordeum bulbosum, a wild relative of cultivated barley (Ruge-Wehling et al 2006;Ruge et al 2003).…”

Sequence diversification in recessive alleles of two host factor genes suggests adaptive selection for bymovirus resistance in cultivated barley from East Asia

“…In Asia, the disease can be even more severe where complete yield losses were recorded in China in the mid-1970s (Chen 2005; Kühne 2009). Breeding for genetic resistance to bymoviruses, therefore, remains the most viable and environmentally safe option for crop protection, and over time eighteen bymovirus resistance loci were genetically characterized in barley (Kai et al 2012; Ordon et al 2005). We previously isolated by positional cloning two recessive resistance genes rym1/11 and rym4/5 , corresponding to two different host factor genes Protein Disulfide Isomerase Like 5 - 1 ( HvPDIL5 - 1 ) and Eukaryotic Translation Initiation Factor 4E ( HvEIF4E ), respectively (Kanyuka et al 2005; Stein et al 2005; Yang et al 2014a, b).…”

A single QTL on chromosome 6DS derived from a winter wheat cultivar ‘OW104’ confers resistance to <i>Wheat yellow mosaic virus</i>

“…Several WYMV-resistance genes in wheat have been reported to be completely dominant, except for Qym1 whose dominance is incomplete ( Suzuki et al 2015 , Zhu et al 2012 ). In contrast, 15 BaYMV-resistance genes are recessive and three are dominant in barley ( Kai et al 2012 , Ordon et al 2009 ). The 8.1-Mb Qym4 region ( Xbarc183 - Xbarc173 ) includes a sequence homoeologous to the diagnostic molecular marker for Rym14 Hb , a BaYMV resistance gene, at the distal end of barley chromosome 6H ( , Howe et al 2020 , Ruge et al 2003 ).…”