QTL analysis of root-lesion nematode resistance in barley: 1. Pratylenchus neglectus

Abstract

The root-lesion nematode Pratylenchus neglectus can cause severe losses in barley cultivation. Multiplication rates had been found to vary greatly between different barley accessions. Two winter barley cultivars, Igri and Franka, had been found to differ in their ability to resist this parasite. An existing Igri × Franka doubled haploid population was chosen to genetically map resistance genes after artificial inoculation with P. neglectus in the greenhouse and climate chamber. A continuous phenotypic variation was found indicating a quantitative inheritance of P. neglectus resistance. An existing map was enriched by 527 newly developed Diversity Array Technology markers (DArTs). The new genetic linkage map was comprised of 857 molecular markers that cover 1,157 cM on seven linkage groups. Using phenotypic data collected from four different experiments in 3 years, five quantitative trait loci were mapped by composite interval mapping on four (3H, 5H, 6H and 7H) linkage groups. A quantitative trait locus with a large phenotypic effect of 16% and likelihood of odds (LOD) score of 6.35 was mapped on linkage group 3H. The remaining four QTLs were classified as minor or moderate with LOD scores ranging from 2.71 to 3.55 and R (2) values ranging from 8 to 10%. The DNA markers linked to the resistance QTLs should be quite useful for marker-assisted selection in barley breeding because phenotypic selection is limited due to time constraints and labor costs.

Genetic analysis of tolerance to the root lesion nematode Pratylenchus neglectus in the legume Medicago littoralis

“…To date, genetic analysis has lead to the identification of five resistance QTL in wheat [14,15] and also in barley [16] but no resistance or tolerance QTL to this pathogen has been described in legumes. To our knowledge, this is the first report on a genetic locus linked to P. neglectus tolerance in a legume species.…”

Resistance to Multiple Soil-Borne Pathogens of the Pacific Northwest, USA Is Colocated in a Wheat Recombinant Inbred Line Population

“…Screening for response to soil-borne pathogens can be time-consuming and variable (Schneebeli et al 2016; Sharma et al 2011; Smiley and Patterson 1996); therefore, the phenotyping assays included several susceptible and resistant checks (Table 1). …”

“…Phenotyping is time-consuming and difficult, and subject to spatial and environmental variation in the field (Collard et al 2005; Schmidt et al 2005; Schneebeli et al 2016; Sharma et al 2011). Often, the identified resistant or partial-resistant germplasm have been wild relatives, landraces, and synthetic hexaploids that also possess nondesirable traits (Li et al 2010; Mahoney et al 2016; Thompson et al 1999, 2016).…”

Expression of a cystatin transgene can confer resistance to root lesion nematodes in Lilium longiflorum cv. ‘Nellie White’

“…Host resistance to Pratylenchus spp. is often limited, and only a few loci have been linked to resistance/tolerance to RLN, such as in wheat (Jayatilake et al 2013;Williams et al 2002), barley (Sharma et al 2011), or Medicago littoralis (Oldach et al 2014). Application of chemicals to control RLN is not a sustainable option, as most of these chemicals increase production costs and present negative effects on the environment.…”