Poster Presentation Science Protecting Plant Health 2017

Characterisation of quantitative trait loci for resistance to two species of root‐lesion nematode (Pratylenchus thornei and P. neglectus) on chromosome 2BS in wheat (#132)

Iman Mohamed ElMor 1 , John Thompson 1 , Rebecca Zwart 1
  1. University of Southern Queensland, Toowoomba, QLD, Australia

Root-lesion nematodes (RLN) Pratylenchus thornei and P. neglectus are microscopic, vermiform, migratory, endoparasitic eel-worms that cause root damage in wheat (Triticum aestivum L.) in many countries. In Australia, high populations of P. thornei and P. neglectus can cause up to 85% and 27% yield loss in intolerant wheat varieties with annual loss in national wheat production estimated at $50 million and $73 million, respectively. Furthermore, mixed RLN populations are common with both species present in 28% of fields surveyed in the Northern region. The most efficient strategy for improving on-farm management of RLN relies on providing wheat growers with cultivars with higher levels of resistance to both species of RLN. Quantitative trait loci (QTL) on chromosome 2BS, conferring dual resistance to both P. thornei and P. neglectus will be fine mapped in a population derived from the synthetic hexaploid wheat CPI133872. Markers flanking the 2BS QTL will be used to screen 1,000 F2 individuals, using DNA extracted from half seeds. The remaining half seeds of selected recombinant genotypes will be grown for phenotypic evaluation. Resolving the map position of the 2BS target QTL is an important step towards identifying the genes underlying resistance to P. thornei and P. neglectus. Introgression of genes responsible for dual nematode resistance into commercially used cultivars will not only be economically and practically significant to breeders, but it will also enrich diversity of RLN resistance in Australian wheat cultivars. Furthermore, candidate gene analysis of this genome region will give insights into biochemical mechanisms of resistance to RLN, and potentially lead to development of novel control strategies for both species of RLN.