Identification of QTLs controlling resistance to rust, aphid and weevil in wild peas by DArTseq SNP-based technology
Résumé
Pisum sativum is the cool season grain legume most cultivated in Europe and the second in the world [1]. However, its yield is still relatively unstable and low due to the limited adaptability to extreme environmental conditions of available cultivars and their susceptibility to diseases and pests. We studied in the past resistance to a number of fungal diseases and parasitic weeds. Here we cover resistance to the biotrophic fungus Uromyces pisi, the causal agent of pea rust, and to the insect pests pea aphid (Acyrthosiphon pisum) and the pea weevil (Bruchus pisorum) [2] [3] [4]. Several studies have been performed, ranging from the screening of pea cultivars to the assessment of the mechanisms involved in the resistance. No complete resistance has been reported against these biotic stresses so far, but different levels of moderately incomplete resistance are available especially in the wild Pisum species. To unravel the genetic control of the resistance, a quantitative trait loci (QTL) analysis was performed using two recombinant inbred line (RIL F7:8) populations. The first one originated from a cross between two P. fulvum accessions, P660 and P651, while the second one originated from the cross between P. sativum ssp. syriacum accession P665 and P. sativum cv. Messire. Both RILs populations were phenotyped for resistance under controlled and field conditions, and genotyped through Diversity Arrays Technology PL’s DArTseq platform (Australia) [2]. The newly constructed integrated genetic linkage maps of wild peas includes high-quality DArT-Seq and SNPs derived-markers, as well as several previously mapped ”anchor” markers, which assembled in both cases in 7 Linkage Groups (LGs) and showed an average density lower than 2 markers cM-1. Genomic regions involved in resistance to rust, aphid and weevil will be presented and critically discussed.