Complementary approaches towards the discovery of genes controlling yield in pea
Résumé
Pea is one of the most important grain legumes in the world. Improving pea yield is a critical breedingtarget in the current context of consumers’ increasing demand for plant proteins for food and feed. Becauseof its polygenic nature and the impact of the environment, breeding for higher yield is challenging. Weinvestigated the genetic determinism of yield (SW), seed number (SN) and thousand seed weight (TSW) usingboth linkage and linkage-disequilibrium approaches.Nine interconnected mapping populations, representing a total of 1,213 recombinant inbred lineswere phenotyped for SW, SN and TSW in six different field environments. These lines were genotyped usingthe GenoPea 13.2K SNP Array [1]. A multi-population quantitative trait loci (QTL) analysis [2] identified 19 QTLfor SW, 18 QTL for SN and 36 QTL for TSW. From this first QTL analysis, a metaQTL analysis [3] detected 27metaQTL and reduced confidence intervals.In addition, two panels of conventional winter pea (376 accessions) and spring pea (300 accessions)were phenotyped for the same traits in seven different field environments. These accessions were genotypedby re-sequencing after exome capture [4]. A Genome Wide Association analysis [5] detected markerssignificantly associated with the 3 traits.The combination of these two genetic approaches highlighted common regions on the pea genomethat represent genomic regions consistently involved in controling yield and its components in pea. Theseresults represent an important step towards marker assisted breeding programs for yield improvement.