Developing a Linkage Map of Yellow Lupin for Mapping Drought and Phenological Adaptation QTL

Yellow lupin (Lupinus luteus) originates from the Mediterranean region but first entered cultivation in Northern Europe in the 19^th Century as a green manure and fodder crop. Its domestication was completed in the 20^thCentury where it made the transition to a high-quality grain (contains 37-40% protein content) legume for human consumption.  However, the cropping area of yellow lupin remains limited in dry Mediterranean-type climates (e.g. California, Southern Europe, Chile and southern Australia) due in part to its narrow phenological adaptation and sensitivity to drought stress. In this project, we will determine the genetic bases of these traits through quantitative trait locus (QTL) mapping. Here we describe our approach for developing a reference linkage map with which to conduct the QTL analysis.

A recombinant-inbred line (RIL) population was developed from a cross between ‘Wodjil’ (cultivar of low rainfall origin) x P28213 (wild type of high rainfall origin). This RIL population is segregating for both phenology and drought adaptation traits, and these are currently being phenotyped in a replicated field trial. The RIL population will be genotyped by next generation sequencing (NGS) of restriction-site associated DNA (RAD) libraries, which will then be used to develop a linkage map for yellow lupin. Once phenotypic and genotypic characterisation of the RIL population is complete, QTL analysis will then be performed in order to investigate the genetic control of drought and phenology traits. This will provide important information and marker tools for plant breeders to broaden the adaptation of this high-protein grain legume crop species.