We report the development of a Diversity Arrays Technology (DArT) marker panel and its utilisation in the development of an integrated genetic linkage map of white lupin (Lupinus albus L.) using an F8 recombinant inbred line population derived from Kiev Mutant/P27174. One hundred and thirty-six DArT markers were merged into the first genetic linkage map composed of 220 amplified fragment length polymorphisms (AFLPs) and 105 genic markers. The integrated map consists of 38 linkage groups of 441 markers and spans a total length of 2,169 cM, with an average interval size of 4.6 cM. The DArT markers exhibited good genome coverage and were associated with previously identified genic and AFLP markers linked with quantitative trait loci for anthracnose resistance, flowering time and alkaloid content. The improved genetic linkage map of white lupin will aid in the identification of markers for traits of interest and future syntenic studies.

Phomopsis blight in Lupinus albus is caused by a fungal pathogen, Diaporthe toxica. It can invade all plant parts, leading to plant material becoming toxic to grazing animals, and potentially resulting in lupinosis. Identifying sources of resistance and breeding for resistance remains the best strategy for controlling Phomopsis and reducing lupinosis risks. However, loci associated with resistance to Phomopsis blight have not yet been identified. In this study, quantitative trait locus (QTL) analysis identified genomic regions associated with resistance to Phomopsis pod blight (PPB) using a linkage map of L. albus constructed previously from an F8 recombinant inbred line population derived from a cross between Kiev-Mutant (susceptible to PPB) and P27174 (resistant to PPB). Phenotyping was undertaken using a detached pod assay. In total, we identified eight QTLs for resistance to PPB on linkage group (LG) 3, LG6, LG10, LG12, LG17 and LG27 from different phenotyping environments. However, at least one QTL, QTL-5 on LG10 was consistently detected in both phenotyping environments and accounted for up to 28.2% of the total phenotypic variance. The results of this study showed that the QTL-2 on LG3 interacts epistatically with QTL-5 and QTL-6, which map on LG10 and LG12, respectively.

L. albus is an annual grain-legume crop mainly grown for high-protein fodder worldwide but also to produce large seeds for human consumption as a snack-food. In order to make genetic gains in grain yield, assessment of the genetic variation in the germplasm and identification of loci associated with agronomic traits are essential. Phomopsis blight (PB) and Pleiochaeta root rot (PRR), caused by the fungal pathogens Diaporthe toxica and, Pleiochaeta setosa respectively, are two major yield-limiting diseases of the L. albus crop. The extent of genetic diversity in 94 accessions of L. albus comprising: Australian and exotic cultivars, advanced breeding lines, and landraces originating from 26 different countries was determined utilizing PCR-based genic, and microarraybased Diversity Arrays Technology (DArT™), markers. All accessions were evaluated for resistance to PB in two plant tissues (leaves and stems) using either sprayed or injected spore inoculum. A subset of 58 accessions was further evaluated for resistance to PRR by growing seedlings in spore-infested potting mix. The combined data of 724 (50 genic-and 674 DArT) markers were used for cluster analysis. A subset of 324 markers with call rate ≥95% and predicted disease scores of different genotypes were used to identify marker loci accounting for phenotypic variation in PB and PRR resistance using linear regression analysis. Several markers showed significant association with PB or PRR resistance at P < 0.05. Our results showed that favourable alleles for PB and PRR resistance are present in the diverse accessions investigated and they will provide