Identification of genetic resistance to Diporthe toxica in Lupinus albus

he experimental design and analysis. Phomopsis pod blight resistance was identified in L. albus genotypes P27273, P27272, P25863, P27174, P27154, P28990, P28507, CH306-S, WALAB2008, WK134, MG110428, 98B001-5-5, TYPTOP and ROSETTA.A mapping population from Kiev-Mutant×P27174 available as F8 recombinant inbred lines (RILs) was phenotyped on two occasions for Phomopsis pod blight resistance. Genetic maps for L. albus have been published for this population and the data was used to identify quantitative trait loci (QTLs) conditioning resistance for Phomopsis pod blight on two linkage groups LG3 and LG10. In one of the phenotyping datasets, the QTLs identified on LG3 and LG10 explained 36.9% and 27.1 % of total phenotypic variance when assessed individually. The combined effect of the QTLs explained an extra 24.6% of the phenotypic variance (a total of 88.6% for these two QTLs). In the second phenotyping dataset, QTLs were also located on LG3 and LG10. Two extra QTLs on LG3 were identified, although in a different location to the previous dataset and explained 29.8% and 11.5% phenotypic variance, respectively. A further QTL was located on LG10 in the same location as the previous dataset and explained 28.2% of total phenotypic variance. The combined effect of the major QTL on LG3 and the major QTL on LG10 explain 25.8% of the phenotypic variance. Minor effect QTLs were also located on LG6, LG12, LG17 and LG27. The precise interaction of these QTLs is unclear; however, it is likely that the QTL on LG12 interacts with the QTL on LG3.The two major QTLs on LG3 and LG10 are prime candidates for the development of PCR-based DNA markers for use in marker“assisted selection for resistance to Phomopsis in breeding populations of L. albus.