Development and implementation of a sequence-specific PCR marker linked to a gene conferring resistance to anthracnose disease in narrow-leafed lupin (Lupinus angustifolius L.)

Anthracnose caused by Colletotrichum gloeosporioides is the most serious disease of lupins (Lupinus spp). A cross was made between cultivars Tanjil (resistant) and Unicrop (susceptible) in narrow-leafed lupin (L. angustifolius). Analysis of disease reaction data on the F₂ population and on the resultant F₇ recombinant inbred lines suggested that Tanjil contained a single dominant gene (Lanr1) conferring resistance to anthracnose. The parents and the representative F₂ plants were used to generate molecular markers liked to the Lanr1 gene using the MFLP technique. A co-dominant MFLP polymorphism linked to the Lanr1 gene was identified as a candidate marker. The bands were isolated, re-amplified by PCR, cloned and sequenced. The MFLP polymorphism was converted into a co-dominant, sequence-specific, simple PCR-based marker. Linkage analysis by the computer program MAPMAKER indicated that the marker was 3.5 centiMorgans (cM) from the gene Lanr1. This marker is currently being implemented for marker assisted selection in the Australian National Lupin Breeding Program.