Abstract
Cucumber Mosaic Virus (CMV) i s a major viral pathogen affecting lupin crops in Western Australia. Infection causes yield losses of up 50% and can persist through seed transmission. Current methods of control rely on the use of virus- free seed, the control of insect vectors through pesticides and breeding for resistance. Natural resistance to CMV has been identified in a cultivar of L. luteus. Resistance is manifested as a hyper sensitive response and is controlled by a single, dominant gene Ncm-1. The aims of this research are to identify molecular markers linked to CMV resistance, for use in marker assisted selection, and to isolate the Ncm-1 resistance gene. Molecular markers linked to Ncm-1 have been identified using fluorescent AFLPs. A number of polymorphic fragments segregating with resistance together with five other characterised traits have been isolated using a preliminary mapping population. A further population consisting of at least 200 individuals has been developed and will be used to confirm these putative markers and evaluate their use in the lupin breeding program. In order to further characterise and isolate Ncm-1, degenerate primers based on alignments of resistance gene analogues (RGAs) have been used to generate resistance genes candidates. Amplicons have been cloned and sequenced and one fragment showing high identity with the Leucine Rich Repeat motif has so far been identified. Further examination of the resistance gene candidate obtained is in progress.