Resistance to Asparagus virus-1 was transferred from a asparagus wild relative to garden asparagus by interspecific hybridisation and recurrent backcrosses. The monogenic inherited AV-1pro gene is located on chromosome 2. GBS study Asparagus

An introgression breeding programme was carried out to transfer the virus resistance gene AV-1pro from the wild species Asparagus prostratus to the garden asparagus A. officinalis. Five AV-1 resistant diploid (2n = 2x = 20) BC2 plants were selected and reciprocally backcrossed with asparagus cultivars. Segregation analyses of fourteen seed borne BC3 progenies suggested a monogenic dominant inheritance of the AV-1 resistance. GBS analysis gave a strong hint for location of the resistance gene on asparagus chromosome 2. Using an Axiom SNP genotyping array for the analysis of three BC3 families with 10 AV-1 resistant and 10 AV-1 susceptible plants each as well as 25 asparagus cultivars, the AV-1pro locus on chromosome 2 was further narrowed down. The SNP with the highest LOD score was converted to a KASP marker shown to be useful for the further backcross programme and serving as starting point for the development of a diagnostic marker.