MAPPING XIPHINEMA INDEX RESISTANCE IN V. RUPESTRIS X M. ROTUNDIFOLIA HYBRIDS

Muscadinia rotundifolia resists a wide range of grape pests, however it is usually genetically incompatible with Vitis species due to differences in chromosome numbers and homology.
A fertile hybrid between V. rupestris and M. rotundifolia was made, providing a unique genetic bridge and allowing introgression of resistance genes into domesticated grape.
Genetic linkage maps of two V. rupestris ‘A. de Serres’ (2n=38) x M. rotundifolia ‘Cowart’ (2n=40) hybrids were constructed using the pseudotestcross strategy.
Five hundred thirteen AFLP, ISSR, RAPD, and microsatellite markers were generated.
Markers segregating 1:1 were used to construct framework maps with confidence levels > 90% using PGRI. In the maternal map, 104 framework markers and 49 accessory markers were ordered in 17 linkage groups (765 cM); the paternal map had 112 framework markers and 37 accessory markers ordered in 19 linkage groups (1087 cM). One hundred seventy-two markers segregating 3:1 were used to connect the two parental maps.
This mapping population was also tested for resistance to Xiphinema index, the dagger nematode vector of grapevine fanleaf virus.
A preliminary assessment has positioned X. index resistance between an AFLP and an ISSR marker on the maternal map.
This mapping population has been expanded in preparation for fine scale mapping, marker development, and efforts to locate resistance genes.

VIII International Conference on Grape Genetics and Breeding

M. Doucleff, Y. Jin, M.A. Walker

Muscadinia, Vitis, linkage map, resistance genes

https://doi.org/10.17660/ActaHortic.2003.603.6