Inheritance of Podosphaera xanthii resistance in melon line ‘90625’

Several races of Podosphaera xanthii have been described on melon. The Indian melon line ‘90625’ (PI 313970) which had already been described as resistant in the USA is a potential source of resistance for strains recently characterized in France. We have studied the inheritance of resistance in a Recombinant Inbred Line population between ‘Védrantais’ (susceptible) and ‘90625’ using a leaf disk technique with 10 strains of P. xanthii. Potentially five genes could be present in ‘90625’. Two independent semi-dominant genes (A and B) are involved in resistance to strains 06Sm10 and S87-7 respectively. Resistance to the other strains seems to be under a digenic control, including A and B or not, with three other recessive genes. Some of these RILs could be used as additional differential lines for the characterization of the races.Cucurbitaceae 2008. IX EUCARPIA Meeting. Avignon (France), May 21-24th, 200