Pachner, M., Department of Crop Sciences, Division of Plant Breeding, University of Natural Resources and Life Sciences, Konrad Lorenz Straße 24, Vienna, Tulln, Austria
Paris, H.S., Department of Vegetable Crops and Plant Genetics, Agricultural Research Organization, Newe Ya'ar Research Center, sRamat Yishay, Israel
Winkler, J., Saatzucht Gleisdorf, GmbH, Am Tieberhof 33, Gleisdorf, Austria
Lelley, T., Department for Agrobiotechnology, Biotechnology in Plant Production, University of Natural Resources and Life Sciences, Konrad Lorenz Straße 20, Vienna, Tulln, Austria

We report on the identification of phenotypic and molecular markers for genes introgressed into oilseed pumpkin Cucurbita pepo from C. moschata germplasm originating in Nigeria, Portugal and Puerto Rico, which provide resistance against zucchini yellow mosaic virus (ZYMV) and on pyramiding these genes for improved and long-lasting field protection of oilseed pumpkins. One SCAR and two SSR markers have been found for three dominant resistance genes, Zym-0, Zym-1 and Zym-2. Characteristic reactions to ZYMV inoculation of plants carrying the recessive genes for resistance zym-4* and zym-6 have been defined. Described are procedures and results of pyramiding various combinations of these genes in oilseed pumpkin using the three markers and the specific phenotypic reactions to infection of some of these genes. The putative combination of all six resistance genes in one genotype resulted in a resistance that appeared to be at least as strong as or even stronger than that of the resistance source germplasm in C. moschata. © 2014 Blackwell Verlag GmbH.