Genes for Resistance to Zucchini Yellow Mosaic in Tropical Pumpkin

Four cultigens of Cucurbita moschata resistant to zucchini yellow mosaic virus were crossed with the susceptible ‘Waltham Butternut ’ and with each other in order to clarify the mode of inheritance of resistance and relationships among the genes involved. Five loci were segregating, with genes for resistance Zym-0 and Zym-4 carried by ‘Nigerian Local ’ and one of them also carried by ‘Nicklow’s Delight, ’ Zym-1 carried by ‘Menina, ’ and zym-6 carried by ‘Soler. ’ A recessive gene carried by ‘Waltham Butternut, ’ zym-5, is complementary with the dominant Zym-4 of ‘Nigerian Local, ’ that is, the resistance conferre