VIEW ARTICLE

Genetics

Inheritance of Resistance to Orobanche cumana in Sunflower. Naomi Ish- Shalom-Gordon, Department of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel; R. Jacobsohn(2), and Y. Cohen(3). (2)Department of Vegetable Crops, ARO, The Volcani Center of Agricultural Research, Bet Dagan, P.O. Box 6, 50250, Israel; (3)Department of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel. Phytopathology 83:1250-1252. Accepted for publication 1 June 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/Phyto-83-1250.

The inheritance of resistance to Orobanche cumana (sunflower broomrape) in the resistant sunflower lines SW-501 and RW-637 and the hybrid Sunbred-254 was studied in crosses with susceptible sunflower cultivars Aya and DI-1, in the field and in the growth chamber. Resistance in SW-501 and RW-637 was conferred by a single dominant gene. SW-501 was homozygously resistant, and RW-637 was heterozygously resistant, having one resistance allele and one susceptible allele. The testcross progeny of Sunbred-254 (SW-501 × RW-637) to the susceptible Aya segregated 3 resistant : 1 susceptible, indicating that Sunbred-254 is composed of two genotypically different subpopulations in equal parts, representing the genetic differences between RW-637 and SW-501 in the resistance to Orobanche cumana.