Evaluation of Cultivated and Wild Tomato Genotypes (Solanum lycopersicum) and (Solanum spp.) for Resistance to Egyptian Broomrape (Orobanche aegyptiaca)

Orobanche aegyptiaca, commonly known as Egyptian broomrape, is a holo-parasite that causes high economic damages on tomato production in Iran. Breeding for resistance is the most economic and feasible method to reduce broomrape infestation. 20 tomato cultivars and four wild tomato species were screened for O. aegyptiaca resistance. Tomato yield reduction, dry weight reduction of shoot and root, total number of attached broomrapes, dry weight of broomrapes and tolerance index were widely varied among tomato genotypes. The results showed that LA2530 (Ora mutant) was a very susceptible genotype while it was previously introduced as O. aegyptiaca resistant. According to the reports, the resistance phenotype is controlled by a dominant gene (Ora) and it seems that it is broken by the parasite because the overcoming of monogenic resistances by parasites is more likely than polygenic resistances. High levels of resistance were found in two wild species Solanum chilense TL00798 and S. pimpinellifolium L00134 respectively. The results suggested that wild relative species of tomato are promising diverse genetic resources for developing resistant crops to broomrape.