New hosts and diagnostic characteristics of Orobanche crenata (Orobanchaceae) in Egypt

The holo-parasitic weed Orobanche crenata Forrsk. is a threat to economically important legumes and vegetables in Mediterranean countries, including Egypt. The crenate broomrape attacks several wild and cultivated plant species, and documentation of new hosts of the parasite is always required. To the best of our knowledge, this study is the first report of parasitism of the crenate broomrape on two ornamental species, Arctotis fastuosa Jacq. and Callistephus chinensis (L.) Nees. (Asteraceae). We also recorded for the first time its parasitism on the wild weeds (Ammi majus L., Lactuca serriola L., and Melilotus indicus (L.) All.) and the cultivated plant species (Carthamus tinctorius L. and Tropaeolum majus L.) from Egypt. The occurrence of O. crenata parasitism was confirmed by the attachment of its haustoria to the roots of host plants. The incidence of crenate broomrape disease was estimated for the seven species. The study also provides a morphological description of the polymorphic O. crenata on the samples from Egypt and determines the most useful characteristics for its easier identification in the field