Morphological studies on some Orobanche L. species in Egypt

Abstract

Broomrapes are root holoparasites in the family Orobanchaceae. These parasites can cause substantial losses, 5%–95%, in important crops . These plants parasitize legumes, oilseeds, nightshades, and crucifers in warmer areas of Europe, Africa, the Americas, and Asia. A full taxonomic study for seven taxa of Orobanche in Egypt; O. ramose L. var. ramose, O. mutelii F. W., O. lavandulacea Rchb., O. aegyptiaca Pers., O. crenata Forssk., O. cernua Loefl., and O. minor Sm. var. minor is presented in this article. The work includes a key to taxa, taxa descriptions, LM and scanning electron microscopy (SEM) images of pollen, seed, and seed‐coat morphology, and a numerical analysis of results. Macromorphological characteristics are key features for differentiation among taxa. Diagnostic characteristics include simple and branched stems, presence and absence of bracteoles, constriction of corolla tubes, and color and length of corollas. SEM of pollen identified three types: prolate-spherical, oblate-spherical, and spherical. Three apertures were also recorded; inaperturate- tricolpate, tricolpate, and inaperturate. Ornamentation included only microreticulate and scabrate-verrucate. LM investigation of seeds recognized three shapes: ellipsoid to ovoid, ovoid to ellipsoid, and ovoid. SEM identified four morphological groups.