The kalanchoe (Kalanchoe blossfeldiana) is an important ornamental species belonging to Crassulaceae. This plant is grown in commercial greenhouses. A survey revealed infections of broomrape, Orobanche aegyptiaca Pers. (syn. Phelipanche aegyptiaca Walp.), on kalanchoe plants in the province of Tehran (Pakdasht, 35°26′ N, 51°40′ E, 1,003 m elevation) in northern Iran in January 2014. About 1% of total Kalanchoe pots in a greenhouse were infected. The infection of kalanchoe was confirmed by verifying the attachment of the broomrape to the kalanchoe roots. Broomrape plant heights (from the soil surface) were between 13 and 28 cm, with flowering stems 5 to 14 cm. The stems were erect, unbranched, slender, 2 to 4 mm diameter, glandular-pubescent, pale yellowish, and inflorescent rather than lax. The leaves were reduced to bracts up to 3 to 6 mm long. There was one bract and two bracteoles surrounding each flower. The bracts measured 4 to 5 mm, had ovate lanceolates shorter than the calyces, and filiform, lanceolate bracteoles measured 5 mm. The calyces measured 4 to 6 mm, and were gamosepalous, hairy, and glandular. Corollas measured 22 to 28 mm, and were medium slate blue with darker veins, slightly curved, conspicuously infundibuliform, and glandular-pubescent. Stamens were epipetalous, inserted 5 mm above the corolla base, filaments (10 to 12 mm) hairy below, anthers were villous. Style (18 to 21 mm) and stigma lobes were light steel blue. Ovary measured 5 to 7 mm. O. aegyptiaca is the most important species of the broomrape, which parasitizes important crops, such as tomato, potato, tobacco, carrot, celery, mustard, and spinach, as well as some ornamental plants, such as chrysanthemum (1,2). In this survey, low infection did not lead to visible symptoms or damage to kalanchoe, but allowed seed production by the parasite. However, the parasite weed could pose a serious threat to production of this important ornamental plant at high infection. To our knowledge, this is the first report of O. aegyptiaca parasitism on kalanchoe in Iran. Additionally, to the best of our knowledge, this finding reports the first occurrence of a Crassulaceae plants as a host for O. aegyptiaca.
References: (1) I. Ghannam et al. Am. J. Plant Sci. 3:346, 2012. (2) J. Rumsey and S. L. Jury. Watsonia 18:257, 1991.