Author: A.A. EL-SHERBINY
Volume: 29 Issue: 2
Phytoparasitic nematodes associated with 22 different species of ornamental shrubs, trees and palms viz., Albizia lebbeck, Callistemon viminalis, Carissa macrocarpa, Chamaerops humilis, Cordia myxa, Duranta repens, Eremophila bowmanii, Ficus religiosa, Hibiscus tiliaceus, Melia azedarach, Parkinsonia aculeata, Phoenix canariensis, Pithecellobium dulce, Pongamia pinnata, Prosopis juliflora, Sabal palmetto, Sterculia diversifolia, Vitex agnus-castus, V. trifolia, V. trifolia variegata, Washingtonia robusta and Zizyphus spina-christi were surveyed in Riyadh region, Saudi Arabia during the period from April 2008 to July 2009. A total of 235 composite soil and root samples were collected for the nematode survey. Twenty one nematode genera were found associated with the rhizosphere soils of surveyed ornamental plants. The nematode genera Meloidogyne, Rotylenchulus, Tylenchorhynchus, Aphelenchus and Zygotylenchus were the most frequent and/or prominent genera found associated with the surveyed ornamentals, whereas Trichodorus, Xiphinema and Longidoruswere the least ones. Mean population densities of all nematode genera ranged between 17-983 nematodes/250 cm3 soil of all surveyed ornamentals. Roots of A. lebbeck, C. myxa, F. religiosa, P. dulce, P. pinnata, P. juliflora, S. diversifolia, V. agnus-castus, V. trifolia, V. trifolia variegata and W. robusta were found infected with M. incognita, while M. javanica was identified on roots of C. viminalis, C. macrocarpa, C. humilis, D. repens, E. bowmanii, M. azedarach, P. canariensis, S. palmetto and Z. spina-chisti. Meloidogyne arenaria mixed with M. javanica were found on roots ofHibiscus tiliaceous. Numerous young and adult females of the reniform nematode, Rotylenchulus reniformis were found attached to roots of Parkinsonia aculeata with high population of immature females in the soil averaged 1837 nematodes/250 cm3 soil. The above mentioned root infections by root-knot and reniform nematodes were first record on these ornamental plants in Saudi Arabia.