In a survey conducted at Al-Hassa, Saudi Arabia, during 2003-05, leaf samples were collected from dates with or without Al-Wijam symptoms and 60 Cicadellidae specimens. The major symptoms consisted of leaf stunting, yellow streaking, marked reduction in fruit and stalk size, and inhibition of fruit set. The total DNA extracted from plants and batches of insects was analysed by PCR and RFLP. Phytoplasma rDNA was amplified from 28 palms with symptoms and 16 batches of insects. The 16s rDNA sequences of the phytoplasmas identified in date palm (DQ13090) and Cicadulina bipunctata (DQ913091) were 100% identical and showed 98% homology to that of Aster yellows phytoplasma (AF322644) from the 16SrI, Candidatus Phytoplasma asteris group. This is thought to be the first report of Ca. P. asteris phytoplasma associated with a disease in date palm in Saudi Arabia, and the identification of a potential vector of Al-Wijam disease.
Alhudaib, K.; Arocha, Y.; Wilson, M.; Jones, P. First report of a 16SrI, Candidatus Phytoplasma asteris group phytoplasma associated with a date palm disease in Saudi Arabia. Plant Pathology (2008) 57 (2) 366-366. [DOI: 10.1111/j.1365-3059.2007.01667.x]