Occurrence of new phytoplasma disease on date palm in Jordan.

Abeer Abu Shirbi*, Ibtihal Abu Obeid*, Jihad Haddadeen*, Hani Ghnam*, Ruba Al Omari*, Khalid Al Hudaib**

*National Agricultural Research Center/Amman Jordan

** King Faisal University/ Saudi Arabia

Abstract

Date palm (Phoenix dactylifera L.) is one of the most important cash crops in Jordan, occupying 33000 donum, where 450000 trees produce 12000 ton of dates annually. A symptoms of mild leaf stunting, yellow streaking and a reduction in fruit and stalk size had been observed in date plam orchards. A total of 262 healthy and symptomatic samples were collected from different date palm cultivars, herbs growing under trees and different possible hosts growing in the orchards in addition to leafhoppers. Total DNA was extracted from all samples. Nested PCR was performed using phytoplasma P1/P7 primer pair at the first PCR round while R16F2n/R2 primer pair was used in the second round. Sequencing of representative PCR products was done in both directions. BLAST analysis of the obtained sequences revealed over than 98% similarity with different reference phytoplasma strains deposited in the Genebank and it shows 98-100% similarities with Candidatus Phytoplasma Ulmi strain.

To our knowledge, it is the first report about detection and identification of phytoplasma infecting date palm in Jordan.

Key words: Phoenix dactylifera, ‘Candidatus Phytoplasma Ulmi’, date palm, , phytoplasma, 16SrI DNA, Jordan