Distribution, etiology, transmission and host range of Cucumber phyllody disease in Jiroft and Kahnouj regions
2006
Azadvar, Mehdi | Salehi, Mohammad | Taghinejad, Mohammad | Amiri, Masoud
Jiroft and Kahnouj with over of 1000 hectars greenhouse-grown cucumber, have the most area cultivation in Iran. Phyllody disease of greenhouse-grown cucumber was reported for the tirst time in Jiroft and Kahnouj in 2004. The major symptoms of the disease are virescence, Phyllody, floral proliferation, witche's broom and stunting. The associated disease agent was transmitted to seed grown priwinkle plants by dodder, to seed-grown cucumber and periwinkle plants by grafting trom infected cucumber and periwinkle, respectively. Transmissions trials with the leatl10pper Orosius albicinctus showed this species is a vector of the cucumber phyllody pathogen. PCR was used to ascertain whether a phytoplasma was involved in the disease or not. Total DNA was extracted from leaves or floral parts of symptomatic and healthy plants. Phytoplasma DNA was amplified by the polymerase chain reaction (PCR) using the universal primer pair PlIP? to amplifY parts of the ribosomal operon comprising the 16S rRNA gene, the spacer region and the start of the 23S rRNA gene. PCR resulted in the amplification product of the expected DNA size (1800 bp) trom all symptomatic plants but not from healthy ones. On the basis of symptoms, PCR assay, transmissibility by dodder, grafting and the leafuopper, the cucumber phyllody disease has phytoplasmal etiology.
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