International Organization of Citrus Virologists Conference Proceedings (1957-2010) · 1993 · 53 citations · 12 references
AgricultureMicrobiologyPlant PathologyBacteriologyDiagnostic MicrobiologyPlant Disease DiagnosisBacterial Disease SymptomsCulture-based DiagnosisDisease DetectionFruit DiseasesFruit PathologyPathogen DetectionBacterial Diseases Of FruitBacterial Fruit DiseasesDna ProbesElectron Microscopy DiagnosisFruit Disease DiagnosisGram-negative Cell WallMolecular Detection Of BacteriaPhloem-restricted Bacterial Diseases
Citrus greeningis one ofthemost severe diseases of citrus. It is widespread throughout Southern and Eastern Africa and in Asia from Pakistan to China. The disease is also present in the southwestern part of the Arabian Peninsula. The disease is due to a bacterium-like organism (BLO) restricted to the phloem sieve tube elements. This bacterium has a membraneous cell wall of the gram-negative type and belongs to the ct subdivision of the proteobacteria. The greening BLO has not been cultured. Symptoms of greening are not specific and are often confused with mineral deficiencies. Confirmation that a citrus tree is affected by greening has, up to now, relied on the electron microscopical detection of the greening BLO. In 1987, monoclonal antibodies (MAS) were produced against the greening BLO from Poona (India). Since then, MAS specific for China and South African greening BLOs have been obtained. However, these MAS are not useful for general diagnosis, because they are highly strain specific. Recently, DNA probes have been obtained for the detection of the BLO. One of these could detect all greening BLO strains tested, with a sensitivity at least equivalent to that of electron microscopy.
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