First report of Fusarium oxysporum f. sp. cubense tropical race 4 in Jordan
Fusarium wilt or Panama disease caused by Fusarium oxysporum f. sp. cubense is a severe fungal disease of banana, and a regulated pest in most banana-producing countries. Planting material, water, soil particles, tools, footwear and machinery can efficiently disseminate the fungus. Different races of F. oxysporum f. sp. cubense have been designated based on their pathogenicity to different reference varieties under field conditions. In particular, race 1 caused severe economic losses during the mid-20th century to the cultivation and trade of the banana cultivar ‘Gros Michel’ in Central America and the Caribbean, until it was replaced by resistant Cavendish cultivars. In 1992 a new variant of F. oxysporum f. sp. cubense called the tropical race 4 (TR4) was identified in Southeast Asia infecting a wide range of banana cultivars, including Cavendish clones. Tropical race 4 has overcome the resistance to F. oxysporum f. sp. cubense in Cavendish clones and can attack other banana cultivars such as plantains, cooking bananas and a diverse range of dessert bananas which are major sources of food in tropical countries. This race has since spread throughout Southeast Asia and Australia [Australia (Northern Territory), China (Fujian, Guangdong, Guangxi, Hainan, Yunnan), Indonesia, Malaysia, Philippines, Taiwan] with unconfirmed records in Pakistan and Oman. In November 2013, its presence was reported for the first time in Africa, in Mozambique. Finally, tropical race 4 has recently been confirmed in Jordan, although Fusarium wilt symptoms were first noticed in 2006. In Jordan, Cavendish bananas are cultivated on 1 000-1 500 ha in the Jordan Valley. Laboratory analysis of collected samples (isolation on growing media, Vegetative Compatibility Groups, molecular and pathogenicity tests) confirmed the presence of tropical race 4. It is noted that currently 80% of the Jordan Valley production area is affected by Fusarium wilt, with a disease incidence ranging from 20 to 80% in the different farms. It is noted that this record in Jordan which is the northernmost outbreak, represents a major expansion of the damaging tropical race 4.
More information about F. oxysporum f. sp. cubense tropical race 4 and its management can be found in a recent FAO technical manual: http://www.fao.org/fileadmin/templates/agphome/documents/Pests_Pesticides/caribbeantr4/13ManualFusarium.pdf
Sources
García-Bastidas N, Ordóñez F, Konkol J, Al-Qasim M, Naser Z, Abdelwali M, Salem N, Waalwijk C, Ploetz RC, Kema GHJ (2014) First report of Fusarium oxysporum f. sp. cubense tropical race 4 associated with Panama disease of banana outside Southeast Asia. Plant Disease 98(5), p 694.
Pérez-Vicente L, Dita MA, Martínez de la Parte E (2014) Technical Manual – Prevention and diagnostic of Fusarium wilt (Panama disease) of banana caused by Fusarium oxysporum sp. cubense tropical race 4 (TR4) prepared for the Regional FAO Workshop on the ‘Diagnosis of Fusarium wilt (Panama disease) caused by Fusarium oxysporum f. sp. cubense tropical race 4: Mitigating the threat and preventing its spread in the Caribbean. FAO, Rome, 74 pp.