First report of Fusarium oxysporum f. sp. cubense tropical race 4 causing Panama disease in Cavendish bananas in Pakistan and Lebanon



  • Authors : Ordonez, N.; Garcia-Bastidas, F.; Laghari, H.; Akkary, M.; Harfouche, E.N.; Al Awar, B.N.; Kema, G.H.J.

  • Document type : Journal article

  • Year of publication : 2016

  • Journal title : Plant Disease

  • Volume (number) : 100 (1)


  • Pages : 209

  • Peer-reviewed : Yes

  • ISSN : 0191-2917

  • Language(s) : English

  • Abstract : Panama disease of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), poses a great risk to global banana production. Tropical race 4 (TR4) of Foc, which affects Cavendish bananas as well as many other banana cultivars (4; see e-Xtra link), was confirmed for the first time outside Southeast Asia in Jordan in 2013 (2). In Pakistan, bananas are produced in the Sindh and Balochistan provinces (91% - 31,000 ha - and 9% of the country's production, respectively). Symptoms of Fusarium wilt, including wilting of leaves and vascular discoloration in rhizomes and pseudostems, were first observed in 2012 in a 2 ha Cavendish plantation in Baoo Pooran (ca. 24°N, 68°E), Sindh province. By January 2014, approximately 121 ha were affected. In Lebanon, bananas are produced for local consumption and regional export, especially to Syria. Yellowing of leaves and internal vascular discoloration in the pseudostems was first observed in Cavendish plants in October 2013 in the Mansouri and Berghliyeh regions. Thus far, 1 ha has been affected. Infected pseudostem tissue samples from Pakistan and Lebanon were processed for Foc isolation and characterization as described by García-Bastidas et al. (2). White colonies developed from the surface sterilized (70% ethanol) tissue on Komada's medium (3) and nine single microconidia isolates were generated, four from the Pakistan sample and five from the Lebanon samples and transferred to quarter-strength PDA. All isolates phenotypically resembled F. oxysporum (3) and were diagnosed as vegetative compatibility group (VCG) 01213 (Fig. 1), which was confirmed by PCR (Fig. 2), thereby corroborating that VCG01213 only represents TR4 strains (4). Subsequently, one of the isolates from Pakistan (Pak1.1A) and one isolate each from Mansouri (Leb1.1A) and Berghliyeh (Leb1.2C) in Lebanon were analyzed for pathogenicity. Inoculum production and inoculation were according to Dita et al. (1) by dipping (30 min, 106 spores/ml) root-wounded 10 week-old Cavendish cv. Grand Naine plants, which were then placed in sand in 3L pots under 28oC, 70% relative humidity and a 16h diurnal light periods for 6 weeks. Sets of three plants were each treated with either Pak1.1A, Leb1.1A, Leb1.2C or TR4 (reference isolate II-5, which was diagnosed as TR4 by PCR and pathogenicity analyses, see (1)). Control sets were each treated with either Foc Race1 (Cruz das Almas, Brazil, see (1)), or water. After 4 weeks, all plants inoculated with the isolates from Pakistan, Lebanon and TR4 (II-5) produced typical symptoms of Fusarium wilt. After 6 weeks, internal symptoms were recorded (Fig. 2) and tissue was collected from all plants and plated on Komada's medium. TR4 was confirmed by PCR from isolates that were recovered from all symptomatic plants. No isolates were recovered from plants infected with Race 1 or the water controls, all of which remained asymptomatic. Thus, we confirm the presence of TR4 in Pakistan and Lebanon and its continued expansion and distribution in Western Asia. Although comparatively limited production areas have been affected to date, increasing damage will undoubtedly occur in these countries in the near future. References: (1) M.A. Dita et al. Plant Pathol. 59: 348, 2010. (2) F. García-Bastidas et al. Plant Dis. 98: 694, 2014. (3) J.F. Leslie, J.F. and B.A. Summerell. The Fusarium Lab Manual. Blackwell, Ames, Iowa, 2006. (4) R.C. Ploetz. Phytopathology 96: 653, 2006.

  • Keywords : FUSARIUM OXYSPORUM F. SP. CUBENSE; PAKISTAN; LEBANON; TROPICAL RACE 4; FIRST REPORT

  • Open access : Yes

  • Document on publisher's site : open View article on publisher's site

  • Musalit document ID : IN150155


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