MOLECULAR CHARACTERIZATION OF Fusarium oxysporum F. SP. CUBENSE (FOC) TROPICAL RACE 4 CAUSING PANAMA DISEASE IN CAVENDISH BANANA IN PAKISTAN

Abstract

Fusarium wilt or Panama disease poses a great risk to banana production worldwide and is caused by Fusarium oxysporum f. sp. Cubense (Foc). Its tropical race 4 (TR4) is a major problem for Cavendish banana growing areas. Basrai (Dwarf Cavendish) is the major cultivated variety in Pakistan and now recently been reported to be affected by Foc TR4 in certain areas in the Sindh province. To genetically characterize, three independent isolates (P.TH1, P.TH2 and P.Th3) were sampled from different fields in district Thatta and fungus was isolated on potato dextrose agar. The pure fungal isolates were used to establish Koch's postulates by testing their pathogenicity on tissue cultured Cavendish banana. A diagnostic PCR assay was optimized and used to sequence a reported molecular marker for specific detection of Foc TR4 and to sequence 28S-18S ribosomal RNA intergenic spacer region (IGS) from these local isolates. The phylogenetic of Pakistani isolates suggests that they belong to previously characterized lineage V of tropical race 4 of F. oxysporum cubense with 99% bootstrap support and show close relationship with Indonesian and Malaysian Foc TR4 isolates. The rapid spread of this disease in different banana growing areas of the Sindh is alarming and necessitates effective control of this through chemical and biocontrol, if remains unchecked, Foc TR4 can raise havoc to banana industry in Pakistan and would be devastating economically.

Antimicrobial Activity of Pinus wallachiana Leaf Extracts against Fusarium oxysporum f. sp. cubense and Analysis of Its Fractions by HPLC

“…Fusarium oxysporum f. sp. cubense (Foc; TR4) was acquired from the Tissue culture department of National Agricultural Research Centre (NARC), Islamabad, the identity of which has been molecularly confirmed [ 66 ]. After the revival of Foc culture on potato dextrose agar (PDA), its morphology was examined, showing 3–5 septate, hyaline, sickle-shaped, macroconidia pointed at both ends and borne on single phialides, whereas microconidia were found to be mostly hyaline, kidney-shaped, aseptate produced on false heads.…”

Roving Survey of Panama Wilt Disease (Fusarium oxysporum f. sp. cubense) of Banana in Bihar

“…In 2013, race TR4 was found in Jordan, the first official report of the presence of TR4 in the Southeast Asia-Pacific region. In 2014 survey conducted found another infected area in the North of the original outbreak [11,12] reporting that TR4 is a serious problem for the Cavendish group of banana developing zones in Pakistan noting that cv. Basrai to be affected by TR4 in specific areas in the Sindh territory creating devastation for the banana industry and seriously affecting the Pakistani economy.…”

Molecular Detection of Fusarium oxysporum f. sp. Cubense Race TR4 Infecting Banana Groups in Indo-Gangetic Plains of India

“…Detection of pathogen is an important consideration and conventionally, pathogenicity test and Vegetative compatibility grouping (VCG) are deployed which having some bottleneck [34,35]. Recently PCR based detection method have been considered as reliable protocol for early and accurate detection of the isolate identity followed by apprehension of diversity and species synteny [23,30,36].…”