The origin and current situation of Fusarium oxysporum f. sp. cubense tropical race 4 in Israel and the Middle East.

ABSTRACT

Fusarium oxysporum f.sp. cubense (Foc) is considered one of the most devastating soilborne fungal pathogens of banana worldwide. Foc causing mortality to Cavendish group bananas, and belonging to the unique vegetative compatibility group (VCG) 01213/16 has been termed tropical race 4 (TR4) and has currently been renamed F. odoratissimum. The pathogen that was first detected approximately 50 years ago in South East Asia, has since spread to countries within the greater Mekong subregion and to Australia. Recently, the pathogen disseminated to India, Pakistan, Oman and Mozambique (Africa) and was identified in the South American continent in Colombia in 2019. In the Middle East, TR4 was first reported from Jordan and Lebanon, and later from Israel in 2016. In Israel, the pathogen was identified as TR4 by VCG tests, pathogenicity assays and molecular verification. The complete genomes of five representative TR4 isolates including two from Israel, one from Jordan, one from the Philippines, and one from Indonesia were sequenced, and single nucleotide polymorphisms (SNPs) analyses were conducted. SNPs were compared to 11 additional sequenced TR4 isolates, to determine the origin of the Israeli isolates. SNP detection and phylogeographical analyses determined that the Middle Eastern isolates are closely related, indicating that the pathogen most likely spread to Israel from Jordan, while those from Colombia are related to a representative isolate from Indonesia.