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. Banana (Musa spp.) is one of the most popular exported fruit and serves as a staple diet for millions of people worldwide 1. In 2017, the approximate volume of global production reached 114 million tons totaling a gross value of about US$8 billion per year 2. An estimated 15% of all production reaches international markets, most of which are from cultivars within the Cavendish subgroup. Cavendish cultivars are the most popularly grown and exported bananas worldwide today, due to their resistance to 'Panama disease' caused by the soil-borne fungus Fusarium oxysporum f.sp. cubense (Foc) race 1, that eliminated the susceptible 'Gros Michel' cultivar and related industry 1,3. 'Panama disease' or Fusarium wilt, caused by F. o. f.sp. cubense (Foc) race 1, was first described in Australia in 1874 4. The pathogen destroyed the well-established 'Gros Michel' cultivar banana industry that was grown in monoculture plantations in the Americas, Africa and in the Far East during the 1900s 5. Thus, Fusarium wilt became known as a pathogen of significant global importance. The cultivar 'Gros Michel' was subsequently replaced by resistant Cavendish group cultivars, however, the disease recurred approximately 50 years ago in the 1970's in the southeast Asian continent and Australia with the detection of a new race of Foc, tropical race 4 (Foc TR4), causing mortality to Cavendish cultivars 6. Since then the disease has spread throughout SouthEast Asia, to the Middle-East, India and Pakistan, and was recently discovered in the African continent in Mozambique in 2015 7,8. Foc TR4 was...

Identification of sources resistant to a virulent Fusarium wilt strain (VCG 0124) infecting Cavendish bananas

“…The production of Cavendish in Asia 13 is also seriously threatened by the virulent Foc TR4 14 . This lethal strain has spread to 19 different banana-growing countries 15,16 and is www.nature.com/scientificreports/ threatening the livelihoods of millions of farmers and the global banana export industry. In India, the devastation of Cavendish banana due to Foc race 1 (VCG 0124) was first reported in the Theni district, Tamil Nadu, in 2009 7 , and a recent survey revealed its spread to other major Cavendish growing states, such as Gujarat, Maharashtra, Madhya Pradesh and West Bengal, where 0.224 million ha of Cavendish banana produces 11.27 million tons 17 .…”

Phytosanitary Interventions for Safe Global Germplasm Exchange and the Prevention of Transboundary Pest Spread: The Role of CGIAR Germplasm Health Units

“…Some examples of introduced pests causing epidemics and pandemics with disastrous consequences for food production, livelihoods, and environmental biodiversity include the Irish potato famine in the 1840s caused by Phytophthora infestans, which was introduced from Central America into Ireland [11,15]. Some recent examples of devastating outbreaks caused by transboundary pest introductions into regions where the CGIAR operates include the maize lethal necrosis (MLN) epidemic in East Africa caused by maize chlorotic mottle virus (MCMV), which was introduced from East Asia [16]; the fall armyworm (Spodoptera frugiperda) outbreak in Africa and Asia, caused by the likely introduction of insect pest from the Americas [17]; the cassava mosaic disease outbreak in East Asia, caused by the Sri Lankan cassava mosaic virus (SLCMV), which was introduced from South Asia [18]; the banana bunchy top virus (BBTV) outbreak in the sub-region of Western Africa due the spread of the virus through planting material from the sub-region of Central Africa [19]; the expansion of banana wilt caused by the Fusarium oxysporum Tropical Race 4, which was introduced from Southeast Asia into South (India) and West Asia (Jordon and Israel), Mozambique and Colombia [20]; the outbreak of potato cyst nematode, Globodera pallida, in Kenya by the likely introduction of the pest from Europe [21]; the wheat blast outbreak in Bangladesh [22] and, more recently, in Zambia [23], caused by the Magnaporthe oryzae pathotype Triticum, introduced from South America; the spread of Candidatus Liberibacter solanacearum haplotype A and its vector, Bactericera cockerelli (potato psyllid), which is responsible for the potato Zebra chip disease and potato purple top disease, which are likely to have spread from the Central American region to Ecuador in South America [24]. The occurrence of these new pests in the territories was recognized during obvious disease outbreaks.…”

Institutional approaches for plant health provision as a collective action problem

“…Viral diseases vectored by insects such as the whitefly Bemisia tabaci or the Western flower thrips Frankliniella occidentalis (Gilbertson et al, 2015), fungal diseases such as 'Panama disease', caused by Fusarium oxysporum f. sp. cubense tropical race 4 (Maymon et al, 2020), or bacterial diseases such as Olive Quick Decline Syndrome, caused by Xylella fastidiosa sp. pauca (Schneider et al, 2020), are current examples of invasive plant diseases that have been detected outside their native habitat and have triggered costly emergency responses.…”