Genetic diversity and phylogeny of Fusarium species associated with panama disease of banana in Jordan
Nida Salem: The University of Jordan
<div><i><span lang="EN" style="font-family:'Palatino Linotype';">Fusarium</span></i><span lang="EN" style="font-family:'Palatino Linotype';"> species are a cosmopolitan group of fungi which infect banana and cause serious diseases as Fusarium wilt (panama disease) and crown rot disease. Panama disease of banana, caused by <i>Fusarium oxysporum</i> f. sp. <i>cubense</i> (Foc) tropical race 4 (TR4), was reported for the first time in Jordan in 2013. Its continued expansion and wide distribution in Jordan Valley presents undoubtedly significant risks to banana plantations. </span><span lang="EN" style="font-family:'Palatino Linotype';">To address this we conducted </span><span lang="EN" style="font-family:'Palatino Linotype';">comprehensive survey</span><span lang="EN" style="font-family:'Palatino Linotype';">s</span><span lang="EN" style="font-family:'Palatino Linotype';"> for </span><span lang="EN" style="font-family:'Palatino Linotype';">banana </span><span lang="EN" style="font-family:'Palatino Linotype';">Fusarium wilt in 60 different banana farms during 2016-2017, in North and South Jordan Valley. Around 759 samples were collected from “Cavendish” banana plantations</span><span lang="EN" style="font-family:'Palatino Linotype';"> showing leaves y</span><span lang="EN" style="font-family:'Palatino Linotype';">ellowing and pseudostems internal vascular discoloration</span><span lang="EN" style="font-family:'Palatino Linotype';">.</span><span lang="EN" style="font-family:'Palatino Linotype';"> The incidence of panama disease ranged from 25-100% with varied severity. Morphological identification of fungal isolates was done using conidial and hyphal structures. Further molecular identification of 40 selected Fusarium isolates was carried out by amplifying the internal transcribed spacer (ITS) region of the conserved ribosomal DNA (rDNA) and the translation elongation factor 1 α (TEF) DNA region, followed by sequencing. Of the 40 Fusarium isolates, 52 % were identified as Foc TR4 that was recovered from most banana farms across Jordan Valley. </span><span lang="EN" style="font-family:'Palatino Linotype';">Five</span><span lang="EN" style="font-family:'Palatino Linotype';"> other <i>Fusarium</i> species including <i>F</i>. <i>brachygibbosum</i>, </span><i><span lang="EN" style="font-family:'Palatino Linotype';">F</span></i><span lang="EN" style="font-family:'Palatino Linotype';">. <i>equiseti, F. musae</i>, <i>F. proliferatum</i> and <i>F. verticillioides</i> were also recovered. </span><span lang="EN" style="font-family:'Palatino Linotype';">All TEF sequences of <i>Fusarium</i> species were compared and analyzed phylogenetically with maximum-likelihood. Our phylogenetic approach clearly indicates that diverse <i>Fusarium</i> species and genetic groups are associated with panama disease in Jordan, and thus raises the necessity of further epidemiological and molecular investigations.</span></div>
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