Thi Loan Le, Mertens Arne, Vu Dang Toan, Vu Tuong Dang, Minh Pham Le Anh, Duc Huy Nguyen, de Backer Sander, Swennen Rony, Vandelook Filip, Panis Bart, Amalfi Mario, Decock Cony, Gomes Sofia I F, Merckx Vincent S F T, Janssens Steven B
Plant Resources Center, Hanoi, Vietnam.
Meise Botanic Garden, Nieuwelaan 38, BE-1860 Meise, Belgium.
MycoKeys. 2022 Feb 10;87:53-76. doi: 10.3897/mycokeys.87.72941. eCollection 2022.
is one of the most important fungal genera of plant pathogens that affect the cultivation of a wide range of crops. Agricultural losses caused by Fusariumoxysporumf.sp.cubense () directly affect the income, subsistence, and nourishment of thousands of farmers worldwide. For Viet Nam, predictions on the impact of for the future are dramatic, with an estimated loss in the banana production area of 8% within the next five years and up to 71% within the next 25 years. In the current study, we applied a combined morphological-molecular approach to assess the taxonomic identity and phylogenetic position of the different isolates collected in northern Viet Nam. In addition, we aimed to estimate the proportion of the different races infecting bananas in northern Viet Nam. The morphology of the isolates was investigated by growing the collected isolates on four distinct nutritious media (PDA, SNA, CLA, and OMA). Molecular phylogenetic relationships were inferred by sequencing partial , , and genes and adding the obtained sequences into a phylogenetic framework. Molecular characterization shows that c. 74% of the isolates obtained from infected banana pseudostem tissue belong to . Compared to , accounts for c.10% of the Fusarium wilt in northern Viet Nam, demonstrating that TR4 is not yet a dominant strain in the region. - considered to cause Race 2 infections among bananas - is only found in c. 10% of the tissue material that was obtained from infected Vietnamese bananas. Additionally, one of the isolates cultured from diseased bananas was phylogenetically not positioned within the species complex (FOSC), but in contrast, fell within the species complex (FFSC). As a result, a possible new pathogen for bananas may have been found. Besides being present on several ABB 'Tay banana', was also derived from infected tissue of a wild , showing the importance of wild bananas as a possible sink for .
尖孢镰刀菌古巴专化型（Fusarium oxysporum f.sp. cubense）是影响多种作物种植的最重要的植物病原真菌属之一。尖孢镰刀菌古巴专化型（TR4）造成的农业损失直接影响着全球数千名农民的收入、生计和营养状况。对越南而言，关于TR4对未来影响的预测十分严峻，预计未来五年香蕉种植面积将损失8%，未来25年内将高达71%。在本研究中，我们采用形态学与分子相结合的方法来评估在越南北部收集的不同尖孢镰刀菌分离株的分类身份和系统发育位置。此外，我们旨在估计越南北部感染香蕉的不同尖孢镰刀菌小种的比例。通过将收集到的尖孢镰刀菌分离株在四种不同的营养培养基（马铃薯葡萄糖琼脂培养基、燕麦片琼脂培养基、玉米粉琼脂培养基和洋葱培养基）上培养来研究分离株的形态。通过对部分EF-1α、β-tubulin和calmodulin基因进行测序并将获得的序列纳入系统发育框架来推断分子系统发育关系。分子特征表明，从受感染的香蕉假茎组织中获得的约74%的尖孢镰刀菌分离株属于尖孢镰刀菌古巴专化型（TR4）。与尖孢镰刀菌古巴专化型（TR4）相比，尖孢镰刀菌（Fusarium）在越南北部的枯萎病中约占10%，这表明TR4在该地区尚未成为优势菌株。被认为在香蕉中引起2号生理小种感染的尖孢镰刀菌古巴专化型（Race 2）仅在约10%的从受感染的越南香蕉中获得的组织材料中发现。此外，从患病香蕉中培养的一个分离株在系统发育上并不位于尖孢镰刀菌物种复合体（FOSC）内，相反，它属于镰孢菌物种复合体（FFSC）。因此，可能发现了一种新的香蕉病原体。除了存在于几种ABB‘Tay香蕉’上，该病原体还源自野生香蕉的受感染组织，这表明野生香蕉作为该病原体可能的宿主的重要性。
