A deep genetic analysis of banana Fusarium wilt pathogens of Cuba in a Latin American and Caribbean diversity landscape

Summary

Fusarium wilt of bananas (FWB) is a devastating plant disease that causes significant economic losses in banana production worldwide and is one of the major concerns for Cuban banana cultivation. The disease is caused by members of the soil-borne Fusarium oxysporum species complex. However, the genetic diversity among Fusarium species infecting bananas in Cuba is currently unknown.

We conducted a comprehensive survey of symptomatic banana plants across all production zones of the country and assembled a collection of 170 Fusarium isolates. Using genotyping- by-sequencing and whole-genome comparisons, we investigated the genetic diversity across this suite of isolates and compared it with the genetic diversity of a global Fusarium panel.

Typical FWB symptoms were observed in varieties of the Bluggoe cooking banana and Pisang Awak subgroups in 14 provinces. Phylogenetic analysis revealed that F. purpurascens, F. phialophorum, and F. tardichlamydosporum cause FWB in Cuba, with the latter dominating the population. Furthermore, we identified between five and seven genetic clusters, with F. tardichlamydosporum isolates divided into at least two distinct subgroups, indicating a high genetic diversity of Fusarium spp. causing FWB in the Americas.

Our study provides unprecedented insights into the population genetic structure and diversity of the FWB pathogen in Cuba and the Latin American and Caribbean regions.