The weed Eleusine indica as an alternative host of Fusarium oxysporum f.sp. cubense tropical race 4 causing Fusarium wilt in Cavendish banana

One of the most common weeds in commercial and abandoned Cavendish banana farms, Eleusine indica was tested on its role as an alternative host of Fusarium oxysporum f.sp. cubense Tropical Race 4 (Foc TR4), causal agent of Fusarium wilt disease of banana. Different isolates of TR4 from various parts of a Cavendish banana were inoculated to the weed E. indica with Cavendish cv. Grand Naine as banana control. Colonization of Foc TR4 in artificially inoculated E. indica and Grand Naine was confirmed through DNA‐based detection (real‐time PCR) from fungal cultures re‐isolated from E. indica and various parts of Grand Naine. Results showed that E. indica can be colonized after artificial inoculation by different Foc TR4 isolates. Percent TR4‐colonized samples of E. indica were, however, lower compared to the primary host Cavendish banana. All Foc TR4‐colonized E. indica did not show wilting and hence were asymptomatic. Compared to Foc TR4 isolates re‐isolated from Cavendish banana Grand Naine, all re‐isolated various TR4 isolates from artificially inoculated E. indica were more pathogenic based on percent Fusarium wilt incidence when re‐introduced back to the primary host Cavendish banana. More Foc TR4 isolates were significantly more aggressive based on shorter incubation period or number of days to onset of symptom expression, and were significantly more virulent based on higher severity of rhizome discoloration of Cavendish banana plantlets. All Foc TR4 isolates re‐isolated from either E. indica or Grand Naine resulted to the same degree of leaf yellowing when re‐introduced to Cavendish banana. This study concludes that E. indica colonized by Foc TR4 could serve as relevant reservoir of the pathogen in the field indicating that weed management should be integral to the management of Fusarium wilt disease of Cavendish banana.