Suppressiveness or conduciveness to Fusarium wilt of bananas differs between key Australian soils

Abstract

Soils are known to differ in suppressiveness to soil-borne diseases, but the suppressiveness or otherwise to Fusarium wilt of Australian soils used to grow bananas is unknown. In this work we tested the relative suppressiveness of six key soil types. Banana (Musa (AAB group) ‘Pome’, cultivar ‘Lady Finger’) was grown in pots of the soils inoculated or not with Fusarium oxysporum f.sp. cubense (Foc) ‘Race 1’. Sixteen weeks after inoculation the plants were harvested and disease severity was assessed by measuring discoloration within the rhizome. In the inoculated pots, disease severity was greatest in the alluvial Liverpool and Virgil soils and least in the basaltic origin Tolga soil. No disease was detected in the non-inoculated pots. Soils with the lowest disease severity had the highest root mass, irrespective of inoculation, and the largest (negative) effect of inoculation on root dry mass. Disease severity in inoculated pots was negatively correlated with soil clay content and β-glucosidase activity. The results indicate that the risk of Fusarium wilt negatively impacting banana growth differs between soils of the main Australian banana-growing region.

The role of soil types on the relation between individual soil properties and Fusarium wilt expression in 'Gros Michel' bananas

“…Furthermore, the role that the soil type played in the plant's response to de disease was evident. Although it agrees with the response in terms of suppression or conduction of the disease according to the soil type in Australia (Bowen et al 2019), the results that we found allowed us to see a complex interaction of the soil type, its properties and the incidence of the disease. The in uence of speci c soil properties linked to the soil type (chemical, physical and microbiological) in each type of soil or each banana region can be part of the scenario of the natural banana's response to the disease.…”

Deciphering Underlying Drivers of Disease Suppressiveness Against Pathogenic Fusarium oxysporum

“…Our results show that although the same amount of Foc spores was added to the conducive and suppressive soils, higher bacterial evenness, richness, diversity, and fungal evenness and diversity were identified in the suppressive soil (Figure 3A and Supplementary Figure S5A). Previous studies revealed that a higher diversity of banana varieties, clay content, pH and lower soil cover by graminoids may contribute to soil disease suppressiveness to Foc race 1 (Deltour et al, 2017), and disease severity caused by inoculation of Foc race 1 was negatively correlated with soil clay content and β-glucosidase activity (Bowen et al, 2019). In this study, we observed microbial diversity linked to pathogen suppression.…”

“…However, in some cases, soil disease suppressiveness can also be induced by continuous cultivation of a susceptible host plant, which is attributed to the soil immune responses by enrichment and activity-specific pathogen-suppressive microbes (Kinkel et al, 2011). Indeed, disease suppressive and conducive soils harbor unique microbial communities (Shen et al, 2015; Deltour et al, 2017; Bowen et al, 2019). Thus, the efficient control of Fusarium wilt disease might be hidden in disease suppressive soil microbiomes, and it is therefore essential to understand the soil microbial taxa and entire microbiome compositions that might induce suppressiveness.…”

Evaluating the potential of soil management to reduce the effect of Fusarium oxysporum f. sp. cubense in banana (Musa AAA)

“…However, despite the need for more insight in Foc TR4, it is practically impossible to carry out field experiments with Foc TR4 in most places around the world for phytosanitary reasons. As a result, many studies use Foc Race 1 and susceptible varieties under the assumption that these results are also valid for Foc TR4 (e.g., Bowen et al 2019).…”