Phylogeny and genetic diversity of the banana Fusarium wilt pathogen Fusarium oxysporum f. sp. cubense in the Indonesian centre of origin
Maryani, N. ; Lombard, L. ; Poerba, Y.S. ; Subandiyah, S. ; Crous, P.W. ; Kema, G.H.J. - \ 2019
Studies in Mycology 92 (2019). - ISSN 0166-0616 - p. 155 - 194.
11 New taxa - Morphology - New species - Panama disease - Pathogenicity - Tropical Race 4
Fusarium oxysporum f. sp. cubense (Foc), the causal agent of Fusarium wilt or Panama disease on banana, is one of the major constraints in banana production worldwide. Indonesia is the centre of origin for wild and cultivated bananas, which likely co-evolved with Foc. This study explored the widest possible genetic diversity of Foc by sampling across Indonesia at 34 geographically and environmentally different locations in 15 provinces at six islands. This resulted in a comprehensive collection of ∼200 isolates from 40 different local banana varieties. Isolates were identified and assessed using sequence analysis of the translation elongation factor-1alpha (tef1), the RNA polymerase II largest subunit (rpb1), and the RNA polymerase II second largest subunit (rpb2). Phylogenetic analyses of these genes allowed the identification of 180 isolates of Fusarium oxysporum f. sp. cubense (Foc), and 20 isolates of the Fusarium fujikuroi species complex (FFSC), the Fusarium incarnatum-equiseti species complex (FIESC), and the Fusarium sambucinum species complex (FSSC). Further analyses, incorporating a worldwide collection of Foc strains, revealed nine independent genetic lineages for Foc, and one novel clade in the Fusarium oxysporum species complex (FOSC). Selected isolates from each lineage were tested on the banana varieties Gros Michel and Cavendish to characterise their pathogenicity profiles. More than 65 % of the isolates were diagnosed as Tropical Race 4 (Foc-TR4) due to their pathogenicity to Cavendish banana, which supports the hypothesis that Foc-TR4 is of Indonesian origin. Nine independent genetic lineages for Foc are formally described in this study. This biodiversity has not been studied since the initial description of Foc in 1919. This study provides a detailed overview of the complexity of Fusarium wilt on banana and its diversity and distribution across Indonesia.
Managing the interactions between soil abiotic factors to alleviate the effect of Fusarium wilt in bananas
Segura, R.A. ; Stoorvogel, J.J. ; Samuels, J.Z. ; Sandoval, J.A. - \ 2018
In: 10th International Symposium on Banana. - International Society for Horticultural Science (Acta Horticulturae ) - ISBN 9789462611924 - p. 163 - 168.
Biomass - Micronutrients - Panama disease - Plant disease - Soil fertility
Soil management offers various options to alleviate the effects of Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) in bananas. Nevertheless, it receives little attention as a strategy in Fusarium wilt management. Literature provides ample evidence linking soil conditions such as soil texture and fertility to the spread and severity of plant diseases. However, the inconsistency of results between case studies limits the attention of soil management in crop disease management. The present study aimed at unravelling the role of soil abiotic factors on nutrient concentrations in plant tissue, biomass production and the incidence of Fusarium wilt (Foc race 1) in bananas (‘Gros Michel’, AAA) under field conditions. A large field trial was established in which the effects of soil pH and nutrients (N, Ca, Mg and Mn) were studied. Around 30% of the plants showed symptoms of Fusarium wilt at flowering in the first season. However, Fusarium wilt incidence did not vary between treatments. Soil pH showed significant interactions with soil N and Mn concentrations resulting in a lower bunch weight and increased micronutrient concentrations in the pseudostem. With a higher pH, bunch weight increased, although higher Mn concentrations suppressed this positive effect. Interactions between a high soil pH and Ca and Mg resulted in a higher bunch weight and lower micronutrient concentrations in the pseudostem. The results can be used to develop soil management strategies for improving banana productivity in infected plantations.