Genetic diversity of Fusarium oxysporum populations isolated from different soils in France

Abstract

The genetic diversity of soil-borne populations of Fusarium oxysporum was assessed using 350 isolates collected from six different French soils. All isolates were characterised by restriction fragment analysis of the PCR-amplified ribosomal intergenic spacer (IGS). Twenty-six IGS types were identified among the 350 isolates analysed. Five to nine different IGS types were detected in each soil. None of the IGS types was common to all of the soils. An analysis of the molecular variance based on IGS type relationships and frequency revealed that the genetic structure of the populations of F. oxysporum varied widely among the soils. Some populations were both highly diverse within the soils and differentiated between the soils. A possible relationship between the intrapopulation or interpopulation level of diversity and some external factors such as the soil type or the crop history was evaluated. A subsample representative of the diversity of the six populations was further characterised by analysing the genomic distribution of two transposable elements, impala and Fot1. One to 10 copies of the impala element were present in most of the isolates, irrespective of their soil of origin. The Fot1 element was only detected in 40% of the isolates originating from the three populations less diverse in terms of IGS types, but in 82.6% of the isolates originating from the three more diverse populations.

Diversity of Fusarium species in cultivated soils in Penang

“…In a similar study by Lim and Chew (1970), F. oxysporum was not recovered from several cultivated soils in Singapore. The low percentage of F. oxysporum may be attributed to the soil type as soil type can influence the population structure of F. oxysporum as the species is particularly adapted to a specific abiotic environment or other environmental factor (Edel et al, 2001).…”

Molecular diagnosis and intraspecific genetic variability of root pathogens of arid legumes in Western Rajasthan, India

“…The diversity analysis based on DNA sequence polymorphisms existing within highly conserved regions of the nuclear ribosomal DNA, such as the internal transcribed spacer or the intergenic spacer region (Edel, Steinberg, Gautheron, Recorbet, & Alabouvette, 2000). Zaccardelli, Vitale, Luongo, Merighi, & Corazza (2008) performed molecular and morphological characterization of Fusarium solani isolates based on host range tests.…”

Current status of the taxonomic position of Fusarium oxysporum formae specialis cubense within the Fusarium oxysporum complex

“…To date more than 150 formae speciales have been described (Baayen et al, 2000;Hawksworth et al, 1995;O'Donnell et al, 2009;O'Donnell and Cigelnik, 1999). Although nonpathogenic strains of F. oxysporum are widespread and genetically more diverse than their pathogenic counterparts (Gordon and Okamoto, 1992), they are not as well studied (Edel et al, 2001). However, after the discovery that nonpathogenic strains play a role in Fusarium wilt suppressive soils (Alabouvette, 1990), interest in these strains increased dramatically Katan et al, 1994).…”