Correlation of molecular markers and biological properties in Verticillium dahliae and the possible origins of some isolates

Abstract

Haploid and amphihaploid Verticillium dahliae isolates were studied using PCR-based molecular markers which: (i) discriminate the defoliating and nondefoliating pathotypes (two primer pairs INTD2f / r and INTND2f / r), and (ii) are speciesspecific (primer pair 19/22). The results were compared with some known biological and other molecular properties of the isolates. Five discrete sequences of the 19/22 amplicon were found. Sequence 4 was associated with both defoliating isolates from Spain and nondefoliating isolates from Spain and USA; these pathotypes were separated by the primer pairs INTD2f / r and INTND2f / r, but the data showed that the primer espdef01 (derived from the 19/22 amplicon) cannot be used for this purpose. Amplicon sizes and sequences with primers 19/22 divided amphihaploid isolates from crucifers (thought to be interspecific hybrids) into those corresponding to the previously reported α and β groups. The β -group isolates had either sequence 4 or 5 (these two differing by a single base). The distinct amplicon sequence 3 given by the α -group isolates demonstrated that the V. dahliae -like 'parent' of this group was molecularly unlike any haploid isolate yet studied. The overall results are discussed in relation to phytosanitary considerations and the probability of defoliating or crucifer pathotypes arising de novo within Europe, either by selection or by interspecific hybridizations.

Polyploidy in fungi: evolution after whole-genome duplication

“…For example, interspecific fungal hybrids were described such as in the phytopathogen species Verticillium dahliae [50] and Melampsora  columbiana [51,52], the cultivated mushroom Agaricus bisporus [53] and other edible mushrooms from the Flammulina genus [54]. The…”

Verticillium wilt of olive: a case study to implement an integrated strategy to control a soil-borne pathogen

“…Olive-infecting V. dahliae isolates have been studied using RAPD (Cherrab et al 2000;Pérez-Artés et al 2000;Lachquer and Sedra 2002;Bellahcene et al 2005a;Nigro et al 2005), AFLP , and PCR-specific markers (Pérez-Artés et al 2000;Bellahcene et al 2005a;Mercado-Blanco et al 2003b;Collins et al 2005;Nigro et al 2005;ColladoRomero et al 2006;Dervis et al 2010). RAPD fingerprints have provided variable results, for instance, this approach was successful in correlating the geographical origin of a collection of olive-infecting Moroccan isolates, but not their colony morphology (Cherrab et al 2000).…”

“…Thus, an improved duplex, nested-PCR procedure was developed eliminating occasional ambiguities observed when detecting D isolates, and reducing time and cost for an effective detection of D and ND V. dahliae in olive tissues (Mercado-Blanco et al 2003b). The duplex, nested-PCR procedure is based on the simultaneous amplification of both the previously described ND PCR markers (Mercado-Blanco et al 2001) and a D-associated PCR marker designed from a V. dahliae species-specific genomic sequence , which has been revealed as highly polymorphic in subsequent studies (Collins et al 2005;Collado-Romero et al 2006;Collado-Romero et al 2010). The procedure was effective in the rapid, unequivocal and simultaneous detection of the two infecting V. dahliae pathotypes in both artificiallyinoculated, self-rooted olive plants and naturallyinfected adult trees of different cultivar, age and growing conditions (Mercado-Blanco et al 2003b).…”

Scientific opinion on the pest categorisation of Verticillium dahliae Kleb

“…Primers have been designed for the identification of V. dahliae and the discrimination between the defoliating and non-defoliating pathotypes in culture, in planta and in soil (MercadoBlanco et al, 2001(MercadoBlanco et al, , 2002(MercadoBlanco et al, , 2003bCollins et al, 2005;Pérez-Artés et al, 2005). In addition, molecular protocols have been developed for the quantification of V. dahliae in planta and in soil (Gramaje et al, 2013).…”