Molecular fingerprinting of Fusarium oxysporum f. sp. passiflorae isolates using AFLP markers

Abstract

Hansen (FOC), resulting in 99% polymorphic fragments, with an average of 40 fragments per primer combination. Specific fingerprints could be generated for most of the isolates evaluated;we observed a high power of discrimination of the AFLP primer combinations, with the presence/ absence of up to 26 specific fragments per isolate. Thus, specific fingerprinting was obtained for 10 of the 15 isolates analyzed. The values of the polymorphic information content, the index and the resolving power of the markers showed wide variation and re� ected the high informaof the markers showed wide variation and re�ected the high informative contents of the primers used in the characterization of the FOP isolates. The FOP isolates were divided into four groups, irrespective of their geographic origins, with the allocation of 5, 7, 1 and 1 FOP isolates into Groups II, III, IV and V, respectively. A wide genetic diversity was observed in FOP isolates, which should be taken into consideration when implementing strategies for the improvement of passion fruit in the search for cultivars with multiple resistance to different isolates.

Genetic variability of Fusarium solani and Fusarium oxysporum f. sp. passiflorae isolates from Pantanal, Amazon and Cerrado biomes of Mato Grosso, Brazil

“…passiflorae from Bahia (BR) and one isolate collected in Minas Gerais (BR), also observed genetic variability among isolates. As mating in F. oxysporum has not yet been reported (Leslie and Summerell, 2006), the generation of variability in this species can be related to different events, such as mutation and parasexual reproduction (Huang et al, 2013;Silva et al, 2013), and environmental factors of the geographic region where the pathogen is located (Silva et al, 2013). The transposable elements constitute a source of mutations likely to be a major cause of genetic variability of F. oxysporum (Daboussi and Langin, 1994;Schmidt et al, 2013).…”

“…The maximum genetic dissimilarity was between the isolates 3A, from São José dos IV Marcos (Amazon biome), and 1C, from Cáceres (Cerrado biome) ( Table 2). Silva et al (2013), working with 14 isolates of F. oxysporum f. sp. passiflorae from Bahia (BR) and one isolate collected in Minas Gerais (BR), also observed genetic variability among isolates.…”

“…The existence of a relationship between genetic similarity and the biomes of collection of F. oxysporum f. sp. passiflorae isolates may be an indication of the influence of (Silva et al, 2013). Through analysis of the dendrogram generated by genetic similarity matrix among 20 F. solani isolates, one can find the formation of two major groups, I and II, with two subgroups in each group (Figure 3).…”

“…In this context, the study of genetic variability of F. solani and F. oxysporum f. sp. passiflorae fungi is fundamental to direct passionflower genetic improvement programs in order to obtain resistant cultivars (Silva et al, 2013).…”

Classification of physiological races of Fusarium oxysporum f. sp. phaseoli in common bean

“…However, Ming et al (1966) showed clear evidence that heterokaryosis is a common phenomenon in Fusarium fujikuroi under natural conditions and concluded that the results of these studies of heterokaryosis can be extended to other disease-causing Fusarium species. Other authors also relate the same results: analyzing molecularly the isolates of Fusarium oxysporum, they found that the isolates of the same geographic region were grouped in different similarity groups and don not have identical fingerprints (Silva et al, 2013). These results can be explained by the parasexuality created by high mutation rates, according to Fourie et al, (2009), who related the existence of the recombination between lineages of Fusarium oxysporum and the relations between VCGs that occurred because of the genome similarity with the evidence of heterokaryosis.…”