Vegetative Compatibility Groups in Acremonium Cucurbitacearum

Assessment of vegetative compatibility of Acremonium cucurbitacearum and Plectosphaerella cucumerina isolates from diseased melon plants*

“…Phenotype determination of P. cucumerina nir mutants, based on their growth on media amended with different nitrogen sources, did not permit verification of mutation at a nitrate assimilation specific regulatory locus (nit3). The same results were observed in vegetative compatibility studies on A. cucurbitacearum (Abad et al, 1997;Vicente, 1999), where no nit3 mutant was identified. Klittich & Leslie (1988) indicate that the nitrogen source used in chlorate medium affects the frequency of nit mutant types generated and absence of mutations at determined loci are either lethal or sensitive to chlorate in Fusarium moniliforme.…”

“…A single conidial culture was prepared from each isolate. The P. cucumerina collection was tested for vegetative compatibility against the nit mutant testers of the 10 known vegetative compatibility groups of A. cucurbitacearum (Abad et al, 1997). The isolates were used only in the form of the anamorph Plectosporium tabacinum.…”

“…Basically, fungal strains that anastomose and form heterokaryons with one another are considered to be vegetatively compatible and are assigned to the same vegetative compatibility group; those strains that are unable to establish heterokaryons with one another are referred to as vegetatively incompatible (Joaquim & Rowe, 1991). The standard procedures proposed by Puhalla (1985) and Correll et al (1987) were applied to analyse the vegetative compatibility of melon isolates of A. cucurbitacearum originating from Spain and USA (Abad et al, 1997;Vicente et al, 1999). The objectives of this investigation were to assess vegetative compatibility diversity within a collection of P. cucumerina isolates recovered from diseased melon plants from several locations in Spain and USA (California and Texas), as well as from other plant species, and to determine whether there was a vegetative compatibility relationship between A. cucurbitacearum and P. cucumerina.…”

Disease Reaction among Selected Cucurbitaceae to an Acremonium cucurbitacearum Isolate from Texas

“…Why A. cucurbitacearum causes little or no detectable damage to melons in the LRGV of Texas is not clear because the isolate appears to be similar in host range to the Spanish isolates (Armengol et al, 1998). Based on morphology (Alfaro-Garcia et al, 1996) and vegetative compatibility groupings, California and Texas isolates were determined to be morphologically and genetically similar to Spanish isolates (Abad et al, 1997;Vincente et al, 1996). Nevertheless, environmental conditions may be the primary reason, since temperatures during the later part of the melon growing season in the LRGV are higher than the optimum temperature for growth of the fungus (Armengol, 1997;Bruton et al, 1999).…”

Host range of Acremonium cucurbitacearum, cause of Acremonium collapse of muskmelon

“…was reported to affect muskmelon and watermelon in California and Texas (Bruton et al, 1996b). Based on randomly amplified polymorphic DNAs (RAPDs) and vegetative compatibility groups (VCGs), the Californian and Texan isolates were found to be similar to or identical with the Spanish isolates (Vicente et al, 1995;Abad et al, 1996). In 1996, the fungus was identified as Acremonium cucurbitacearum (Alfaro-García et al, 1996).…”