ABSTRACT
Considering the great variability presented by the Diaporthe/Phomosis complex, analysis of seeds for health, used in the detection of the Diaporthe spp., is not reliable because for its identification are used morphological characters of the colonies growing on the seed. The objective of this research was to compare morphological characters of the conidia, mycelial growing and coloration of the isolates proceeding from stem and soybean seeds of Diaporthe phaseolorum var. sojae (Dphs) and Diaporthe spp. (Dph) with isolates of Diaporthep haseolorum var. meridionalis (Dphm). Tests of pathogenicity, as well as techniques of PCR were used to compare different isolates of (Dph). In this study it was verified that: a) all the isolates of Dphm had only developed alfa conidia, however in some isolates of Dph there was also observed only the presence of alfa conidia; b) Mycelial colaration in PDA and Czapeck media, Dphm and Dph were grouped in 9 classes. In Czapeck medium, all isolates identified as Dphm were grouped in classes 8 and 9, showing wooled micelial pattern (like felt), except isolate 43; c) considering the mycelial growth it was not possible to distinguish Dphm from Dph; d) all isolates were pathogenic to cultivar IAC14, showing different agressivity percentage in soybean plants; e) two DNA isolates (3 and 44) were not amplified using polimerase chain reaction (PCR), however these isolates showed high homology within the ITS region for the caulivora and meridionalis varieties of Diaporthe phaseolorum.
KEY WORDS:
Glycine max; Diaporthe spp.; characterization; morphological; PCR
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