Resumen
Single-septate conidial isolates of Cylindrocladium were collected from spathiphyllum and leatherleaf fern. To differentiate isolates into species C. spathiphylli and C. pteridis, isolates were compared using standard morphological characteristics, host pathogenicity, and molecular genomics. The molecular genomic comparison was completed using both random and rep-PCR primers. The isolates from leatherleaf fern produced significantly (P= 0.05) larger conidia (72×4.9µm) than those produced by spathiphyllum isolates (65×5.5µm). Vesicle shape of most leatherleaf fern isolates was clavate while those of spathiphyllum were globose. Pathogenicity on host species was examined at a standard conidial concentration. All spathiphyllum isolates produced leaf spots on leatherleaf fern similar to those produced by leatherleaf fern isolates. However, average number of lesions formed on fern fronds was 36% higher with leatherleaf fern isolates. All spathiphyllum and 13% of the leatherleaf fern isolates produced root rot on spathiphyllum. Morphological characteristics and pathogenicity are the key factors normally utilized in species identification. However, when identifying individual isolates, variation within these parameters may make it impossible to separate isolates to species level. Using multiple sets of RAPD or rep-PCR primers it is possible to separate C. pteridis and C. spathiphylli into two populations.
