Image analysis of urediniospores that infect Mentha

Urediniospores of isolates of two principle groups of races of Puccinia menthae have similar morphological appearance when examined with SEM. Native spearmint rust infects Mentha spicata but not M. X piperita. Peppermint rust infects M. X piperita but not M. spicata. Prism image analysis was used to quantify morphological differences between the two types of mint rust urediniospores. Eighteen morphological parameters of either size or shape were measured for sample populations of 138 native spearmint rust spores and 244 peppermint rust spores. Descriptive statistics by sample of the means, minimums, maximums, standard deviations, and variances were obtained for each of the characteristics evaluated. Tukey honestly significant difference (HSD) was used to identify characteristics with significantly different means at the 95% confidence level. The native spearmint and peppermint rust urediniospores differed with 15 characteristic morphometries; breadth, width and inscribed radius did not differ. Image analysis was a useful tool to morphologically differentiate between urediniospores of two groups of races of P. menthae.