Foliar epidermal micromorphology and its taxonomic implications in some selected species of Athyriaceae.

Abstract

For the robust identification of taxonomically complex fern family like Athyriaceae, light and scanning electron microscopy is significance implications. This article present first microscopic investigation of foliar micromorphology of 3 genera and 10 species belonging to Athyriaceae namely, Athyrium, Deparia, and Diplazium were collected from different localities in Malakand Division, Northern Pakistan. In present study we compare foliar micromorphology of all 10 species using standard protocols of light microcopy (LM) and scanning electron microscopy. Qualitative micromorphological variations in shape of epidermal cells, anticlinal wall pattern, stomatal type and shape, stomatal pore shape, guard cells shape, and trichomes types were studied. In addition, some quantitative characters were also studied and data were statistically analyzed in epidermal cell size, stomatal size, stomatal pore size, stomatal density, and stomatal index. The pivotal result of study include; shape of epidermal cell in all species is irregular on both abaxial and adaxial surfaces. The anticlinal walls are sinuous in most of the species but some species have irregular lobed and broadly lobed wall. Leaves are hypostomatic in all studied species. Two main categories of stomatal type were found: polocytic and anomocytic. Unicellular nonglandular trichomes were observed in only one species Athyrium mackinnoni. The variation in foliar micromorphological characters between the genera and within the species was useful in identification and classification and have potential taxonomic significance for species differentiation. An identification key using micromorphological characters are provided to distinguish genera and species.