Foliar micromorphology of Convolvulaceous species with special emphasis on trichome diversity from the arid zone of Pakistan

Abstract In present study, 18 plant species belonging to 7 genera of the family Convolvulaceae has been investigated by using the light microscope for foliar epidermal anatomy. Despite the medicinal importance of family Convolvulaceae, there is no evidence regarding the secretory structure and their effect of environmental conditions on their density is unknown. The aim of the study was to describe the morphology of these secretory structures and to estimate the hypothesis that glandular trichomes density decreases with increased aridity. Foliar micromorphology of Convolvulaceous taxa, gathered from arid parts of Northern Punjab Pakistan, was first time conducted with an aim to utilize this information as an aid in plant taxonomy. Significant diversity was observed in both qualitative and quantitative characteristics using light microscopy. Variations were observed in stomatal number, size, guard cells shape, epidermal cell number, subsidiary cells, and trichomes. Unique ornamentation was observed in trichomes diversity. A taxonomic key was prepared for the identification of species. The main goal of this study was to describe the morphology of glandular trichomes and to estimate the hypothesis that glandular trichomes density decreases with increased aridity. Based on these findings, Light microscopy of foliar epidermal features can be of special interest for taxonomists in the identification of complex taxa. Studied taxa were also separated from each other by using Cluster Analysis (MVSP ver.3.22). Statistical analysis by using the Software XLSTAT exhibited that some anatomical features are the main characteristics in the identification of the taxa. Principal component analyses (PCA) used as a statistical tool for data analyses that show the importance of these characteristics for the characterization and identification of the family Convolvulaceae in an arid land. The study shows many novel characters that provide baseline information about trichome diversity in relation to aridity for future taxonomist.