Palyno-anatomical Studies of Dicot Phytodiversity in Northern Baluchistan, Pakistan

Abstract

This is the first study presenting the systematics of the dicots from northern Baluchistan, Pakistan. Field trips were conducted for the collection of dicots from different areas of Northern Baluchistan. Brassicaceae, Fabaceae, and Lamiaceae were the selected families based on their abundance. In total 107 species from three families Brassicaceae, Fabaceae, and Lamiaceae were studied using Light microscopy (LM) and scanning electron microscopy (SEM) to characterize the micromorphological features of the pollen. Light microscopy was used to examine the anatomical characteristics of the transverse sections of petioles prepared via microtomy. The statistical analysis was performed on the quantitative measurements of anatomical and palynological features. The maximum polar axis 52.95μm was noted in Salvia moorcroftiana and minimum 15.6μm in Cardaria draba. The exine thickness was maximum 4.5μm in Isatis minima and minimum 1.3μm in Crotalaria medicaginea. The largest petiole length 4995.4μm was observed in Otostegia limbate and minimum 261.2μm in Sisymbrium altissimum. Maximum length of vascular bundles 211.25μm was observed in Caragana ambigua, and minimum 34.5μm in Cardaria chalepense. Reticulate, coarsely reticulate, scabrate exine, polygonal and amorphous lumen (regular or irregular shapes), the Number, Position, and Character (NPC) of aperture was N3P4C3, and petiole shapes sulcate, flat, oval, or circular with blunt or acute wings, vascular bundles collateral closed, collateral open, bi-collateral, or hadrocentric, arrangements of 1, 1+2, numerous, and trichomes unicellular, uniseriate, and multiseriate were the significant diagnostic features for pollen morphology and petiole anatomy in Brassicaceae. The distinguished palynological and petiole anatomical characters for Fabaceae were exine psilate, verrucate, macroreticulate, microreticulate, reticulate, N3P4C5, Amb peritreme, and goniotreme, polar view (triangular obtuse convex, circular, triangular obtuse concave, triangular obtuse convex to straight, circular to elliptic), equatorial view (rectangular obtuse convex, oval, elliptic truncate, quadrangular, rhombic, circular), shapes subprolate, prolate spheroidal, oblate spheroidal, rarely prolate pollen, vascular bundles amphicribral, collateral closed, collateral open, and bicollateral, the number of vascular bundles 1, 1+2, 2, 3, 9, collenchyma angular, lacunar, and lamellar. Significant variations in pollen apertures (tricolpate, tricolporate, hexacolpate, hexa to multi syncolpate), exine (reticulate, macroreticulate, microrteiculate, gemmate, foveolate, gemmate verrucate, perforate, non-perforate), aperture membrane (varruacte, scabrate, xvi gemmate, psilate) amb (ptychotreme, peritreme, goniotreme), shape (oblate, spherical, prolate spheroidal, oblate spheroidal, sub-prolate, sub-oblate), formulas (N6P4C5, N3- 6P4C3, N4-6P4C3, N4-6P4C3, N3-6P4C3), petiole shape (oval, flat, sulcate, and round), collenchyma (lacunar, angular, annular, and lamellar), vascular bundles (collateral closed, collateral open, amphicribal) were observed in Lamiaceous species. The taxa of each family were taxonomically differentiated by the Principal Component Analysis (PCA), dendrogram, correlation, box-jatter plot, and normal probability distribution plot. The petiole anatomical and pollen micromorphological characteristics were employed as markers to develop the taxonomic keys for the delimitation of the examined dicot flora. The present findings may provide the baseline for correct identification of the flora of Northern Baluchistan using palyno-anatomical features in order to use for future studies at global perspectives.