Palyno-morphological assessment of Asteraceae taxa grown in Qarshi Botanical garden at Qarshi Industries (Pvt.) Ltd by using LM and SEM, Pakistan

Abstract

The present study covers the micro-morphological characteristics of 32 taxa of Asteraceae family from Qarshi Botanical Garden at Qarshi Industries (Pvt.) Ltd., Hattar Haripur, Pakistan. The morphopalynological characters studied were size, shape, polar and equatorial diameter and their exine ornamentation using light microscopy (LM) and scanning electron microscopy (SEM) for its taxonomic significance. In the present investigations the pollen apertures of examined taxa were tricolporate, tricolpate, trizonocolporate, pentaporate and tetracolporate. mesocolpium orientation according to P/E ratio was identified as reticulate, echinate, oblate-spheroidal, echino-lophate, densely perforated and echinate perforate. It was found that the following 32 types of exine sculpture occurred in the investigated species: Echinate-perforate, aerolate-echinate, echinate-microreticulate, verrucateechinate, scabrate-Echinate, reticulate and shortly spinulate, echinate, elliptic to rarely circular and hexagonal view and spinulose-verrucate. Similarly, variation in polar diameter was prominent and the largest pollen was recorded on Artemisia vulgaris, Chicorium intybus, Helianthus annuus and Carthamus oxyacantha which have polar diameter. This was found with large size of 42.65 µm while the smallest polar diameter size was found in Chrysanthemum leucanthemum, Artemisia absinthium, Stevia rebaudiana, Tanacetum vulgare, Saussurea costus and Tanacetum cinerariifolium. Exine thickness of maximum value was examined in Centratherum punctatum 1.7 µm, while the minimum one was recorded in Seriphidium kurramense 0.5 µm (0.15-0.90). Pollen fertility was estimated with the highest percentage which was counted in C. leucanthemum (89.55%), while the highest sterility percentages were observed in Lactuca sativa (63%). The lowest fertility and sterility percentages were observed in L. sativa and S. kurramense (40 and 36.80%), respectively. The findings from the analysis of pollen morphological data show species level and taxonomic importance.