Microscopic implication and evaluation of herbaceous melliferous plants of southern Khyber Pakhtunkhwa-Pakistan using light and scanning electron microscope

Abstract

The aim of the present study is to investigate the pollen morphology of melliferous plant taxa of Southern Khyber Pakhtunkhwa-Pakistan. Using light microscope (LM) and scanning electron microscope (SEM), the palynological study of 18 species of melliferous plants namely Calendula arvensis, Cenchrus pennisetiformis, Citrullus colocynthis, Cucumis melo subsp. agrestis var. agrestis, Cucurbita maxima, Cymbopogon jwarancusa, Cynodon dectylon, Dactyloctenium aegyptium, Helianthus annus, Lagenaria siceraria, Launaea procumbens, Luffa cylindrica, Pennisetum glaucum, Saccharum spontaneum, Sonchus asper, Verbesina encelioides, Xanthium strumarium, and Zea mays was carried out. Both qualitative and quantitative characteristics of pollen were studied. Variations were observed in pollen morphology. The dominant pollen shape was prolate-spheroidal (11 species). All the pollen units were monad. The highest exine thickness was found in Citrullus colocynthis (8.45 mu m). The maximum polar and equatorial diameter (102 and 97.55 mu m) was found in Luffa cylindrica. Similarly, the highest P/E ratio was found in Cucurbita maxima (1.46). Most of the species showed tricolpate and monoporate type of pollen. The exine sculpturing, number of spines per pollen and between colpi and the pollen fertility and sterility provided significant results for the documentation of melliferous plants. Thus, the information listed in this article will prove helpful to identify the potential melliferous plants in the area, geographical origin of the honey, and the availability of pure honey in the local and international market.