Pollen morphological analogue of some Himalayan angiosperm species from Arunachal Pradesh, Northeast India

The morphological diversity of pollen grains can provide important information about several aspects of plant science. The pollen morphological database remains scarce in this eastern Himalayan province of the Indian biogeographic zone, despite the rich diversity of angiosperms. The detailed pollen morphometry of various plant taxa from the Arunachal Pradesh region will enhance the palynological database of the eastern Himalaya. Light compound microscopy (LM) and scanning electron microscopy (SEM) were employed to identify and characterize pollen grains. Based on the qualitative and quantitative morphological data of 60 angiosperm species from 35 families, statistical analyses (principal component analysis, cluster analysis, and correlation analysis) were performed, explaining the phylogenetic relationships among these families. In addition to their interrelationships, these morphological data also provide insights into the primary pollination modes (entomophily or anemophily) and the evolutionary trends of pollen grains in these families. Besides, the pollen morphological data of endemic angiosperm species, along with data from other families, could provide preliminary insights into the vegetation and palynology-related research of the eastern Himalayan landscape of Arunachal Pradesh.