Palynological Studies on Some Conifers of Himachal Pradesh

The conifers comprise 52 genera and nearly 560 species. Only 29 species belonging to 11 genera occur in India, mostly confined to North- West and Western Himalayas. Out of 14 conifer species found in Himachal Pradesh, 12 species were worked out palynologically in the present study. Study include pollen size, number of wings and percentage of variation in normal and abnormal pollen grains. The data thus collected is not only of taxonomic value but also helps to understand the evolutionary process of pollens from winged stage to the wingless stage. To explain the multiallelic gene interaction behind the formation of wings of pollens in Pinaceae, the Gene Blocks Hypothesis was tested. It is probably the multiallelic gene interaction that leads to the formation of monosaccate, Bisaccate, trisaccate, multisaccate and nonsaccate pollen grains in Pinaceae. In Cupressaceae and Taxaceae, pollen grains are nonsaccate. Abnormal pollens with incomplete separation or well formed apparently macropollens have been observed. The species with smallest and largest pollen size have been identified.