Variation In Rate Of Pollen Fertility In Some Members Of Family Rubiaceae

Abstract

Aerobiology is a scientific and multidisciplinary approach focus on the transport of organisms and biologically significant materials (Edmonds 1973). It deals with the study of air spora such as algal filament, fungal, bryophyte and pteridophyte spores and pollen grains of gymnosperms and angiosperms and other microorganisms (S. T. Tilak 1982). Since air currents play significant role in the dispersal and pollination of pollen grains, the palynological studies can be interestingly associated with aerobiology. The pollen grain which is a highly reduced male gametophyte in flowering plants is one of the efficient research tools for studying the effect of various chemicals on its metabolism since it carries the male genetic material. Sucrose is reported as  the best source of carbohydrate for pollen germination and pollen tube growth [Adams (1916), Brink (1924), Hrebetova and Tupy (1964)]. The Rubiaceae family is world’s fourth largest flowering plant family with around 11,000 species, including coffee (coffea), quinine (cinchona), and beautiful tropical ornamentals such as Gardenia. Around 400 species of this family have become rare and endangered. Therefore, the members of Rubiaceae family are an important collection for conservation, research, horticulture and education. In the present study, three members of Rubiaceae family were used as experimental models to study their pollen physiology. The pollen grains of plant species, Hamelia patens, Mussaenda sps., Gardenia thunbergia , were studied for pollen germination and pollen tube growth. The pollen grains of the above plant species were treated with 10%, 15% and 20% sucrose concentrations. Effect of  Brewbaker and Kwack’s  medium (Brewbaker and Kwack, 1963) on the pollen grains of above species was also examined. Hamelia patens showed best results followed by Mussaenda sps followed by Gardenia thunbergia. Interestingly both Hamelia patens and Gardenia thunbergia  showed best efficiency in 20% sucrose concentration while Mussaenda sps  was most efficient in 10% sucrose concentration.  The results obtained lead to the conclusion that Brewbaker and Kwack’s medium gives more satisfactory results as compared to the results obtained using only sucrose as a growth medium.