Pollen biology in shoe flower

Abstract

A widely divergent collection of 36 types/varieties/species of Hibiscus was utilized to study the pollen morphology, production, fertility and germination. Studies on pollen morphology showed that while colour of pollen grains varied, the shape was more or less constant in all types, varieties and species. Individual pollen grain was pantoporate, spheroidal and spinose. The types/varieties/species exhibited wide variation in pollen size, pollen out put, fertility, germination and tube elongation of pollen grains. Standardisation of media for pollen germination and tube growth indicated that a medium containing 20 per cent sucrose, 1 per cent agar and 100 ppm boric acid was the best. Pollen grains commenced germination within 30 min of dusting and gave satisfactory germination even after 4 hours of incubation. Polysiphonous germination was observed in majority of cases.