Palynology and Mode of Pollination in Different Species of Solanum

In the present study, palynology and mode of pollination prevalent in various selected species of Solanum were traced. Comparison was made between the cultivated S. melongena varieties Haritha and Surya and the wild variants of Solanum viz., S. viarum, S. incanum, and S. gilo. The shape of the pollen grain was uniformly round in all the types evaluated. Pollen grains were oblong and bi or trizonocolporate. Exine was with ornamentation in all the species. There was significant variation among the types of the length of pollen grains. Pollen viability lasted for only three days in all the genotypes evaluated. In S. incanum, S. gilo and S. melongena variety Haritha pollen fertility was at peak during the second day of flower opening and declined on the third day of a flower opening. In S. viarum and S. melongena variety Surya, pollen fertility declined during the second day of flower opening (90.08% and 87.95% respectively). However, on the third day of flower opening an increasing trend was noticed (97.33) and the fertility reached the peak on the third day of a flower opening. With the closing of the flower on the third day, evening the fertility was completely lost in all the species evaluated. None of the protected buds set fruits. It indicates the absence of self pollination. With unprotected buds, fruit set ranging from 60% in S. viarum to 100% in S. melongena type Surya was observed. This indicates that Solanum species are adapted to cross pollination. No fruit set observed in emasculated, but unprotected buds also. It may be because of the absence of sufficient pollinators. Cross pollination occurred in brinjal due to transfer of pollen by thrips, ants and bees.