STYLAR HETEROMORPHISM IN SOLANUM KHASIANUM CLARKE

Solanum khasianum Cl. is an alkaloid (solasodine) yielding plant. The concentration of alkaloid is maximum in its berries. S. khasianum bears two types of flowers: long-style (berry forming, female fertile); and short-style (non-berry forming, female sterile). Optical and electron microscopic studies reveal structural variation in the stigma of long-style and short-style flowers. Unlike short-style stigma, the stigma of long-style has 2–3 celled papillae which open outside through an apical pore. The pollen tubes enter the stigma through the pore of the papillae. Histochemically, long-styles have more polysaccharides, nucleic acids, particularly RNA, and protein in comparison to short-style. The ovules in the short-style ovaries abort at an early stage of development and reveal arrested embryosacs. Compared to short-style flowers, long-style flowers have more protein but less peroxidase activity. Long-style and short-style flowers have different peroxidase isozyme banding pattern. Kinetin favours long-style development while GA promotes short-style development.