Delayed self-fertilization and chemical analysis of floral nectar of a perennial relative of the tomato and potato from Mexico

Abstract

We studied the floral reproductive biology and nectar chemistry of Jaltomata grandiflora (Solanaceae), an apparently rare perennial of Michoacán, Mexico. During day 1, flowers are pistillate (stigma receptive, anthers not yet presenting pollen); flowers close for the night. Early in the morning of day 2, the corolla re-opens, stamens elongate to five times their earlier length, and anthers dehisce; the dehisced anthers remain about 2 mm from the stigma for much of day 2. In the afternoon of day 2, the corolla again closes, the corolla–androecium abscises, and only then can pollen be seen on the stigma. Protogyny and herkogamy likely promote outcrossing during days 1 and 2, respectively. Autonomous self-pollination takes place at the end of the corolla's life and allows fruit and seed production in the absence of pollinators but results in fruits that are lighter and contain fewer seeds than fruits resulting from manual self-pollinations. Carbohydrates from floral nectar samples were separated and quantified using hydrophilic interaction liquid chromatography coupled with corona charged aerosol detection. In nectar, mean sucrose concentration (0.482 mg/mg nectar), is about 10 and five times higher than glucose (0.043 mg/mg nectar) and fructose (0.095 mg/mg nectar) concentrations.