FLORAL NECTAR COMPOSITION OF AN OUTCROSSING BEAN SPECIES MUCUNA SEMPERVIRENS HEMSL (FABACEAE)

Abstract

Mucuna sempervirens is a perennial woody climber belonging to family Fabaceae. Hand pollination experiments have proved it to be an out crossing species. In the present study, the chemical composition of M. sempervirens’s floral nectar was analysed. Concentrations of sugars, proteins, phenolics, and hydrogen peroxide were determined through spectrophotometry. Free amino acids were identified and quantified, among which aspartic acid was the most abundant. GCMS analysis showed that aromatic compounds were responsible for the nectar scent which lacked sulphur compounds. ICPAES analysis determined calcium to be the nectar’s major inorganic ion. The presence of high levels of hydrogen peroxide in the nectar might serve as defence against invading microorganisms. Phenolics may act as to repel nectar thieves repeller or serve a defensive function. Our findings show that M. sempervirens’s pollination system is different from other neotropical Mucuna species. Analysis of these differences may help to better understand how Asian Mucuna species adapted and coevolved with pollinators.