Characteristic differences in metabolite profile in male and female plants of dioecious Piper betle L.

Piper betle is a dioecious pan-Asiatic plant having cultural and medicinal uses. It belongs to the family Piperaceae and is a native of the tropics although it is also cultivated in subtropical areas. Flowering in P. betle occurs only in tropical regions. Due to lack of inductive floral cycles the plant remains in its vegetative state in the subtropics. Therefore, due to lack of flowering, gender distinction cannot be made the in the subtropics. Gender distinction in P. betle in vegetative state can be made using Direct Analysis in Real Time Mass Spectroscopy (DARTMS), a robust highthroughput method. DARTMS analysis of leaf samples of two male and six female plants showed characteristic differences in the spectra between male and female plants. Semi-quantitative differences in some of the identified peaks in male and female landraces showed gender-based differences in metabolites. Cluster analysis using the peaks at m/z 151, 193, 235 and 252 showed two distinct clusters of male and female landraces. It appears that male and female plants besides having flowers of different sexes also have characteristic differences in the metabolites representing two metabolic types.