Biological and Chemical Study of Apios (Groundnut)

Faculty Mentor(s)

Dr. Kenneth Brown, Hope College
Dr. Jianhua Li, Hope College

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Apios is a genus of herbaceous vines found in North America and Asia. The plant has characteristic edible tubers which are said to contain the chemicals genistein and resveratrol as well as high levels of protein. The genus may be broken up into 6-8 species, two which are found in North America and the rest found in southwest Asia. Of the American species, A. americana is quite unique in the fact that it can be found as either diploid or triploid which are almost visually indistinguishable. The triploid populations are found in the northern growth range for the species while the diploids are found in the south. The goal of the study was to determine the presence and concentration of protein, genistein and resveratrol in the plants, to create a phylogenetic tree of the genus, to investigate the distribution of diploid and triploid A. americana and attempt to create a method to differentiate the diploid and triploid plants through their stomata guard cell size. It was found that genistein can be detected in most structures of the plant although the concentration is highest in the tuber cortex. Phylogenetic trees for the genus were created using DNA sequences from the plastid gene matK and the nuclear gene ITS. The trees differ as the matK tree groups one Asian species, A. fortunei, as being more closely related to North American species whereas the ITS tree groups A. fortune as being more closely related to the other Asian species. Finally, data was collected to investigate the relationship between stomata guard cell length and ploidy level. Triploid have slightly longer guard cells on average, but the relationship is not statistically significant.


This research was supported by the Howard Hughes Medical Institute.

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