Document Type



Master of Science (MS)



First Advisor's Name

Kelsey R. Downum

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

David W. Lee

Third Advisor's Name

Bradley C. Bennett

Date of Defense



Variation of phenylheptatriyne (PHT) concentrations in leaves of Bidens alba (Linn.) var. radiata (Schultz-Bip.) was investigated across it's Florida range, throughout the year and in response to photoenvironment. Natural surveys of PHT concentrations in B. alba leaves were done at 13 sites in Florida and three sites throughout the year. PHT concentrations were significantly different between populations (p<0.001) but showed little relationship with latitude (R2 =0.024) and none with longitude. Concentrations in leaves fluctuated throughout the year (p<0.001). They were highest in October, followed by June and lowest in January and April. Photoenvironmental influences were experimentally tested. PHT concentrations decreased under low R/FR treatments and increased under filtered UV treatments. Low light quantity did not significantly influence PHT concentrations but decreased PHT levels and leaf biomass. The results suggests that PHT concentrations in B. alba leaves vary in nature and that light quality, R/FR and UV, may effect PHT biosynthesis.



Included in

Biology Commons



Rights Statement

Rights Statement

In Copyright. URI:
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).