Bidens Species Research Articles

Involvement of Foliar Absorption and Translocation in Differential Response between Bidens tripartita and B.frondosa to Bensulfuron Methyl.

Response of two Bidens species (B. tripartita and B. frondosa) to bensulfuron methyl (Methyl=α-(4, 6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-o-toluate) was compared and factors accounting for their differential response were investigated. A greenhouse experiment showed that B. tripartita had greater tolerance to the herbicide than B. frondosa, although the latter had moderate tolerance which was comparable to that of barnyardgrass (Echinochloa crusgalli). Absorption of 14C from aboveground (shoot) tissue following 14C-bensulfuron methyl application was more rapid in B. frondosa than in B. tripartita. Absorption from cotyledon was also much greater in B. frondosa and absorbed 14C was distributed throughout the shoots of the species. Differential foliar absorption and translocation between the Bidens species may partly explain their differential response to bensulfuron methyl.

Phylloplane fungi of hawaiian plants and their photosensitivity to polyacetylenes from Bidens species

Many polyacetylenes are toxic to living organisms in the presence of UV-A radiation. These effects have led to speculation about the putative functions of polyacetylenes in the organisms which produce them. Nineteen species of phylloplane yeasts and yeast-like fungi were isolated from species of Hawaiian Bidens with and without leaf acetylenes, and from other Hawaiian plants. Although all these organisms, members of the Sporobolomycetaceae, Cryptococcaceae and Fungi Imperfecti, were photosensitive to some polyacetylenes and resistant to others, there was no correlation between the presence or absence of leaf polyacetylenes and the distribution of these saphrophytes among species of Bidens. Nevertheless, it is significant that the only pathogenic species isolated in this study, Colletotrichum gloeosporiodes (Penzig) Penzig et Sacc., did not colonize Bidens leaves containing C 13 aromatic acetylenes to which it is extremely sensitive in vitro.