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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #358721

Research Project: Identification, Evaluation, and Implementation of Biological Control Agents for Invasive Weeds of Southeastern Ecosystems

Location: Invasive Plant Research Laboratory

Title: Plant phylogenetics inform efforts at biological control of Dioscorea bulbifera

item LOBATO, AMANDA - St Thomas University
item Dray, F Allen
item MAUL, PILAR - St Thomas University
item Blair, Zizah-Wossen
item Madeira, Paul

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/8/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: Relationships between Dioscorea species support biological control efforts at controlling this invasive vine. Phylogenetic trees reflecting DNA relationships within the genus Dioscorea show that the target weed, Dioscorea bulbifera, is only distantly related to Florida native species (D. floridana and D. villosa) as well as species native to, or commercially produced in, the Caribbean. These results help confirm bioassays showing that proposed biological control agents are unlikely to attack Dioscorea species found in the Western Hemisphere except for the target weed.

Technical Abstract: Dioscorea bulbifera (air potato), a member of the true yam family, is an invasive weed species whose vining habit smothers neighboring plants and that produces dense canopies which shade out native understory species. A biological control agent for this species needs to be introduced to reduce the invasion and bulbil production of the species. A first biological control agent, Lilioceris cheni, was released in late 2011 and this beetle aided in the increase of native species by combating Dioscorea bulbifera. Currently, Lilioceris egena Weise is being tested at the USDA-ARS-IPRL as a potential second biological control agent, one that attacks the bulbils of these plants. The research methodology used was molecular genetics to delineate the origins of invasive weeds and the phylogenetic relationships on related plants to develop biological controls for the weeds. The priority is to ensure that an introduced agent will not complete its life cycle on any native plants. After DNA extraction, PCR, sequencing, and phylogenies, the findings were that D. bulbifera sits on a relatively long branch in relation to the other Dioscorea species in the host range testing. Therefore, we would expect that there will be a reduced chance that Lilioceria egena will be unable to complete its life cycle on any Dioscorea other than D. bulbifera. Additionally, L. egena does not lay eggs, nor do neonates develop, on any of the other Dioscorea tested.