Global ETD Search

1	RESPONSES OF THE CATALPA SPHINX, CERATOMIA CATALPAE, AND ITS PRIMARY PARASITOID, COTESIA CONGREGATA, TO VARYING LEVELS OF IRIDOID GLYCOSIDES IN CATALPA Bray, Jessica L 01 January 2015 (has links) The catalpa sphinx, Ceratomia catalpae, is a specialist on Catalpa trees, which produce iridoid glycosides (IGs). Whereas some trees are defoliated every year, others escape herbivory. Caterpillar populations are either heavily parasitized by the braconid wasp, Cotesia congregata, or remain unparasitized. We hypothesized that these patterns could be explained by variable IG concentrations among trees and insect responses to these chemicals. IG concentrations varied among trees. Percent defoliation was positively related to IG concentration. In comparisons of insect responses to relatively high or low IG concentrations, moths preferred to oviposit on trees with high IG concentrations. Caterpillars did not display a feeding preference nor did wasps differ in searching responses to leaf discs with high or low IG concentrations. Results indicate that observed patterns of herbivory can be explained by moth oviposition preferences for trees with high IG concentrations. Catalpa Catalpa sphinx Ceratomia catalpae Cotesia congregata Iridoid glycosides Sphingidae Behavior and Ethology Entomology
2	MECHANISMS OF SUCCESS: PLANT-HERBIVORE INTERACTIONS AND THE INVASION OF NON-NATIVE LONICERA SPECIES IN NORTH AMERICA Lieurance, Deah January 2012 (has links) No description available. Ecology Environmental Studies Lonicera maackii Lonicera reticulata Enemy Release Hypothesis Zaraea inflata tolerance resistance herbivory secondary metabolites iridoid glycosides phenolic compounds common garden
3	Fixation, Partitioning and Export of Carbon in two Species of the Plantaginaceae Szucs, Ildiko 05 April 2013 (has links) During photosynthesis Plantaginaceae species can produce glucose derivatives such as iridoid glycosides and alcohol sugars that in addition to sucrose can be exported from leaves. Plantago lanceolata transported sorbitol in addition to sucrose especially at warmer leaf temperatures. However, two iridoids, catalpol and aucubin, found in P. lanceolata were not readily labelled from 14CO2 under any conditions examined. In contrast, in two greenhouse, cut-flower cultivars of Antirrhinum majus the iridoids, antirrhinoside and antirrhide, were readily 14C-labelled along with sucrose but little 14C was recovered in alcohol sugars (e.g., mannitol). The amount of 14C-partitioned into antirrhinoside increased at higher temperatures. Exposing leaves of P. lanceolata and A. majus to reduced-photorespiratory conditions (e.g. short-term CO2 enrichment and/or low O2) increased fixation and export. Under low O2 in P. lanceolata sorbitol 14C-labelling increased relative to sucrose and in A. majus 14C-labelling of sucrose increased relative to antirrhinoside. Also 14C-labelling of antirrhide increased more than antirrhinoside. During both short-term and long-term acclimation to high CO2, whole plant NCER, leaf photosynthesis and export increased in A. majus. Taken together the temperature and CO2 enrichment studies show plasticity in Plantaginaceae species to synthesize and transport sucrose and auxiliary glucose esters and alcohol sugars in a species-specific manner (depending on the rate of carboxylation). Iridoid glycoside terpenoid terpene monoterpene Antirrhinum majus Plantago lanceolata Plantaginaceae whole plant photosynthesis reduced photorespiratory low O2 elevated CO2 CO2 14CO2 14C-labelling 14C-partitioning temperature alcohol sugar sorbitol mannitol snapdragon aucubin catalpol antirrhide antirrhinoside leaf long term short term export phloem partitioning glucose derivative gas exchange

1

Page generated in 0.0295 seconds