The Phytotoxicity, Translocation and Fate of 2. 3. 5. 6-tetrachloroterephthalate (Dcpa) in Resistant and Susceptible Weed Species

Date
1966
Authors
Osgood, Robert Vernon
Contributor
Advisor
Department
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
Satisfactory bioassays were developed for the determination of weed resistance or susceptibility to DCPA using hypocotyl and root growth measurements as criteria. The hypocotyls of susceptible species, purslane (Portulsca oleracea) and spiny amaranth (Amaranthus spinosus), were inhibited by 50 percent at 45 and 2 ppm, respectively, while the resistant species, flora’s paintbrush (Emilia javanica), required 7,000 ppm for equivalent inhibition. Spanish needle (Bidena pilosa) hypocotyls were not inhibited at concentrations up to 10,000 ppm. Roots were, is all cases, more tolerant to DGPA then hypocotyls. Purslane and spiny amaranth roots were inhibited by 50 percent at 101 and 40 ppm, respectively; however, flora’s paintbrush and Spanish needle roots were not inhibited at concentrations up to 10,000 ppm. DCPA had a pronounced effect on the elongation of hypocotyl epidermal cells and root hairs of spiny amaranth. In addition, the root hairs of the same species were observed to be highly distorted in the presence of DCPA. Autoradiographic studies showed that radioactive DCPA was translocated to approximately the same extent in both resistant and susceptible weed species at the cotyledon-stage of development. The hypocotyl was shown to be the primary site from which DCPA was translocated in all species studied. Roots absorbed DCPA, but did not translocate appreciable amounts. By means of thin layer chromatography and strip counting, it was found that DCPA-C14 was not hydrolyzed in vitro by either susceptible or resistant weed species. The radioactive regions on the chromatograms were detected by means of a strip counter. It was concluded that selective translocation was probably not responsible for the difference in DCPA selectivity in the species studied at the cotyledon-stage of development. A limited study of DCPA metabolism indicated that this compound was not metabolized in extracts of resistant or susceptible species.
Description
Keywords
Citation
Extent
Format
Geographic Location
Time Period
Related To
Table of Contents
Rights
Rights Holder
Local Contexts
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.