Fluorescence Properties of Paraquat Resistant Conyza Leaves

  • Z. Szigeti
  • E. Pölös
  • E. Lehoczki


Fluorescence parameters /Fv, Fs, Fo, Rfd/ derived from fast and slow induction curves of paraquat treated susceptible and resistant Conyza plants were investigated by a newly developed micro-computerized apparatus. Resistant plants sprayed with Gramoxone /4 μM paraquat/ showed a transient inhibition which means that paraquat can penetrate into the chloroplasts. The recovery of the fluorescence parameters began 2 h after spraying, and it was completed in more than 48 h. pI50 values of induction parameters were determined in Conyza leaves floated on paraquat solution of different concentration for 24 h. Fv and Rfd values were the most sensitive parameters giving a resistance factor of about 3oo and more than 450, respectively.

Key words

Conyza canadensis fluorescence induction Gramoxone paraquat resistance 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Fuerst EP, Nakatani HY, Dodge AD, Penner D and Arntzen CJ, 1985. Paraquat resistance in Conyza. Plant Physiol. 77:984–989.CrossRefPubMedPubMedCentralGoogle Scholar
  2. Lichtenthaler HK, Buschmann C, Rinderle U and Schmuck G, 1986. Application of chlorophyll fluorescence in ecophysiology. Radiat. Environ. Biophys. 25:297–308.CrossRefPubMedGoogle Scholar
  3. Pölös E, Laskay G, Szigeti Z, Pataki Sz and Lehoczki E, 1987. Photosynthetic properties and cross-resistance to some urea herbicides of triazine resistant Conyza canadensis Cronq /L./. Z. Naturforsch. 42c:783–793.CrossRefGoogle Scholar
  4. Pölös E, Mikulás J, Szigeti Z, Matkovics B, Do Qui Hai, Párducz Á and Lehoczki E, 1988. Paraquat and atrazine coresistance in Conyza canadensis /L./ Cronq. Pestic. Biochem. Physiol. 3o: 142–154.CrossRefGoogle Scholar
  5. Shaaltiel Y and Gressel J, 1986. Multienzyme oxygen radical detoxifying system correlated with paraquat resistance in Conyza bonariensis. Pestic. Biochem. Physiol. 26:22–28.CrossRefGoogle Scholar
  6. Shaaltiel Y and Gressel J, 1987. Kinetic analysis of resistance to paraquat in Conyza. Evidence that paraquat transiently inhibits leaf chloroplast reactions in resistant plants. Plant Physiol. 85:869–871.CrossRefPubMedPubMedCentralGoogle Scholar
  7. Strasser RJ, Schwarz B and Bucher JB, 1987. Simultane Messung der Clorophyll Fluoreszenz-Kinetik bei verschiedenen Wellenlängen als rasches Verfahren zur Frühdiagnose von Immissionsbelastungen an Waldbäumen: Ozoneinwirkungen auf Buchen und Pappeln. Eur. Zeitschr. Forstpath. 17:149–157.Google Scholar

Copyright information

© Kluwer Academic Publishers 1988

Authors and Affiliations

  • Z. Szigeti
    • 1
  • E. Pölös
    • 2
  • E. Lehoczki
    • 3
  1. 1.Department of Plant PhysiologyEötvös UniversityBudapestHungary
  2. 2.Research Institute of Viticulture and EnologyKecskemétHungary
  3. 3.Department of BiophysicsJózsef Attila UniversitySzegedHungary

Personalised recommendations