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(W/EH052) LINDANE EFFECTS ON TWO SOLANUM TUBEROSUM L. CULTIVARS: STUDIES AT THE CHLOROPHYLL FLUORESCENCE LEVELS. cavaleiro, lurdes 1, costa, armando1, gonçalves, fernando1, santos, conceição1, 1 ABSTRACT- LINDANE EFFECTS ON TWO SOLANUM TUBEROSUM L. CULTIVARS: STUDIES AT THE CHLOROPHYLL FLUORESCENCE LEVELS Lurdes Cavaleiro, Armando Costa, Fernando Goncalves and Conceicao Santos Department of Biology, University of Aveiro, Portugal Lindane (g-hexachlorocyclohexane) is a halogenated organic insecticide and fungicide that has been largely used mainly for agriculture and pharmacy purposes. However, for the last years, lindane use was restricted or banned because of its persistency in the environment, bioaccumulation in food chain and high toxicity to humans. It is important, therefore not only to define the way it is being used by farmers, but also to define rapid methods for the evaluation of this product effects in potato plants and to evaluate the presence of this compound in commercial potatos. For the study of lindane effects in potato plants we used two cultivars of Solanum tuberosum L (cv. Raja and cv. Marfona) grown on hydroponic Long Ashton medium, and supplemented with increasing concentrations (0; 0.3; 3 and 30 mg/l) of the lindane. Plants were grown for three weeks and during this period growth rates and some senescence parameters associated with the photosynthetic apparatus (chlorophyll content, F0, Fm, Fv, Fv/Fm) were determined. Different degrees of tolerance to lindane were observed between the cultivars. Photosynthetic efficiency (PEA) was only slightly affected in one cultivar mainly due to an increase of Fo. This effect was accompanied by variation of chlorophyll contents and chla/chlb ratio suggesting that chlorophyll synthesis/degradation is affected by lindane in plants. The advantages/disadvantages of application of these parameters to assay lindane toxicity in plants is discussed. Key words: lindane toxicity, potato, chlorophyll fluorescence, senescence |
