Impact de l'approvisionnement en eau sur l’absorption racinaire en relation avec les paramètres de rendement chez la chicorée à inuline (Cichorium intybus var.sativum)
(2012)
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- (en) Root-chicory is a biannual crop cultivated in Western Europe to extract inulin from its tap root. Our aim was to understand the impacts of drier summers and summer floods on its physiology, water uptake and yield. We found that chicory is able to survive to water shortage by reducing its growth and leaf surface. This stress did not damage the plant metabolism. Even if gas exchanges were reduced due to growth reduction and stomatal closure, photosynthesis and sugar production were maintained. The yield was strongly reduced by growth inhibition but the inulin concentration and the length of the chains stayed constant. We followed the water content in the soil thanks to two geophysical techniques: Time Domain Reflectometry and Electrical Resistance Tomography. Using those data and root growth information, we modeled the water uptake. Before the reduction in transpiration, the lack of water in the upper layers was compensated by uptakes in deeper horizons thanks to a passive mechanism called compensation. We found also that the plants reacted actively against drought by sending new lateral roots in the layers where compensation occurred. In case of flooding, it appeared that growth was maintained in waterlogging situations. Contrary to drought, photosynthesis and sugar metabolism were affected by this stress. In terms of yield, the final quantity of inulin produced was not modified by flooding but its quality was reduced. To conclude, this study showed that chicory is able to cope with abiotic stresses thanks to physiological mechanisms and its deep root system which helps the plant to extract water from deep horizons. Nevertheless, drought stress induced yield decrease. On an agronomical point of view and in the conditions we applied, chicory can be qualified as tolerant only to flooding.
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Vandoorne, B. (2012). Impact de l’approvisionnement en eau sur l’absorption racinaire en relation avec les paramètres de rendement chez la chicorée à inuline (Cichorium intybus var.sativum). https://hdl.handle.net/2078.5/158413