Modulation de la force des sources et des puits de carbone sur la croissance du bulbe de l'érythrone d'Amérique, Erythronium americanum

Authors: Gutjahr, Sylvain
Advisor: Lapointe, Line
Abstract: Reduction in light intensity as well as seasonal increase in temperature are considered the main factors inducing the senescence of the leaves of deciduous forest spring ephemerals. However, these two factors cannot completely explain the interannual variations in belowground organ growth. We suggest that leaf longevity of spring geophytes is determined by carbohydrate storage conditions (size and growth duration of the perennial organ, storage duration) and not that leaf lifespan determine the size of the perennial organ. Our results on Erythronium americanum suggest that leaf senescence appears prematurely under the higher temperature regime when plants are cultivated at 12/8°C or 18/14°C; when the bulb stops to grow, the leaf is still photosynthetically active and the nutrient concentration is high, meaning their mobilisation is not achieved. CO2 air enrichment increases plant net assimilation rate but does not increase bulb growth rate, and thus does not enhance carbohydrate storage. The strength of a sink of carbon such as the bulb might influence leaf longevity in single-leaved individuals of this species.
Document Type: Mémoire de maîtrise
Issue Date: 2007
Open Access Date: 12 April 2018
Permalink: http://hdl.handle.net/20.500.11794/18877
Grantor: Université Laval
Collection:Thèses et mémoires

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