Triques K., Rival Alain, Beulé Thierry, Morcillo Fabienne, Hocher Valérie, Verdeil Jean-Luc, Hamon Serge.
1998. Changes in photosynthetic parameters during in vitro growth and subsequent acclimatization of coconut (Cocos nucifera L.) zygotic embryos.
In : Proceedings of the First International symposium on biotechnology of tropical and subtropical species, Brisbane, Queensland, Australia, September 29-October 3, 1997. Part 2. Drew R.A. (ed.). ISHS
Autre titre : Evolutions des paramètres photosynthétiques au cours de la phase d'acclimatation et de croissance d'embryons zygotiques de cocotiers (Cocos nucifera L.)
Résumé : In coconut, #in vitro# development and acclimatization of plantlets still constitute the major bottlenecks for the implementation of tissue culture protocols. In the present paper, the photosynthetic status of #in vitro# grown plantlets resulting from zygotic embryo culture is investigated, combining various complementary approaches, both #in vitro# and #in planta#. Patterns of chlorophyll fluorescence were similar in #in vitro# grown coconut plantlets (aspiré: phi MAX= 0.72 and aspiré: phi = 0.45) and in autotrophic adult palms (aspiré: phi MAX= 0.76 and aspiré: phi = 0.50), whereas the chlorophyll content was lower in #in vitro#-cultured plantlets(0.92 mg.g-1 FW) than in autotrophic plants (2.43 mg.g-1 FW). The photosynthetic rate (1.14 micro-mol CO2 m-2s-1) was two times lower in #in vitro# grown plantlets, while transpiration rates were similar in bath #in vitro#-cultured plantlets and in autotrophic palms. Changes in the PEPC: Rubisco carboxylase ratio during the development of #in vitro# grown zygotic embryos (from 89.17 to 0.04 micro-mol CO2 h1mg1rsp) reflected an early transition towards a RubisCO-mediated mode of CO2 fixation. The RubisCO content (172.8 mg.g-1) measured in #in vitro#-cultured plantlets was lower than in autotrophic palms (217.6 mg.g-1). During the acclimatisation phase, the #in vitro# grown coconut plantlets showed a faster decrease in their PEPC: RubisCO ratio than the seedlings, suggesting that an earlier transition from a heterotrophic to an autotrophic mode of carbon fixation takes place in the #in vitro#-derived material. Just before acclimatization, the RubisCO activity in #in vitro# derived plantlets was lower than that in seedlings of the same age. After acclimatisation, RubisCO activities were comparable in both #in vitro# and# in planta# germinated material. #In vitro# grown plantlets displayed several photosynthetic characteristics (aspire: phiMAX, aspiré: phi, PEPC: RubisCO ratio and transpiration rates) similar to those of acclimatized plants. These results suggest an early establishment of a photosynthetic metabolism during the #in vitro# development of coconutplantlets.
Mots-clés Agrovoc : Cocos nucifera, embryon végétal, photosynthèse, culture in vitro, culture de tissu, rubisco, micropropagation, adaptation, facteur du milieu
Classification Agris : F62 - Physiologie végétale - Croissance et développement
Auteurs et affiliations
- Triques K.
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Rival Alain, CIRAD-CP-PALMIER (FRA)
ORCID: 0000-0001-6304-3268
- Beulé Thierry, CIRAD-CP-PALMIER (FRA)
- Morcillo Fabienne, CIRAD-CP-PALMIER (FRA)
- Hocher Valérie
- Verdeil Jean-Luc, CIRAD-CP-COCOTIER (FRA)
- Hamon Serge
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/389997/)
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