DESSICAL - Data acquisition regarding seeds desiccation tolerance for New Caledonian flora species

 

> GOPS 2012 action

Key-words : Desiccation tolerance, Ecosystem, Flora, Seed

Geographic area : New Caledonia

Issues : Seeds assure plant survival when environmental conditions are adverse, and their dispersal so as to colonize new sites. Their tolerance to abiotic constraints required by the environment when they are separated from their mother-plant and from the fruit is therefore essential for species maintenance and evolution within an ecosystem.
Desiccation tolerance is the property of a living organism to survive its celular water withdrawal without non-reversible damage. It gives organisms the capacity to survive under extreme environmental conditions. In a tropical environment, seed germination is mainly conditioned by the presence of favourable hydric conditions. The seed‘s ability to survive when separated from its mother-plant is thus aproximated through the analysis of the functional biological trait essential for this constraint: viz. desiccation tolerance.
Today, the large variability noted between plant species based on the level of desiccation tolerated by the seeds suggests the hypothesis of the existence of a continuum in desiccation tolerance between species. This variation could reflect species differential adaptations to diverse habitats.

Fruits de Syzygium

Syzygium multipetalum mature fruits in the scrubland, on ultramafic rocks.
© Philippe Marmey

 

Expected results and deliverables : The aims of this project are to acquire physiological data related to desiccation tolerance of seeds belonging to species from contrasting ecosystems and to study the level of sensibility to desiccation of seeds from varied vegetation units in relation to the characteristic of their original biotope.
The final target of this program forms the basis of a database called DESSICAL that will group the results on the seed physiological behaviour, its taxonomical classification and the ecological characteristics of the ecosystems in which it grows.
This database will be expanded in the future through the addition of new species. Over time, DESSICAL would permit to clarify whether the seed's ability to tolerate a certain grade of desiccation plays a role in the identification of the species community structure and in the maintenance of species coexistence in some habitats
 

Contact and GOPS partners :
- Institut de Recherche pour le Développement (IRD), UMR DIADE, Equipe DESSITROP, Centre IRD de Nouméa, Philippe Marmey - philippe.marmey(at)ird.fr
- IRD, UMR DIADE : Stéphane Dussert, Philippe Marmey
- Institut Agronomique néo-Calédonien (IAC) – Bruno Fogliani, Gildas Gâteblé, Casimir Véa
- IRD, UMR AMAP : Céline Chambrey, Sandrine Isnard, Tanguy Jaffré

Tests de germination

Seed germination test after  desiccation in thel IRD-Nouméa greenhouse.
© Philippe Marmey