Prediction of desiccation sensitivity in seeds of woody species: a probabilistic model based on two seed traits and 104 species.
OBJECTIVE
Seed desiccation sensitivity limits the ex situ conservation of up to 47 % of plant species, dependent on habitat. Whilst desirable, empirically determining desiccation tolerance levels in seeds of all species is unrealistic. A probabilistic model for the rapid identification of woody species at high risk of displaying seed desiccation sensitivity is presented.


METHODS
The model was developed using binary logistic regression on seed trait data [seed mass, moisture content, seed coat ratio (SCR) and rainfall in the month of seed dispersal] for 104 species from 37 families from a semi-deciduous tropical forest in Panamá.


RESULTS
For the Panamanian species, only seed mass and SCR were significantly related to the response to desiccation, with the desiccation-sensitive seeds being large and having a relatively low SCR (i.e. thin 'seed' coats). Application of this model to a further 38 species, of known seed storage behaviour, from two additional continents and differing vegetation types (dryland Africa and temperate Europe) correctly predicted the response to desiccation in all cases, and resolved conflicting published data for two species (Acer pseudoplatanus and Azadirachta indica).


CONCLUSIONS
This model may have application as a decision-making tool in the handling of species of unknown seed storage behaviour in species from three disparate habitats.
Daws
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Seed Conservation Department, Royal Botanic Gardens Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK. m.daws@rbgkew.org.uk
Garwood
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NC
Pritchard
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HW
D000349:Africa; D002980:Climate; D003890:Desiccation; D005060:Europe; D008954:Models, Biological; D010176:Panama; D018521:Plant Physiological Phenomena; D011891:Rain; D012044:Regression Analysis; D012639:Seeds / Q000033:anatomy & histology / Q000502:physiology*; D014197:Trees; D014329:Tropical Climate; D014867:Water; D014934:Wood
D014867:Water