Developmental heat sum influences recalcitrant
seed traits in Aesculus hippocastanum across Europe
Daws MI, Lydall E, Chmielarz P, Leprince O, Matthews S, Thanos CA,
Pritchard HW
NEW PHYTOLOGIST
162 (1): 157-166 APR 2004
Abstract:
An analysis was made of seed traits along a north-south gradient spanning
19degrees of latitude in Europe using Aesculus hippocastanum, which originates
from Greece and the Balkans and has been introduced throughout Europe.
Because summer temperatures decrease with increasing latitude in Europe,
we tested the hypothesis that the heat sum during seed development influences
physical, physiological and biochemical seed traits.
Seeds from Greece (within the natural range) had a fresh mass five times
higher than those from Scotland (most northerly seed lot), and a lower axis
moisture content and solute potential. In addition, Greek seeds germinated at
cooler temperatures, and were more desiccation tolerant. Principal component
analysis (PCA) showed that the observed patterns in seed characteristics were
consistent and predictable: a single PCA axis explained 86.6% of the variation
in the dataset. This axis correlated strongly with the heat sum accumulated by
the seeds during development.
The results support the notion that seeds from further north were shed
less developed as a consequence of cooler temperatures during development, and
provide a quantitative explanation for intraspecies variability in recalcitrant
seed traits for this and, possibly, other species.
Author Keywords:
Aesculus hippocastanum, desiccation, heat sum, seed germination, thermal time
KeyWords Plus:
DESICCATION-TOLERANCE, GRAIN LEGUMES, CONSTANT TEMPERATURES, GERMINATION RATE,
ZIZANIA-PALUSTRIS, DORMANCY LOSS, WATER-CONTENT, THERMAL TIME, DEHYDRATION,
SENSITIVITY
Addresses:
Daws MI, Royal Bot Gardens Kew, Seed Conservat Dept, Ardingly RH17 6TN, W
Sussex, England
Royal Bot Gardens Kew, Seed Conservat Dept, Ardingly RH17 6TN, W Sussex,
England
Polish Acad Sci, Inst Dendrol, PL-62035 Kornik, Poland
Univ Angers, INRA, INH, UMR Mol Seed Physiol, F-49045 Angers, France
Univ Aberdeen, Dept Agr & Forestry, Aberdeen, Scotland
Univ Athens, Dept Bot, Athens 15784, Greece
Publisher:
BLACKWELL PUBLISHING LTD, OXFORD
IDS Number:
802PL
ISSN: