Seed mass and the evolution of early-seedling etiolation

Gislene Ganade*, Mark Westoby

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    27 Citations (Scopus)

    Abstract

    The influence of seed mass on the evolution of seedling-foraging strategies for light acquisition under deep shade was assessed in a comparative study of etiolation behavior. This was done across 50 Australian species varying in seed reserve mass by eight orders of magnitude during the first week after germination. Proportional increase in hypocotyl length in shade compared to light was similar across the range of seed reserve mass. Etiolation did not lead to increase in hypocotyl length per wet mass, in other words, etiolated hypocotyls were not thinner. However, hypocotyl length per dry mass did increase, more so in smaller-seeded species. Thus, part of the hypocotyl elongation was because of increased water content, which would increase vulnerability to loss of turgor. There was also reallocation of dry matter from root to hypocotyl, again more so in smaller-seeded species, which would decrease anchorage strength and increase vulnerability to soil drying. Results were very similar when considered as correlated evolutionary divergences, compared to the cross-species patterns. The higher-risk etiolation behavior of smaller-seeded species can be understood through their having little to lose. Because they hold less reserve resource uncommitted and attempt a faster initial growth rate, their chances of sustained longevity in shade below the compensation point are very low.

    Original languageEnglish
    Pages (from-to)469-480
    Number of pages12
    JournalAmerican Naturalist
    Volume154
    Issue number4
    DOIs
    Publication statusPublished - 1999

    Keywords

    • Etiolation
    • Foraging behavior
    • Seed mass
    • Seedling strategy
    • Shade
    • Syndrome

    Fingerprint

    Dive into the research topics of 'Seed mass and the evolution of early-seedling etiolation'. Together they form a unique fingerprint.

    Cite this