Premium
Only seed size matters for germination in different populations of the dimorphic Tragopogon pratensis subsp. pratensis (Asteraceae)
Author(s) -
Mölken Tamara,
JorritsmaWienk Linda D.,
Hoek Paul H. W.,
Kroon Hans
Publication year - 2005
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.92.3.432
Subject(s) - biology , germination , seedling , sexual dimorphism , botany , asteraceae , poa pratensis , morphology (biology) , poaceae , zoology
Many studies have focused on the ecology of seed dimorphism, the production of two seed types by a single plant. Morphology and seed size are usually correlated, but how morphology affects germination percentage and seedling growth is poorly understood. Here we explicitly separate these effects for nine populations of the dimorphic species Tragopogon pratensis subsp. pratensis . Larger seeds yielded higher germination percentages, yet seed morphology had no additional direct effect on germination. Neither seed size nor seed morphology affected seedling growth. Neither germination nor seedling growth varied among populations, but seed head varied significantly. Results show that germination is mainly controlled by seed size rather than by seed morphology. This study is one of the few to distinguish explicitly between seed size and seed morphology effects on ecological characteristics and suggests that seed dimorphism may exert its ecological effects predominantly through its correlated size.