Premium
Disruptive Selection in Flowering Time of Wyethia amplexicaulis (Asteraceae)
Author(s) -
SUZUKI KAZUO
Publication year - 1993
Publication title -
plant species biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 36
eISSN - 1442-1984
pISSN - 0913-557X
DOI - 10.1111/j.1442-1984.1993.tb00234.x
Subject(s) - biology , seed predation , ovule , asteraceae , predation , botany , insect , germination , ecology , population , pollen , seed dispersal , biological dispersal , demography , sociology
Disruptive selection was observed in the flowering time of Wyethia amplexicaulis between two sites at different altitudes. Flowering time varied with elevation. Flowering occurred in late June in the lower sites and in mid July in the higher sites. In the lower sites, earlier blooming flowerheads produced more good seeds, but in the higher sites later blooming flowerheads were more successful. Successful seed production observed in this study was very low (4.0% on average) since some ovules or developing seeds are attacked by insect seed predators and others are aborted. In the early flowering plants, seed production was reduced primarily by the high predation rate, while in the late flowering plants the high abortion rate was important. In early July, the interval between the two flowering peaks, both factors had a significant effect on seed production. Causes of seed abortion are also discussed.