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Variation in flowering size and age of a facultative biennial, Aster kantoensis (Compositae), in response to nutrient availability
Author(s) -
Kagaya Mitsuko,
Tani Takashi,
Kachi Naoki
Publication year - 2009
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.0800327
Subject(s) - bolting , biology , facultative , nutrient , population , leaf size , phenotypic plasticity , botany , agronomy , ecology , demography , sociology
Although the flowering of facultative biennials is size‐dependent, flowering size varies markedly within a single population as well as among populations. In this study, 15 half‐sib families of the facultative biennial Aster kantoensis were grown from seeds at three nutrient levels (low, medium, and high). A significant nutrient × family interaction effect was found for bolting size, and among‐family variation in bolting size increased with decreasing nutrient level. Growth from bolting to flowering tended to be greatest at the high nutrient level. Such responses of bolting size and growth from bolting to flowering resulted in an increase in flowering size at the high nutrient level and a significant variation in its reaction norm among families. For flowering age, there was a significant interaction of nutrient × family, and its among‐family variation increased with decreasing nutrient levels, as was the case with bolting size. These results indicate that genetic variation in phenotypic plasticity of bolting size with nutrient availability was one cause of the variation in flowering size and age in the A. kantoensis population on the floodplain with the spatially heterogeneous nutrient availability. Moreover, responses of growth from bolting to flowering to nutrient availability could enhance the variation in flowering size.