Premium
Sex Allocation Ratio in a Wind‐Pollinated Self‐Incompatible Monoecious Tree, Alnus firma Sieb. et Zucc. (Betulaceae)
Author(s) -
MURAKAMI NORIAKI,
MAKI MASAYUKI
Publication year - 1992
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.1442-1984.1992.tb00223.x
Subject(s) - plant reproductive morphology , inflorescence , betulaceae , biology , anemophily , sex allocation , botany , sex ratio , horticulture , pollination , demography , pollen , pregnancy , population , genetics , pollinator , sociology , offspring
Biomass sex allocation of Alnus firma , a wind‐pollinated self‐incompatible monoecious tree species, was directly measured at the inflorescence (prezygotic) stage. Sex allocation ratio at the fruit stage was estimated from the number of female inflorescences, percent fruit production, and the mean dry weight of a female inflorescence and a fruit catkin. Investment in male function far exceeds that in female function at the prezygotic stage. When the costs of fruit catkins and seeds were included in the estimation of female function, then the sex allocation bias was reversed towards female. Intrapopulational variation of the sex allocation ratio with respect to tree height and size was also investigated. A strong negative correlation was observed in both cases, although a positive relationship has been predicted by theorists and some previous empirical data have supported this prediction.