
%0 Journal Article
%A Hermanutz, Luise 
%A Innes, David 
%A Denham, Andrew 
%A Whelan, Robert 
%T Very Low Fruit : Flower Ratios in <emph type="2">Grevillea</emph> (Proteaceae) are Independent of Breeding System
%J Australian Journal of Botany
%D 1998/11/23
%V 46
%N 4
%P 465-478
%K 
%R https://doi.org/10.1071/BT97046
%U https://www.publish.csiro.au/paper/BT97046 
%X Members of the family Proteaceae have extremely low mature fruit : flower (FR : FL) ratios (range 0.001&#8211;0.163) compared with other temperate, hermaphroditic, woody perennials. Sutherland&#8217;s (1986) survey of FR : FL ratios indicated that compatibility was an important factor explaining levels of fruit set. The role of compatibility in regulating FR : FL ratios was tested in five closely related species of Grevillea (Proteaceae). Species-specific compatibility was compared using the self-compatibility index (SI = ratio of selfed fruit set to crossed fruit set) calculated at fruit initiation to minimise the confounding effect of other post-fertilisation fruit losses, such as inbreeding depression and pre-dispersal predation. Fruit : flower ratios at initiation ranged from 0.041&#8211;0.249, and at maturity 0.015&#8211;0.096. Grevillea species showed highly variable breeding systems: G. linearifolia was self-incompatible (SI = 0.003), G. sphacelata, G. mucronulata, and G. oleoides were partially self-compatible (SI = 0.07&#8211;0.28) and G. longifolia was self-compatible (SI = 0.61). Intrapopulation variability in the level of self-incompatibility was high in all species but G. linearifolia. The correlation between SI and FR: FL ratios was non-significant, indicating that compatibility has a minimal effect on fruit set in the Grevillea species studied, and that these data, together with other data on proteaceous species do not support trends observed in Sutherland&#8217;s survey. Low FR : FL ratios resulted from of a combination of pollen limitation, and high levels of flower and fruit predation. 
