
TY  - JOUR
A1  - Williams, EG 
A1  - Rouse, JL 
T1  - Disparate Style Lengths Contribute to Isolation of Species in <I>Rhododendron</I>
JF  - Australian Journal of Botany
JO  - Aust. J. Bot.
Y1  - 1988
VL  - 36
IS  - 2
SP  - 183
EP  - 191
KW  - 
UR  - https://doi.org/10.1071/BT9880183 
N2  - For a group of closely related Rhododendron species in section Vireya, it is shown that success of interspecific pollinations is significantly dependent on male/female style length ratio (SLR), and apparently independent of whether both species belong to the same taxonomic subsection. Crosses with SLR < 0.2 or SLR > 6 were unsuccessful, with the probability of success increasing as SLR approached 1.0. When SLR was < 0.2 pollen tubes of the shorter-styled species were unable to reach the ovary. When SLR was > 5-6, pollen tubes of the longer-styled species penetrated deeply into the ovary but were rarely observed to enter ovules. Disparate style lengths are therefore a major incongruity factor among Vireya rhododendrons, and may contribute to species isolation. 
ER  -

