M. Waycott et Jf. Sampson, THE MATING SYSTEM OF AN HYDROPHILOUS ANGIOSPERM POSIDONIA-AUSTRALIS (POSIDONIACEAE), American journal of botany, 84(5), 1997, pp. 621-625
The hydrophilous seagrass Posidonia australis has a wide range of mult
ilocus outcrossing rates (t), which vary from 0 to 0.89, with ''appare
nt'' outcrossing rates varying from 0 to 0.42 among the seven populati
ons sampled. This pattern of outcrossing rate indicates that water pol
lination (hydrophily) is less uniform than wind pollination and more s
imilar to animal pollination in its variability. Variation in levels o
f outcrossing between populations may be due to differences in water m
ovement; for example, open bays have greater pollen dispersal and high
er outcrossing rates. Considerable pollen movement within meadows was
inferred from a high frequency of nonmaternal alleles in the pollen po
ol. The distribution of genetic diversity among populations (G(ST) = 0
.229) suggests moderate gene flow on the local scale. These results de
monstrate that successful submarine cross-pollination occurs in the hy
drophile P. australis, which has a diverse mating system with populati
ons that range from predominantly inbred to predominantly outcrossed.