K. Havens, CLONAL REPEATABILITY OF IN-VITRO POLLEN-TUBE GROWTH-RATES IN OENOTHERA-ORGANENSIS (ONAGRACEAE), American journal of botany, 81(2), 1994, pp. 161-165
The concept that pollen selection is an important force driving angios
perm evolution has received a lot of attention in recent years. In ord
er for pollen competition to have evolutionary significance, heritable
variation for pollen tube growth rate must exist. In this study, I te
sted the clonal repeatability, a measure of broad-sense heritability,
of in vitro pollen tube growth rate in Oenothera organensis. Although
I found significant phenotypic differences in pollen tube growth rate,
the calculated clonal repeatability value of 9.4% indicates that heri
tability of pollen tube growth rate in this species is quite low. In c
ontrast, both flower identity and plant identity had highly significan
t effects on pollen tube growth rate, suggesting that the environment
may be more important than genotype in determining pollen performance
in this species.