Reproductive isolation in five hybridizing species of western gooseberries (Ribes: Grossulariaceae)
Graduation Date
2000
Document Type
Thesis
Program
Other
Program
Thesis (M.A.)--Humboldt State University, Biology, 2000
Committee Chair Name
Michael Mesler
Committee Chair Affiliation
HSU Faculty or Staff
Keywords
Humboldt State University -- Theses -- Biology, Gooseberries, Hybridization
Abstract
Five species of western gooseberries (Ribes: Grossulariaceae) hybridize to varying degrees in northwestern California and southwestern Oregon. Pollinator surveys and hand-pollination experiments were conducted to identify reproductive barriers between the species pairs. I found little evidence of isolation due to pollinator behavior, since the five species tended to attract the same pollinators. My attempts to assess the level of post-pollination isolation were hindered by high rates of fruit abortion. Nevertheless, it appears that R. roezlii and R. menziesii are fully interfertile, and that unilateral barriers operate when R. lobbii, which has the longest styles of the set, is the maternal parent in crosses with the other species. Since the level of post-pollination isolation is not correlated with the observed frequency of hybridization in the field, ecological and/or geographical differences may play the most important role in isolating the species.
Recommended Citation
Kalt, Jennifer L., "Reproductive isolation in five hybridizing species of western gooseberries (Ribes: Grossulariaceae)" (2000). Cal Poly Humboldt theses and projects. 1804.
https://digitalcommons.humboldt.edu/etd/1804
https://scholarworks.calstate.edu/concern/theses/z029p745n