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Updated: May 31, 2026
08:08
Determination of Self- and Inter-(in)compatibility Relationships in Apricot Combining Hand-Pollination, Microscopy and Genetic Analyses
Published on: June 16, 2020
A mating system conundrum: hybridization in Apocynum (Apocynaceae).
S A Johnson1, L P Bruederle, D F Tomback
1Department of Biology, Campus Box 171, University of Colorado at Denver, P.O. Box 173364, Denver, Colorado 80217-3364.
American Journal of Botany
|June 21, 2011
Summary
Apocynum x-floribundum is confirmed as a hybrid using allozyme evidence. Despite hybridization, this plant species primarily reproduces clonally, with low fruit set observed in most populations.
Area of Science:
- Botany
- Genetics
- Plant Science
Background:
- Apocynum x-floribundum has been morphologically classified as a hybrid between A. androsaemifolium and A. cannabinum.
- Floral morphology and low fruit set in Apocynum challenge traditional hybridization assumptions.
Purpose of the Study:
- To test the hypothesis of a hybrid origin for Apocynum x-floribundum using molecular data.
- To investigate the reproductive strategies and genetic diversity of Apocynum x-floribundum.
Main Methods:
- Allozyme electrophoresis was used to analyze genetic variation at diagnostic loci in parent species and hybrid populations.
- Statistical analyses were performed on morphological traits including plant height, leaf and petal dimensions, and seed characteristics.
Main Results:
- Allozyme data revealed heterozygosity at diagnostic loci in all A. x-floribundum populations, supporting a hybrid origin.
- Evidence indicated that A. x-floribundum populations are predominantly clonal, with low heterozygosity in parental species suggesting inbreeding or bottlenecks.
- Morphological analyses corroborated the genetic findings, with no support for backcross or secondary hybrid origins.
Conclusions:
- Apocynum x-floribundum is confirmed as a hybrid, but its persistence is largely due to clonal reproduction and vegetative spread.
- The study refutes previous assumptions about backcrossing and secondary hybridization in this species.
- Low reproductive success via sexual reproduction may contribute to the prevalence of clonal growth in hybrid populations.
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01:17What is a Species?
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02:27Trihybrid Crosses
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Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
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Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
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01:31Formation of Species
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02:38Asexual Reproduction
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