Related Experiment Video
Updated: May 6, 2026

Non-radioactive in situ Hybridization Protocol Applicable for Norway Spruce and a Range of Plant Species
Published on: April 17, 2009
Evolutionary analysis of Pinus densata Masters, a putative Tertiary hybrid : 1. Allozyme variation
X R Wang1, A E Szmidt, A Lewandowski
1Institute of Forest Genetics and Plant Physiology, The Swedish University of Agricultural Sciences, S-90183, Umeå, Sweden.
Abstract:
Allozyme differentiation at 13 loci was studied in populations of Pinus tabulaeformis, P. densata, and P. yunnanensis from China. It was previously suggested that P. densata represents a Tertiary hybrid between P. tabulaeformis and P. yunnanensis. The observed levels of allozyme variation within and among the investigated species were comparable to those of other conifers. P. tabulaeformis differed markedly from P. yunnanensis with respect to allozyme frequencies, while P. densata was intermediate between the two putative parents. There was evidence of homozygote excess in embryos from all investigated species, as compared to Hardy-Weinberg expectations. The observed allozyme composition of P. densata conformed to earlier morphological and molecular evidence indicating hybrid origin of this taxon. It was proposed that fusion of gene pools from P. tabulaeformis and P. yunnanensis has led to adaptive evolution of a new species, P. densata.
Related Concept Videos
Evolutionary Relationships through Genome Comparisons
Hybrid Zones
Formation of Species
Trihybrid Crosses
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).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal...
Genetics of Speciation
Gene Evolution - Fast or Slow?
In contrast, regions which code...

