Columbus, Ohio
November 6, 2007
- 'TRAP' preserves genetic
properties of popular geranium
- Method streamlines collection while maintaining genetic
diversity
Reseachers at
The Ohio State University have
demonstrated that Target Region Amplification Polymorphism, or
TRAP, is an effective method for preserving the important
genetic diversity of ornamental flower collections.
Pelargonium, commonly know as geranium, are some of the most
popular flowers the world. So popular, in fact, that the
Royal Horticultural Society
listed more than 3,000 varieties of geranium in their 2004
distribution catalogue. Sold in hanging baskets, flats and
decorative pots, geranium plants accounted for more than $206
million in wholesale revenue in the U.S. during 2004. Essential
oils from some scented geraniums are finding new uses in
perfumes and food flavorings.
There are over 280 documented species of Pelargonium. The
interest in breeding has resulted in many novel and improved
cultivars. According to Rose Palumbo, Department of Plant
Pathology at The Ohio State University (OSU), ornamental plants
like the geranium are often bred for their ornamental qualities
rather than their ability to survive in diverse environments.
Palumbo and a team of researchers recently completed a study of
Pelargonium grown at The Ornamental Plant Germplasm Center
(OPGC) at Ohio State. OPGC collects heirloom cultivars, breeding
lines and wild species.
Intending to find a way to preserve the genetic diversity of
Pelagonium, the team tested a method known as Target Region
Amplification Polymorphism, or TRAP. Palumbo explained, "The
TRAP method uses molecuar markers targeted to a specific gene.
Target sequences that have been generally successful in most
plants tested the applicability of this method to OSU's geranium
collection. Using TRAP allowed us to divide the population into
groups of similiar species and groups known to share parents."
Palumbo continued, "TRAP has the advantage of producing a large
number of markers through use of sequence information that is
already available. Our first goal was to determine the
feasibility of TRAP for the analysis of this large collection,
so that in the future the most diverse genotypes may be
retained. To achieve this goal, we first modified existing DNA
extraction techniques to account for the high levels of phenolic
compounds present in some Pelargonium species. Second, we
evaluated the TRAP procedure using the DNA isolated from 46
accessions. Based on these results, the molecular analysis of
the collection was completed, and the collection has decreased
in size by approximately 25%. Continuing analyses should shrink
the collection from approximately 800 plants to close to 200
plants by the end of this year."
Using the TRAP method will allow the OPGC to streamline their
collection of geraniums into a much more manageable size.
According to Palumbo, the smaller collection will be more
efficient to maintain, while still providing the diverse genetic
resources needed by breeders and researchers.
The complete study and abstract are available on the ASHS
HortScience electronic journal web site:
http://hortsci.ashspublications.org/cgi/content/abstract/42/5/1118/
Founded in 1903, the American
Society for Horticultural Science (ASHS) is the largest
organization dedicated to advancing all facets of horticultural
research, education and application. |
|
