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Genotyping and Marker Chemical Profiling of Hypericum
spp.
A. N. Aziz,
D. Long, M. Cherry, and R. J. Sauve
Cooperative
Agricultural Research Program
Seminar Series
Tennessee State University, Nashville, TN
November 20, 2002
St. John’s Wort (Hypericum
spp.) has a long history of medicinal use in Occidental culture. From
the time of the ancient Greeks through the middle Ages, this plant was
used to ward off evil and protect against disease. In folk-remedies, St.
John’s Wort has widely been used to heal wounds, as a remedy to renal
troubles, and to alleviate nervous disorders. In the last thirty years
St. John’s Wort has undergone extensive clinical and laboratory testing
to identify medicinally important compounds that have antibacterial,
antidepressant and anti-inflammatory effects.
Because of its increased popularity in homeopathic remedies, there is a
vital need to identify
superior
cultivars of St. John’s Wort that have enhanced concentrations of
pharmaceutically significant compounds.
In this study
phytochemical profiles
and DNA fingerprints were obtained from a sample of 11 species and
cultivars of Hypericum (H. androsaemum, H.
calycinum, H. frondosum ‘Sunbrust’, H. grandiflorum, H.
inodorum ‘Rheingold’, H. monseranum, H. olympicum, H.
patulum ‘Sungold’, H. perforatum, H.
perforatum ‘Anthos’ and ‘Topas’). High performance liquid
chromatography (HPLC) was used to quantify
pharmaceutically important compounds and amplified fragment
length polymorphism (AFLP) based
genetic
markers (DNA fingerprints)
to
identify 11
Hypericum
accessions.
Methanol extracts of phytochemical
from all accessions were prepared using Soxhlet and sonication methods.
The HPLC system was used to identify and quantify chlorogenic acid,
rutin, hypericin, pseudohypericin, and hyperforin contents in methanol
extracts.
Hypericum
grandiflorum contained most quantity of marker phytochemicals while H.
perforatum ‘Anthos’ contained the least. DNA fingerprints (AFLP
profiles) were detected with an automated DNA analyzer.
We
found that there was correlation between structurally similar plants and
their DNA markers. However, each accession had distinctive DNA
fingerprints. The TreeCon-Dendogram software was used to analyze DNA
banding patterns between each accession and graph their genetic
distances.
Hypericum
perforatum ‘Anthos’ was genetically distant as well as lower
producer of the marker phytochmeicals than other two H. perforatum
samples.
Hypericum
olympicum and H. grandiforum, shared identical
banding patterns while the former had low phytochemical content.
Genetic similarity was observed among H. monseranum (a
hybrid line) and its parental species H. patulum and H.
calycinum.
Hypericum
monseranum exceeded its parental species in levels of marker
phytochemicals. Results obtained in this study can be used to
genetically characterize plants with higher levels of marker
phytochemicals. In addition, potential applications of AFLP markers can
be used in true to type identification of cultivars and marker-assisted
breeding programs.
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