Biomedical Engineering Reference
In-Depth Information
improvement program but have found utility in helping understand its population
genetics and taxonomy and assist in germplasm curation.
Allozyme markers were the first to be employed in the study of the species. Five
enzymes and seven polymorphic loci were used to genotype early and late germi-
nating
P. fendleri
plants, as well as those grown under two water treatments
[
89
]. Subsequently, random amplified polymorphic DNA (RAPD) marker amplifi-
cation have been tested to work during optimization of DNA extraction protocols in
the species
P. fendleri
,
P. ovalifolia
,
P. rectipes
, and
P. douglasii
. However, only
preliminary results from using one RAPD primer, OPL03, were available in the
literature, but the initial work presuppose that other RAPD primers can be useful in
genotyping work in the species [
90
].
Microsatellite markers have been developed for
P. fendleri
and were found to
successfully cross-amplify with the following species:
P. acutifolia, P. angustifolia
,
P. cinerea
,
P. douglasii
subsp.
tuplashensis
,
P. gordonii
,
P. gracilis
,
P. lindheimeri
,
P. mexicana
,
P. pallida
, and
Paysonia lyrata
[
91
]. Microsatellite markers are being
used to determine genetic diversity in
P. congesta
and
P. obcordata
, both sister
species of lesquerella that are under threatened status in Colorado [
92
].
Intersequence simple repeat (ISSR) markers have been used in a
Physaria
relative,
P. bellii
, to determine whether native populations in the Colorado Front
Range are under threat of hybridization with a more common
Physaria
species
[
93
]. Three ISSR primers (UBC890, UBC809, UBC841) were found to work and
have enabled the analysis of genetic variability within and among
P. bellii
populations [
94
]. ISSRs along with internal transcribed sequences (ITS) of nuclear
ribosomal DNA have also been used to assess the taxonomic classification of the
genus, consequently providing support for reclassification uniting
Lesquerella
with
the genus
Paysonia
[
38
].
Amplified fragment length polymorphism (AFLP) markers were utilized to
determine the genetic composition of intertribal sexual hybrids between
P. fendleri
and
B. napus.
A total of 1,271 bands were obtained from 26 primer
pairs and were used to analyze the parental materials and their F
1
hybrids [
31
].
More recently, Diversity Arrays Technology (DArT) marker systems have been
developed and used to analyze the genetic diversity of the
Physaria
and
Paysonia
germplasm in the US National Plant Germplasm System. A total of 2,833 marker
loci have been analyzed using microarray DArT while 27,748 marker loci using
DArTseq [
51
,
52
]. Results of analysis using these two DArT marker systems
provided support to the previous taxonomic revision of the genus and gave infor-
mation on the genetic diversity of
the USDA-ARS lesquerella germplasm
collection.
Tissue Culture and Genetic Transformation Systems
Biotechnologies may help overcome the reproductive incompatibility issues in
lesquerella and allow transfer of desirable traits to related genera in the Brassica
family. Tissue culture studies have been done in
P. fendleri
to support genetic
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