Camelina sativa: For Biofuels and Bioproducts - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 162

the oil) to a value that is below the acceptable limit of 120 as established by the
European biodiesel standard [ 53 ].
Recent analysis of Eastern European camelina germplasm collections has iden-
tified an accession with desirable oil profile of greater than 30 % linolenic fatty acid,
less than 3 % erucic acid, less than 10 % saturated fatty acids, and a ratio of
linolenic to linoleic acid greater than one [ 22 ].
Breeding Strategies and Integration of New Biotechnologies
Analysis of the agronomic characteristics of recombinant inbred lines (RIL) formed
from a cross between the varieties Lindo and Licalla showed that 25 % of the
offspring outperformed both parents, meaning that camelina shows transgressive
segregation [ 31 ]. Of these RILs, Gehringer et al. [ 31 ] identified five promising
varieties as candidates for possible release. Two of these were also identified at
Colorado State University as containing QTL for yield and drought tolerance and
demonstrating significantly higher yields [ 32 ]. These are currently undergoing
further yield evaluations with the possibility for commercial release [ 32 ]. The
difference in climate between Germany and Colorado suggest that these varieties
are widely adapted and show high yields in a variety of environments.
Gamma ray irradiation was used by Vollmann et al. [ 37 ] to induce mutations in
camelina germplasm for improving linolenic acid content. Lines were isolated that
contained higher concentrations of the fatty acid (40.8 %). In addition, some
mutants were identified that contained lower concentration of erucic acid (less
than 2 %).
Camelina is a suitable candidate species for transgenesis. It is widely considered
a primarily self-pollinating species with a low rate of outcrossing [ 23 ]. Field
experiments have estimated the outcrossing rate in camelina to vary between 0.01
and 0.28 % [ 54 ]. This is nearly equal to soybean, which is approximately 0.30 %
[ 55 ]. The fact that camelina is a facultative outcrossing species means that it can be
bred through recurrent selection or through the creation of hybrids by creating male
sterile lines for crossing. A methodology for developing doubled haploid camelina
would also greatly reduce the number of generations necessary for new lines of
camelina to reach homozygosity [ 39 ].
Research looking to characterize the genome of camelina has been ongoing for
some time. There have been notable efforts to identify several target genes with
respect to their potential for genetic manipulation. Hutcheon et al. [ 27 ] targeted
genes regulating fatty acid synthesis in Arabidopsis that were hypothesized to be
homologous in camelina. These genes include fatty acid desaturase 2 (FAD2),
which converts oleic acid (C18:1) to linoleic acid, and fatty acid elongase
1 (FAE1), which adds two carbons to an 18-carbon chain. It is presumed that
downregulation of these genes could lead to increased production of oleic acid, a
favorable fatty acid for biodiesel feedstocks. RNA sequencing techniques revealed
that unlike in Arabidopsis , where only one copy of each gene is found, the camelina