Camelina sativa: For Biofuels and Bioproducts - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 160

Mutagenesis has been used as a technique to introduce new and novel traits into
existing camelina germplasm. Ethyl methanesulfonate (EMS) has been used by
researchers interested in developing camelina lines with resistance to residual
herbicides. Walsh [ 36 ] used EMS mutagenesis to develop two camelina genotypes
that demonstrated tolerance to acetolactate synthase (ALS) inhibitor herbicides.
These mutant camelina lines showed increased resistance to imazethapyr and
sulfosulfuron herbicides. Limited quantities of these mutant lines are available
from Washington State University.
A mapping population was developed in Germany (Deutsche Saatveredelung,
Lippstadt, Germany) and has been used to create linkage maps and identify QTL for
favorable agronomic traits in several studies. This mapping population was derived
from a cross between the European varieties “Lindo” and “Licalla.” Gehringer
et al. [ 31 ] created a linkage map of camelina with 157 amplified fragment length
polymorphism (AFLP) markers and 3 Brassica SSR markers and identified quan-
titative trait loci (QTL) for seed yield, oil content, plant height, thousand-seed
weight, and fatty acid composition. Using this same mapping population, Enjalbert
[ 32 ] identified 29 significant QTLs for yield, drought tolerance, and oil quality
characteristics. Of these, six were found to be in common with Gehringer et al. [ 31 ].
Target Traits and Current Breeding Goals
Yield
Yield is the subject of most improvement programs. Camelina seed yield has shown
a high degree of heritability at 86.5 % [ 37 ]. Oil content and thousand-seed weight
also demonstrate high degrees of heritability at 95.6 % and 97.6 %, respectively
[ 38 ]. Thousand-seed weight could be a characteristic of interest for breeders
interested in increasing yield, as this character is easier to select than yield and
has a higher heritability than yield [ 31 ]. There is evidence that higher thousand-seed
weight comes at the expense of oil content and the number of seeds per plant [ 39 ].
Breeding for yield stability over environments will become more important in
the future as climate change and global warming affect both absolute environmental
conditions and variability of environmental conditions. Optimizing camelina
growth habits to better avoid summer heat can potentially minimize environmental
effects on yield. Flowering time may be a useful characteristic as a target for
selection, as earlier flowering varieties can better escape heat stress and earlier
flowering is positively correlated with seed yield and linolenic acid content [ 32 ].