Freezing stress is an important abiotic stress that limiting the yield and
the spatial distribution of many important crops. This study was undertaken
to screen 136 doubled haploid (DH) lines of camelina (Camelina sativa L.)
along with four canola (Brassica napus) cultivars (Hyola 401, Lord, Roska and
Cascade) as experimental control under freezing stress conditions (-14?C for
6 h) to identify lines with high or low level of tolerance to freezing stress
for further studies. First, a protocol was developed for large scale
screening of camelina germplasm under freezing stress conditions. For this
purpose, an experiment with different freezing temperatures (-5, -10, -15 and
-20?C) was conducted to find an appropriate temperature that discriminated
best between genotypes (i.e. the LT50 temperature). The LT50 values for
camelina lines were varied between -10.2 and -17.1?C with an average of
-13.94?C for all of the camelina lines. Therefore, we selected the -14?C
exposure for 6 h as an appropriate temperature to screening of camelina
lines. The principal components of measured parameters (LT50, survival
percentage, relative conductivity and scoring) was using principal component
analysis that determine freezing-tolerant and freezing-sensitive lines. Among
136 doubled haploid lines, some lines (58, 62 and 101) had higher level of
freezing tolerance and some of them (8, 16, 32, 91 and 107) were freezing
sensitive. The selected lines in a preliminary freezing screening are useful
for further evaluations.
Analysis of Camelina sativa transcriptomes identified specific transcription factors and processes associated with freezing tolerance in a winter biotype
