Sensitivity of winter and spring camelina to salinity during germination

Abstract

Camelina [Camelina sativa (L.) Crantz] is an oilseed of interest as a feedstock for sustainable aviation fuels due to its low carbon intensity. Camelina is reported to have salinity tolerance and able to establish in marginal lands but there is no knowledge on how spring and winter biotypes tolerate exposure to different salts and salt concentrations. The objective of this study was to determine seed germination and vigor of spring camelina (C046) and winter camelina (Joelle) under salinity and sodicity. A set of 50 seeds and a subset of 15 seeds were germinated in Petri dishes saturated with of NaCl, CaCl₂, and Na₂SO₄ solutions at concentrations of 0, 40, 80, 120, and 160 mM L⁻¹, in an incubator set to a constant temperature of 20°C. The experimental design was a randomized complete block with three replicates. Germinated seeds were counted daily for 7 days. With the exception of seedling dry weight and hypocotyl length, the winter biotype of camelina produced significantly lower values for measured parameters than the spring biotype. Averaged across varieties and salt concentrations, Na₂SO₄ reduced germination, vigor, and seedling dry weight more than NaCl and CaCl₂. In addition, Na₂SO₄ almost completely inhibited radicle and hypocotyl growth at concentrations > 80 mM L⁻¹. This is of significance, because Na₂SO₄ is commonly present in sodic soils in the northern Great Plains and sodium is known to disrupt soil structure and reduce water infiltration, which can inhibit root growth. Results from future studies using an advanced and genotyped recombinant inbred line (RIL) population from a cross between Joelle and C046 will help to identify loci and candidate genes associated with salinity tolerance, and provide breeders and genetic engineers knowledge for improving salinity tolerance in camelina.