The response of canola cultivars to lipo-chitooligosaccharide (Nod Bj V [C18:1, MeFuc]) and thuricin 17

Lipo-chitooligosaccharides (LCOs) are signal molecules that play a role in initiating the symbiotic legume-rhizobia and arbuscular mycorrhizal processes. Thuricin 17 is a bacteriocin produced by Bacillus thuringiensis strain NEB 17. Previous work has shown that the application of a 10 −6 M LCO solution, or a 10 −11 M thuricin 17 solution, can stimulate the germination and growth of a wide range of plants. The objectives were: to grow canola cultivar 04C111 under optimal temperature conditions in a greenhouse, and to assess the effect of LCO seed application and spray treatment on 04C111 floral initiation, architecture, and factors that contribute to yield; to assess the effect of a thuricin 17 seed application treatment upon factors that contribute to 04C111 yield in a stressfully high temperature greenhouse system; and to assess the effect of an LCO seed application and spray treatment on Topas floral initiation, architecture, and factors that contribute to yield, and seed quality, in a simulated “cool spring” greenhouse system. According to the 95 % confidence limits, Brassica napus cultivars grown from untreated seed produced 39 % fewer to 1 % fewer branches than plants grown from LCO-treated seed. Application of an LCO foliar spray increased the total of branch lengths per 04C111 plant by 16.93 ± 8.41 cm. Based on the stem-to-branch length ratio, LCO-sprayed 04C111 plants were 68 % less apically dominant than unsprayed plants. Topas plants that were sprayed with LCO produced seed with approximately 4.45 ± 0.23 % more oil (% d.w.) than unsprayed plants. For both cultivars, seed treatment with 10 −6 M of LCO produced plants with a higher average sum of primary, secondary, and tertiary branch (≥1 cm) frequencies.