The Plant Growth Regulator Lipo-chitooligosaccharide (LCO) Enhances the Germination of Canola (Brassica napus [L.])

In agricultural environments where canola (Brassica napus) is grown, slow germination can increase the susceptibility of seedlings to pathogens, delay maturity, and decrease yield. Bacterial products that enhance germination have been identified for a variety of plants. Three signal molecules were investigated: Bradyrhizobium japonicum 532C product lipo-chitooligosaccharide (LCO), Bacillus thuringiensis NEB17 product thuricin 17, and chitopentaose, which is the undecorated chitin backbone of LCO. Gompertz functions were estimated and used for inferences regarding the signal, cultivar-by-temperature, and signal-by-temperature effects on 6 cultivars (02C3, 02C6, 04C111, 04C204, Polo, and Topas). LCO (10(-6) M) was found to increase Polo germination by 75.0 %, during the 5-15 growing degree day period. Such early B. napus germination can, under field conditions, increase canopy coverage and yield. Further experimentation with the other experimental cultivars discerned an improvement in the germination of Topas, following treatment with LCO, under ideal (24 h 25 A degrees C) and abiotic stress (24 h 10 A degrees C) growing conditions, as compared to Polo and 04C204. The response to LCO was discernable for Polo under AOSA (J Seed Technol 16:112, 1993) standard temperature conditions and for Topas when considered across temperature conditions in comparison to Polo and 04C204.