The Response Of Canola Brassica Napus L To A Novel Set Of Plant Growth Regulators

Download or read book The Response of Canola (Brassica Napus L.) to a Novel Set of Plant Growth Regulators written by Timothy Schwinghamer and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "As a member of the Brassicaceae family, canola (Brassica napus [L.]) forms neither arbuscular mycorrhizal (AM) symbiotic relationships nor symbioses with rhizobia, but brassicaceous plants may detect lipo-chitooligosaccharides (LCOs), ubiquitous signal compounds that can mediate the legume-rhizobia symbiosis, and other chitin-based signals through lysin motif (LysM) receptor-like kinases (RLKs). LCOs and compounds produced by other rhizosphere microflora have been shown to promote plant growth. New agricultural genotypes of spring annual type canola cultivars 02C3, 02C6, 04C111, 04C204, Polo, and Topas, that were developed for biodiesel production, having a range of seed oil contents, were assessed for their response to LCO signal molecules produced by Bradyrhizobium japonicum 532C (Nod Bj V [C18:1, MeFuc]) and thuricin 17, which was produced by Bacillus thuringiensis non-Bradyrhizobium endophytic bacterium 17 (NEB17). The objective of this work was to assess the potential of these signal compounds to act as plant growth regulators of B. napus. The effects of treatment concentrations on germination variables were evaluated under cool, standard, and moderately high temperature conditions. The effects on emergence and surface coverage due to LCO and thuricin 17 irrigation treatments were determined using young plants grown in growth cabinet experiments. Rapid cycling B. napus plants are small compared to the commercial types; they can grow to their full height and produce seed after 6 weeks of growth in the controlled environments in growth cabinets (Williams and Hill 1986). The effects of acute treatment with a 10-6 M LCO solution at planting, and subsequent foliar spray treatment, on factors contributing to yield were assessed using rapid cycling B. napus plants in a growth cabinet experiment. The effect of the LCO treatment on branching architecture and yield were investigated, using agricultural B. napus cultivars Topas and 04C111, grown under simulated cool spring and optimal temperature conditions, respectively, in greenhouse experiments. The response of B. napus to these signals was found to depend on the context, that is, the concentration, the temperature, the cultivar, and the salinity of the growth media; in many cases there were useful enhancements, although in some instances there were small or even negative effects, indicating the potential utility of these compounds but also that there is still much to learn. The application of 10-6 M LCO solution to the seed at planting can accelerate emergence. Acute treatments of LCO stimulated 04C111 and Topas plants to develop ramose forms, but triggered the elongation of branches for 04C111 and reduced branch lengths for Topas. A 10-6 M LCO solution applied to the seed at planting, and a foliar spray at the flowering stage of plant development, stimulated higher seed weight from rapid cycling B. napus and Topas, respectively, as compared to untreated controls. This work has shown that 10-6 M LCO can be applied to B. napus to increase factors that contribute to yield: plant emergence, branch number, and the number of siliquae produced on the apical raceme." --