Testing the Efficacy of Methylobacterium oryzae Bacterial Inoculation to Improve the Quality of Hydroponic, Salt-Stressed Tomatoes
Disciplines
Agriculture | Food Science | Life Sciences | Microbiology | Physiology
Abstract (300 words maximum)
Increasing market demand for hydroponic produce requires methods to improve either fruit quality or yield without significantly compromising the other. High nutrient or salt concentrations in hydroponic solutions generally improves tomato fruit quality, but at the tradeoff of reduced yields due to salinity stress experienced by the plants. We are testing whether foliar application of Methylobacterium oryzae, a leaf-borne symbiotic bacteria that manipulates plant hormonal ethylene levels, can be used with hydroponic tomatoes to offset this quality-quantity tradeoff. We measured chlorophyll fluorescence, leaf gas exchange parameters, and leaf methylotrophic bacteria from fruiting tomato plants exposed to various levels of M. oryzae inoculation and salinity stress. After two months, tomato fruits were harvested, weighed, and assessed for the presence of Blossom-end-rot (BER) disease. Salinity stress reduced leaf stomatal conductance, fruit weight, and increased the frequency of BER, but M. oryzae inoculation significantly reduced the incidence of BER in salt-stressed tomatoes. Inoculated, salt-stressed tomatoes likewise produced significantly more fruits than their uninoculated, salt-stress counterparts. Future studies considering the inoculation delivery method, the timing of stress initiation, and the intensity of salt stress are required to sufficiently assess the full utility of M. oryzae as a promoter of crop salt tolerance.
Academic department under which the project should be listed
Ecology, Evolution, and Organismal Biology
Primary Investigator (PI) Name
Mario Bretfeld
Additional Faculty
Christopher Cornelison, Molecular and Cellular Biology, ccornel5@kennesaw.edu
Daniel Ferreira, Ecology, Evolution, and Organismal Biology, dferrei2@kennesaw.edu
Testing the Efficacy of Methylobacterium oryzae Bacterial Inoculation to Improve the Quality of Hydroponic, Salt-Stressed Tomatoes
Increasing market demand for hydroponic produce requires methods to improve either fruit quality or yield without significantly compromising the other. High nutrient or salt concentrations in hydroponic solutions generally improves tomato fruit quality, but at the tradeoff of reduced yields due to salinity stress experienced by the plants. We are testing whether foliar application of Methylobacterium oryzae, a leaf-borne symbiotic bacteria that manipulates plant hormonal ethylene levels, can be used with hydroponic tomatoes to offset this quality-quantity tradeoff. We measured chlorophyll fluorescence, leaf gas exchange parameters, and leaf methylotrophic bacteria from fruiting tomato plants exposed to various levels of M. oryzae inoculation and salinity stress. After two months, tomato fruits were harvested, weighed, and assessed for the presence of Blossom-end-rot (BER) disease. Salinity stress reduced leaf stomatal conductance, fruit weight, and increased the frequency of BER, but M. oryzae inoculation significantly reduced the incidence of BER in salt-stressed tomatoes. Inoculated, salt-stressed tomatoes likewise produced significantly more fruits than their uninoculated, salt-stress counterparts. Future studies considering the inoculation delivery method, the timing of stress initiation, and the intensity of salt stress are required to sufficiently assess the full utility of M. oryzae as a promoter of crop salt tolerance.