BIOLOGICAL CONTROL FOR THE MANAGEMENT OF SUDDEN DEATH SYNDROME OF SOYBEAN

GONZALEZ, C; MEINI, MR; LUQUE, AG; SCANDIANI, MM; SPAMPINATO, CP; LARIO, LD

Parana, Entre Ríos

Congreso; 54th Annual Meeting Agentine Society for Biochemistry and Molecular Biology LIV Reunion Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2018

Sudden death syndrome (SDS) is one of the most yield-limiting diseases of soybean. The disease is caused by at least four distinct Fusarium species, with Fusarium tucumaniae being the main causal agent in Argentina. Currently, there is no effective treatment for SDS. Therefore, the use of biological control agents could be an effective strategy for disease management. Three bacteria previously isolated from the soybean rhizosphere, Pseudomonas fluorescens BNM 297 and BNM 296 and Bacillus amyloliquefaciens BNM 340, were examined for their in vitro antagonism tests against F. tucumaniae and for their capability to increase plant growth. Results indicated that BNM 297 inhibited mycelial growth of the pathogen by 40% and the other two strains by 35%. Plant growth promotion was evaluated by germination efficiency and vigor of healthy soybean seeds inoculated with the bacteria. These studies revealed that BNM 297 and BNM 296 showed a modest inhibitory activity (< 30% inhibition) while BNM 340 did not affect germination and vigor compared to control plants. These results suggest that B. amyloliquefaciens BNM 340 could be a potential biocontrol agent against F. tucumaniae, although this hypothesis has to be tested in vivo. Thus, phenotypic parameters such as plant weight, leaf pigment contents and root isoflavone accumulation will be scored. We have observed that plant weight and photosynthetic pigment contents were reduced by 25% and 30%, respectively, while isoflavones accumulated in soybean seedlings infected with F. tucumaniae by 10 days post-inoculation compared to the uninoculated cultivar.