Protection against target spot by the bioproduct PSP1 in genetically distant soybean cultivars.

TOULET MARÍA LAURA; PARDO ESTEBAN MARIANO; GARCÍA MARÍA GABRIELA; DI PETO PÍA; MICHAVILA MARÍA GABRIELA; PADILLA AGUSTÍN; PLOPER LEONARDO DANIEL; WELIN BJÖRN; CHALFOUN NADIA R.

Corrientes

Congreso; V Argentino de Fitopatología , 59th Meeting of the APS Caribbean Division; 2021

Asociación Argentina de Fitopatólogos

Target spot (TS) caused by Corynespora cassiicola is an increasingly important disease of soybean crop in the Northwest region of Argentina, causing significant yield losses since 2015. The plant defense-elicitor biostimulant PSP1 (HowlerR), developed by ITANOA work group, efficiently controls multiple fungal diseases of soybean in the Pampean region. The aim of this work was to evaluate the effect of Howler to control TS in different soybean cultivars. For this purpose, thirty cultivars from the EEAOC germplasm bank were selected, including different maturity groups and technologies (conventional, RR1 and RR2Bt) and the genetic distance between them was evaluated using microsatellite molecular markers. Subsequently, the 9 most distant cultivars were selected, which were representative of the groups generated in the dendrogram, and Howler's protection against TS was evaluated using induced resistance assays. A foliar application of Howler 3 days before inoculation with a virulent isolate of C. cassiicola, showed a significant reduction in the area under disease progress curve values as compared to pathogen-infected control plants in 8 out of the 9 genotypes tested, with a minimum degree of protection of 39% in cv. Shulka and a maximum of 91% in the cv. NS8288. Due to the lack of TS resistant cultivars, the use of Howler would be a valid sustainable biological strategy for the control of TS, based on the induction of plant defense.