Multi-resistant RILs Population assessed for Peanut Blight caused by Sclerotinia minor

ROSSO, MELINA; BUTELER, MARIO I.; SEIJO, J. GUILLERMO; BRESSANO, MARINA; SOAVE, SARA; DE BLAS, FRANCISCO; SOAVE, JUAN H.; ODDINO, CLAUDIO

Sally

Congreso; Avance in Arachis through Genomics and Biotechnology; 2018

International Peanut Genome Initiative

Peanut blight caused by Sclerotinia minor became a concern of farmers in Argentina for its high impact on yield losses. The current strategies to control soilborne diseases by decreasing the amount of inoculum adopting long term rotations and no-till practices have been insufficient. Thus, the development of resistant peanut varieties arose as a need for peanut producers in Argentina. Several accessions of wild Arachis species showed no symptoms of peanut blight during three seasons (2003-2005) of field trials at ?Criadero El Carmen? in General Cabrera, Córdoba, Argentina, and were considered resistant to peanut blight. A fertile amphidiploid derived from a multiple cross ((A. cardenasii x A. correntina) x A. batizocoi)4x was also considered resistant after a multiple year field assay. On these bases, a RIL population developed from the cross of this amphidiploid with an elite high-oleic line (initially developed to test resistance to the peanut smut) was evaluated for resistance to peanut blight. A total of 93 recombinant inbred lines (RILs) and their parents were field inoculated with an inoculum suspension generated in the laboratory. This experimental approach was used to provide an intense inoculum pressure, which ensured high infectivity and pathogenicity. After the first season (2017) of peanut blight field trials, statistically significant differences (P=0.05) of disease incidence and severity were detected among RILs and their progenitors. The results suggest that these RIL population has promissory materials to be used in following pre-breeding programs focused on obtaining multi-disease peanut resistant lines.