Mapeo por asociación de loci de resistencia a la enfermedad Mal de Río Cuarto en maíz

ROSSI, E.A.; RUIZ, M.; BALZARINI, M.G.; BONAMICO, N.C.

Congreso; XI Congreso Nacional de Maíz; 2018

Mal de Rio Cuarto (MRC) is the most important viral disease of maize (Zea mays L.) in Argentina. The development of resistant genotypes is the most economical, environmentally sustainable and effective means for controlling this disease. The objective of this work was to detect genomic regions associated with resistance to MRC disease in maize lines. Disease severity index (DSI) measured across three environments and 45,925 SNPs in a population of 291 genotypes were used to identify genomic regions associated with disease resistance. An augmented partially repeated design was used in each trial to estimate DSI per genotype. Mixed models were used to estimate the best linear unbiased prediction (BLUP) of maize lines. Association mapping in each environment was used to detect Quantitative Trait Loci (QTL). The results show 32 significant resistances QTL to MRC disease in all environments. The phenotypic variation explained by these QTL ranged between 11% and 20% with a mean of 16%. Half of QTL identified are located in chromosomes 1, 2 and 8. The genomic regions associated with resistance to MRC disease should be validate and could be of use to improve these traits in maize breeding programs.