MAIZE INBRED LINES PERFORMANCE FOR THREE MAIN DISEASES IN SOUTH CÓRDOBA, ARGENTINA

RUIZ M.; ROSSI E.A.; VISENTIN D.; BIANCONI G.; FISCHER S.E.; BONAMICO N.C.

Congreso; XXXVI Reunión Científica Anual Sociedad de Biología de Cuyo; 2018

Germplasm collections are a valuable resource in genetic plant breeding. The CIMMYT (International Maize and Wheat Improvement Center) Maize Lines (CMLs) have been developed over the last 25 years. The CMLs represent one of the most widely distributed sources of publically generated elite lines, which are freely available to both public and private sector breeders, research and growers, worldwide. The objective of this study was to describe the performance of a 200 maize inbred lines collection developed and provided by the CIMMYT against the three main diseases that occur in south Córdoba, Argentina. The collection was evaluated by a partially replicated experiment with a 12% of test lines in three replications. The experiments were located at Río Cuarto and Sampacho during the summer cycle of 2017/2018. In each location, for each genotype, the common smut incidence (INCCS), common rust severity (SEVCR), Mal de Río Cuarto Virus incidence (INCMRC), severity (SEVMRC) and disease severity index (DSIMRC) were estimated. A multivariate approach, principal component analysis (PCA), was used to describe the relationship among genotypes, traits and genotypes-traits. A cluster analysis, to group genotypes, was also used. The first two principal components of the biplot graph explained 80% of the variation. Positive correlations were observed between INCCS and SEVCR, and among INCMRC SEVMRC and DSIMRC. There is not correlation between these two groups. The 35% of the genotypes did not present disease. The cluster analysis indicated eight groups. Such as shown by the PCA, one of the groups included the 35% of the genotypes that did not present disease. These results allow us to identify promising genotypes to obtain maize hybrids with good behavior against common smut, common rust and Mal de Río Cuarto Virus.