Herana da resistncia mancha-foliar de feosfria em milho

Abstract – Phaeosphaeria leaf spot (PLS) has caused an expressive reduction in the corn grain yield inBrazil. The increment in sowing date amplitude, conjugated with the use of irrigated areas and zerotillage, had major contribution in the increase of phaeosphaeria leaf spot (PLS) incidence and severity.For this reason, it is important to develop resistant genotypes to this disease; however, an efficientselection depends upon the understanding of the genetic variability and inheritance of the resistance.Aiming to determine combining ability and the mode of inheritance for PLS, seven corn inbreds werecrossed for diallel and generation mean analysis. The experiments were conducted in Xanxere, SC.Percentage of foliar area affected by the disease was evaluated 30 days after flowering. The genotypespresented amplitude of 4.3% to 67.0% of foliar area affected by PLS. The LA06 and its hybrids showedhigh level of resistance. Results indicated that selection for PLS resistant genotypes could be success-fully accomplished in corn breeding programs. At least two major independent genes were identifiedwith a preponderant participation of addictive effects in the inheritance of the trait.Index terms: