Heterosis and combining ability in bell pepper lines with resistance to multiple pathogens

Abstract

The aim of this study was to develop bell pepper hybrids with resistance to multiple pathogens and make
inferences in regard to components of heterosis in hybrids obtained from lines presumed to be resistant to Pepper yellow
mosaic virus (PepYMV), Phytophthora capsici, or Meloidogyne incognita. The studies were carried out in a greenhouse. We
used ten lines, thirty experimental hybrids, and seven controls (Konan-R, Magali-R, Martha-R, Stephany, Mallorca, Magnata
Super, and Criollo de Morelos-334). For all experiments, a randomized block design was used with three replications (with
plots composed of 16 plants). For evaluation of the reactions to P. capsici and to PepYMV, the percentages of asymptomatic
plants were considered. For evaluation of the reactions to M. incognita, the reproduction index and the reproduction factor
of the nematode were calculated. The additive gene effects were important for all the traits evaluated, and for percentage of
plants resistant to PepYMV and P. capsici, the non-additive effects were also important. The alleles that control resistance to
PepYMV, to P. capsici, and to M. incognita have a degree of dominance near 1, in absolute value, which indicates a favorable
situation for obtaining hybrids that accumulate multiple resistance to these pathogens.