Análise dialélica e heterose em pimentas do tipo páprica

Abstract

The objective of this work was to quantify heterosis in non pungent paprika-type pepper hybrids, as well as heterosis components for yield, percent seed weight (on a dry fruit basis), amounts of carotenoid pigments (measured in degrees ASTA), and resistance to the pathogen Phytophthora capsici. Fifteen hybrids were obtained through diallel crosses among six proprietary paprika breeding lines from HortiAgro Sementes S.A., four of which originally introduced from Peru (P1=PIM 032-03; P2=PIM 033-11; P3=PIM 034-19; P4=PIM 035-01) and two from the U.S.A. (P5=PIM 036-08; P6=PIM 037-18). Heterosis was detected for fresh and dry fruit yields, and degrees ASTA. Epistatic gene action is involved in the expression of heterosis of these traits. No significant heterosis was detected for P. capsici resistance, and the predominant type of gene action was incomplete dominance. Parental lines P1 and P5 showed high values for general combining ability (GCA), and were considered suitable for breeding programmes aimed at obtaining new improved lines, or for use as parents in new high-yielding hybrid combinations. Hybrids P3xP5, P1xP4 and P5xP6 stood out among the hybrids tested, and were considered suitable as commercial paprika hybrids. P3xP5 was considered the most suitable of the hybrids, outperforming the standard open pollinated check cultivar Papri Queen in both fresh and dry fruit yields and in degrees ASTA, in addition to being resistant to P. capsici. The line P5 was resistant do P. capsici, as were all the hybrids in which it was included as one of parents.