Heterosis and combining ability for ornamental chili pepper

Resumo

Ornamental use of Capsicum genus chili peppers has expanded due to easy seed propagation, short germination period, diversified fruit colors and harmony of potted plants. The ornamental plant sector requires cultivars adapted to different cultivation conditions in pots and gardens.  Breeding programs can use heterosis and combining ability information, aiming to commercially explore hybrids or develop populations for lineage selection with desirable characteristics. However, the ornamental chili pepper field lacks studies with this data. In this study, combining ability of Capsicum annuum accessions was determined for ornamental purposes and hybrid combinations were identified based on heterosis values. Fifteen hybrids were obtained through diallelic crossing among six accessions of Capsicum spp., and cultivated in greenhouse using a completely randomized experimental design with ten replications. Morpho-agronomic characterization was conducted based on eight quantitative descriptors: plant height (before and after fruiting); canopy diameter; days to flourishing; days to fruiting; fruit length and diameter, and number of fruits per plant. Both additive and dominance effects play important role in controlling the studied characters, indicating hybrid exploitation as well as development of superior lineages from the progress of segregating generations. Negative heterosis values resulted in reduction in height, time for flourishing and fruiting, as well as fruit diameter and length, which are desirable for ornamental Capsicum breeding program. Considering an ideotype for ornamental chili pepper cultivars, the hybrids UENF 1626 x 1750, UENF 1750 x 2030 and UENF 1626 x 2030 can be recommended for cultivation with ornamental purposes.