Variation for bioactive compounds in aji (Capsicum baccatum L.) and rocoto (C-pubescens R. & P.) and implications for breeding

Aji (Capsicum baccatum L.) and rocoto (C. pubescens R. & P.) are two Capsicum pepper species native to the Andean region that have not been subjected to intensive breeding. However, the increase in its demand in European markets has sparked the development of breeding programmes for adaptation to Mediterranean climates, which include breeding for higher levels of bioactive compounds. We have studied the composition of red and yellow carotenoids (C-R and C-Y, respectively), ascorbic acid (AA), and total phenolics (TP) in 34 accessions of Capsicum, including 23 of C. baccatum, eight of C. pubescens, and 3 controls of C. annuum, which were grown in Spain both under greenhouse (GH) and open field (OF) conditions. The results show that in both growing conditions C. baccatum presents a considerable variation for most of the traits studied, with several accessions having similar or higher levels than C. annuum for the compounds studied. This indicates that C. baccatum is an important source of antioxidant compounds with nutritional value. On the contrary, C. pubescens had a poor performance, with low levels for all the compounds studied, and a poor adaptation to the conditions of Mediterranean climates. When considering the GH or OF growing cycles separately, heritability values were high (>0.75) for C-R, C-Y and AA, and moderate (0.42 for GH and 0.62 for OF) for TP. The existence of an important genotype 9 environment interaction resulted in lower levels for heritability when considering both growing cycles together, although the values were still high for C-R and AA (>0.6). Positive significant genotypic correlations among all the traits studied were found, except for TP with C-R and AA in the OF cycle. This information indicates that there are good prospects for developing C. baccatum varieties with higher levels of bioactive compounds.