Morphological and Physico-Chemical Characteristics of Fruits of Pepino (Solanum muricatum), Wild Relatives (S. caripense and S. tabanoense) and Interspecific Hybrids. Implications in Pepino Breeding

摘要

Wild species could be useful for the genetic improvement of pepino (Solanum muricatum Alton) fruit quality. We studied several agronomic and physico-chemical traits in accessions of S. muricatum (EC-37), wild relatives Solanum caripense(EC-40) and Solanum tabanoense (EC-26), and their corresponding interspecific hybrids. Interspecific hybrids involving EC-37 had yield and fruit weight intermediate between the cultivated and the wild parents, while yield and mean fruit weight of EC-37 X EC-26 were greater than those of EC-40xEC-37. Dry matter content (DM) was higher in the wild accessions (>13 %) than in the cultivated pepino (<10 %). Wild species had similar (S. caripense) or lower (S. tabanoense) concentrations of total sugars than S. muricatum, EC-37 and EC-26xEC-37 had similar relative concentrations of the soluble sugars glucose, fructose, and sucrose, while sucrose was predominant (>60 %) in the rest of the tested species and hybrids. Concentration of organic acids was much higher in EC-26 andEC-40 (total acids >=2500 mg 100 g~(-1) and pH<4.0) than in EC-37 (275 mg 100 g~(-1) and pH=5.36), while interspecific hybrids had concentrations more similar to S. muricatum than to wild species. Citric acid was the predominant organic acid in the composition of all the studied accessions (>75 % of total acids). Ascorbic acid content of S. caripense and some interspecific hybrids was more than three times greater than that of S. muricatum. The results indicate that the studied wild species can be utilized to modify and improve the composition of pepino, especially by increasing acidity and ascorbic acid content.