Strategies for breeding a new greenhouse crop, the pepino (Solanum muricatum Aiton)

The introduction of pepino (Solanum muricatum Aiton) as a new greenhouse cr op relies on the development of clones that produce high fruit yields with an increased soluble solids concentration (SSC). We have evaluated two bree ding strategies aimed at obtaining new, improved clones of this heteroygous vegetatively propagated crop: selection in the segregating generation F-1 (hybrids) or in the first generation of selfing (selfings). We recorded the total yield, SSC, fruit weight, shape, firmness, titratable acidity and as corbic acid concentration in seven populations of hybrids and in five popul ations of selfings. Four populations of clonal replicates were used to esti mate environmental variability. Total yield and its heritability were highe r in the hybrids than in the selfings. Expected responses to selection show ed that it might be possible to select clones with a yield higher than 80 t ha(-1) with selection pressures lower than 5% in some hybrid populations. Heritabilities for SSC were moderate, but clones with a SSC higher than 9.0 female Brix could be selected. We also found an important variation in the other characters studied, indicating that improved clones could be selecte d for all of them. Values for genotypic correlations between characters wer e very variable. In most hybrid populations, however, we did not find negat ive genotypic correlations between yield and fruit quality characters. Our results indicate that new hybrid clones of pepino that exceed present clone s in yield and, fruit quality might be obtained.