COMBINING ABILITY AND HETEROSIS IN GERBERA (Gerbera × hybrida) VARIETIES

Abstract

Crops that have a considerable number of cultivated varieties such as gerbera (Gerbera × hybrida) can be evaluated by diallel cross experiments for the formation of new hybrids. The aim of this research was to estimate the general combining ability (GCA) of six varieties of gerbera and the specific combining ability (SCA) of their diallel crosses and the heterosis on yield components and flower quality. The Griffing method 1 of parents and their direct and reciprocal F1 crosses was used with model II of random effects. The evaluation was carried out under a randomized complete blocks experimental design with four replications. The statistical analysis detected significant differences (P ≤ 0.01) within and between parents and crosses, as well as in the interactions, which showed wide variability between parents and significant maternal effects due to cytoplasmic inheritance. The greatest effects of GCA (P ≤ 0.01) for yield of floral stems were obtained by the IGL, MG2 and FAS progenitors, while the greatests effects of SCA were shown by crosses FAS × JES, ALC × IGL and DIN × IGL. Positive effects of heterosis for yield were found in the crosses FAS × IGL, JES × IGL, ALC × IGL, DIN × IGL, MG2 × IGL and FAS × MG2. The results suggest that Igloo and Fascination can be used as superior parents in breeding programs for the development of new gerbera varieties. Highly significant GCA values for flower yield indicate the relative importance of additive gene action over non-additive effects.