QUANTITATIVE GENETIC-ANALYSIS OF FLOWERING TIME IN THE DAVIS-POPULATION OF GERBERA .2. CORRELATIONS WITH YIELD, FLOWER QUALITY TRAITS AND THE EFFICIENCY OF INDIRECT SELECTION

Phenotypic and genetic correlations of flowering time (FT) with cut-fl ower yield (Y) were estimated from six generations of the Davis Popula tion of gerbera (Gerbera hybrida, Compositae). The phenotypic correlat ion was -0.34; the genetic correlation was -0.47 when estimated from A NOVA of a NCII design and -0.72 when estimated from parent-offspring a nalysis. An indirect selection model was constructed to assess the eff iciency of indirect selection for Y using FT as a marker. This model i ncludes population size and generation time as variables because they differ for FT and Y. The results indicate that indirect selection will be more efficient than direct selection. Correlations of FT with flow er quality traits, including scape length (SL), flower diameter (FD), scape dry weight (SDW) and newer dry weight (FDW), were also estimated . FT was phenotypically independent of these traits. However, statisti cally significant estimates of genetic correlation indicate that FT ma y be correlated with flower quality traits. Thus, indirect selection o n FT to increase Y may result in undesirable correlated responses for flower quality.