POPULATION MEANS AND CORRELATION ANALYSES OF GROWTH-PARAMETERS IN LISIANTHUS (EUSTOMA-GRANDIFLORUM SHINN)

The variation in growth characteristics among lisianthus (Eustoma gran diflorum Shinn.) genotypes was investigated. The genetic control of se veral growth parameters was studied by analysing parental, F1, BC1 and F2 populations. The parameters analysed were stem elongation rate (SE ), stem diameter (SD), leaf width (LW), number of nodes (NN), node len gth (NL) and days to flowering (DF). The genotypes tested exhibited gr eat variation for all parameters. A particularly wide variation was no ted for SE, ranging from 3 to 56 mm/week. This variation was partially attributed to a differential sensitivity to rosette formation. There was a marked positive heterosis for SE, SD, LW and NN; these parameter s proved to be genetically correlated within segregating populations. DF was slightly negatively correlated with SE, NN and NL. It was concl uded that SE and DF were independently controlled.