The effects of leaf size and varied calcium nitrate levels on gloxinia leaf-disk explants

Uniform disks cut from three leaf sizes of florist's gloxinia (Sinningia speciosa 'Cherry Bell') were placed on Knop's media containing five concentrations of calcium nitrate. After 10 weeks of growth on the culture medium, dry weights of the disks were recorded. Quality of shoot and root growth were scored subjectively and percentage of disks containing shoots was recorded.

Highly significant differences among calcium nitrate levels and among leaf sizes were shown for disk weight and disk quality. No significant differences among calcium nitrate levels and among leaf sizes were shown for percentage of disks with shoots. Small leaf disks with 250.0 or 500.0 mg/liter calcium nitrate greatly enhanced disk dry weight and disk quality. Highly significant differences among calcium nitrate level/leaf size combinations were shown for disk weight. No significant differences among calcium nitrate level/leaf size combinations were shown for disk quality or percentage of disks with shoots. Therefore, leaf size and nitrate level may influence rapid callus growth but not subsequent shoot development.