Abstract
A comparative study was performed to elucidate root development and growth of Eucalyptus camaldulensis shoots/plantlets cultured photoautotrophically in vitro for 6 weeks in four different types of supporting materials (agar matrix, Gelrite matrix, plastic net or vermiculite) under CO2 enriched or CO2 non-enriched conditions. CO2 enrichment significantly promoted the growth (dry weight of shoots and roots, length of primary roots and rooting percentage) and net photosynthetic rate of the shoots/plantlets regardless of the type of supporting materials. Growth was greatest in the vermiculite, followed by the plastic net, Gelrite matrix and agar matrix (in descending order) under either the CO2 non-enriched or CO2 enriched conditions. The correlative coefficient between water potential of leaves and number of primary roots at 2 weeks after the beginning of culture was high. Length of primary roots and rooting percentage increased with an increase in the net photosynthetic rate in vitro.
