Cost Effective Culture Medium for Micropropagation of Paulownia (Paulownia tomentosa Steud.) and Catalpa (Catalpa bignonioides Walt.)

Abstract

An attempt was done to achieve a cost effective culture medium for paulownia and catalpa micropropagation. Different types of culture media including MS, WPM and GD were tested with the addition of BA and NAA at various concentration in the successive micropropagation stages. The results showed that 100% aseptic cultures were obtained through disinfesting the seeds of both plants in 2.5% sodium hypochlorite for 10 minutes. In vitro seed germination rates of paulownia and catalpa reached to 98% and 95% respectively. Paulownia alternative node explants grown on MS medium enriched with 2.0 mg.l -1 BA gave the highest number of shoots per explant (2.46 shoots/ explant). Whereas, the least number of shoots (1.37 shoots/ explant) were recorded for explants grown on GD medium with 00.0 mg.l -1 BA. The longest shoots were found for explants grown on WPM medium enriched with 2.0 mg.l -1 BA (1.39 cm). The addition of BA was increased the number of shoots per explants and the mean length of shoots of catalpa by giving 1.86 shoots/ explant and 1.29 cm respectively. The highest number of shoots per explant 1.92 shoots/ explant was recorded for the explants grown on MS medium with 2.0 mg/l -1 BA. The addition of 1.0 mg.l -1 NAA raised the number of roots per explant by producing 6.84 roots/ explant and the highest rooting percentage (100%) on paulownia micro-shoots grown on WPM. The highest rooting percentage (100%) and longest roots (4.88 cm) were found on micro-shoots grown on NAA-free WPM. The addition of 1.0 mg.l -1 NAA to WPM was significantly effective in raising the number of roots per explant to reach 14.26 roots/ explant and the rooting percentage to 98% for catalpa micro-shoots. NAAfree WPM produced the longest roots (4.40 cm) with the 98% of يناثلا دللمجا ةيعارزلا مولعلل ةيبرعلا ةللمجا – ( ددعلا 4 ربوتكأ ) 9102 33 3 rooting. A 100% successful acclimatization process was achieved for both tree plantlets.