Medium components for shoot cultures of chlorophyll-deficient mutants of petunia inflata.

Selected medium components were tested for 30 day growth promotion of shoot tips of Petunia inflata wild type, a cytoplasmic and a nuclear inherited chlorophyll-deficient mutant. Experiments were conducted independently with iron, sucrose, thiamine-HCl, indole-3-acetic acid (IAA), Kinetin (K), 6-benzylaminopurine (BA), coconut milk (CM), casein hydrolysate (CH), and plant extract (PE) an aqueous leaf extract, added to modified Murashige and Skoog (MS) salts and vitamins medium, and pH between 4.0 and 7.0 was also compared. The optimum concentrations of all test components were used to formulate revised MS media especially designed for in vitro shoot growth of chlorophyll-deficient petunia mutants. The optimum medium for the nuclear albino was: MS salts+1.5 mg/l thiamine-HCl+100 mg/l myo-inositol+3.5% sucrose+1% PE+5.0 mg/l IAA+0.3 mg/l K at pH 6.0; for the wild type: MS salts+0.6 mg/l thiamine-HCl+100 mg/l myo-inositol+4% sucrose+1.0 mg/l IAA+0.3 mg/l K at pH 5.0 and for the cytoplasmic albino: MS salts+0.4 mg/l thiamine-HCl+100 mg/l myo-inositol+4% sucrose+20% CM+3% PE+1.0 mg/l K at pH 5.0. On the revised MS media a 3-, 4- and 5- fold increase in 30 day plant fresh weight occurred for the nuclear, wild type and cytoplasmic chlorophyll-deficient plants, respectively.