ANBAR JOURNAL OF AGRICULTURAL SCIENCES

Abstract

Several experiments were carried out to propagate Dahlia variabilis throughout tissue culture during period of 2004 to 2005. In tissue culture lab.- Horticulture- College of Agriculture- University of Baghdad. The studies included the effects of type of explants, plant growth regulators, adenine sulphate and seed extraction of Johnson grass.
The results indicated that 100% response was achieved when apical shoots and single nods explants were cultured on free MS medium. The highest number of shoots/explant (4.00) were achieved when shoots were cultured on MS medium supplemented with 2µM of both BA and IAA. Adding of 60 mg/l adenine sulphate to the medium increased shoots number to 6.80 with 7.27 cm length. The addition of 300 ml/l of alcoholic extract from immature seeds of Johnson grass increased shoot number ( 2.50 shoots/explants), while modifying the medium with 200 ml/l of water extract of mature seeds of Johnson grass was superior on shoots length (7.76 cm).
The highest root number/explant (5.00) and length (5.00 cm) were achieved when MS medium supplemented with 3 µM IBA. Shoots cultured on half MS salt strength supplemented with 45 g/l sucrose and 3 µM of IBA gave the highest number and length of roots (8.00 roots/explants, 10.40 cm). A 100% success of acclimatized of plantlets was achieved when they were planted in 1:1 peatmoss and loam under controlled humidity.