Effect of growth regulators on callus induction and regeneration of Crataegus pseudohetrophylla from leaf segment

Crataegus pseudohetrophylla Pojark. of the genus Crataegus is a member of the Rosaceae family that isimportant in terms of ornamental, food, medicinal, exported, shelter for wildlife and birds, soil conservationand erosion control applications. For callus induction, Leaf pieces (0.5–1.0 cm2) produced by plantlets aftersurface sterilization in MS medium containing 2, 4-D at concentrations of 0.25, 0.5, 1, 2, and 3 mg l-1 and BAPat concentrations of 0, 0.5, and 1 mg l-1, placed in a growth chamber under dark conditions. In the next step,the calli were transferred to culture medium supplemented with growth regulators of BAP, TDZ, NAA, andIBA in different concentrations for regeneration and then characteristics of callus induction (%), callusdiameter (mm), callus type, and callus color were recorded. 100% callusing at concentration of 2 mg l-1 2, 4-D in combination with 0.5 and 1 mg l-1 BAP with the greatest diameter at concentration of 2 mg l-1 2, 4-D incombination with 1 mg l-1 BAP and hard, globular and embryonic in texture with light green to dark green incolor were observed on MS medium. 100% explants forming shoots (regeneration) was obtained using of 12and 14 mg l-1 BAP in combination with 2 mg l-1 NAA and the highest means number of shoots per explantswas observed at concentration of 10 mg l-1 BAP in combination with 2 mg l-1 NAA.