Hawthorn ( Crataegus sp. ) is a large genus of shrubs and trees in Rosaceae , which is used as iron chlorosis and drought tolerant rootstocks, planting in urban green space and production of medicinal herbs. The challenges seedling manufacturers facing is double dormancy and decrease in germination, which it takes 2-3 years time to produce Hawthorn seedling. Tissue culture and micropropagation techniques could be used for fast proliferation of this plant. This study was conducted as a completely randomized factorial design. We used mature embryo of seeds as explants in sterile conditions under laminar airflow cabinet that was separated from the endosperm. The first in vitro experiment was the effect of different concentrations of 2,4-D (0,2 and 4 mgl -1 ) and NAA (0,1 and 2 mgl -1 ) hormones on callus production in two specie C. atrosanguinea and C. meyeri with 3 replications. The second in vitro experiment was the effect of different concentrations of Kin (0, 1 and 2 mgl -1 ) and BAP (0, 2 mgl -1 ) hormones on plant regeneration of mature embryo with 3 replications. Callus size and callus fresh weight were measured. Result of the first expeviment showed that treated explant with 4 mgl -1 2,4-D + 1 mgl -1 NAA increase fresh weight and callus size in both species. Unfortunately, it was not possible to do experimental analysis in the second exeperiment due to high contamination. However we found that charcoal active decrease the amount of contamination and cold treatment did not have any effect on embryo regeneration. Keywords : hawthorn, mature embryo, micropropagation, regeneration, callus
