Dorema ammoniacum D. Don. (Apiaceae), a native medicinal plant in Iran, is classified as a vulnerable species. Root, hypocotyl, and cotyledon segments were cultured on Murashige and Skoog (MS) (1962) medium supplemented with either 2,4-dichlorophenyoxyacetic acid (2,4-D) or naphathalene acetic acid (NAA), at 0-2 mg l -1 , alone or in combination with either benzyladenine (BA) or kinetin (KN), at 0-2 mg l -1 for callus induction. The best response (100%) was observed from root segments on MS medium containing 1 mg l -1 NAA and 2 mg l -1 BA. The calli derived from various explants were subcultured on MS medium supplemented with BA (1-4 mg l -1 ) alone or in combination with NAA or indole-3-butyric acid (IBA), at 0.2 or 0.5 mg l -1 for shoot induction. Calli derived from hypocotyl segments showed significantly higher frequency of plantlet regeneration and number of plantlets than the calli derived from root and cotyledon segments. Therefore, MS medium supplemented with 2 mg l -1 BA and 0.2 mg l -1 IBA produced the highest frequency of shoot regeneration (87.3%) in hypocotyl-derived callus. The optimal medium for rooting contained 2.5 mg l -1 IBA on which 87.03% of the regenerated shoots developed roots with an average number of 5.2 roots per shoots within 30 days. These plantlets were hardened and transferred to the soil. The described method can be successfully employed for the large-scale multiplication and conservation of germplasm this plant.

The present study concentrated on introducing a micropropagation protocol for a drought resistant genotype from , which is the second most naturally widespread pear species in Iran with proper physiological and medicinal properties. Proliferating microshoot cultures were obtained by placing nodal segments on MS medium supplemented with BAP and IBA or NAA. The highest number of shoots (27 shoots per explant) were obtained with 1.5 mg l BAP and 0.05 mg l IBA, but this combination did not produce shoots of desirable length (>1.7 cm). Combination of 1.75 mg l BAP and 0.07 mg l IBA was the best for the shoot multiplication in with a sufficient number of shoot production (22.33 shoots per explant) and relatively more appropriate shoot length. The larger and greenish leaves were obtained when PG was added to the best multiplication treatment. Microshoot elongation was carried out in 1/2 and 1/4 MS medium containing 50-100 mg l PG with different concentrations of IBA or NAA at intervals of 30-60 days. Significant increase in shoot length was detected after 45-60 days of culture in the presence of PG. The highest shoot length (8 cm) was recorded on 1/2 MS medium supplemented with 0.5 mg l IBA and 100 mg l PG. GA negatively affected number and length of shoots and generally caused generation of red leaves. The highest percentage of root induction (100%) and root length (9 cm) were obtained on 1/6 strength MS medium supplemented with 0.005 mg l IBA. All plantlets were hardened when transferred to ex vitro conditions through a period of 25-30 days. The results suggest axillary shoot proliferation of could successfully be employed for propagation of candidate drought resistant seedling.

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