كليدواژه :
ژنتيك گياهي , جنگل ها , كشاورزي , منابع طبيعي , دخت كنار , ازدياد غيرجنسي , بيوتكنولوژي , ريزازديادي
چكيده لاتين :
The Christʹs thron (Ziziphus spina-christi) belong to the family Rhamanaceae is an evergreen tree natural grown and distributed in tropical regions. Drought and salinity tolerance, having tannin and saponin materials in the leaves and organs, adaptable in warm areas, having desirable and edible fruits are well known characteristics of this species, so that it is propagated annually for afforestation and reforestation plans and also using as a multipurpose tree in southern part of Iran. At the present time, this species is only regenerated from seed which often results highly variable progeny. According to high percentage of cross-pollination in this tree, many segregation is occurred, and maintenance of improved traits is impossible in next regenerations. Therefore, it is worth to seek for asexual propagation. This research demonstrates that complete plantlets of Z. spina-christi could be cloned and micropropagated from single axillary bud using tissue culture techniques. Shoot segments (fourth to eighth axillary buds under apical bud) from mature trees were excised and used as explants during February-March, July-August and October-November. Several experiments carried out to determine the best disinfectant chemicals, media type, shoot multiplication and auxin-cytokinin ratios for root induction. The most proper treatment of sterilization, was the use of 70% ethanol (30 sec), and %7.5 Ca(OCL)2 (20 min) and frequent cleaning with sterile distilled water. There were no significant differences between hormonal and hormone-free media as well as media type. The best root formation treatment was achieved in liquid White medium supplemented with 25 mgH IBA and subsequently cultured in semi-solid hormone free White medium containing I gM active charcoal. Young rooted plantlets transferred to jiffy pot and kept in plant propagator to pass autotrophic stage.
