عنوان مقاله [English]
Production of common yew (Taxus baccata L.) seedling by in vitro culture and embryo rescue
Background and objectives: Taxus baccata L. is one of the rare native coniferous species of Iran which it has distribution from Astara to Ali Abad. This species is very important wise protection of genetic resources, medicinal usages (cure of lung, bladder, breast, uterus cancers and HIV disease) and etc that at present, it is exposed to overthrow for long seed dormancy, slow growth, illegal utilization and other disturbance factors. Therefore production of yew seedling by embryo culture on in vitro condition was carried out in order to conservation of present sites and their extension.
Materials and methods: Seeds divided into two groups; Mature and immature and then they stratified in sand layers and low temperature for 9 months, after collection of natural site in Afra Takhteh region. Then, seeds were soaked in running water for 48 hours and they disinfected. In order to seed sterilization 7 treatments were considered. In this study the embryo of sterilized seeds split from endosperm and was cultured in Murashige and Skoog medium (MS) that it was enriched with ascorbic acid (50. 100 mg/l), casein hydrolysate (50, 100 mg/l), yeast extraction (0.5, 1 g/l) and activated charcoal (2%). The grown embryos were subcultured biweekly because of yew slow growth, providing of nutrients and medium. Data were analyzed with one way Anova and Duncan tests.
Results: The results were shown that the best seed sterilization was H2O2 10% for 15 min, and ethanol 70% for one minute that any infection was not observed. Other results were shown that the embryos started to regeneration about 10 days. The maximum of regeneration and normal seedling belonged to treatment 1 that it was consisted mature seed, ascorbic acid and casein hydrolysate (100 mg/l), yeast extraction (1 g/l) and activated charcoal (2%). Its mention that seed stratification was very useful in embryo regeneration.
Conclusion: mass production of seedling can be easily achieved by using mature seeds and MS medium containing 100 mg/l ascorbic acid and casein hydrolysate, plus 1 g/l yeast extraction and 2% activated charcoal. Meanwhile cold stratification is very effective on development and growth of yew embryo. Therefore is suggested that to use from this technique in all of researches about yew seed either in vitro conditions or in vivo conditions.
Key words: Taxus baccata L., Embryo, In vitro culture, Cold stratification