الفهرس | Only 14 pages are availabe for public view |
Abstract In vitro and ex vitro experiments were conducted at the Plant Tissue Culture Laboratory and the greenhouse facilities of the Department of Horticulture, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt during the period 2009 -2012. Organogenic potential of leaf disc explants from different strawberry cultivars were tested in different medium types and growth conditions. Ex vitro performances of tissue culture-derived plants from different propagation methods (meristem, direct regeneration and callus derived plants) were examined with standard runner propagated (RP) cold stored transplants. Histological analysis of the regenerating structures was performed along with testing the genetic stability of these plants using RAPD –PCR technique. High regeneration capacity was obtained in medium amended with TDZ compared with BA as source of cytokinin. Strawberry cultivars from USA origin were the highest to regenerate shoots followed by cultivars from European origin. Histological analysis revealed that TDZ-amended medium (MS+4 mg/L TDZ) developed clear meristemoids with regeneration of several leaf primordia as indicative of direct shoot regeneration. Ex vitro growth performance examination showed that leaf morphology and serration pattern were almost similar among plants obtained from meristem, direct or callus regeneration. Tissue culture plants have higher number of runners while standard runner plants were higher in flower production compared to in vitro propagated plants. RAPD-PCR analysis indicated that plants of cv. Tudla from meristem propagation method were genetically stable as compared with runner propagated plants, while cv. Festival, callus-derived plants and Cal5 plants regenerated via adventitious shoot formation deviate from normal genotype and could be considered as new somaclones which await further investigations Keywords:Fragaria × ananassa – regeneration- direct shoot regeneration- callus- leaf disc- TDZ- histological analysis. |