| Strawberry (Fragaria ananassa Duch) , which is a kind of herbage and belongs to the rose family in the plant kingdom. The fruit of Strawberry contains plentiful nutrient materials and richer sweet juice, and therefore has maximum nutritive value and significant market prospect. However, the present problem which severely affects strawberry production is how to keep the fruit green or to retard softening for longer time after harvesting. In addition, the vegetative propagation may result in many negative effects such as virus attacks, strain degeneration, and both yield and quality reductions. Recently, more and more technics of molecular and cell biology including high efficient plant regeneration, plant genetic transformation, have been used in the studies of improvement of the quality and disease resistance in Strawberry.The present primary cultivars of strawberry 'Fengxiang' and 'Zhangji' were used as experimental materials. To establish a reliable, rapid and effective in vitro regeneration system and to carry the strawberry genetic transformation out successfully, the factors affecting adventitious shoots regeneration were studied. The results indicated that the frequencies and amounts of shoot organogenesis were significantly affected by the hormone concentrations for a given genotype. Compared with 6-BA, TDZ had a better effect on inducing shoot regeneration. The regeneration frequency of cultivar 'Fengxiang' reached the highest level of 83.2% in MS+TDZ2.0mg/L+2,4-D 0.1mg/L+IBA0.2mg/L, while cultivar 'Zhangji' obtained the highest level of 65.7% in MS+TDZ4.0mg/L + NAA0.1mg/L+IBA0.2mg/L medium. The corresponding numbers of shoots regeneration were 1.4 and 1.3 per leaf disc, respectively. The regeneration of the leaf disc was better than that of petiole in the same genotype and the 10-day-old leaf had higher regeneration ability. Our data also showed that AgNO3 played an important role in controlling the browning of explants, and the concentration of 8.0mg/L was recommended. While using the rooting medium of l/2MS+IBA0.1mg/L, the rooting rate achieved nearly 100%. In addition, the anther culture of 'Zhaotunl' was studied and the regeneration plants were obtained when cultured with F+6-BA1.0mg/L+NAA0.5mg/L+CH300mg/L medium.To investigate the role of endo-l,4-glucanase gene in strawberry fruit ripening, total RNAs were isolated from the pink strawberry fruits. By using the specific primers designed from the FaEGl and FaEGS cDNAs, 1491bp and 1863bp fragments were amplified by reverse transcriptional polymerase chain reaction (RT-PCR). The FaEGl and FaEG3 cDNAs were inserted into expressional vector pROK2 in reverse orientations.The antisense clonings pROK2-FaEGl and pROK2-FaEG3 were therefore mobilized into Agrobacterium tumefaciens AGL-1 by electroporation. The strawberry transgenic plants were developed by Agrobacterium-mediated plant transformation with kanamycin resistance selection. Among the twenty-four Kan-resistant calli, seventeen of them showed PCR positive. At the same time, we have further studied the factors such as the pre-culture of explants, the time of infection with Agrobacterium and co-cultivation to demonstrate the appropriate conditions for genetic transformation in Strawberry. The results have clearly shown that the conditions of pre-cultured for 1 day, co-cultured for 3 day and infected for 15-20min were favourable for the transformation!.
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