Abstract
Objective: Tomato (Solanum lycopersicon L.) is one of the most important vegetable crops and a genetic model for improving other dicotyledonous crop plants. In basic and practical studies for tomato improvement, successful transformation is essential. The aim of this study was to assess and compare different transformation procedures in tomato cultivar Rio Grande transformed with the Agrobacterium tumefaciens strain LBA4404 containing pPM7 carrying the HAL1 and NPTII gene.
Methods: Three different transformation procedures were carried out in this project. One of them was tissue culture dependent and the others were in planta transformation protocols i.e. in vitro fruit injection method in which fruits are infiltrated with Agrobacterium suspension for different incubation periods and in vivo fruit/flower injection method which involves simple injecting bacterial culture into intact fruits and flowers attached to the mature plants.
Results: The tissue-culture approach in tomato showed transformation efficiency from 10-13% with apical meristems yielding best results. In the in planta in vitro fruit-injection method, the percentage of seed germination on selection medium was higher for treated seeds as compared to control showing transformation efficiency in the range of 34 - 42%. During in planta in vivo fruit / flower injection method, out of 1100 seeds assayed, only 8 were found to be resistant to antibiotic with transformation rate 0.0018%. Transformed plants were selected on 100 mu g/ml kanamycin and final selection of transformed plants was made on the basis of PCR.
Conclusion: Among different transformation procedures depicted in tomato (Solanum lycopersicon L.), in vitro fruit injection method was found to be easier and economical way of getting transformed plants as compared to conventional tissue culture based transformation methods.