A rapid and efficient tomato regeneration and transformation system

Tomatoes have great economic importance in greenhouse and field production in Egypt. Tissue culture and molecular engineering have provided rapid modes to develop desirable varieties of cultivated plant species. Genetic engineering will allow adding new fruit quality genes, one at a time, with simultaneous avoiding introduction of the rouge characteristics. In this work, rapid regeneration and transformation systems of tomato cultivar CastleRock has been developed using hypocotyl with a part of cotyledon (hypocotyledonary), after removal of primary meristem, as an explant. The explants were cultured on ten different combinations of hormones and vitamins. The highest frequency and earliest regeneration were obtained on medium X1N which composed of MS medium supplemented with 1 mg/l BAP, 1 mg/l Zeatin ripozide, 5mg/l AgNO3 and Nitch&Nitch vitamin. Shoots were developed after only 10 - 12 days with a percentage of 92 %. In addition, transformation system has been established with two different methods, Agrobacterium mediated transformation and Biolistic gun. In the case of Agrobacterium transformation, the binary vector pISV2678 which contains the gus-intron and bar genes was used. While, the plant vector pMONRTG harboring the gus gene was used with biolistic gun transformation. Putative transgenic shoots were regenerated on the selected regeneration medium and developed shoots were transferred to rooting media. T0 plants were analyzed using histochemical gus assay and the PCR.