A NEW In Vitro REGENERATION PROTOCOL IN TOMATO (Lycopersicon esculentum Mill.)

Abstract

A protocol has been established for a rapid, high frequency plant regeneration of normal tomato plants. Dried mature seeds of tomato (Lycopersicon esculentum Mill.) from four cultivars were used to obtain adventitious shoot buds. Sterilised seeds were sown on filter paper that had been wet with water and precultured from zero to three days in the light at 25oC. Precultured seeds were cut into two parts; the portion consisting of the proximal part of the hypocotyls was cultured on a medium with Murashige and Skoog salts, Gelrite 2g.L-1, Mio-Inositol 100 mg.L-1, Tiamine 4 mg.L-1 , 3 % commercial sucrose, without growth regulators. After two weeks, more than 60 % of the elongated shoots were excised individually from the explants and subcultured on the same medium for rooting. At the same time, calli were subcultivated on a fresh medium to obtain more adventitious shoots. Morphological characteristics of regenerated plants and fruits were similar and they set normally shaped fruits with mature seeds; on the other hand, 40 regenerated plants showed no variations in chromosome number (2n=24). The advantages of this regeneration method are: it does not employ exogenous growth regulators, it is feasibly handled, regenerated plants are obtained in a short time and also whole plants were obtained in other four cultivars applying this simple procedure. This paper reports an efficient system for plant regeneration from adventitious shoot buds.