Investigations on the regeneration ability of squash cultivars

Abstract

Pumpkin, squash and zucchini are important vegetable crops in tropical and temperate regions. The development of genetic transformation methods offers the potential of introducing valuable traits into these crops. An efficient in vitro plant regeneration system is a critical point for genetic manipulation. The regeneration ability of three Cucurbita varieties was tested on Murashige and Skoog medium supplemented with different growth regulators. Cotyledons of all the varieties were cultured to investigate the effect of 2,4-D (0, 1, 2, 3, 4 mg l −1 ) with or without KIN (0, 0.5, 5 mg l −1 ) and of BA (0, 1, 1.2 mg l −1 ) combined with IAA (0, 0.9, 1, 1.2 mg l −1 ), on the efficiency of shoot induction. Abscisic acid (0.26 mg l −1 ABA) was also added to one medium. To find the most suitable combination for shoot induction, cotyledon segments of the three varieties were also cultivated on media with different concentrations of BA (0–1.2 mg l −1 ) and IAA (0–0.9 mg l −1 ). Shoot induction was achieved via organogenesis in the tested varieties. Leafy shoots were transferred to root induction media. Regenerated plantlets with roots were transferred to sterile soil. This is the first report on in vitro regeneration from cotyledon explants of the pumpkin cultivar Nagydobosi and the pattypan squash cultivar Óvári fehér.