INDUCTION OF GENETIC VARIATION IN GARLIC

Abstract

This study was carried out during the period from 2017 to 2021 at Kaha vegetable research farm, Qalyubia, Egypt, for the open field experiment. While tissue culture experiment was carried out in tissue culture Laboratory, Vegetable Research Departments, Horticulture Research Institute, Giza, Egypt. The aim of this work was to induce genetic variations in garlic by using of chemical mutagens as well as somatic embryos grown in vitro then evaluate the result under Egyptian local conditions. The study was divided into two parts as (1) treat garlic cv. El Balady cloves with chemical mutagens [Ethyl methane sulfonate (EMS), Sodium azide (SA) and colchicine (Col)] for periods (6 and 12 h) at concentrations (0.01, 0.05 and 0.1%) in the open field and (2) induce genetic variation through indirect somatic embryogenesis of garlic cv. El Balady by using various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) ( 0, 1, 2, 3, and 4 mg/l) for callus formation. The formed callus were subcultured into MS medium supplemented with a combination of 2,4-D and 6-Benzyladenine (BA) at concentrations (0, 1 and 2 mg/l) for embryos induction. The results in field showed that SA at concentrations 0.05 and 0.1% led to not germinating any clove, which confirms that they are lethal doses, while the concentration 0.01 % achieved the lowest characteristics of vegetative growth and yield in the first season but it gave the highest characteristics of vegetative growth and yield in the third season. EMS and Col induced positive effects on vegetative growth and yield characteristics. Five new clones were obtained from the field treatments, and the clones were superior as compared with control for vegetative growth and yield characteristics as well as chemical characteristics of the cloves in the third season. For the in vitro experiment, 2,4- D at concentration 1 mg/l gave the highest callus formation traits and 1 mg/l BA was the best concentration for embryos induction traits. Four new clones were obtained from the embryogenesis in vitro and planted in the greenhouse for evaluation. The results of RAPD test showed that the obtained nine clones, from both experiments, were different from the control.