Factors affecting the incidence of vitrification of in vitro propagated fruit trees

Abstract

In vitro Clonal propagation of fruit trees to produce large number of plants, often leads with the problem of vitrification or hyperhydric transformation. This physiological disorder was observed in pear, quince, grape and date palm. The frequency of vitreous shoots was increased in the presence of high BAP and NH+4 concentrations, as well as on Murashige and Skoog mineral salts in culture medium. In pear and quince, the formation of normal shoots from vitreous explants was obtained by using mineral salts of Quoirin & Lepoivre supplemented with low concentration of BAP and high concentration of sucrose in the media. In date palm, the traits to correct the vitreous plants were not succeeded, however, the formation of high percentage of vitrification was reduced by using Beauchesne mineral salts in the medium. A histological study showed in pear that vitreous explants containing a low level of lignification and a limited number of xylem layers in comparison with normal shoots. The role of different factors studied was discussed.