A xyloglucan from seeds of the native Brazilian species Hymenaea courbaril for micropropagation of Marubakaido and Jonagored apples

Abstract.

Xyloglucan was extracted from seeds of Hymenaea courbaril and mixed with agar to prepare a solid culture medium used for micropropagation of the Marubakaido apple rootstock (Malus prunifolia Borkh) and cv. Jonagored (Malus domestica). The performance on gels created from a blend of 0.4%agar and 0.2% xyloglucan (w/v) was compared with that on media gelled with a standard concentration 0.6% (w/v) of agar. The growth of shoots and the multiplication rate were higher on the modified culture medium than on the agar-gelled medium. The occurrence of hyperhydric shoots was lower on the modified medium. In the absence of auxin, shoot rooting reached 70% (Marubakaido) and 66% (Jonagored) on the agar-xyloglucan medium and 6.7% and 10.4%, respectively, on the agar medium. When 0.25 µM indole-3-butyric acid (IBA) was added to both media, the modified medium gave better results in terms of rooting percentage and quality of roots than the agar-gelled medium.