Maltose in culture media improves the in vitro regeneration of Urochloa brizantha cv. ‘Marandu’ plants

Abstract

The improvement of the in vitro regeneration of Urochloa brizantha is an important step to toward the development of transgenic cultivars. The objective of this work was to test the effect of the amino acid proline and the replacement of sucrose by maltose as carbon source in culture media to optimize the somatic embryogenesis. Mature seeds of U. brizantha cv. ‘Marandu’ were used as initial explant. The seeds were scarified in sulfuric acid, manually peeled disinfested and washed. The callus induction media were composed basically by Murashige and Skoog salts supplemented with 30 g l-1 sucrose, 3 mg l-1 2,4-dichlorophenoxy acetic acid, 300 mg l-1 hydrolyzed casein and 8 g l-1 agar. Carbon sources maltose or sucrose at 30, 40 and 50 g l-1 was added in the callus induction medium. In another experiment the L-proline was added to the media at 100, 200 and 400 mg l-1 . It was evaluated the number of seeds that produced callus, calluses growth after 14 weeks (mg) and number of regenerated plants. The results showed maltose was more efficient than sucrose for regenerate the plants. Nevertheless, the addition of proline to the media not improved it. Therefore, substitution of sucrose by maltose to the in vitro culture media of U. brizantha increase the plant regeneration.