New explant for somatic embryogenesis induction and plant regeneration from diploid banana (‘Calcutta 4´, <em>Musa</em> AA)

Abstract

A method has been developed for plant regeneration via embryogenic cell suspensions from diploid cultivar `Calcutta 4´. For callus induction with embryogenic structures, different plant tissues such as scalps from cauliflower-like meristems and meristematic domes of axillary sprouted buds in combination with several culture media were evaluated as explants. The best embryogenic response (8%) was noticed with meristematic domes of axillary sprouted buds in culture medium Murashige and Skoog salts at 50%, MS vitamins, 30 g l-1 sucrose, 10 mg l-1 ascorbic acid, 1 mg l_1 2,4-D, 0.22 mg l_1 Zeatine and supplemented with 100 mg l_1 malt extract, 100 mg l_1 glutamine, 1 mg l_1 biotin, 200mg l_1 casein hydrolysate, 4.0mg l_1 proline and solidified with 2.0 g l_1 Gelrite. Embryogenic cell suspensions were established and the highest increase of cellular biomass with 0.50 ml settled cell volume (SCV) was obtained 18 days after culture initiation. In a RD1 culture medium, embryogenic masses from 1362 to 2480 embryos were formed. An average of 54.5% germinated embryos in Temporal Immersion System (TIS) was obtained. Results were significantly higher in comparison with the use of semisolid culture media (28%). Regenerated plants are in field conditions to value their genetic stability. Keywords: axillary buds, somatic embryogenesis, Temporal Immersion System.