Plantlet regeneration technique from nucellar tissue-derived/somatic embryos of mango (Mangifera indica L.) var. Carabao

anglais. The strains of 'carabao' mango were induced to form somatic embryos (SEs) using nucellar tissues from seeds of immature fruits harvested six weeks from flowering. The effects of 2,4-D, kinetin (Ki) and 6-benzylaminopurine (BAP) on root and shoot formation in SEs were compared. Cotyledonary leaf and root formation (1 deg and 2 deg) were best observed in modified B5 (Gamborg, 1978) and BP (Barba and Poteña, 1998) basal media supplemented with either 0.5 mg/L Ki or BAP maintained in lighted condition. Addition of 0.5 mg/L 2,4-D to these media inhibited root formation. Shoot and root formation were enhanced when germinating somatic embryos were transferred onto modified B5 and BP media without growth regulators. True leaves were induced from germinating SEs with two cotyledonary leaves. No shoot development was observed in germinating SEs with fused cotyledon. In contrast to previous report (Pateña, et.al., 2003) wherein true leaf formation was ach ieved after 18-24 months, in this study, true leaf formation was recorded 6-8 weeks after subculture onto the regeneration media. Plantlets (with shoots and roots) were regenerated and transferred to soil. A set of experiment using seeds from ripe fruits and planted to soil was done to compare with somatic embryo germination in-vitro. It was remarkable to note that germination and the pattern of shoot and root growth were similar in both cases. Results of this study show that planlets can be obtained from SEs and they behave similar to plantlets derived from ripe seeds.

anglais. Scientific Conference of the Federation of crop Science Societies of the Philippines Lapasan, Cagayan de Oro City (Philippines) 2-6 May 2005