Callus induction, somatic embryogenesis and protoplast isolation from sweet orange varieties

Intending to produce embryogenic citrus calli (Citrus sinensis L. Osbeck), aborted ovules of ripe fruits from six sweet orange varieties (‘Bahia Cabula’, ‘Baianinha’, ‘Hamlin’, ‘Orvalho de Mel’, ‘Rubi’ and ‘Valencia’) were introduced onto modified MT medium with and without benzyladenine (BA). Calli obtained from ‘Bahia Cabula’, ‘Orvalho de Mel’, ‘Rubi’ and ‘Valencia’ varieties were grown on MT basal medium modified with the carbohydrates maltose, galactose, lactose, glucose and sucrose at 18; 37; 75; 110 and 150 mM. The effect on somatic embryogenesis was studied. Calli from the same genotypes were submitted to protoplast isolation, using three different enzymatic solutions. Results revealed the genotype effect in the callus induction. Somatic embryogenesis was stimulated in the presence of galactose, for most varieties. Enzymatic solution composed of 1% cellulase, 1% macerase and 0,2% pectolyase was the best for protoplast isolation from calli of all genotypes tested.

Citrus sinensis; tissue culture; cultivar improvement

São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" USP/ESALQ - Scientia Agricola, Av. Pádua Dias, 11, 13418-900 Piracicaba SP Brazil, Tel.: +55 19 3429-4401 / 3429-4486, Fax: +55 19 3429-4401 - Piracicaba - SP - Brazil