Preliminary studies on encapsulation of gametic and somatic embryos of Citrus clementina Hort. Ex Tan. And Citrus reticulata BLANCO: effect of cold storage.

Preliminary studies on encapsulated somatic embryos were performed with four genotypes of Citrus reticulata Blanco (‘Nules’, ‘Monreal’, ‘SRA63’ and ‘MTC’), in order to evaluate the effect of the coating and of the storage period (0, 60 and 120 days) at 4°C on the viability and on the conversion of the synthetic seeds. Somatic embryos were regenerated from anther culture and encapsulated in sodium alginate solution (2,5% w/v), enriched by artificial endosperm composed by half strength Murashige & Skoog basal medium, supplemented with 0.25 g l-1 malt extract, 0.25 g l-1 ascorbic acid, 1 mg l-1 gibberellic acid, 0.02 mg l-1 naftalenacetic acid and 6.8 g l-1 sucrose. After the different period of cold storage, the synthetic seeds were sown on agarised medium (MS supplemented with 0.5 g l-1 malt extract, 0.5 g l-1 ascorbic acid and 6.8 g l-1 sucrose) and the cultures were transferred in growth chamber. After 45 days from sowing, viability and conversion were monitored. Satisfactory levels of viability were recorded in encapsulated somatic embryos of ‘Monreal’ (90,0%), ‘Nules’ (76,7%), ‘MTC’ (73,3%) and ‘SRA63’ (70,0%), after 60 days of cold storage. After the same period of cold storage the synthetic seeds of ‘Monreal’ and ‘SRA63’ showed 46,7% and 36,7% of conversion, respectively, whereas this parameter showed unsatisfactory values in the other genotypes.