Hasan Basri Jumin
Abstract
Protoplasts isolated from embryogenic callus of Citrus sinensis were electrically fused with embryogenic protoplasts isolated from seedless Citrus relatives. Hybrid of somatic embryos were obtained after 2 months of culture. The somatic hybrid embryos were obtained by screening on the basis of chromosomes count. The number of chromosome of embryogenic callus counting revealed plantlets tetraploids (2n = 4x = 36) and the other were diploids (2n = 2x = 18). Percentage of multinucleat of protoplast increasing linearly with increase the AC voltage / cm from 15 volt /cm until 45 volt/cm, and decreasing significantly after 60 volt/cm. Number of broken protoplast significant increased linearly until 250 DC volt / cm, and decreased afterward, however the total fusion was only increased until 200 DC volt/cm. The effect of AC field strength on percentage of overall fusion and percentage of heteronucleat was shown a positive effect where the percentage of fused protoplast increased with the same trend with percentage of heteronucleat. The high number of total fusion of protoplast was reached on 30 volt /cm and decreased after 45 volt /cm. This somatic hybrid after regenerated into plants will be utilized as a possible pollen parent for improving the Citrus sinensis.