SOMATIC EMRYOGENESIS OF DUONG MANDARIN (CITRUS RETICULATA BLANCO) FROM NUCELLAR CULTURE

Abstract

Duong mandarin (Citrus retieulata Blanco) has been cultivated popuparly in The Mekong Delta. Study on embryogenesis of Duong mandarin could be very useful in further applications such as micro propagation or creating new cultivar via in vitro selection. In order to obtain somatic cells with characteristics similar to mother plants, nucellar culture should be applied. Somatic embryos were genetically similar to the plantlets because they derived from the same somatic cells. This study was carried out to determine the effects of sugar types on formation of somatic embryos. Experiments were conducted to create cam from nucellar culture, to determine effects of sugar types such as sucrose, galactose and lactose on embryogenesis and development of embryos to plantlets. Results showed that nucellar calli formed on basal medium (8M) containing MS medium supplemented with 1 mg/l pyridoxine-HCI, I mg/l nicotinic acid, 0.2 mg/l thiamine-HCI, 100 mg/l  myo-inositol, 500 mg/l  malt extract, 50 g/l sucrose, 8 g/l agar and 1 mg/l 2,4 D. Embryogenesis from nucellar calli was achieved on BM medium , to which was galactose added at concentration 20 g/l. Two types of somatic embryos appeared were normal and abnormal embryos. Normal embryos developed to complete plantlets on basal  medium (BM) supplemented with 2 g/l of activated charcoals. Abnormal embryos developed to plantlets via shoots rooted on basal BM medium added 3 g/l of activated charcoals.