发根农杆菌对柑桔的离体转化和植株再生作用

Wounded and Precultured cotyledon explantes of Citrus sinensis L.Osbesk were infected with the wild type strains of Agrobacterium rhizogenes (A. Rl000 &. 15834) which were at the logarithmic growth phase. The infected explants were cocultured for three days at 25℃ and under weak light on the MT medium without any hormones. Transformed roots were produced after culturing for15days. The frequeney of the explants transformed by A.rhizogenes was estimed ca·25一36%. The transformed roots were identified by their ability to proliferate roots on the hormone一free medium and to contain agropine and manopine in their cells. There sult indicated that theT-DNA of Ri plasmid in A.rhizogenes was transferred and integrated into the nuclear genome of CItrus sinensis and got exprssed. Some Ri plasmid transformed roots coulds spontaneously produced adventitious shoots on the hormone一free media. By adding appropriate plant growth regulators in the media, we could have all of the root line transformed produced adventitious shoots，which would develope into intact plantlets on a hormone一free media or half strength MT added 0.2 α-naphthalene aceficacid(NAA). The electrophoresis indieated that leaf cells of transformed plantlets contain opines (agropine or manopine) and therefor genes harboured on T-DNA were expressed in the transformed plants.