Induction Of Somatic Embryos And Plant Regeneration From Hairy Root Line Of Gentiana Macrophylla Pall.

Somatic embryogenesis(SEM)is one of plant regeneration in vitro,and is very useful for not only studying the mechanism of plant embryogenesis and cell differentiation,but also screening new valuable crop variety via cell and gene engineering method.Hairy roots is a kind of root-like organ,which produced from the wound plant portion infected by Agrobacterium rhizogenes.In some proper cultures,hairy roots could be induced to produce callus,even whole plantlets. Because of the plasmid Ri inserted,some new plants with excellect charaters could be gotten.Gentiana macrophylla Pall.is a widely used as tranditional herbal medicine because of containing gintiopicrin.The compound synthesized and accumulated in its root was reported to show medicinal functions including abirritation, anti-bacterium,anti-inflammatory and antipyretic activities,and have been used to cure various diseases.In order to realize the purpose of reasonable and long-time ultilization of this limited resource,using hairy roots of Gentiana macrophylla Pall.,we established a efficient system of plant regeneration through somatic embryogenesis.At the same time,the effects of plant hormones on somatic embryos formation was studied,and the conditions for hairy root induction were optimized.Main results follow as:30 days after cultured on solid MS medium with 0.1～10.0 mg/L 2,4-D,all the hairy root segments of Gentiana macrophylla Pall.,produced by infecting wounded cotyledon with Agrobaterium rhizogenes,converted into yellowish compact embryogenic calli.After transferred into hormone free MS medium 30 days,these calli developed into loose yellowish calli consisting of many small compact particles(global somatic embryos).More 30 days after cut into smaller pieces and transferred onto fresh MS agar medium without hormone,many single and fasciculate shoots formed on the surfaces of these calli.Under the anatomical microscopy,these cultures were found containing many globe-,heart-,torpedoand cotyledon-shaped somatic embryos and plantlets with well developed root. The majority of the regenerated plantlets were able to survive after transplanted in mixture of soil and vermiculite(1:1).In comparison with corresponding wild seedlings,those regenerated plantlets displayed widened and color-darkened leaves.The optimal medium which could produces somatic calli is solid MS medium with 1.0 mg/L 2,4-D.