In Vitro Propagation For Platycladus Orientalis Via Somatic Embryogenesis

Platycladus orientalis is widely distributed in China.Its root system is well-developed,and it is resistant to cold and drought,has important ecological value.In this paper,immature zygotic embryos of P.orientalis were used as experimental materials to induce somatic embryogenesis.The effects of zygotic embryo development stage,plant growth regulator types and concentrations,sugars and etc.on the induction of embryogenic callus were studied,and the effect of culture methods,frequency of the incubator and plant growth regulators on the proliferation of embryonic tissues were discussed,studied the maturation and culture of somatic embryos.The embryogenic tissue induction program was optimized,and the cell suspension culture system was initially established.The results are as follows:(1)The development of zygotic embryos to the pre-cotyledon stage is conducive to the induction of embryogenic callus of P.orientalis;adding 10 g/L to the medium of DCR+4.0mg/L2,4-D+0.5 mg/L6-BA,the induction rate of embryogenic callus can reach 16.3%.In addition,the mother tree genotype is different,and the induction rate is also different.(2)The embryogenic callus of P.orientalis is subcultured in the solid proliferation medium containing 2,4-D for a long time,the surface will be hydrated,the texture will lose its viscosity,and even the embryogenic ability will be lost.Substituting 1 mg/LNAA for2,4-D is beneficial to maintain embryogenic ability.The appropriate subculture cycle is about 21 d.(3)During the proliferation process of liquid suspension culture,add 2.0g embryogenic callus to every 100 ml medium,rotate at 110 r/min,and the subculture cycle is about 11 days.The embryogenic cell proliferation rate is the highest,reaching 288%.(4)ABA is conducive to somatic embryo maturation of P.orientalis.At the combined concentration of 60 um/LABA+100 g/LPEG,the maturation rate of somatic embryos is high;different sucrose concentration tests are not conducive to somatic embryo maturation.Using45g/L maltose instead of sucrose,mature embryos were obtained.