Study On Tissue Culture And Rapid Propagation Of Lagerstroemia Indica

Lagerstroemia indica ’Ziyu’ is a improved breed,which has the characteristics of rapid growth,mature leaves purplish red,pure white flowers and so on.Although crape myrtle can be propagated by conventional propagation methods,but the propagation speed is slow,and plant tissue culture can not only maintain the fine species of crape myrtle,but also has the characteristics of high propagation coefficient and fast propagation speed,and can obtain a large number of high-quality plantlet in a short period of time.It has important application value for the industrialization production of crape myrtle seedlings and the conservation of germplasm resources.In this paper,the regeneration system of Lagerstroemia indica ’Ziyu’ was established with axillary bud as the explant,and the effects of explant disinfection,growth regulators on primary culture,subculture and rooting culture,the effects of basic culture medium on proliferation and the effects of active carbon on rooting were explored,and the effects of explant disinfection,growth regulators on primary culture,subculture and rooting culture,basic medium on proliferation and activated carbon on rooting were studied.At the same time,the changes of endogenous ZR,ABA,GA3 and IAA in tissue culture and rooting were systematically analyzed,and the effects of growth regulators on the growth and development of tissue culture seedlings were also discussed.The main results are as follows:1.In different seasons,the lowest contamination rate of explants was 10.67% and the highest survival rate was 89.33%when the explants were disinfected with 0.1%Hgcl2 in 6 minutes in spring.Therefore,the explants should be disinfected with 0.1%Hgcl2 in 6 minutes in spring.When the concentration of 6-BA was 1.0 mg·L-1,the germination rate of axillary buds was 88.37%,and the growth of axillary buds was fast,the height of axillary buds was 2.54 cm.2.The basic medium of subculture proliferation has a significant effect on the proliferation coefficient.The suitable basic medium is the improved DKW medium with the highest proliferation coefficient four point eight seven.And grow vigorously.In proliferation culture,the type of cytokinin,the type of auxin and the ratio of auxin concentration all have significant effects on Subculture proliferation.The optimal combination of proliferation medium is:improved DKW+6-BA 1.0 mg·L-1+NAA 0.25 mg ·L-1,at this time,the proliferation coefficient is high,and the proliferation cluster buds are robust and grow well.The sucrose concentration also had a significant effect on the subculture proliferation.The sucrose concentration of 30 g·L-1 was suitable.3.Adding suitable concentration of active carbon and auxin to the rooting medium of Lagerstroemia indica can promote rooting.The suitable content of activated carbon is 200 mg·L-1,and the suitable auxin type and concentration are NAA0.5 mg·L-1,cytokinin NAA and IBA all had significant effects on the rooting induction of 0.5 mg·L-1 had the highest rooting rate.4.In the stage of tissue culture,higher concentration of endogenous GA3,higher concentration of Endogenous IAA and lower concentration of endogenous ABA are beneficial to subculture,proliferation and differentiation of cluster buds.High concentration of Zr is needed to promote the proliferation and differentiation of Plantlets in the early and middle stages of proliferation and culture,and the demand for endogenous ZR and endogenous GA3 is reduced after the period of vigorous proliferation and growth.GA3/ZR ratio and GA3/ABA ratio play a leading role in the proliferation process.In the process of rooting culture,high concentration of Endogenous IAA,high concentration of ABA and low concentration of GA3 can promote the formation of root primordium.The growth and development stage of root primordium needs low concentration of GA3 and ABA.5.Adding exogenous hormones 6-BA and NAA in the proliferation stage has a great influence on the content of endogenous GA3 and IAA in the early stage of subculture,can increase the content of endogenous GA3 and IAA,has a certain influence on the content of endogenous ABA in the proliferation stage,and is conducive to the proliferation and culture of tissue culture plantlet.The addition of exogenous hormones 6-BA and NAA to the proliferation medium increased the content of endogenous ZR during the vigorous growth period,which was beneficial to the proliferation,differentiation and proliferation of cluster buds.Adding appropriate concentration of NAA to rooting medium can increase the concentration of Endogenous IAA and ZR during the differentiation and growth of rooting primordium,and it is beneficial to the growth and development of root primordium of tissue culture plantlet.