Changes Of Leaf Color Of Crape Myrtle And Construction Of Genetic Transformation System Of ’Zi Jinglling’

Lagerstroemia indica L.is a woody plant belonging to the genus Lagerstroemia in the family chelidae.The breeding of crape myrtle started late and mainly focused on flower color breeding.At present,there are few reports on leaf color breeding.The leaf color of crape myrtle has an important influence on its ornamental value and horticultural value.However,there are few varieties of crape myrtle with colored leaves in the market at present.Therefore,through the study of leaf pigment content of six different crape myrtle varieties,this study analyzes the relationship between leaf color and pigment content,summarizes the change law of leaf color,and provides a theoretical basis for crape myrtle leaf color breeding;Establish the genetic transformation system of ’Zi Jingling’ crape myrtle,and realize the transfer of the anthocyanin related gene LiMYB44(transcription factor)regulating the leaf pigment of crape myrtle into ’Zi Jingling’ crape myrtle,so as to lay a foundation for the subsequent genetic engineering breeding of crape myrtle and promote the innovation and application of crape myrtle leaf color breeding research.The main research contents are as follows:(1)Through the determination of chlorophyll content in six crape myrtle varieties’ Zi Jingling ’,’ Red Rocket ’,’ Linglong red’,’ Ziying ’,’ Ebony Fire’and’ ’Ebony Embers’at different growth stages,the results show that chlorophyll is the pigment that determines the color matching of crape myrtle leaf base,and chlorophyll was the pigment that determined the color matching of crape myrtle leaf base,Carotenoids and anthocyanins are important pigments regulating the transformation of leaves from green to other colors,and the anthocyanin content of ’Ebony Fire’ crape myrtle is the highest,followed by’Ebony Embers’ crape myrtle and ’Zi ying’ crape myrtle.The results showed that the change of leaf color of crape myrtle was mainly affected by the content of anthocyanin.The higher the content of anthocyanin,the leaf color of crape myrtle was purple.(2)Through the study on the correlation between leaf color parameters and leaf color pigment content of six species of crape myrtle,the a*value(redness)of crape myrtle is positively correlated with anthocyanin content,that is,the higher the anthocyanin content,the greater the a*value(redness).The higher the content of photosynthetic pigment,the higher the a*value(redness),and the leaf hue is purple.On the contrary,the higher the b*value(yellowness),and the leaf hue is green.It is concluded that the anthocyanin content of crape myrtle has a great impact on leaf color.The higher the anthocyanin content,the higher the a*value(redness),the leaf color will be purple.Therefore,in conclusion,the leaf color can be changed by regulating the anthocyanin in crape myrtle leaves.(3)The genetic transformation system of adventitious buds from Calli of ’Zi Jingling’ was established.Agrobacterium tumefaciens was used for co culture for 3 days.The OD600 value of Agrobacterium tumefaciens was 0.6,the soaking time was 13 min,and the concentration of acetylsyringone was 150 μmol/L,after infecting 593 explants,two transgenic plants were obtained,and the transformation rate was 0.34%.The related gene LiMYB44(transcription factor)regulating anthocyanin in crape myrtle leaf pigment was transferred to the receptor material to change crape myrtle leaf color.Therefore,it provides a new idea for crape myrtle leaf color breeding.