The Establishment Of Tissue Culture And Regeneration Of Four Lagerstroemia Species & Cultivars

Crape myrtle (Lagerstroemia indica), belonging to the genus Lagerstroemia of the Lythraceae family, is well known for its value as the ornamental plant. Moreover, it is popular worldwide due to its long flowering period during midsummer with colorful flowers and easy production and cultivation. Tissure culture was an effective technique for germplasm preservation and the basis for genetic transformation research. L. intermedia originated from Simao and Lancang of China. It was the perfect breeding parents because of the early florescence and evergreen feature. Due to vandalism, L. intermedia was endangered and needed to establish the tissure culture system for germplasm conservation. Black Diamond was hybrids with purple leaf through whole year. It owned important application values, but there was no report on tissure culture system. The establishment of tissue culture system was the foundation for future large-scale marketing. Currently, transgenic breeding is a hot topic of molecular breeding and regeneration system was an important basis for the genetic transformation of transgenic breeding. In this study, seeds and shoots were used as explants to establish the tissure culture system for two kinds of crape myrtle, while immature embryos, cotyledons and leaves were used to establish the regeneration system for another two kinds of crape myrtle. The main results are as followings:1、Established the rapid propagation for L. intermedia and L. indica Black Diamond. For L. intermedia, the highest number of shoots up to 7.3. For Black Diamond, the highest number of shoots up to 8.5. The high root frequency of both were up to 100.0%.2、Established regeneration system for L. indica ’Sarah Favorite’ and ’Fen Jin’. Direct shoots were inducted when the media was supplemented with 6-BA and NAA or IBA; and callus was inducted when the media was supplemented with 6-BA and 2,4-D. Immature embryo was used as explant, the highest frequency of callus inducton was 80.8%, the highiest frequency of callus differentiation up to 51.8% and the highest direct shoot regeneration frequency was 38.3%. Cotyledon was used as explant, the highest frequency of callus inducton was 98.7%, the highiest frequency of callus differentiation up to 53.4% and the highest direct shoot regeneration frequency was 45.3%. Leaf of L. intermedia and L. indica’Sarah Favorite’ were used as explant, the highest frequency of callus inducton was 87.5% and 45.6%.The rooting frequency was 100.0%. After acclimatization, the survival frequency was more than 80.0%.3、Primary study on genertic transformation of L. indica. The leaf of L indica’Sarah Favorite’ was used in this research. The results indicated that the best transient express condition of GUS gene was 10min infection and 2d co-culture.This study established the tissure culture system for L. intermedia and Black Diamond. It was important basis for germplasm conservation and to get a lot of plant materials. The regeneration system of L. indica would lay a foundation for genetic transformation.