| Ginkgo Biloba L, with a common name of white fruit is a primitive species of China. Longago grown in China, Ginkgo is considered as symbol of the country in tree plants as that giant panda in animals. Ginkgo Biloba L. is considered as a living fossil. This tree is one of the remaining evidence of biologic origin and evolutionthe.It is thought important as dinosaur. It has many important uses including food, medicine, wood and ornamental with industrial development of Ginkgo. It has a long juvenile period and seedlings come into flowering after twenty years. Long juvenile period severely restricts the progress of its breeding. To shorten the juvenile period, LEAFY gene is thought as key gene in the early flower formation and its superfluous expression may tend the plants flower early. Studies on expression of homologous LEAFY gene can help to learn function of LEAFY gene in Ginkgo. Breeding through tissue culture and gene transformation techniques is a new method for the improvement of Ginkgo Biloba L.1. Being a gymnosperm Ginkgo Biloba L.is very difficult to differentiate in tissue culture. Embryonic axis, cotyledon,endosperm,different size of immature and mature embryos and different stages of immature embryos were induced as explants to study callus formation and embryogenesis in different culture condition in Ginkgo biloba. A kind of new culture medium-MK is made. Results showed that somatic embryos could be induced only through embryo,embryonic axis and cotyledon of immature embryos. MK + NAA 1 mg . L-1 + BA 1 mg . L-1 was the best medium for somatic embryogenesis from embryonic axis, and somatic embryogenesis rate was 45.3%. MK + NAA 1.5 mg .L-1 + BA 1 mg . L-1 was the best medium for somatic embryogenesis from cotyledon, and somatic embryogenesis rate was 12.9%. Highest rate (53.6%) of somatic embryogenesis was obtained on MK medium containing NAA 1.0 mg.L-1+ BA 1.0 mg mg.L-1.Maximum number of embryoids observed on callus was 38 with 3 mm plus embryos. Darkness is not suitable for somatic embryogenesis. Induction frequency of callus and embryogenesis is different in different stages.2. Embryoids were cultured into plants, which is the first report and Ginkgo Biloba L regeneration system was established. Embryoids stop growing after growing into some phase in the callus. Embryoids is taken off from callus in the sterile condition and is inoculated in MK culture medium with active carbon, sucrose and coconut milk in different concentration. The growth and development of somatic embryos were promoted. When MK culture medium is addedby active 3 g/L carbon, 10% of embryoids can develop into plants,When MK culture medium is added by 40 g/L sucrose, 19.2% of embryoids can develop into plants. When MK culture medium is added by 10% coconut ,34.5% of embryoids can develop into plants.3. A rapid method of isolation of total RNA from gymnospermic plant was developed by improving method of routine CTAB. Concentration of p-mercapto ethanol was added in the extract solution to separate the phenolic compounds from the total RNA .A proper amount of PVP is added during grinding to prevent oxidation of phenolic compounds. Using this technique, high quality RNA was seprepared from Ginkgo, Torrega and Cerdar species. The results of ultraviolet spectrophotometer and agarose gel electrophoresis analysis show that the RNA obtained has no obvious degradation and a good purity sufficient for RT-PCR and Northern blotting. The method can be used for the isolation of total RNA from gymnosperm such as Ginkgo Biloba L and it would make a good foundation for molecular studies of Ginkgo Biloba L.4. LEAFY gene is thought as key gene that controls flower formation and initiation. Longjuvenile period of Ginkgo Biloba L. being a gymnosperm perhaps is controlled by LEAFYhomologous genes. By Ginljy and GinNdly probes were labeled with [32P]-dCTP, Northern blotting was done to study expression of Ginljy, GinNdly gene from root, stem, leaf of juvenile and male and female trees, immature... |
