| Oil-tea camellia or Camellia oleifera is one of the most important oil tree crops native to Southeast China and introductions have been made into several non-indigenous countries. The history of growing this edible oil plant is long in China; however, because of poor management and inadequacy in fine cultivars, the yield of oil per unit area is generally very low. Recently, many clones with good biological and genetic characters are widely used to improve the oil production. With the development of genetic studies and breeding technology at the molecular and cellular levels, a good number of improved varieties will be created. The extension of these varieties needs depending closely on the tissue culture technique and at the same time on the advancement of the molecular technology for logining and preserving these new variety entries. The molecular biotechnology is particularly instrumental when the molecule-assisted selection is applied. Besides, the construction of cDNA library in Camellia oleifera will be a crucial research emphasis in variety breeding and clone selection. Hence in this doctorate project, tissue culture, molecular identification using randomly amplified polymorphism DNA (RAPD) markers, and the construction of cDNA library in Camellia oleifera were studied, hoping to provide a sound basis for variety improvement, cloning of vital genes, and promotion of the oil production.Auxiliary buds and cotyledons as explants from material 'xianglin-4' (XL-4) were cultured in MS medium with different hormones. Experiment results show that the optimal medium for shoot regeneration from auxiliary buds is MS with 6-BA 3.0 mg. L-1 and NAA 1.0 mg. L-1; the optimal medium for embryogenetic callus formation is MS with 2,4-D 2.0 mg. L-1 and KT 1.0 mg. L-1; the optimal medium for shoot development via embryos is MS with 6-BA 2.5 mg. L-1 and IAA 1.5 mg. L-1 or MS with 6-BA 3.0 mg. L-1 and NAA 0.05 mg. L-1; the optimal medium for root inducement is MS with NAA 7.0 mg. L-1. Somatic embryos were induced from cotyledons and its formation process was observed in the microscope. Results indicate that embryos were derived from single cell embryo or cell aggregate in embryogenetic callus and most of them were induced from embryogenetic callus of epidermis cells. In addition, some materials from different processes of plantlet regeneration were discriminated, but no mutations were discovered. Therefore, it can be concluded that plantlets from tissue culture do not have any difference with quondam clone and can well maintain the hereditary consistency. Regenerated plantlets from auxiliary buds could be used in rapid propagation, and those from embryos induced from cotyledons could not only satisfy the need for general breeding, they could also serve as a good basis for gene transformation in the future.After the genomic DNA was isolated with the modified CTAB process from 12 selected clones from Hunan province as target samples and one common cultivar of Camellia oleifera as control, their genetic diversity and molecular identity were ready for analysis by RAPD markers. Firstly, an optimized PCR program for RAPD analysiswith high stability and good repetition was developed by modifying such important factors as the Mg2+, which affected the RAPD-PCR reaction. Then, 22 random oligo primers screened from 180 arbitrary 10 mer primers were used for PCR amplification, which produced an array of polymorphic profiles. Finally, 22 pieces of DNA fingerprint profiles containing 141 bands with 91 distinct polymorphic bands (64.54%) were obtained. Many repetition experiments were conducted to verify the findings.Each primer produced 3 to 10 bands with the band size ranging from 305 bp to 2,918 bp. Similarity coefficient analysis shows that there is a low similarity between the control and the target samples, and the difference among the target samples is small. On the basis of these findings, the cluster diagram with UPGMA was produced. When the D value is 0.4, the materials can be divided into four groups, with the c...
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