Analynized On The Longan Floral Reversion (Dimocarpus Longan Lour.) By CDNA-AFLP

Longan floral reversion is regarded as the major cause of longan poor production. As the production of "small" year is always less than half of "big" year, longan floral reversion has become a great problem in the production of longan. Therefore, to further make sure the molecular mechanisms of longan floral reversion and to definite the rules from genes to characters during longan floral reversion are of great theoretical and practical importance to the regulation of floral reversion, seeds breeding and reduce the economic loss. This study compared normal floral with reversion floral of expression differences on RNA level by the cDNA-AFLP technique to find the cDNA differential fragment , which close related to longan floral reversion, in order to lay the foundation for cloning the close related gene on longan floral reversion.This research took longan normal floral and reversion floral as objects , extracted total RNA respectively and synthesized first strain using reverse transcriptase. Then synthesized cDNA double-strained to analyze by AFLP. In cDNA-AFLP operation , double-strained cDNA was digested with EcoR I and Mse I. Specifically designed adaptors were ligated to the ends of restriction fragment. Pre-amplified them with pre-amplified primers , and diluted the templates 90-folds by water Amplified the templates with 64 pairs of selective primers, and then extended by two selective based at the 3' end. The resulting products were size-fractionated on a 6% polyacrylamide sequencing type gel and stained with silver to fingerprint analysis .After fingerprint analysis , 25 differentially expression fragments was obtained. 25 fragments were re-amplification and purification , then sequenced by company. 14 differnetially express fragment sequences were obtains. The homology of the sequences were determined by comparison with the database by using BLAST at NCBI. The results showed that 7 sequences were highly homologied , 6 sequences were low homologied, and one sequence was not matched . In the 7 sequences, there are 3 sequences speculated related to longan floral reversion : TDF331, which is longan EGases gene;TDF112, which is longan NIMA related protein kinases gene; And TDF313 ,which is longan chitinase CHI 1 gene. TDF331 and TDF313 were up-regulated on the period of longan floral reversion, and TDF was down-regulated on the period of longan floral reversion.