The RAPD Analysis Of Citrus Germplasms In Fujian & Cloning And Expression Analysis Of A LEAFY Homologue From Longan (Dimocarpus Longan Lour.)

In the part about "the RAPD Analysis of Citrus Germplasms in Fujian", the method of isolation of genomic DNA from citrus was studied. Consulting the relational program of RAPD reaction, Some essential factors that might affect the results of RAPD reaction were compared, after iterative experiments, the optimal amplification system and program for citrus RAPD-PCR were established. Identification, classfication and genetic relationship of 54 citrus germplasms (including the citrus hybrid varieties) of Fujian province were measured at molecular level by random amplified polymorphic DNA (RAPD) with twenty one primers of 10 bases. Meanwhile, the genetic diversity of several citrus varieties was analysed again to test the veracity of the first cluster. And the two cluster analysis based on discordant coefficient showed that the genetic relationships between 54 citrus germplasms of Fujian province were closer related. 54 citrus germplasms were divided into three groups (Fortunella Swingle, Poncirus Raf., and Citrus L.) when the heredity distance was 0.45, which was the same to the traditional classification system. And the germplasms of the Citrus L. were divided into three groups again when the heredity distance was 0.39. We propose RAPDs in citrus could be used as molecular markers to assess the genetic of citrus and its related genera and clarify their evolutionary relationships.In the part about "Cloning and Expression Analysis of a LEAFY Homologue from Longan (Dimocarpus longan Lour.) ", the extraction methods of total RNA and genomic DNA from Longan were optimized firstly. Secondly, A 425bp cDNA fragment and a 1816bp genomic fragment were isolated from longan using degenerate primers, which were designed based on several LEAFY homologs. Comparision of sequence similarity showed that the sequences were LEAFY homolog gene. This two sequences have been submitted in the GenBank, and the submission numbers were DQ247694 and DQ307391. Thirdly, The expression patterns of the LEAFY homolog gene were also analyzed by quantitative RT-PCR. Its transcripts were detectable stronger in inflorescence and floral buds, weakly in shoot buds, no expression was detected in leaves and stems. In vegetative buds, which reversed from inflorescence, its expression was obviously higher than that in shoot buds. Finally, we gained the 3'- terminal sequence of the LFY gene by the 3'-RACE method.