Study On Genes Differenitally Expressed Between Triploid And Diploid Loquat (Eriobotrya Japonica Lindl.) Using CDNA-AFLP Analysis

The triploid loquat showed more significant growth adventages in the growth potential of the branches, diameter, leaf size,thickness,leaf tissue structure,fioral organs and fruit characteristic.And nuclear-free,greatly improved the fruit edible.However,its gene express and regulation mechanism are not clear.In this experiment,the young leaves,buds and young fruits of homologous triploid varieties "senwei zaosheng"and"changbai yihao"were as materials,and theirs diploid young leaves,buds and young fruits were as controls.The method of LiCl-CTAB was used to extrat total RNA,and cDNA was synthesized to used as the template for cDNA-AFLPanalysis.Differential fragments were recovered,cloned and sequenced,and the results are as follows:(1)3695transcript derived fragments were got by using fourteen pairs of primers frompairs combinations,and of148transcript derived fragments were got,accounting for4%of the total amplified bands.(2) It is only about1%of sites had changed in homology triploid loquat,and the sites of expression was different in all organs.The number of silent sites was more than the active sites in the young leaves of tripliod loquat, and the number of active sites was more than the silent sites in the buds of tripliod loquat, while in young fruit showed unregularity.(3) The polymorphism of the same locus in different triploid monoclonal showed more gene silencing locus among148differential gene fragments.(4)148differential gene fragments sequence through the NCBI blastx analysis, involved in transcriptional regulation, material and energy metabolism, d. isease resistance, signal transduction, protein synthesis and degradation of the cell structure of the composition of functions, unknown or hypothetical proteins,as well as low homology sequences and no found sequences. (5) The difference segments of homologous triploid loquat showed gene activation and high homology to known sequences.They wereTDF1,TDF27,TDF42,TDF46,TDF47, TDF53, TDF93, TDF109,TDF117. And10segments showed low homology to known sequences or were no found sequences such as TDF60,TDF82,TDF91,TDF95,TDF101, TDF102,TDF107,TDF116,TDF136,TDF142. The numbers of these10segments in order were as A1-A10(A-activation).(6)The difference segments of homologous triploid loquat showed gene silence were TDF10,TDF51,TDF70,TDF85,TDF103,TDF110,TDF112,TDF120,TDF121,TDF122, TDF124,TDF144,and they were unkown genes.The numbers of these12segments in order were as S1-S12(S-silence).(7) TDF74in homologous triploid loquat species and their diploid was coexpression It had highly homologous to castor zinc finger proteins.