Molecular Phylogeny Of Walnut(Julans.lnn) Based On Chloroplast Matk Gene Sequence Data

This article studied the the system classification problems and genus relationship of22species of walnut which belong to Juglans.lnn using the matK sequence analysis technology on the molecular level. The research is good for walnuts’germplasm resources protection, cross-breeding and development and provides the theoretical basis and reference data for the latter studying of walnuts.Main conclusions are as follows:1.By comparing the traditional CTAB and improved CTAB method and better it, we put forward the suitable way to extract the nucleic acid DNA of walnut genus.When using modified CTAB method to extract,we found that all experimental steps are conducted at room temperature, without using RNA enzyme, extracted products are available for subsequent molecular experiment.2.Measure the sequence length of the chloroplast matK nearly3’end which is from genera22species of walnut is the726bp. We registered the sequences in GenBank and get12numbers, the numbers were KC533799, KC533800, KC920668, KC920669, KC920670, KC920671, KC920672, KC920673, KC920674, KC920675, KC920676, KC920677.3.The matK gene sequence has17varied sites and8information sites, their percentage are2.4%and less than1.2%in all squence. The chloroplast matK gene sequence are much conservative in the3’end for Walnut. We get the sequence length of MatK which are234amino acid beside the specie named Bokexiang173amino acid. Build the molecular phylogenetic tree with two method and get the NJ-tree and the MP-tree. The result shows that the22species of walnut is devided into five groups, among the species Zha343show the obvious differences with other21species. Among the21species,the species named Liaohe1、Jinbofeng1、Xifu1and Bokexiang have obvious differences with the remain species.4.Adding outside groups to build system of evolutionary tree. Select11sequences which have high homology(more than90%) with our materials in BLASTP database, these outgroups are from different genera or family but they are also belong to Hamamelis, Dicotyledons plant. Use outgroups and our matericals to make system tree, better analyzed intraspecific and interspecific genetic relationship and families and older species. According to the results, the juglandaceae plants is close to fagales plant in evolutionary relationships, and fagales plants is relatively similar with Bayberry mesh in evolutionary relationships.