Molecular Systematics Of Galatella Group(Astereae,Asteraceae)

Trib.Astereae,the second largest group in Asteraceae family is widely distributed and has a rich diversity of species.The complicated multisource origins of the group lead to the widespread difficulty in defining the phyletic classification of all classification layers.Based on the relevant research evidences for classification in the Asteraceae family,Nesom(1994)established a taxonomic group of Galatella among the Trib.Astereae family,including about 35-45 types of Galatella Cass.,13 types of Crinitina Sojak.and the Tripolium Nees.Due to the unique morphological characteristics of each genus and the lack of molecular bioinformation for a long time,scholars hold different opinions on the taxonomic statuses of the three genuses and intergeneric relationships,and this has become one of the difficult issues in Trib.Astereae classification in the Asteraceae family.For this reason,it is of important value and significance to conduct the molecular systematics research on the three genuses of Trib.Astereae.This paper mainly conducts the molecular systematics research on the three genuses of Trib.Astereae(Trib.Astereae in the Asteraceae family),including the related species in 12 subtribes,36 internal groups and 4 external out-groups.The ITS,ETS,trnl-F,trnK and matK molecular systematics researches for the three genuses were carried out,and the maximum parsimony and Bayes Low were adopted to build a phylogenetic tree.The ITS and ETS of the two materials of Galatella Cass.were highly heterozygous,and the two genes were cloned and sequenced.According to the analysis on the tree,we've learned those below:(1)All phylogenetic trees built through the karyogene and chloroplast gene support that the Galatella Cass.is a monophyletic group.(2)The close genetic relationship among the Galatella Cass.,Crinitina Sojak.and Tripolium Nees.is higly supported,so it is reasonable to include the Linosyris Cass.and Tripolium vulgare Nees.into the Galatella Cass.(3)Although the tree genuses can be included into the Galatella Cass.,Linosyris Cass.and Tripolium vulgare Nees.have their uniqueness respectively and can separately become the subordinate groups or subgenus levels.(4)The Galatella fastigiiformis Novopokr.and Galatella altaica Tzvel.in the Galatella Cass.have hybrid origins.(5)Although they belong to the same branch with the Aster handelii Onno.,they have largely different morphological characteristics,so further researches are needed to determine whether they belong to convergent evolution.Through this research,we've found that there are still some limitations in work.First,the collection of not comprehensive sample materials resulted in the defects in some research data.Second,without the research regarding micro cell morphology,some experimental conclusions need to be studied further.Thus,we will seek further confirmation for this aspect in our future researchers so as to obtain more comprehensive evidences.