|
Charadriiformes (Charadriiformes) Birds are an the wetlands important component of a very important ecological significance. About the class for group Branch and the taxonomic status of order, has been one of the main issues of debate in the study of ornithology. Over the years, large shorebirds are based on morphology and ecology. Due to shorebird are many aspects of the morphology and life habits have greater similarity, based on morphological characters so that its classification has been controversial, it is necessary to adopt means of molecular biology to study the phylogenetic relationships between taxa. This paper mainly uses the techniques and tools of molecular biology, through amplification and determination of Charadriiformes 4 families, 15 species of birds of the mitochondrial 12S rRNA gene sequence, combined with the five downloaded from GenBank shorebirds 12S rRNA gene sequences, the use of software for the analysis of sequence variants and construct a phylogenetic tree provides a theoretical basis, in order to clarify the phylogenetic relationship of this taxon. The main findings are as follows: 12S rRNA gene sequence (1031bp) Features: T, C, A, G, the average content of 21.4%, 26.9%, 31.4% and 20.2%, purine content of 51.6% was slightly higher at the pyrimidine nucleotide content of 48.3%. 12S rRNA gene sequence average R-value of 3.3, greater than the critical value, the sequence far from saturated replaced. Sequence between the average genetic distance of 0.115. 2. Entire system tree constituted by the three major clades: one for shorebirds, a gulls and puffins class, another branches plovers class. And the plovers class located in the base of the tree, first differentiation taxa. 3 in the snipe Section separate analysis found that broad-billed Sandpiper (Limicola falcinellus) in the system tree from the law or parsimony do, and always Stint within the genus. Due to the variation of the 12S rRNA gene sequence is quite rich, the entire gene fragment contains from interspecific evolutionary genetic information between the Division, constructed molecular phylogenetic trees reflected in the phylogenetic relationships of the shorebirds and morphological classification different, molecular phylogenetic studies of this taxon evidence also shows that the 12S rRNA gene in the system the birds between families and interspecific relations has a positive effect, you can think that the 12S rRNA gene is a good molecular markers. Draw the following conclusions: 1 6 families studied, the plovers Branch is the most primitive branch the first differences Branch; then Gull Branch, thief gulls, terns and Guillemot gull-class one; last snipe Branch. 2. In snipe Branch, the the Stint case of a Latest differences. 3 snipe Branch, Broad-billed sandpiper Stint is several Stint poly with Broad-billed sandpiper should contain the in Stint genus;, snipe are clustered into a Stint, indicating the genus snipe and shore snipe is a genetic relationship. 4 in plovers Division, ring-necked plover plover genus and Ringed plovers to accumulate one, and then the Americas and plover is a the golden plover clustering, these types of birds in the plover family relationships studied in this paper morphological classification of higher consistency.
|