search
for
 About Bioline  All Journals  Testimonials  Membership  News  Donations


Zoological Research
Kunming Institute of Zoology, Chinese Academy of Sciences
ISSN: 2095-8137
Vol. 31, No. 3, 2010, pp. 205-220
Bioline Code: zr10029
Full paper language: Chinese
Document type: Research Article
Document available free of charge

Zoological Research, Vol. 31, No. 3, 2010, pp. 205-220

 en Spatial Patterns of Genetic Differentiation in Brachionus calyciflorus check for this species in other resources Species Complex
XIANG, Xian-Ling; XI, Yi-Long; WEN, Xin-Li; ZHANG, Jin-Yan & MA, Qin

Abstract

To understand spatial patterns of genetic differentiation in the Brachionus calyciflorus check for this species in other resources species complex, the rDNA ITS regions of 124 rotifer clones collected from eight geographic regions in East China were sequenced and analyzed. A total of 73 haplotypes were defined, and were grouped into three clades by the phylogenetic trees. The divergences of ITS sequence among the three clades ranged from 4.2% to 25.3%, indicating the occurrence of three cryptic species (cryptic species I, cryptic species II and cryptic species III). The sympatric co-occurrence of these cryptic species was observed at Guangzhou, Danzhou and Wuhu. The nucleotide diversity in B. calyciflorus complex was higher, and so was haplotype diversity. Within cryptic species III, the higher genetic differentiation might attribute to fragmentation, restricted gene flow, and interfered effective gene flow and accelerated differentiation of geographic populations by the rapid increase of colonizers after an ambiguous glacial bottleneck. The nested clade analysis suggested to some extent the geographic structure, and the non-significant correlation existed between the geographic distance and the average pairwise difference between populations (Da) as well as Fst. The Younger Dryas Event after the last full glacial period might has considerable effect on the patterns of geographic structure and distribution of cryptic B. calyciflorus species. During the YD event, the three cryptic species probably retreated and co-occurred in multiple relict refugia to the south of Nanling area. Long-distance colonization possibly coupled with subsequent fragmentation might be the main reason of the current patterns of geographic structure. The geographic distribution of B. calyciflorus complex on a global scale might attribute to the motion of continental plates.

Keywords
Brachionus calyciflorus; Species complex; Genetic differentiation; Spatial pattern; Nested clade analysis; Phylogeography

 
© Copyright 2010 Kunming Institute of Zoology, the Chinese Academy of Sciences
Alternative site location: http://www.zoores.ac.cn/

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2017, Site last up-dated on 05-Dec-2017.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil