02540nas a2200253   4500008004100000245016000041210006900201260001200270300001200282490000700294520168100301653001901982653002202001653001502023653001202038653001902050653002902069100001602098700001302114700001102127700001402138700001702152856011702169       2009                        eng d00aHigh allozyme diversity and unidirectional linear migration patterns within a population of tetraploid Isoetes sinensis, a rare and endangered pteridophyte0 aHigh allozyme diversity and unidirectional linear migration patt  c2009///  a52 - 580 v903 aIsoetes sinensis (Isoetaceae), an aquatic quillwort which occurs only in two fragmented sites of China as an allotetraploid, is critically endangered. Genetic variation among eight subpopulations of I. sinensis was examined in the Xin'an River (119°14′-15′E, 29°28′N) by using allozyme polymorphism. Eighteen loci of 10 enzyme systems were examined and used for the analysis of population genetic parameters. As expected for allotetraploids, fixed heterozygosity was found at four loci. A high level of genetic diversity was observed in the population, with mean number of alleles per loci of 1.8, and mean percentage of polymorphic loci of 55.6%, which were much higher than the average values in fern species. The genetic variation within each subpopulation was not positively correlated with its size, which may be explained by high gene flow (Nm = 2.57), clonal reproduction and fixed heterozygosity of allopolyploid. The I. sinensis population contained high clonal diversity (PD = 0.39, D = 0.95), indicating the successful seedling recruitment of the population. Significant positive relationship was detected between clonal diversity and the size of subpopulation. Partitioning the genetic diversity indicated that 91.1% of the genetic variation was within subpopulations and only 8.9% existed among subpopulations. The migration pattern of I. sinensis along the Xin'an River is best explained by a source-sink model, but with unidirectional gene flow among subpopulations underlined by hydrochoric force. The results were then discussed in relation to both in situ and ex situ conservation efforts of the population. © 2008 Elsevier B.V. All rights reserved.10aAllotetraploid10aGenetic diversity10aHydrochory10aIsoetes10aRiparian plant10aUnidirectional migration1 aChen, Y.-Y.1 aYang, W.1 aLi, W.1 aLi, Z.-Z.1 aHuang, H.-W.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-54249105798&partnerID=40&md5=962f14606c468408a8b8d98333cd329201941nas a2200253   4500008004100000245015600041210006900197260001200266300001200278490000700290520107700297653001901374653002201393653001201415653002201427653001901449653002501468100001601493700001601509700001701525700001401542700001401556856011701570       2012                        eng d00aMicrosatellite analysis reveals the genetic structure and gene flow of the aquatic quillwort Isoetes sinensis, a critically endangered species in China0 aMicrosatellite analysis reveals the genetic structure and gene f  c2012///  a52 - 570 v963 aIsoetes sinensis is a critically endangered aquatic quillwort, occurring in two fragmented sites of China (Xiuning county of Anhui; Jiande county of Zhejiang). During a five-year period (2004-2009), the areas and sizes of the two populations diminished dramatically due to intensive human activities. Genetic structure of the species was investigated using simple sequence repeat makers (SSRs). For seven nuclear microsatellites, high levels of genetic diversity were found within populations (H E=0.324-0.447). Strong genetic differentiation was detected between populations (G ST=0.376), while weak genetic differentiation was found within populations (G ST=0.026-0.080). Notably, in contrast to the source-sink model suggested by previous study (Chen et al., 2009), the migration pattern of I. sinensis along the Xin'an River is best explained by the linear symmetrical non-adjacent flow model (LSNF), which indicates that intensive human activities of recent years have greatly affected the gene exchange pattern among I. sinensis subpopulations. © 2011 Elsevier B.V.10aAllotetraploid10aGenetic diversity10aIsoetes10aMigration pattern10aRiparian plant10aStepping-stone model1 aChen, Y.-Y.1 aKong, D.-R.1 aHuang, C.-H.1 aXu, Y.-X.1 aLi, Z.-Z.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-84855293635&partnerID=40&md5=824e647a2989ecda4486a69d98cdaac2