01188nas a2200241   4500008004100000245007900041210006900120260001200189300001400201490000700215520045700222653001000679653001400689653001500703653001200718653001400730653002700744100001600771700001200787700001700799700001400816856011600830       2002                        eng d00aIsoetes yunguiensis (Isoetaceae), a new basic diploid quillwort from China0 aIsoetes yunguiensis Isoetaceae a new basic diploid quillwort fro  c2002///  a587 - 5910 v123 aIsoetes yunguiensis, a basic diploid species with a chromosome number of 2n = 22, is described and illustrated. This species occurs on the Yunnan-Guizhou Plateau in southwest China. It is similar to I. japonica in its appearance and emergent aquatic habit. Herbarium specimens of I. yunguiensis previously have been misidentified as I. japonica. Isoetes yunguiensis differs from I. japonica in megaspore and microspore morphology and chromosome number.10aChina10aEast Asia10aIsoetaceae10aIsoetes10aQuillwort10aYunnan-Guizhou Plateau1 aWang, Q.-F.1 aLiu, X.1 aTaylor, W.C.1 aHe, Z.-R.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-0036939584&partnerID=40&md5=da8d4d4668c03846b51b3df5877e860201566nas a2200169   4500008004100000245013100041210006900172260001200241300001400253490000700267520094200274100001501216700001601231700001601247700001701263856011601280       2003                        eng d00aRelationship between Water Chemistry and the Distribution of the Endangered Aquatic Quillwort Isoetes sinensis Palmer in China0 aRelationship between Water Chemistry and the Distribution of the  c2003///  a361 - 3670 v183 aThe progressive decline in populations of Isoetes sinensis Palmer in China has been attributed to deteriorating water quality; however, no data have been adduced to support this assumption. In this study we identified locations in China that presently have populations of I. sinensis and locations where the species has been extirpated. We measured various water chemistry parameters at these sites, as well as at similar sites within the distribution range of I. sinensis but from where the species has never been recorded. The results indicate that distribution and occurrence of I. sinensis are closely correlated with water chemistry. Water samples drawn from habitats from where I. sinensis has been extirpated had higher concentrations of heavy metal ions, particularly chromium VI (Cr 6+). In addition, these samples consistently yielded higher readings for dissolved carbon dioxide, water hardness, and concentration of nitrates.1 aWen, M.-Z.1 aPang, X.-A.1 aWang, Q.-F.1 aTaylor, W.C.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-0242275988&partnerID=40&md5=c81ad2c1833c6a70e17163c958e43e5002081nas a2200241   4500008004100000245012600041210007000167260001200237300001200249490000700261520129100268653001701559653001501576653002201591653002301613653000901636100001601645700001201661700001601673700001701689700001601706856011701722       2005                        eng d00aGenetic variation within the endangered quillwort Isoëtes hypsophila (Isoetaceae) in China as evidenced by ISSR analysis0 aGenetic variation within the endangered quillwort Isoëtes hypsop  c2005///  a89 - 980 v823 aThe genetic diversity of 56 individuals of Isoëtes hypsophila Hand.-Mazz. from China was investigated by ISSR. Twelve primers were screened from 65 primers, and a total of 119 DNA fragments were scored, of these, 82% were polymorphic bands, which indicated that high levels of genetic variation existed in the natural populations. Genetic diversity varied greatly among populations with the percentage of polymorphic band (PPB) values ranging from 8 to 35%. An analysis of molecular variance (AMOVA) was used to apportion the variation between regions, among populations within regions, and within populations. Results indicated that most of the variance (85%) occurred between Yunnan and Sichuan. The variances among populations within regions and within populations, however, were only 5 and 10%, respectively. In the among-population analysis, the larger part of genetic variation (77%) resided among populations, and less (23%) presented differences within populations. UPGMA cluster analysis showed that there was no distinct genetic differentiation between populations from Sichuan province. A number of causes including limited gene flow, genetic drift and inbreeding might have led to these observed genetic profiles of I. hypsophila. © 2005 Elsevier B.V. All rights reserved.10aConservation10aEndangered10aGenetic variation10aIsoetes hypsophila10aISSR1 aChen, J.-M.1 aLiu, X.1 aWang, J.-Y.1 aRobert, G.W.1 aWang, Q.-F.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-20444420155&partnerID=40&md5=c58709593caeba345cf50c4fba7d621302141nas a2200217   4500008004100000245008300041210006900124260001200193300001600205490000700221520145500228653001001683653001701693653001201710653002101722653001401743100001601757700001701773700001601790856011701806       2006                        eng d00aEcology and conservation of the endangered quillwort Isoetes sinensis in China0 aEcology and conservation of the endangered quillwort Isoetes sin  c2006///  a4069 - 40790 v393 aIsoetes sinensis Palmer is an East Asia endemic fern that faces impending extirpation from the expansive area of Mainland China. Presently, only two natural populations are known to exist in this vast region. Both populations have decreased by about 50% within the last 4 years. This reduction is most probably related to the decline in the size of the wetlands since reproductive activity, spore production, and recruitment were noticeably lower at the microsites occurring in smaller ponds. The decline in population size seems to be associated with succession from marsh to dry land at the habitats of both populations. The study revealed that individuals in both populations produced copious numbers of spores suggesting adequate fecundity, furthermore high levels of spore germination were obtained in laboratory experiments. However, inefficient spore dispersal appears to have contributed to the limited spread of the species. The sex ratio in both populations was male-biased. Several factors are identified here as posing a threat to Isoetes sinensis populations in China, chiefly the loss of habitat due to infrastructure construction and competition with adventive weed species for establishment on available sites. Disturbance by introduced mammals during browsing and trampling by livestock farm workers, as well as tourists, further contribute to the diminishing numbers of Isoetes sinensis at the study sites. © 2005 Taylor & Francis.10aChina10aConservation10aEcology10aIsoetes sinensis10aRare fern1 aWang, J.-Y.1 aGituru, R.W.1 aWang, Q.-F.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-33646483501&partnerID=40&md5=91677e55ca7f81da659db6f0f6afe26002208nas a2200217   4500008004100000245005800041210005600099260001200155300001400167490000700181520157700188653001001765653001401775653001201789653001101801653002101812100001201833700001201845700001601857856011701873       2008                        eng d00aSpore morphology of Isoëtes (isoëtaceae) from China0 aSpore morphology of Isoëtes isoëtaceae from China  c2008///  a479 - 4890 v463 aMicromorphological characters of mega- and microspores of five Isoëtes species from China were observed under scanning electron microscope (SEM). Megaspores of I. hypsophila have a levigate ornamentation, and are 358 μm in diameter (mean, n=30), microspores of this species have a gyrus ornamentation, and are 22 μm in length (mean, n=30); megaspores of I. yunguiensis have a cristate-reticulate ornamentation, with a size of 390 μm in diameter (mean, n=30), while microspores nearly smooth with some fine granulates, and with a size of 22 gm in length (mean, n=30); megaspores of I. taiwanensis are tuberculate and 312 μm in diameter (mean, n=30), echinate microspores are 24 μm in length (mean, n=30); cristate megaspores of I. sinensis are 409 μm in diameter (mean, n=30), and echinate microspores are 28 μm in length (mean, n=30); megaspores of I. orientalis have a cristate-reticulate ornamentation, with diameter of 420 μm (mean, n=30), microspores of this species have an echinate-tuberculate ornamentation with a size of 34 μm in length (mean, n=30). Based on the morphological characters of spores and chromosome numbers among taxa, it was found that mean spore size in each species of Isoëtes generally reflected the ploidy level. I. hypsophila, I. yunguiensis and I. taiwanensis, with smaller mean spore size, are diploidy with 2n=22; I. sinensis (2n=44) and I. orientalis (2n=66), with larger mean spore size, are polyploidy. The spore morphology of Isoëtes still plays an important role in identification and classification of Isoëtes from China.10aChina10aEvolution10aIsoetes10aOrigin10aSpore morphology1 aLiu, X.1 aLiu, H.1 aWang, Q.-F.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-57349117891&partnerID=40&md5=f310ff0165e440259efb4b7c6431474302062nas a2200229   4500008004100000245011900041210006900160260001200229300001400241490000800255520127100263653002101534653003101555653002301586653002601609653001901635100001601654700001201670700001701682700001601699856011701715       2008                        eng d00aChloroplast DNA phylogeography of the Chinese endemic alpine quillwort Isoetes hypsophila hand.-mazz. (isoetaceae)0 aChloroplast DNA phylogeography of the Chinese endemic alpine qui  c2008///  a792 - 7980 v1693 aWe examined chloroplast trnL intron sequence variation within Isoetes hypsophila, a Chinese endemic alpine quillwort species. Sequence data were obtained from 46 individuals in six populations throughout the natural distribution of the species. Sequences appeared to have neutral evolution (Tajima's criterion D = -1.66453, 0.1 &gt; P &gt; 0.05; Fu and Li's test D* = -1:92897, 0.1 &gt; P &gt; 0.05; F* = -2.17823, 0.1 &gt; P &gt; 0.05). Eleven haplotypes were identified in I. hypsophila. A relatively high level of haplotype diversity (h = 0.817) and a low level of nucleotide diversity (π = 0:0045) were detected in I. hypsophila. Indirect estimates of gene flow based on cpDNA variation revealed significant genetic differentiation between the ZD1 population in Yunnan Province and the populations from Sichuan Province. High genetic differentiation between Yunnan and Sichuan populations was consistently indicated by both hierarchical analyses of molecular variance (AMOVA; GST = 0.5011) and the structure of a neighbor-joining tree. From nested clade analysis, restricted gene flow with isolation by distance was inferred to be responsible for the current spatial genetic structure of I. hypsophila. © 2008 by The University of Chicago. All rights reserved.10aAlpine quillwort10acpDNA trnL intron sequence10aIsoetes hypsophila10aNested clade analysis10aPhylogeography1 aChen, J.-M.1 aLiu, F.1 aGituru, W.R.1 aWang, Q.-F.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-47649125533&partnerID=40&md5=8f27b208869f24aef198146456c288ea