02429nas a2200217   4500008004100000245010100041210006900142260001200211300001400223490000700237520170000244653002801944653001401972653001801986653002102004653002202025100001902047700001402066700001402080856011702094       2007                        eng d00aIrregular meiotic behavior in Isoetes sinensis (Isoetaceae), a rare and endangered fern in China0 aIrregular meiotic behavior in Isoetes sinensis Isoetaceae a rare  c2007///  a358 - 3630 v603 aChromosomal abnormalities including cytomixis occurred in meiotic process of pollen mother cells of many angiosperm species at high frequency, but similar phenomenon was rarely reported in low vascular plants. This study we investigated the microsporogenesis of Isoetes sinensis Palmer, a quillwort of ancient heterosporous lycopsids Isoetaceae plants. Irregular chromosomal behavior especially cytomixis was emphasized. It appeared in each stage of meiotic division from prophase I to telophase II. The cytoplasmic channels between microspore mother cells were narrow and stretched. The genetic material connection was maintained mainly by visible chromatin fiber. The cytomixis was just occurred between two adjacent microspore mother cells of same stages. A variety of other abnormal chromosomal behaviors including chromosomal stickiness, fragmentation, bridge, laggards, micronucleus, were observed, albeit with low frequency. All sorts of chromosomal abnormalities were counted at two stages, anaphase I and anaphase II. They were approximately 24.4% and 26.9% respectively. This number was slightly higher than that of microspore abortion which was about 14.8%. I. sinensis was listed as a critical endangered species due to habitat fragmentalization, water pollution and wetland degradation. Human being activities are without doubt the immediate forces resulting in the population decreasing of I. sinensis. Whether the individual numbers dropping or habitat withdraw has consequently caused the producing of the overall high abnormalities of chromosomal behaviours is not determined yet. However, cytomixis and other irregular chromosomal phenomenon seemed not to be a natural process.10aChromosomal abnormality10aCytomixis10aEastern China10aIsoetes sinensis10aMicrosporogenesis1 aHeng-Chang, W.1 aLi, J.-Q.1 aHe, Z.-C.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-49449109278&partnerID=40&md5=10a888a1588bfcc9524b7cca2102091202025nas a2200229   4500008004100000245009100041210006900132260001200201300001400213490000700227520128000234653002501514653001901539653002001558653002101578100001901599700001401618700001401632700001601646700001601662856011701678       2007                        eng d00aDetermination of phytogenetic relationships among isoetes species using random primers0 aDetermination of phytogenetic relationships among isoetes specie  c2007///  a367 - 3720 v313 aIsoetes L. is an ancient, primitive genus of lycopsids. The genus occupies a unique position in plant evolution as the closest relatives of tree lycopods. The morphological characters, namely leaf size, comb, and sporophyll size, are used diagnostically to help in the identification of the Isoetes species. Thus, species identification of Isoetes is always problematic and the knowledge on the genetic relationship of Isoetes species is also limited. Therefore, in order to find a suitable method for species identification and estimation of genetic relationship among different species of Isoetes, a Random Amplified Polymorphic DNA (RAPD) technique based on Polymerase Chain Reaction (PCR) was used for the described purpose. Out of 150 decamer primers tested, 58 produced good amplification products. A total of 4442 amplification products were scored and only 3479 bands (78.11%) were found to be polymorphic, with sizes ranging from 200 to 5500 bp. Unweighted pair group method using arithmetic average cluster analysis revealed a clear genetic difference among Isoetes species. The scientific data presented in this study suggest that RAPD-PCR could be a valuable tool for identification and estimation of genetic relationship among species of Isoetes L. © TÜBİTAK.10aGenetic relationship10aIdentification10aIsoetes species10aRAPD fingerprint1 aTripathi, Y.K.1 aGurha, P.1 aGhosh, D.1 aKumar, R.V.1 aPrakash, V.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-35048852487&partnerID=40&md5=8d7ea4295bc545c5c38b6e44f6b9cd8500784nas a2200181   4500008004100000245006700041210006600108260001200174300001400186490000700200520019800207653001200405653001600417653001800433100001700451700001700468856011700485       2007                        eng d00aIsoetes araucaniana, a new species from southern South America0 aIsoetes araucaniana a new species from southern South America  c2007///  a220 - 2240 v973 aIsoetes araucaniana is newly described from central Chile. This aquatic species is endemic to Araucanía and is the only southern Andean species with strongly and densely reticulate megaspores.10aIsoetes10aNew species10aSouth America1 aMacLuf, C.C.1 aHickey, R.J.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-39449094567&partnerID=40&md5=187a92568719c2772ed711b49957998d02202nas a2200241   4500008004100000245007100041210006800112260001200180300001400192490000700206520146300213653001401676653003301690653001201723653001101735653001101746653001601757653002801773653001001801100001801811700001401829856011701843       2007                        eng d00aFoliar diagnostic characters in Isoetes (Pteridophyta, Isoetaceae)0 aFoliar diagnostic characters in Isoetes Pteridophyta Isoetaceae  c2007///  a202 - 2350 v943 aFoliar characters were studied in 25 European, North African, North American, and South American terrestrial, amphibious, and aquatic: taxa of the genus Isoetes L. (Pteridophyta, Isoctaceae). The foliar characters investigated have a variable diagnostic value. The presence and types of cuticular ornamentations, types of margins, epidermal patterns and cell ratios of the epidermis, types of IPP (intercellular peetic protuberances) in the cells of the leaf diaphragms, epidermal patterns and cell ratios of velum, epidermal patterns, and nature of walls in the adaxial epidermis of sporangia may be good diagnostic specific characters that should be included in taxonomic descriptions. Transverse sections of the microphylls, the types and distribution of collenchyma (fascicular, lacunar, or partially laminar collenchyma, with the latter two types described here for the first time), the cell types of leaf diaphragms, the presence of IPP in these cells, the partial or complete endodermis in the air chambers, and the presence of a persistent mucilage-secreting or an early lignified ligule are features that characterize species groups in Isoetes. The mucilage-secreting ligula and the types of endodermis can be considered as generic traits in Isoetes. The genus was hugely considered as lacking good diagnostic characters or having rather environmentally influenced traits, two concepts that are discussed here after presentation of the new evidence.10aEpidermis10aFoliar diagnostic characters10aIsoetes10aLabium10aLigula10aMicrophylls10aSporangial adaxial wall10aVelum1 aRolleri, C.H.1 aPrada, C.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-34248570912&partnerID=40&md5=aa7a39e226168462b49230d818ab399101875nas a2200229   4500008004100000245009000041210006900131260001200200300001200212490000600224520112400230653001701354653002201371653001201393653004401405653002401449100001301473700001701486700001201503700001301515856011701528       2007                        eng d00aGenetic diversity in Isoetes yunguiensis, a rare and endangered endemic fern in China0 aGenetic diversity in Isoetes yunguiensis a rare and endangered e  c2007///  a46 - 490 v23 aIsoetes yunguiensis is an endangered and endemic fern in China. Field survey indicated that only one population and no more than 50 individuals occur in the wild. The genetic variation of 46 individuals from the population remaining at Pingba (Guizhou Province, China) was assessed by Random Amplified Polymorphic DNA (RAPD) finger-printing. Twelve primers were screened from sixty ten-bp arbitrary primers, and a total of 95 DNA fragments were scored. Of these, 62.1% were polymorphic loci, which indicated that high level genetic variation existed in the natural population. The accumulation of genetic variation in the history of the taxon and the apparent minimal reduction effect on genetic diversity following destruction of habitat might be responsible for the high level genetic diversity presently remaining in the I. yunguiensis population. However, with the continuing decrease of population size, the genetic diversity will gradually be lost. We suggest that the materials from the extant population should be used for re-establishment of the populations. © 2007 Higher Education Press and Springer-Verlag.10aEndemic fern10aGenetic diversity10aIsoetes10aRandom amplified polymorphic DNA (RAPD)10aRare and endangered1 aChen, J.1 aGituru, W.R.1 aLiu, X.1 aWang, Q.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-33847396236&partnerID=40&md5=ee6f56a9a5fcf2d93d7218f43862d556