云南报春花属(报春花科)一新变种--长萼铁梗报春

报道了云南报春花属一新变种,即长萼铁梗报春Primula sinolisteri Balf．f．var．longicalyx D．W．Xue＆C．Q．Zhang。新变种与原变种的不同之处在于：花冠喉部具环状附属物,外面无毛,花萼与冠筒近等长,长7—10mm。     

Effect of storage time,site and floral morph on seed germination of the threatened distylous primrose Primula cusickiana var. maguirei

Ex situ conservation of rare plant species requires an understanding of germination requirements. We report the first successful germination trials for Maguire primrose (Primula cusickiana var. maguirei[L.O. Williams] N.H. Holmgren & S. Kelso), a threatened perennial herb narrowly restricted to a 20‐km canyon in northern Utah, USA. Seeds collected from different sites (upper or lower canyon populations) and flower morphs (pin or thrum) that had been stored for either 1 or 2 years were cold, moist stratified in darkness at 1–2°C for 270 days. Independent of treatment, time to first germination was approximately 75 days, time to 50% germination (T₅₀) was approximately 165 days, and total germination was 55.8%. Higher mean germination was observed in seeds stored for 2 years compared with seeds stored for 1 year, as well as in seeds from pin flowers compared with thrum flowers. There was not a significant effect of site on mean germination, but there was a significant storage time × site interaction. Seeds stored for 2 years also had a lower mean T₅₀ versus seeds stored for 1 year. In addition, seeds from upper canyon populations had a higher mean T₅₀ than those from lower canyon populations. Our results suggest that short‐term storage should not significantly decrease seed viability, and that both flower morph and canyon location may influence germination. Evidence suggests that germination patterns are adaptive. Our results contribute to our understanding of the germination biology of P. cusickiana var. maguirei and inform future conservation efforts for this threatened species.     

Unveiling the origin of Quercus serrata subsp. mongolicoides found in Honshu,Japan, by using genetic and morphological analyses

Quercus mongolica is a tree found in temperate deciduous forests in east Asia. In Japan, Q. mongolica var. crispula is commonly found; moreover, an oak whose morphology is similar to that of Q. mongolica var. mongolica of the Asian continent has been found in certain areas of Honshu and Hokkaido. Recently, the oak found in Honshu was described as Q. serrata subsp. mongolicoides (QSM). However, genetic comparison between this oak and Q. mongolica var. mongolica of the Asian continent has not been performed; the origin of QSM is thus unknown. Therefore, we aimed to determine the origin of QSM by conducting nuclear microsatellite (nSSR), chloroplast DNA (cpDNA) and leaf morphology analyses for the three taxa, as well as other congeners. The cpDNA variation overlapped among the three taxa, suggesting low discrimination ability for these taxa. Although morphological congruency was found between QSM and Q. mongolica var. mongolica, results of nSSR analyses showed that QSM contained a genetic admixture of Q. mongolica var. mongolica of the Asian continent and Q. mongolica var. crispula of Japan, bolstering an admixture hypothesis. The nSSR and cpDNA analyses suggested that Q. mongolica var. crispula can be the progenitor of Q. mongolica var. mongolica and harbors the ancestral cpDNA haplotypes. Therefore, we concluded that QSM might have been created by an admixture that likely occurred within Japan between Q. mongolica var. crispula and putative relict Q. mongolica var. mongolica, which might have diverged in or around Japan from Q. mongolica var. crispula during the late Pleistocene.     

龙骨星蕨与膜叶星蕨的关系:来自叶绿体rbcL、rps4和trnL-trnF、rps4-trnS序列的证据

龙骨星蕨(Microsoriummembranaceumvar. carinatum)是新近发表的一个变种,从形态特征看,它与原变种膜叶星蕨(M. membranaceumvar. membranaceum)可以很容易地区分。但将龙骨星蕨与另外 3种国产星蕨属 (Mi crosorium)植物叶绿体基因组中rbcL、rps4基因和trnL trnF、rps4 trnS基因间隔区进行PCR扩增和序列分析,并与已经发表的真蕨类的相应序列进行比较发现,龙骨星蕨与膜叶星蕨在所研究的 4个DNA片段中均未表现出序列差异(除了trnL trnF区的一个 2bp长度差异外 ),而所比较的其他真蕨类变种间的相应DNA片段均存在一定的差异。因此DNA序列证据不支持龙骨星蕨变种的成立。     

Multiple hybrid origins, genetic diversity and population genetic structure of two endemic Sorbus taxa on the Isle of Arran, Scotland

Understanding the processes that have given rise to polyploid hybrid taxa is central to our understanding of plant evolution. In this study, we use an array of genetic markers in a population analysis to elucidate the hybrid origins of the Arran whitebeams Sorbus arranensis and S. pseudofennica, two woody plant taxa endemic to the Isle of Arran, Scotland. It has been proposed that S. arranensis was derived by hybridization between S. aucuparia and S. rupicola, and that subsequent hybridization between S. arranensis and S. aucuparia gave rise to S. pseudofennica. Analyses of species-specific isozyme, nuclear intron and chloroplast DNA markers confirm the proposed origin of S. arranensis, and indicate that S. aucuparia was the female parent in the hybridization. Analysis of microsatellite markers suggests that there have been at least three origins of S. arranensis on Arran. Microsatellite markers also support the proposed hypothesis for the origin of S. pseudofennica, and indicate at least five hybrid origins of this taxon. In total, three multilocus genotypes of S. arranensis and eight of S. pseudofennica were detected on Arran and multilocus genotypic diversity levels Hg were 0.09 and 0.63, respectively. Genetic differentiation (thetaST) values based on multilocus genotypes are substantial (0.344 and 0.470 for S. arranensis and S. pseudofennica, respectively) implying limited seed flow among populations. These results indicate that the endemic Sorbus taxa on Arran are the products of multiple and ongoing evolutionary events. This information must be incorporated into management policies for their future conservation.     

Clonal structure and patterns of allozyme diversity in the rare endemic Cycladenia humilis var. jonesii (Apocynaceae)

The rare endemic Cycladenia humilis var. jonesii (Jones cycladenia) has low levels of sexual reproduction. Enzyme electrophoresis was used to explore possible causes of low seed set and high fruit abortion by assessing the clonal structure and genetic diversity in populations. The seven populations studied were composed of multiple, highly interdigitated clones; thus low fruit set is not likely to be due to a scarcity of mates. Genotype frequencies did not differ significantly from Hardy-Weinberg proportions, suggesting that populations are not highly inbred. Jones cycladenia exhibited high levels of genetic diversity at both the population level (A = 1.7; P = 37; He = 0.14) and the taxon level (A = 2.7; P = 60) in comparison to other plants. These data suggest that genetic drift is unlikely to have left this taxon genetically depauperate. Furthermore, we detected little divergence among geographically disjunct populations of Jones cycladenia (FST = 0.10). In comparison, Jones cycladenia populations were highly differentiated from a population of the taxon's close relative, C. h. var. humilis (mean genetic identity = 0.76). Our study suggests that other reasons for low fruit set in Jones cycladenia, such as resource or pollinator limitation, or genetic load, should be explored in future research.     

Gene flow and inbreeding depression inferred from fine-scale genetic structure in an endangered heterostylous perennial, Primula sieboldii

We estimated the gene dispersal distance and the magnitude of inbreeding depression from the fine-scale genetic structure in the endangered heterostylous perennial Primula sieboldii. We indirectly estimated the neighbourhood size (Nb) and the standard deviation of gene dispersal distance (sigma(g)) from the detected genetic structure by using 10 microsatellite markers. We also estimated the fitness reduction in mating among neighbouring individuals caused by biparental inbreeding according to the genetic structure. We found clear fine-scale genetic structure (a significantly positive kinship coefficient within 42.3 m), and the indirect estimates of sigma(g) and Nb were 15.7 m and 50.9, respectively. These indirect estimates were similar to the direct estimates (18.4 m and 44.0). The slightly larger indirect estimate of Nb may reflect that inbreeding depression and genetic structure or rare long-distance dispersal that were overlooked in the direct estimate have elongated the long-term average of gene dispersal distance. P. sieboldii is also likely to suffer about 19% fitness reduction in progenies from mating among individuals 5 m apart. Our results suggest that biparental inbreeding and genetic structure can affect the range of gene dispersal and seed reproductive success in P. sieboldii.     

Demographic genetic structure of Cryptomeria japonica var. sinensis in Tianmushan Nature Reserve, China

Genetic changes over space and time provide insights into the relative roles of evolutionary factors in shaping genetic patterns within plant populations.However,compared with spatial genetic structure,few studies have been conducted on genetic changes over time.In this study,we used six polymorphic microsatellite loci to assess genetic variation of six size-classes of the population of Liushan,Cryptomeria japonica var.sinensis,in the Tianmushan National Nature Reserve,whose origin was debatable.The mean number of alleles per locus and expected heterozygosity were 4.583 and 0.5999 respectively,lower than other conifers with the same life history characteristics.FST was 0.002 4- 0.003,and the pairwise test revealed no significant differentiation in any pair of size classes.Significant heterozygosity excesses were detected in five size classes except the oldest one,indicating bottleneck event(s).The above results support the hypothesis that Tianmushan population was introduced and followed by natural regeneration.     

Genetic diversity and gene flow within and between two different habitats of Primula merrilliana (Primulaceae), an endangered distylous forest herb in eastern China

Understanding whether and how different habitats shape population genetics is a fundamental question and a specific goal for evolutionary and conservation biology research. This study examined genetic diversity and gene flow within and between mountain and foothill habitats of Primula merrilliana, an endangered distylous forest herb in eastern China. Eleven population characteristics, including area, size and density variation, from the two habitats were also investigated. Mountain populations had significantly higher mean genetic diversity than foothill populations, which may be explained by stronger self‐incompatibility breeding system, more opportunity to use elevational shifts to track suitable sites under conditions of climate change and more heterogeneous environments in the former habitat, rather than by the differences of population size, gene flow and genetic drift intensity between them. Genetic analysis revealed that two distinct lineages, corresponding to the two habitats, diverged at China's ‘Last Glaciation’ (11 700–67 500 yr BP), suggesting this divergence was probably triggered by warmer climates during inter‐ (or post‐) glacial periods. Low unidirectional gene flow from mountain to foothill habitats, chiefly by seed dispersal, played a more important role in overall gene flow between habitats than within‐habitat gene flow. Within habitats, pollen contributes more substantially to gene flow than seed dispersal, especially in foothill habitats, possibly due to higher individual density and larger population sizes. These results have implications for the conservation in this and similar landscape areas and indicate the need to protect suitable habitats with wide elevational spans and sufficient size to permit ecological and elevational shifts in response to climatic changes. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 172–189.     

Effect of plant traits and population structure on the female reproductive success of the endemic Primula elatior subsp. bergidensis (Primulaceae)

This study explores the possible causes of variation in female reproductive success of the subspecific taxon Primula elatior subsp. bergidensis, a distylic endemic to the north-western Iberian Peninsula, by analysing both vegetative and reproductive traits. In three populations, we marked vegetative and reproductive individuals either by mapping the spatial position of every individual (in one population), or by establishing permanent quadrats (in the remainder two populations). We recorded floral morph (pin or thrum), width and length of the largest leaf, scape length, and number of flowers produced; all individuals were monitored to estimate the number of fruits and seeds produced. The results show that the morph ratio did not differ significantly from 1:1 in any of the populations. The number of flowers per plant varied between populations, and longer scape length was associated with higher fruit set in all populations. Plant size, scape length, and population spatial structure all had major effects on reproductive success, but the strength—and in some cases the direction—of the effects varied among populations.     

滇西北玉龙雪山报春花种质资源的调查

滇西北玉龙雪山地处报春花属的现代形成与分布中心,有非常丰富的报春花种类。根据作者2003~2004年对玉龙雪山报春花属植物进行系统调查和资料整理,表明该地区有报春花40种(包括亚种与变种),占我国产报春花属植物总数的12%及云南产报春花属植物总数的29%;同时研究了该属植物在玉龙雪山的分布规律及其资源的生境类型并介绍了主要种类的生物学性状及观赏价值(包括花、叶及其开花期);而且对玉龙雪山报春花资源的保护及合理开发利用提出了建议。     

Natural hybridization of Yezo and Sakhalin spruce in central Hokkaido,revealed by DNA markers with contrasting modes of inheritance

Yezo spruce (Picea jezoensis var. jezoensis) and Sakhalin spruce (Picea glehnii) occur across Hokkaido and co‐occur in some forest habitats. This leads to the potential for natural hybridization between these two species, which has been shown to occur at low frequencies. The purpose of this study was to identify these hybrids and their possible mating patterns, using various Pinaceae DNA markers with different modes of inheritance. The markers used were maternally inherited mitochondrial DNA (mtDNA), paternally inherited chloroplast DNA (cpDNA) and biparentally inherited nuclear microsatellites (nSSRs). Seven putative natural hybrids, four artificially‐crossed F₁ hybrids, four parent plants from each species, and two artificially‐backcrossed hybrids of putative natural hybrids and their parents were analyzed using the diagnostic DNA markers developed in this study. We found Yezo spruce and Sakhalin spruce to be distinct (J and G types, respectively), and the modes of inheritance held true for the two species, as was previously reported to be the case in Pinaceae. Four of the seven putative natural hybrids harbored J‐type cpDNA, G‐type mtDNA and J/G‐type nSSRs, indicating that natural F₁ hybrids are likely to arise from a G (female) × J (male) crossing. One natural hybrid harbored G‐type cpDNA, J‐type mtDNA and J/G‐type nSSRs, which implies that hybrids produced by J (female) × G (male) crossings occur at low frequencies. The two remaining hybrids harbored J‐type cpDNA and mtDNA with either J/G or J/J‐type nSSRs, suggesting that they may be F₂ hybrids resulting from backcrossing between an F₁ hybrid and a Yezo spruce.     

Population genetic structure and diversity of the endangered Cantabrian capercaillie

The Cantabrian capercaillie (Tetrao urogallus cantabricus) occupies the southwestern edge of the grouse family distribution range in Eurasia. It is endemic to the Cantabrian Mountains in northwestern Spain and is geographically isolated and separated from the neighboring population in the Pyrenees by a distance of 300 km. Over the last decades, the population has undergone a dramatic decline and is now threatened with extinction. This study presents the genetic analysis of the Cantabrian capercaillie population using non-invasive samples. We performed genotyping of 45 individuals using 20 microsatellites and a sex marker. The data highlight the need for using a large number of markers when considering fragmented small populations. Genetic diversity (H_E = 0.50) and average number of alleles (3.40) in the population were low. The population is fragmented into 2 clusters (F_ST = 0.113) that fit with areas on both sides of the transportation ways that divide its range. Both clusters exhibited additional heterozygote deficits. Geographical distance was negatively correlated with genetic relatedness (r = −0.44, P ≤ 0.001). The data show a recent decline in effective population size that can be related to an ongoing process of population reduction and fragmentation. Conservation actions should focus on the protection of local demes by maintaining a dense network of suitable patches to maximize reproductive output and the number of potential dispersers to reconnect the 2 subpopulations. © 2012 The Wildlife Society.     

Isolation and characterization of microsatellite loci from Quercus mongolica var. crispula

Microsatellites were isolated and characterized for the Japanese oak species, Quercus mongolica var. crispula, distributed in temperate deciduous forests of Japan. Eleven of the 48 primer pairs designed successfully amplified unambiguous and polymorphic single loci among 67 Q. mongolica var. crispula individuals within a plot in southwestern Japan. The observed and expected heterozygosities of the 11 microsatellite markers ranged from 0.522 to 0.896 and from 0.536 to 0.882, respectively. These polymorphic microsatellite markers are useful for estimating pollen‐mediated gene flow in Q. mongolica var. crispula.     

Clonal and fine-scale genetic structure in populations of a restricted Korean endemic, Hosta jonesii (Liliaceae) and the implications for conservation

BACKGROUND AND AIMS: In plant populations the magnitude of spatial genetic structure of apparent individuals (including clonal ramets) can be different from that of sexual individuals (genets). Thus, distinguishing the effects of clonal versus sexual individuals in population genetic analyses could provide important insights for evolutionary biology and conservation. To investigate the effects of clonal spread on the fine-scale spatial genetic structure within plant populations, Hosta jonesii (Liliaceae), an endemic species to Korea, was chosen as a study species. METHODS: Using allozymes as genetic markers, spatial autocorrelation analysis of ramets and of genets was conducted to quantify the spatial scale of clonal spread and genotype distribution in two populations of H. jonesii. KEY RESULTS: Join-count statistics revealed that most clones are significantly aggregated at < 3-m interplant distance. Spatial autocorrelation analysis of all individuals resulted in significantly higher Moran's I values at 0-3-m interplant distance than analyses of population samples in which clones were excluded. However, significant fine-scale genetic structure was still observed when clones were excluded. CONCLUSIONS: These results suggest that clones enhance the magnitude of spatial autocorrelation due to localized clonal spread. The significant fine-scale genetic structure detected in samples excluding clones is consistent with the biological and ecological traits exhibited by H. jonesii including bee pollination and limited seed dispersal. For conservation purposes, genetic diversity would be maximized in local populations of H. jonesii by collecting or preserving individuals that are spaced at least 5 m apart.