Maternal effects and ecological divergence in aquatic plants: a case study in natural reciprocal hybrids between Potamogeton perfoliatus and P. wrightii

When parental taxa are adapted to different habitats, hybrid genotypes are often highly heterogeneous, such that habitat or ecological factors influence hybrid fate and ecological performance. Trait expression in hybrids is not always intermediate between the parents, but may instead be either parental‐like or extreme (transgressive) depending on genetic control of the phenotypes. Maternal effects arising from interspecific interaction between cytoplasmic and nuclear genomes are widely recognized as playing a role in character expression of natural hybrids. Such interaction often leads to hybrid sterility or inviability. When hybrids are viable, however, cytonuclear interaction may contribute to hybrid persistence through its influence on trait expression. To date, maternal influence on hybrid performance has been examined primarily in experimentally produced hybrids, or in natural hybrids without identification of the cross direction owing to difficulty in obtaining species‐specific molecular markers. In aquatic plants, many hybrids persist by extensive clonal growth and are important components of aquatic communities. Many such hybrids are known in Potamogeton (pondweeds), the largest aquatic genus. Because Potamogeton species are ecologically highly diverse and maternal lineages are readily distinguished using molecular markers, natural hybrids of Potamogeton are well‐suited for studies of maternal effects, especially those affecting vegetative performance. As a case study, we have focused on maternal effects on drought tolerance and depth distribution in the natural hybrid P. × anguillanus derived from the closely related species P. perfoliatus and P. wrightii.     

Persistence of transgenes in wild rice populations depends on the interaction between genetic background of recipients and environmental conditions

The persistence of transgenes in wild populations may cause unintended ecological consequences, and the possibility of transgenes' persistence and introgression is dependent on fitness performance of transgenic crop–wild hybrids. To investigate the effects of transgene and genotype × environment on the fitness of crop–wild rice hybrids, a total of 11 cross‐combination progenies between insect‐resistant transgene (CpTI and Bt/CpTI) rice lines and wild rice (Oryza rufipogon) were evaluated at different sites with contrasting insect treatments. The results showed that fitness performance varied between transgenic hybrids having different wild parents and under different environmental conditions, indicating that fitness effects of transgenes on hybrid progenies depend heavily on the genetic background of recipient plants and growing environment. Significant fitness advantages conferred by transgenes were found only in some hybrids under high insect pressure condition, demonstrating that the level of target insects in the field environment influences the persistence and spread of insect‐resistant transgenes in wild rice populations. These findings suggest that evolutionary fate of escaped transgenes is different in wild populations with diverse genetic backgrounds under various environmental conditions.     

Some butterflies do not care much about topography: a single genetic lineage of Erebia euryale (Nymphalidae) along the northern Iberian mountains

The phylogeography of montane species often reveals strong genetic differentiation among mountain ranges. Both classic morphological and genetic studies have indicated distinctiveness of Pyrenean populations of the butterfly Erebia euryale. This hypothesis remained inconclusive until data from the westernmost populations of the distribution area (Cantabrian Mountains) were analysed. In the present study, we set out to describe the population structure of Erebia euryale in western Cantabria, where the species occurs in scattered localities. For this goal, we estimate the genetic diversity and differentiation found in 218 individuals from six Cantabrian (North Spain) localities genotyped by 17 allozyme loci. We also sequence 816 bp of the cytochrome oxidase subunit I mitochondrial gene in 49 individuals from Cantabrian localities and 41 specimens from five other European sites. Mitochondrial data support the recognition of four major genetic groups previously suggested for the European populations based on allozyme polymorphisms. Both mitochondrial and nuclear markers reveal genetic distinctiveness of a single Pyrenean–Cantabrian lineage of E. euryale. The lack of geographical structure and the star‐like topology displayed by the mitochondrial haplotypes indicate a pattern of demographic expansion in northern Iberia, probably related to Upper Pleistocene climatic oscillations. By contrast, within the Pyrenean–Cantabrian lineage, Cantabrian samples are genetically structured in nuclear datasets. In particular, San Isidro is significantly differentiated from the other five populations, which cluster into two groups. We recognize an evolutionary significant unit for Pyrenean–Cantabrian populations of Erebia euryale. Our results also illustrate that the evolutionary history of a species may be shaped by processes undetectable by using mtDNA alone.     

Genetic Diversity and Chemical Polymorphism of Some Thymus Species

To ascertain whether there are chemical and genetic relationships among some Thymus species and also to determine correlation between these two sets of data, the essential‐oil composition and genetic variability of six populations of Thymus including: T. daenensis ?elak. (two populations), T. fallax Fisch . & C.A.Mey ., T. fedtschenkoi Ronniger , T. migricus Klokov & Des .‐Shost ., and T. vulgaris L. were analyzed by GC and GC/MS, and also by randomly amplified polymorphic DNA (RAPD). Thus, 27 individuals were analyzed using 16 RAPD primers, which generated 264 polymorphic scorable bands and volatiles isolated by distillation extraction were subjected to GC and GC/MS analyses. The yields of oils ranged from 2.1 to 3.8% (v/w), and 34 components were identified, amounting to a total percentage of 97.8–99.9%. RAPD Markers allowed a perfect distinction between the different species based on their distinctive genetic background. However, they did not show identical clustering with the volatile‐oil profiles.     

Ex situ cultivation affects genetic structure and diversity in arable plants

Worldwide, botanical gardens cultivate around 80,000 taxa, corresponding to approximately one‐quarter of all vascular plants. Most cultivated taxa are, however, held in a small number of collections, and mostly only in small populations. Lack of genetic exchange and stochastic processes in small populations make them susceptible to detrimental genetic effects, which should be most severe in annual species, as sowing cycles are often short. In order to assess whether ex situ cultivation affects genetic diversity of annuals, five annual arable species with similar breeding systems were assessed with 42 in situ populations being compared to 20 ex situ populations using a random amplified polymorphic DNA (RAPD) analysis approach. Population sizes tended to be lower under ex situ cultivation and levels of genetic diversity also tended to be lower in four of the five species, with differences being significant in only two. Ex situ populations showed incomplete representation of alleles found in the wild. The duration of cultivation did not indicate any effect on genetic diversity. This implies that cultivation strategies resulted in different genetic structures in the garden populations. Although not unequivocally pronounced, differences nonetheless imply that conservation strategies in the involved gardens may need improvement. One option is cold storage of seeds, a practice that is not currently followed in the studied ex situ collections. This may reflect that the respective gardens focus on displaying living plant populations.     

Morphological, molecular and cytological analyses of Carica papaya×C. cauliflora interspecific hybrids

 Morphological, molecular and cytological analyses were performed to assess the hybridity of 120 putative interspecific hybrids of Carica papaya L.×C. cauliflora Jacq. In the putative interspecific hybrids the number of main leaf veins was intermediate between the two parents while the hermaphrodite flower sex form and the low vigour were distinctive features of these hybrids. Petiole length, stem diameter, leaf length, leaf width and flower colour were similar to C. papaya, whereas leaf shape, type, serration, venation, petiole hairiness and flower shape were similar to C. cauliflora. Markers generated by the polymerase chain reaction using 72 10-mer primers (random amplified polymorphic DNA) revealed a high level of polymorphism (64%) between C. papaya and C. cauliflora. Seventeen of these primers yielded reliable and easily scorable polymorphic banding patterns that were further screened to reveal hybrids. A range of 1–5 RAPD primers consistently confirmed that all 120 plants were genetic hybrids, with all of them containing at least one band from the male parent. Cytological analysis revealed that 7–48% of the cells in many of the interspecific hybrids were aneuploid suggesting that chromosome elimination was occurring. The frequency of aneuploid cells was negatively associated (r=0.88) with the number of bands from the male parent integrated into the hybrid. Pollen fertility of the hybrids was from 0.5 to 14.0% while C. papaya and C. cauliflora had 88.0–99.0% and 90.0–97.0% fertile pollen, respectively. Received: 28 February 1996 / Accepted: 27 September 1996     

Detection of section-specific random amplified polymorphic DNA (RAPD) markers in Lilium

Random amplified polymorphic DNA (RAPD) markers were utilized for the identification of Lilium species and inter-specific hybrids. The optimum annealing temperature of the polymerase chain reaction (PCR) for the RAPD assay in Lilium was 54 °C, which is relatively higher than the temperature used for other genera reported by previous researchers. Among 76 primers used to amplify genomic DNA by PCR, 18 primers (24%) generated polymorphic DNA fragments in Lilium species and hybrids. Cultivars were also identified by RAPD markers. Some amplified fragments were unique to species of each section and to hybrids derived from these species; that is, they were the section-specific DNA markers. Sections, Sinomartagon, Leucolirion b, Leucolirion a and Archelirion could be identified by 6 section-specific markers amplified with five primers. Seven inter-section hybrids showed the section-specific bands of both parental sections, indicating that these markers would be useful for identifying the parental sections of inter-section hybrids.     

Life history variation between species of the relictual genus Borderea (Dioscoreaceae): phylogeography, genetic diversity, and population genetic structure assessed by RAPD markers

The genus Borderea consists of two species, B. pyrenaica and B. chouardii, taxa which have been previously considered as conspecific due to their overall close morphology. These two sole species of the rare genus of Dioscoreaceae are endemic to the Pyrenees (Spain, France). This mountain range likely operated as a refugium for these plants during the last glaciations. B. chouardii is only known from a single population in the Spanish Prepyrenees and has been classified as at risk of extinction in the Red List of Endangered Species (IUCN); B. pyrenaica shows a narrow distribution range in the central Pyrenees and Prepyrenees. We analysed genetic variation, population structure and differentiation in these two taxa using RAPD markers. Our study was conducted on the same seven populations for which very low levels of genetic differentiation were detected previously through allozyme analysis. By contrast, high levels of genetic variability were detected through the RAPD hypervariable markers. Twelve RAPD primers produced 112 distinct bands in the 397 surveyed individuals, totalling 395 different RAPD phenotypes. Only four bands were monomorphic across all samples of Borderea, whereas 21 of the polymorphic bands were species‐specific (20 for B. chouardii, and one for B. pyrenaica). The largest genetic distances were those between the B. chouardii and the B. pyrenaica phenotypes. An analysis of molecular variance showed greater variance between groups (B. chouardii vs. B. pyrenaica, 76.08%) than within groups (3.60%). RAPD band specificity, phenotypic distances, and the partitioning of variance all support the taxonomic separation of the two species. Statistical evaluation of within‐ and among‐population RAPD genetic variability in B. pyrenaica showed that genetic variability was higher within populations (>80%) than among them. No clear pattern of RAPD differentiation could be observed among the six studied populations of this taxon though slight differences in genetic diversity could be observed in the more isolated Prepyrenean populations compared with the more widespread Pyrenean ones. These results suggest a recent postglacial origin of the present B. pyrenaica populations. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 80 , 483–498.     

Microsatellite evidence for low genetic diversity and reproductive isolation in tetraploid Centaurea seridis (Asteraceae) coexisting with diploid Centaurea aspera and triploid hybrids in contact zones

Survival of polyploids in nature depends on several factors, including competition from diploid relatives and increased genetic diversity. Unlike other reported Centaurea polyploid complexes, diploid Centaurea aspera and tetraploid Centaurea seridis coexist in hybrid zones with frequent triploid individuals. The polyploid origin of C. seridis, the genetic diversity and population structure of the three cytotypes, and the degree of genetic differentiation among them were analyzed in seven mixed‐ploidy zones, involving different subspecies and ecological conditions. Ploidy was determined by flow cytometry. Microsatellite data suggested an allopolyploid origin of C. seridis. In the contact zones, diploids and tetraploids were genetically differentiated. When compared with the related C. aspera, a low genetic diversity was observed in C. seridis, which is uncommon in tetraploids. Furthermore, although diploid individuals were grouped in a single widespread genetic cluster, tetraploids were grouped in two highly differentiated clusters and showed significant isolation by distance. This genetic pattern in C. seridis may be related to a minimal gene flow with diploid relatives and/or other genetic factors, such as rare polyploidization events, founder effects or an increased selfing rate. Neither taxonomic assignment at subspecies level, nor ecological conditions could explain the genetic differentiation between tetraploid clusters. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 82–98.     

Variation in circadian rhythms is maintained among and within populations in Boechera stricta

Circadian clocks have evolved independently in all three domains of life, and fitness benefits of a functional clock have been demonstrated in experimental genotypes in controlled conditions. Still, little is known about genetic variation in the clock and its fitness consequences in natural populations from heterogeneous environments. Using Wyoming populations of the Arabidopsis relative Boechera stricta as our study system, we demonstrate that genetic variation in the clock can occur at multiple levels: means of circadian period among populations sampled at different elevations differed by less than 1 h, but means among families sampled within populations varied by as much as 3.5 h. Growth traits also varied among and within populations. Within the population with the most circadian variation, we observed evidence for a positive correlation between period and growth and a negative correlation between period and root‐to‐shoot ratio. We then tested whether performance tradeoffs existed among families of this population across simulated seasonal settings. Growth rankings of families were similar across seasonal environments, but for root‐to‐shoot ratio, genotype × environment interactions contributed significantly to total variation. Therefore, further experiments are needed to identify evolutionary mechanisms that preserve substantial quantitative genetic diversity in the clock in this and other species.     

A molecular study of hybridization and homoploid hybrid speciation in Argyranthemum (Asteraceae) on Tenerife,the Canary Islands

Examples of recurrent homoploid hybrid speciation are few. One often‐cited example is Argyranthemum sundingii. This example includes two described species, A. lemsii and A. sundingii, resulting from reciprocal hybridization between A. broussonetii and A. frutescens on Tenerife. The four species and artificial F₁ and F₂ hybrids have previously been investigated morphologically and cytologically. Here, we examine population differentiation based on amplified fragment length polymorphism to get a better understanding of the genetic relationships among the species and the extent of hybridization. We aim to investigate if there is molecular support for treating the hybrid species as one taxon. Seven parental and four hybrid species populations (149 individuals) were analysed and we scored 85 polymorphic markers. A few (2–5) were private to each species but variably present and mostly rare. Our principal coordinate, STRUCTURE and BAPS analyses and AMOVA resulted in a clear separation of the parental species. The hybrid species were genetically less divergent but not identical. Our data indicate that hybridization and introgression are common in all these species on Tenerife and support the hypothesis that homoploid hybrid speciation has occurred repeatedly. Intrinsic post‐zygotic barriers are notoriously weak in Argyranthemum and reproductive isolation and speciation result primarily from strong ecological selection. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 19–31.     

Morphometric and population genetic analyses elucidate the origin,evolutionary significance and conservation implications of Orchis × angusticruris (O. purpurea × O. simia), a hybrid orchid new to Britain

We report the first confirmed occurrence in Britain of Orchis × angusticruris Franch. ex Rouy, a hybrid between two closely related orchid species of anthropomorphic Orchis (O. purpurea Huds. × O. simia Lam.) that hybridize frequently in Continental Europe. Seven individual hybrids, most likely F1 plants representing a single interspecific pollination event, first flowered with both parents in May 2006 at a nature reserve in the Chiltern Hills near Goring, Oxfordshire. Univariate and multivariate morphometric analyses (43 characters plus 12 indices), internal transcribed spacer sequencing, plastid microsatellites and amplified fragment length polymorphism (AFLP) analyses together readily separate the parents and confirm that O. purpurea was the ovule parent and O. simia the pollen parent, presumably reflecting the greater frequency and/or later flowering period of the latter at the site. This study reinforces a more general observation that, in most orchids, the ovule parent contributes substantially more to the hybrid phenotype than does the pollen parent, perhaps reflecting cytoplasmic inheritance. In contrast, the hybrids are placed closer to O. simia than to O. purpurea in the AFLP tree. Apparently recent arrivals, the few O. purpurea plants at Goring contrast genetically with the two other small populations of this species known in the Chilterns, but rather are consistent with relatively uncommon Continental populations. This suggests that the plants may have been deliberately introduced at Goring by man, although transport from the Continent in high‐level air currents cannot be ruled out. The Goring population of O. simia is likely to have become genetically impoverished through (1) preferential removal of many relatively fit plants to herbaria in the 19^th century and/or (2) a catastrophic population crash in the first half of the 20^th century. However, both our re‐examination of herbarium specimens and our population genetic data indicate past hybridization among anthropomorphic Orchis species occurring naturally in the Chilterns. Thus, we tentatively recommend retention of the hybrid plants at Goring, despite their likely anthropogenic origin from Continental material and the partial viability of their pollen and seeds, which offers opportunities for future introgression. Although the Goring hybrids broadly resemble morphologically O. militaris, another anthropomorphic Orchis still found at two Chiltern localities, sufficient morphological and molecular differences were observed to strongly refute our initial hypothesis that O. militaris could have originated through hybridization between ancestors that resembled O. purpurea and O. simia. The comparatively complex genetic properties evident in both O. simia and O. purpurea merit further study. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 687–711.     

Genetic differentiation,speciation, and phylogeography of cactus flies (Diptera: Neriidae: Odontoloxozus) from Mexico and south‐western USA

Nucleotide sequences from the mitochondrial cytochrome c oxidase subunit I (COI) gene, comprising the standard barcode segment, were used to examine genetic differentiation, systematics, and population structure of cactus flies (Diptera: Neriidae: Odontoloxozus) from Mexico and south‐western USA. Phylogenetic analyses revealed that samples of Odontoloxozus partitioned into two distinct clusters: one comprising the widely distributed Odontoloxozus longicornis (Coquillett) and the other comprising Odontoloxozus pachycericola Mangan & Baldwin, a recently described species from the Cape Region of the Baja California peninsula, which we show is distributed northward to southern California, USA. A mean Kimura two‐parameter genetic distance of 2.8% between O. longicornis and O. pachycericola, and eight diagnostic nucleotide substitutions in the COI gene segment, are consistent with a species‐level separation, thus providing the first independent molecular support for recognizing O. pachycericola as a distinct species. We also show that the only external morphological character considered to separate adults of the two species (number of anepisternal bristles) varies with body size and is therefore uninformative for making species assignments. Analysis of molecular variance indicated significant structure among populations of O. longicornis from three main geographical areas, (1) Arizona, USA and Sonora, Mexico; (2) Santa Catalina Island, California, USA; and (3) central Mexico (Querétaro and Guanajuato), although widely‐separated populations from Arizona and Sonora showed no evidence of structure. A TCS haplotype network showed no shared haplotypes of O. longicornis among the three main regions. The potential roles of vicariance and isolation‐by‐distance in restricting gene flow and promoting genetic differentiation and speciation in Odontoloxozus are discussed. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 245–256.     

Phylogenetic Analysis of Different Breeds of Domestic Chickens in Selected Area of Peninsular Malaysia Inferred from Partial Cytochrome b Gene Information and RAPD Markers

The present investigation was carried out in an attempt to study the phylogenetic analysis of different breeds of domestic chickens in Peninsular Malaysia inferred from partial cytochrome b gene information and random amplified polymorphic DNA (RAPD) markers. Phylogenetic analysis using both neighbor-joining (NJ) and maximum parsimony (MP) methods produced three clusters that encompassed Type-I village chickens, the red jungle fowl subspecies and the Japanese Chunky broilers. The phylogenetic analysis also revealed that majority of the Malaysian commercial chickens were randomly assembled with the Type-II village chickens. In RAPD assay, phylogenetic analysis using neighbor-joining produced six clusters that were completely distinguished based on the locality of chickens. High levels of genetic variations were observed among the village chickens, the commercial broilers, and between the commercial broilers and layer chickens. In this study, it was found that Type-I village chickens could be distinguished from the commercial chickens and Type-II village chickens at the position of the 27th nucleotide of the 351 bp cytochrome b gene. This study also revealed that RAPD markers were unable to differentiate the type of chickens, but it showed the effectiveness of RAPD in evaluating the genetic variation and the genetic relationships between chicken lines and populations.     

Comparisons of Isolates of Fusarium avenaceum from White Lupin and Other Crops by Pathogenicity Tests,DNA Analyses and Vegetative Compatibility Tests

Isolates of Fusarium avenaceum, mostly from crops of white lupin or wheat, were tested for pathogenicity on white lupin and wheat plants and compared by DNA tests and, in a limited study, vegetative compatibility. Most of the 80 isolates were pathogenic on both plant species after inoculation on shoot bases. Disease severity was greater at higher incubation temperatures that ranged from 15/10°C to 25/20°C (day/night temperatures). Isolates from lupin crops tended to be more pathogenic, on average, on lupins than on cereals. Polymerase chain reaction (PCR)‐restriction fragment length polymorphism (RFLP) analysis of the internal transcribed spacer region of the rDNA distinguished two groups of isolates that occurred in different proportions among isolates from lupins and cereal crops. Random amplified polymorphic DNA (RAPD)‐PCR analyses indicated considerable genetic variation among isolates, but there was some similarity among groups of isolates from populations in the same field. Genetic diversity was confirmed by a high degree of vegetative incompatibility among 20 isolates using nitrate nonutilizing mutants. There were no relationships among pathogenicity, RFLP group, RAPD group and vegetative compatibility group.     

Population genetic diversity in the polyploid complex of wheatgrasses using isoenzyme and RAPD data

Thirty five bands (alleles) from six enzyme systems and fifty seven random amplified polymorphic DNA (RAPD) fragments were selected to analyse the genetic diversity of 33 polyploid wheatgrasses (Triticeae) populations of species Thinopyrum junceiforme and Elytrigia pycnantha, and two hybrids, one pentaploid and one novel 9-ploid. Dice’s similarity coefficient, the UPGMA-derived phenograms from RAPD, and allozymes markers showed that the clustering of wheatgrass populations was based on ploidy level. These markers had similar levels of diversity between populations, with high genetic similarity within the same ploidy-level and within population’s individuals. The tetraploid Th. junceiforme populations are closely related, with a large similarity distances varied from 0.8 to 1. Based on the isozyme and RAPD analyses, diploid taxa are related to polyploids with similarity coefficients 0.4.     

Molecular and morphological variation of rare endemic oncocyclus irises (Iridaceae) of Lebanon

Oncocyclus irises endemic to Lebanon form a complex of three closely related taxa replacing each other over short geographical distances in a linear habitat. In order to characterize the appropriate taxonomic levels and to assess their conservation status, we investigated patterns of phenotypic variability and the partitioning of genetic variation within and among populations using random amplified polymorphic DNA (RAPD) markers. Multivariate analysis (principal components analysis and multiple correspondence analysis), based on 16 quantitative and six qualitative characters, revealed no separation between populations or taxa. Moreover, no morphological character could be used to define clear boundaries between populations/taxa. The genetic characterization revealed high levels of polymorphism and diversity (H_s). Principal components analysis showed population delimitations, but no groupings reflecting the currently defined taxa could be identified. Both morphological and genetic data showed that Lebanese oncocyclus irises could not be fitted into clear taxonomic boundaries. Consequences for conservation are discussed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 123–135.     

Genetic mapping in pea. 1. RAPD-based genetic linkage map of Pisum sativum

 A genetic linkage map of Pisum sativum L. was constructed based primarily on RAPD markers that were carefully selected for their reproducibility and scored in a population of 139 recombinant inbred lines (RILs). The mapping population was derived from a cross between a protein-rich dry-seed cultivar ‘Térèse’ and an increased branching mutant (K586) obtained from the pea cultivar ‘Torsdag’. The map currently comprises nine linkage groups with two groups comprising only 6 markers (n=7 in pea) and covers 1139 cM. This RAPD-based map has been aligned with the map based on the (JI281×JI399) RILs population that currently includes 355 markers in seven linkage groups covering 1881 cM. The difference in map lengths is discussed. For this alignment 7 RFLPs, 23 RAPD markers, the morphological marker le and the PCR marker corresponding to the gene Uni were used as common markers and scored in both populations. Received: 13 March 1998 / Accepted: 29 April 1998     

Genetic diversity analysis of Hepatacodium miconioides at different altitude in Tiantai Mountain, Zhejiang Province, China and its relationship with environmental factors

The genetic diversity within and among populations of Hepatacodium miconioides collected at three different altitudes in Tiantai Mountain, Zhejiang Province and its relationships to environmental factors were analyzed by random amplified polymorphic DNA (RAPD) technique. Amplification using 12 random primers of 60 plants and 122 repetitive loci were produced. The percentage of polymorphic loci of three populations ranged from 18.85% to 23.77% with an average of 21.86%, indicating the relatively low genetic diversity of H. miconioides. The average Shannon index of phenotypic diversity (0.1329) and Nei index (0.0925) within populations were relatively low. A distinct genetic differentiation existed among populations of H. miconioides in spite of the relatively small geographical distribution. The average genetic diversity within populations of H. miconioides accounted for 33.58% of the total genetic diversity while the genetic diversity among populations accounted for 66.42% as estimated by the Shannon index of phenotypic diversity, The genetic differentiation among populations of H. miconioides was 0.6546, as estimated by Nei index. The gene flow estimated from G _ST was only 0.2656 and it indicated that gene flow among populations of H. miconioides was relatively low. The mean value of the genetic identity among populations of H. miconioides was 0.7126 and the average of genetic distance of H. miconioides was 0.3412. The genetic identity between populations at the elevation of 990 m and at the elevation of 780 m was the highest. The genetic identity between population at the elevation 500 m and other two populations was relatively low. The correlation analysis showed that the genetic diversity within populations was significantly related with the soil total nitrogen. __________ Translated from Journal of Zhejiang University (science Edition) 2005, 32 (4)[译81EA;: 浙江大学学报(理学版), 2005,32(4)]