Early colonization of Protea flowers enable dominance of competitively weak saprobic fungi in seed cones,benefitting their hosts

Sporothrix and Knoxdaviesia fungi use pollinators to colonize Protea flowers at anthesis. These saprobes remain dominant in the nutrient-rich, fire-retardant Protea seed-cones (infructescences) for at least a year after flowering. We tested the hypothesis that they competitively exclude potentially detrimental fungi from infructescences during this time. We compared seed set and longevity of infructescences containing Sporothrix and Knoxdaviesia vs. those that contain ‘contaminant’ saprobes. Hereafter we evaluated their competitive abilities against the ‘contaminant’ saprobes. Infructescences devoid of Sporothrix and Knoxdaviesia were dominated by Penicillium cf. toxicarium, Cladosporium cf. cladosporoides and Fusarium cf. anthophilum. Sporothrix and Knoxdaviesia presence did not affect seed viability, but infructescences persisted longer than those colonised by ‘contaminant’ fungi. The ‘contaminant’ species were stronger competitors than Sporothrix and Knoxdaviesia. However, Sporothrix and Knoxdaviesia could defend captured space well against ‘contaminant’ species. This effect was enhanced when fungal taxa grew on media prepared from their usual Protea host species, clarifying their dominance and host consistency observed in the field. Sporothrix and Knoxdaviesia from Protea are therefore weak competitors against common saprobes, especially when growing on alternative hosts, and need to colonise flowers very early (before colonization by other fungi) to dominate in this environment. They may delay seed release from infructescences longer than if these are colonised by other saprobes, increasing chances of seed release to occur after fire, when conditions are more favourable for Protea recruitment.     

Persistence of ecologically similar fungi in a restricted floral niche

Fungi in the genera Knoxdaviesia and Sporothrix dominate fungal communities within Protea flowerheads and seed cones (infructescences). Despite apparently similar ecologies, they show strong host recurrence and often occupy the same individual infructescence. Differences in host chemistry explain their host consistency, but the factors that allow co-occupancy of multiple species within individual infructescences are unknown. Sporothrix splendens and K. proteae often grow on different senescent tissue types within infructescences of their P. repens host, indicating that substrate-related differences aid their co-occupancy. Sporothrix phasma and K. capensis grow on the same tissues of P. neriifolia suggesting neutral competitive abilities. Here we test the hypothesis that differences in host-tissues dictate competitive abilities of these fungi and explain their co-occupancy of this spatially restricted niche. Media were prepared from infructescence bases, bracts, seeds, or pollen presenters of P. neriifolia and P. repens. As expected, K. capensis was unable to grow on seeds whilst S. phasma could. As hypothesised, K. capensis and S. phasma had equal competitive abilities on pollen presenters, appearing to explain their co-occupancy of this resource. Growth of K. proteae was significantly enhanced on pollen presenters while that of S. splendens was the same as the control. Knoxdavesia proteae grew significantly faster than S. splendens on all tissue types. Despite this, S. splendens was a superior competitor on all tissue types. For K. proteae to co-occupy infructescences with S. splendens for extended periods, it likely needs to colonize pollen presenters before the arrival of S. splendens.

     

Asexual Propagation of a Virulent Clone Complex in a Human and Feline Outbreak of Sporotrichosis

Sporotrichosis is one of the most frequent subcutaneous fungal infections in humans and animals caused by members of the plant-associated, dimorphic genus Sporothrix. Three of the four medically important Sporothrix species found in Brazil have been considered asexual as no sexual stage has ever been reported in Sporothrix schenckii, Sporothrix brasiliensis, or Sporothrix globosa. We have identified the mating type (MAT) loci in the S. schenckii (strain 1099-18/ATCC MYA-4821) and S. brasiliensis (strain 5110/ATCC MYA-4823) genomes by using comparative genomic approaches to determine the mating type ratio in these pathogen populations. Our analysis revealed the presence of a MAT1-1 locus in S. schenckii while a MAT1-2 locus was found in S. brasiliensis representing genomic synteny to other Sordariomycetes. Furthermore, the components of the mitogen-activated protein kinase (MAPK)-pheromone pathway, pheromone processing enzymes, and meiotic regulators have also been identified in the two pathogens, suggesting the potential for sexual reproduction. The ratio of MAT1-1 to MAT1-2 was not significantly different from 1:1 for all three Sporothrix species, but the population of S. brasiliensis in the outbreaks originated from a single mating type. We also explored the population genetic structure of these pathogens using sequence data of two loci to improve our knowledge of the pattern of geographic distribution, genetic variation, and virulence phenotypes. Population genetics data showed significant population differentiation and clonality with a low level of haplotype diversity in S. brasiliensis isolates from different regions of sporotrichosis outbreaks in Brazil. In contrast, S. schenckii isolates demonstrated a high degree of genetic variability without significant geographic differentiation, indicating the presence of recombination. This study demonstrated that two species causing the same disease have contrasting reproductive strategies and genetic variability patterns.     

Assessing the genetic diversity and population structure of Culter alburnus in China based on mitochondrial 16S rRNA and COI gene sequences

The genetic diversity and population genetic structure of Culter alburnus were investigated using mitochondrial cytochrome c oxidase subunit I (COI) and ribosomal 16S subunit (16S rRNA) gene sequences. A total of 89 individuals from four localities were included in the analysis. Overall, 12 polymorphic sites were observed and 10 haplotypes were defined. The C. alburnus populations were characterized by high haplotype diversity (0.587 ± 0.047) and low nucleotide diversity (0.00197 ± 0.00073). Pairwise fixation index (F_ST) analysis indicated significant genetic differentiation among different populations. The hierarchical analysis of molecular variance (AMOVA) analysis also showed significant genetic divergence (φ_ST = 0.3792, P < 0.01) among these populations. The present results suggest that subdivisions exist among four C. alburnus populations, and should be considered as different management unit for effective conservation and management purposes. This study provides new information for genetic assessment and will be crucial for establishing fisheries management and strategies for this species.     

A molecular approach to understand the riddle of the invasive success of the tarantula,Brachypelma vagans,on Cozumel Island,Mexico

Invasive populations typically demonstrate genetic isolation which results in a loss of genetic diversity and a reduction in invasion success. This study focused on the genetic population of a successful invasive species of tarantula. Individuals were sampled in two mainland localities of the Yucatan Peninsula (Zoh-Laguna and Raudales), in addition to two island localities (El Cedral and Rancho Guadalupe on Cozumel Island). All populations present high genetic diversity (mean: H_e = 0.23, P = 99%), with significant differences between the Raudales and Rancho Guadalupe localities. The AMOVA analysis revealed a significant population structure (14.5% variation among populations), consistent with the gene differentiation coefficient (G_ST = 0.21), and spatial analysis of population structure. Our results suggested that the original introduced population did not suffer a loss of genetic diversity during establishment on the island, possibly a result of different biological conditions. Population structure analysis leads us to suggest that one island population is similar to the original genetic profile, whereas the genotypic profile of the other island population reflects recent introductions from the mainland. We identified a potential risk of extinction for one local mainland population, suggesting that this species may be a successful invader in a new environment but endangered in some parts of its natural area.     

Knoxdaviesia capensis: dispersal ecology and population genetics of a flower-associated fungus

Protea-associated fungi are dispersed between flower heads by mites, beetles and possibly birds. For the ophiostomatoid fungus, Knoxdaviesia proteae, these vectors offer regular dispersal between distant floral hosts. Unlike K. proteae, Knoxdaviesia capensis occupies multiple Protea host species. In this study, we aimed to determine whether the generalist K. capensis shares the long-distance dispersal pattern with specialist K. proteae and whether it moves freely between different host species. We evaluated the genetic structure of K. capensis from five populations of a wide-spread host and between sympatric hosts. Twelve K. capensis-specific microsatellite markers were developed and applied to 90 individuals. K. capensis showed high genetic diversity and almost maximal genotypic diversity. All populations were poorly differentiated, indicating the presence of long-distance dispersal. No differentiation could be detected between sympatric host populations, suggesting free dispersal between different hosts. This implies that the beetle and bird vectors that pollinate Protea species show the same non-specific movement.     

A new duplex PCR assay for the rapid screening of mating-type idiomorphs of pathogenic Sporothrix species

Sporothrix schenckii and allied species are thermodimorphic fungi widely distributed in nature which causes human and animal sporotrichosis, the most common subcutaneous mycosis globally. Sporotrichosis is acquired after a traumatic inoculation of soil or plant material contaminated with Sporothrix propagules or through bites and scratches from diseased cats. In Ascomycota, the master regulators of sex are MAT genes that lie in a single mating-type locus, in Sporothrix these are determined by two nonhomologous alleles, MAT1-1 and MAT1-2. We assessed the whole-genome sequences of medically relevant Sporothrix to develop a single-tube duplex PCR assay to screen S. brasiliensis, S. schenckii, S. globosa, and S. luriei idiomorphs (MAT1-1 or MAT1-2) and understand the distribution and incidence of mating-type strains from natural populations. Using our duplex PCR assay, a 673 bp amplicon (α-box protein) was consistently amplified from all MAT1-1 isolates, while a 291 bp fragment was only amplified from the isolates harboring MAT1-2 (HMG box). Molecular evidence suggests heterothallism (self-sterility) as the unique mating strategy among the species evaluated. The mating-type identity of 93 isolates revealed a nearly equal distribution (1:1 ratio) of mating type alleles within species but deviating between different outbreak areas. Remarkably, for S. brasiliensis in Rio de Janeiro, we report an overwhelming occurrence of MAT1-2 (1:13 ratio; χ² = 10.286, P = 0.0013) opposing the high prevalence MAT1-1 in the Rio Grande do Sul (10:1 ratio; χ² = 7.364, P = 0.0067). Therefore, the population structure of Sporothrix species refers from paucity to regular cycles of sexual recombination in most of the studied regions. Our PCR-based mating-type diagnostic assay is proposed here as an important marker to track the geographical expansion during the long-lasting outbreak of cat-transmitted sporotrichosis driven by S. brasiliensis.     

Genetic diversity and structure of Pinus dabeshanensis revealed by expressed sequence tag-simple sequence repeat (EST-SSR) markers

Assessing patterns of genetic variation in rare endangered species is critical for developing both in situ and ex situ conservation strategies. Pinus dabeshanensis Cheng et Law is an endangered species endemic to the Dabieshan Mountains of eastern China. To obtain fundamental information of genetic diversity, population history, effective population size, and gene flow in this species, we explored patterns of genetic variation of natural populations, in addition to an ex situ conserved population, using expressed sequence tag-simple sequence repeats (EST-SSR) markers. Our results revealed moderate levels of genetic diversity (e.g., H_E = 0.458 vs. H_E = 0.423) and a low level of genetic differentiation (F_ST = 0.028) among natural and conserved populations relative to other conifers. Both contemporary and historical migration rates among populations were high. Bayesian coalescent-based analyses suggested that 3 populations underwent reductions in population size ca. 10,000 yr ago, and that two populations may have experienced recent genetic bottlenecks under the TPM. Bayesian clustering revealed that individuals from the ex situ population were largely assigned to the ‘red’ cluster. Additionally, our results identified private alleles in the natural populations but not in the ex situ population, suggesting that the ex situ conserved population insufficiently represents the genetic diversity present in the species. Past decline in population size is likely to be due to Holocene climate change. Based on the genetic information obtained for P. dabeshanensis, we propose some suggestions for the conservation and efficient management of this endangered species.     

Determination of genetic diversity of the cuttlefish Sepiella japonica inhabiting Chinese coastal waters using the mitochondrial D-loop region: The valuable inspiration to artificial releasing project

The cuttlefish Sepiella japonica, was once one of the four major marine fisheries of China and has dramatically declined since the 1980s to near extinction. The artificial releasing project was launched for resource restocking since 2006. Aiming to provide some valuable information to the management of the releasing project, the mitochondrial DNA control region sequence was employed to assess the genetic variation of various geographical populations in present study. The genetic diversity of S. japonica was characterized with the low value of nucleotide diversity (0.00313 ± 0.070). Pairwise fixation index (Fst) analysis indicated insignificant genetic differentiation among southern populations (p > 0.05). However, the QD population showed the significant genetic differention with other populations (p < 0.05). The highest genetic diversity was detected in ND population and was recommended to be the germplasm resources for artificial releasing project. In summary, the presented results provided some new information for genetic assessment in this study that would be crucial for establishing effective releasing strategies for this species.     

Genetic diversity and population structure of Schizopygopsis younghusbandi Regan in the Yarlung Tsangpo River inferred from mitochondrial DNA sequence analysis

The genetic diversity and population structure of Schizopygopsis younghusbandi from six sites in the middle reach of the Yarlung Tsangpo River were examined based on mitochondrial DNA cytochrome b (Cyt b) gene and control region (D-loop) sequences. 1141 bp of complete Cyt b sequences and 737 bp of partial D-loop sequences for 153 individuals of S. younghusbandi were obtained by using PCR amplification and sequencing. The results showed that S. younghusbandi populations had high haplotype diversity and low nucleotide diversity, and the population genetic diversity of this species was at a low level. Analysis of molecular variance revealed that most genetic variation occurred within populations, and that genetic differentiation was at low or moderate levels. The network of haplotypes based on Cyt b gene showed that there were two groups within the examined populations. Neutrality tests and mismatch distribution analysis suggested that this species might have undergone a population expansion and the expansion time was estimated to be 0.25–0.46 Ma BP. All these results would be crucial to establish scientific strategies for effective conservation and sustainable exploitation of wild resources of S. younghusbandi.     

Genetic diversity of a dominant species Stipa bungeana and its conservation strategy in the Loess Plateau of China

In order to investigate the genetic diversity and population structure of Stipa bungeana under the background of grassland utilization and grazing exclusion, ten S. bungeana populations were selected from different steppe type in the Loess Plateau of China. Sequence-related amplified polymorphism (SRAP) marker was used to assess the genetic diversity. Fifteen SRAP primer combinations generated a total of 482 amplification bands, 418 (86.72%) were polymorphic bands. A relatively high level of genetic diversity (PPB = 89.80%, h = 0.1972, H = 0.3154) was detected at the species level, but the genetic diversity was low at the population level (PPB = 17.01–33.33%, h = 0.0438–0.0967, H = 0.0361–0.1447). AMOVA analysis revealed a high level of genetic differentiation among populations (Φ_ST = 0.6757), and a limited among-population gene flow (N_m = 0.1200). There was no significant correlation between genetic distance and geographic distance by Mantel test (r = 0.1126, P = 0.204). Conservation implications were proposed for S. bungeana.     

Surprisingly little population genetic structure in a fungus‐associated beetle despite its exploitation of multiple hosts

In heterogeneous environments, landscape features directly affect the structure of genetic variation among populations by functioning as barriers to gene flow. Resource‐associated population genetic structure, in which populations that use different resources (e.g., host plants) are genetically distinct, is a well‐studied example of how environmental heterogeneity structures populations. However, the pattern that emerges in a given landscape should depend on its particular combination of resources. If resources constitute barriers to gene flow, population differentiation should be lowest in homogeneous landscapes, and highest where resources exist in equal proportions. In this study, we tested whether host community diversity affects population genetic structure in a beetle (Bolitotherus cornutus) that exploits three sympatric host fungi. We collected B. cornutus from plots containing the three host fungi in different proportions and quantified population genetic structure in each plot using a panel of microsatellite loci. We found no relationship between host community diversity and population differentiation in this species; however, we also found no evidence of resource‐associated differentiation, suggesting that host fungi are not substantial barriers to gene flow. Moreover, we detected no genetic differentiation among B. cornutus populations separated by several kilometers, even though a previous study demonstrated moderate genetic structure on the scale of a few hundred meters. Although we found no effect of community diversity on population genetic structure in this study, the role of host communities in the structuring of genetic variation in heterogeneous landscapes should be further explored in a species that exhibits resource‐associated population genetic structure.     

Population genetic structure and germplasm conservation of Stipa purpurea on Qinghai-Tibetan Plateau under grazing

At what intensity the grazing should be practiced on the Qinghai-Tibetan Plateau in China is always confusing farmers, scientists and policy makers for a long time owing to its geographical exception. In order to develop a strategy for sustainable grazing management, we used the dominant Stipa purpurea as a model species to detect genetic diversity and fine spatial structure under different grazing intensities. Intra-population neutral genetic diversity in non-grazed population was significantly higher than three grazed populations; however, the highest value among grazed populations appeared in the moderately grazed population. A relatively low degree of genetic differentiation among populations by AMOVA analysis and a high level of gene flow existed among populations (Gst = 0.2649, Nm = 1.3875 〉 1). The genetic ‘patch’ size increased from 4 m to 16 m and subpopulation number within the S. purpurea populations ranged from 7 to 5 with increasing grazing intensity, therefore grazing will be beneficial to reduce the fragmentation and to increase the population-level adaptation. Though enclosure or no grazing is the best protection of plant germplasm like wind-pollination S. purpurea, moderate grazing is better strategy for grassland use on the Qinghai-Tibetan Plateau.     

Genetic variation and clonal diversity in populations of Nelumbo nucifera (Nelumbonaceae) in central China detected by ISSR markers

To obtain accurate estimates of population structure for purposes of conservation planning for wild lotus (Nelumbo nucifera Gaertn.) in central China, genetic diversity among and within six populations, and clonal diversity within another two populations of the species were analyzed. The genetic diversity was high (percentage of polymorphic bands, PPB = 90.0%; Shannon's information index, I = 0.383 ± 0.234) at the species level, but low within individual study populations (PPB = 35.8%; Shannon's information index I = 0.165 ± 0.241). The mean coefficient of gene differentiation (G_st) was 0.570, indicating that 43.0% of the genetic diversity resided within the population. Analysis of molecular variance (AMOVA) indicated that 50.47% of the genetic diversity among the study populations was attributed to geographical location while 12.3% was attributed to differences in their habitats. An overall value of mean estimated number of gene flow (N_m = 0.377) indicated that there was limited gene flow among the sampled populations. The level of clonal diversity found within the populations was considerably high (Simpson's diversity index, D = 0.985) indicating that clonal diversity contributes to a major extent to the overall genetic variation in the genetic structure of N. nucifera. On the basis of the high G_st and D values detected in this study we recommend that any future conservation plans for this species should be specifically designed to include those representative populations with the highest genetic variation for both in situ conservation and germplasm collection expeditions.     

Genetic diversity of the threatened Chinese endemic plant,Sinowilsonia henryi Hemsi. (Hamamelidaceae), revealed by inter-simple sequence repeat (ISSR) markers

Sinowilsonia henryi Hemsi., the only representative of the monotypic genus Sinowilsonia Hemsi. (Hamamelidaceae), is a threatened plant endemic to China with high phylogenetical, ecological and economical values. In the present study, inter-simple sequence repeat (ISSR) markers were employed to investigate the genetic diversity and differentiation of 214 individuals sampled from 14 populations. Fifteen selected primers yielded a total of 178 bright and discernible bands. The genetic diversity was low at the population level (h = 0.1025; I = 0.1506; PPL = 26.7%), but quite high at the species level (h = 0.2449; I = 0.3690; PPL = 72.5%). In line with the limited gene flow (N_m = 0.3537), the hierarchical analysis of molecular variance (AMOVA) revealed pronounced genetic differentiation among populations (Φ_ST = 0.6639). Furthermore, the Mantel test revealed a significant correlation between genetic and geographic distances among populations (r = 0.688, P = 0.001), indicating the role of geographic isolation in shaping its present population genetic structure. The present patterns of genetic diversity of S. henryi were assumed to result largely from its evolutionary history and geographic factors. Based on these findings, conservation strategies were proposed to preserve this threatened plant.     

Population genetic differentiation of Schisandra chinensis and Schisandra sphenanthera as revealed by ISSR analysis

Schisandra chinensis (Turcz.) Baill. and Schisandra sphenanthera Rehd. et Wils. are well-known Chinese medicinal plants. The population genetic variation of the two species was studied using inter simple sequence repeat (ISSR) molecular markers. High levels of genetic diversity are revealed in both S. chinensis (P = 88.36%, h = 0.2894, I = 0.4396) and S. sphenanthera (P = 84.09%, H = 0.2782, I = 0.4280). However, the population genetic differentiation is significantly different between the two species. The S. sphenanthera harbors as high as 27% of the genetic variation among populations but 73% within populations, whereas in S. chinensis 17% of the genetic variation occurs among populations and 83% within populations. Both significant (P < 0.05) heterozygosity excess and shifted mode of allele frequency distribution are detected in four out of six populations of S. chinensis and one out of five populations of S. sphenanthera, suggesting the occurrence of recent population bottlenecks in the two species. The different patterns of genetic variation in S. chinensis and S. sphenanthera are discussed in relation to their differences in pollination mechanism, geographic distribution and historical events, and the level of gene flow and genetic drift.     

Genetic diversity and population structure of endangered endemic Paeonia jishanensis in China and conservation implications

Paeonia jishanensis, one of the most important ancestral species of cultivated tree peonies, is an endangered ornamental and medicinal plant endemic to China. A total of 236 individuals of P. jishanensis from 10 extant populations were analysed using 21 EST-SSR markers to assess their genetic diversity and population structure. Moderate genetic diversity levels (H_E = 0.340) and high genetic differentiation among populations (F_ST = 0.335) were revealed. Combining the results of STRUCTURE, PCoA and neighbour-joining analyses, the 10 populations were divided into four genetic groups that were significantly related to their geographical origins, which was further supported by hierarchical AMOVA showing the highest variation of 17.9% among groups. The Mantel test showed a significant positive correlation between genetic distance and geographic distance among populations (r = 0.873, P < 0.0001). The genetic structure of P. jishanensis may be due to limited gene flow hindered by vicariance and its breeding system: facultative vegetative reproduction. This study carries significant implications for the conservation and utilization of this endangered species.     

Genetic diversity of Astragalus nitidiflorus, a critically endangered endemic of SE Spain,and implications for its conservation

Inter-simple sequence repeats (ISSR) markers were used to assess the genetic diversity and population structure in five populations of Astragalus nitidiflorus, a critically endangered species endemic to southeast Spain. Eight primers amplified 78 bands with 40 (51.3%) being polymorphic. Statistical results indicated a low genetic diversity at the population and species level, with percentages of polymorphic bands (PPB) ranging from 28.2 to 37.2% (an average of 31.8%), and means of gene diversity (H_E) of 0.129 and 0.171 respectively. The Shannon’s index (SI) ranged from 0.160 to 0.214 at the population level and was 0.260 at the species level. A low level of genetic differentiation among populations was detected, based on the Shannon’s information index (0.297), the coefficient of genetic differentiation between populations (G_ST = 0.2418) and AMOVA analysis (Φ_ST = 0.255). The estimated gene flow (Nm) was 0.789. The high genetic connectivity found among populations of A. nitidiflorus is an evidence of a recent habitat fragmentation. In addition, a bottleneck event in the past has been revealed, with a subsequent reduction of population size and a loss of genetic variation. Based on these results, the conservation strategy of A. nitidiflorus was proposed.     

Genetic Diversity and Population Structure of Sitodiplosis mosellana in Northern China

The wheat midge, Sitodiplosis mosellana, is an important pest in Northern China. We tested the hypothesis that the population structure of this species arises during a range expansion over the past 30 years. This study used microsatellite and mitochondrial loci to conduct population genetic analysis of S. mosellana across its distribution range in China. We found strong genetic structure among the 16 studied populations, including two genetically distinct groups (the eastern and western groups), broadly consistent with the geography and habitat fragmentation. These results underline the importance of natural barriers in impeding dispersal and gene flow of S. mosellana populations. Low to moderate genetic diversity among the populations and moderate genetic differentiation (F _ST = 0.117) between the two groups were also found. The populations in the western group had lower genetic diversity, higher genetic differentiation and lower gene flow (F _ST = 0.116, Nm = 1.89) than those in the eastern group (F _ST = 0.049, Nm = 4.91). Genetic distance between populations was positively and significantly correlated with geographic distance (r = 0.56, P<0.001). The population history of this species provided no evidence for population expansion or bottlenecks in any of these populations. Our data suggest that the distribution of genetic diversity, genetic differentiation and population structure of S. mosellana have resulted from a historical event, reflecting its adaptation to diverse habitats and forming two different gene pools. These results may be the outcome of a combination of restricted gene flow due to geographical and environmental factors, population history, random processes of genetic drift and individual dispersal patterns. Given the current risk status of this species in China, this study can offer useful information for forecasting outbreaks and designing effective pest management programs.     

Genetic diversity of the endangered Chinese endemic plant Monimopetalum chinense revealed by amplified fragment length polymorphism (AFLP)

Monimopetalum chinense Rehd. is an endangered woody vine endemic to eastern China. Using amplified fragment length polymorphism (AFLP) markers, we examined levels of genetic variation within and among eleven populations located across the species’ distribution. Although modest levels of heterozygosity were detected, other measures of genetic diversity registered relatively high levels of variability, both at the species level (P = 91.0%, H_E = 0.232, I_S = 0.365) and at the population level (P = 53.0%, H_E = 0.155, I_S = 0.239). Populations also exhibited high levels of genetic differentiation (Nei’s genetic diversity analysis, G_ST = 0.330), corresponding to isolation-by-distance and hierarchical population structure. These results indicate that, despite low levels of gene flow, populations of M. chinense still harbor substantial amounts of genetic diversity. Management plans for the species should include measures that ensure genetic diversity remains high within and among extant populations.