Genetic diversity of endangered Manglietia patungensis assessed by inter simple sequence repeat and sequence-related amplified polymorphism markers

Manglietia patungensis Hu is an endangered plant native to China. Knowledge of its genetic diversity and structure would aid its conservation. This study assessed nine natural populations of M. patungensis using two methods: inter simple sequence repeat (ISSR) and sequence-related amplified polymorphism (SRAP) markers. Using 10 ISSR primer pairs, 334 bands were generated, and 10 SRAP primer pairs generated 276 bands. The percent of polymorphic bands (91.32% and 93.48%), Nei's genetic diversity (0.3448 and 0.3323), and Shannon's information index (0.5075 and 0.4935) revealed a high level of genetic diversity at the species level. Total heterozygosity was 0.3439 by ISSR and 0.3281 by SRAP. The mean heterozygosity was 0.2323 by ISSR and 0.2521 by SRAP. The coefficient of genetic differentiation among natural populations was 0.3245 by ISSR and 0.2316 by SRAP. These data indicated higher levels of genetic diversity of M. patungensis within, rather than among, populations. Estimates of gene flow among natural populations were 1.0411 and 1.0589, which implied a certain amount of gene exchange among populations. A Mantel test revealed no significant correlation between genetic and geographic distance. ISSR and SRAP markers are both effective for genetic diversity research in M. Patungensis. Based on these results, conservation of M. patungensis should be performed both in situ and ex situ.     

Molecular Insights of Genetic Variation in Erianthus arundinaceus Populations Native to China

Background

E. arundinaceus (Retz.) Jeswiet is a warm-season, tall-growing perennial species native to much southern portion in China. The grass has been extensively used in sugarcane breeding and is recently targeted as a bioenergy feedstock crop. However, information on the genetic structure of the Chinese wild germplasm is limited. Knowledge of genetic variation within and among populations is essential for breeding new cultivars in the species. The major objective of this study was to quantify the magnitude of genetic variation among and within natural populations in China.

Methodology/Principal Findings

In this experiment, we analyzed genetic variation of 164 individuals of 18 populations collected from natural habitats in six Chinese provinces using 20 sequence-related amplified polymorphism (SRAP) primer pairs generating 277 polymorphic bands. Among and within the populations, the percentage of polymorphic bands (PPB) was 80.00% and 27.07%, genetic diversity (H_E) was 0.245 and 0.099, effective number of alleles (N_E) was 1.350 and 1.170, and Shannon''s information index (I) was 0.340 and 0.147, respectively. The populations were clustered into six groups exhibiting a high level of genetic differentiation, which was highly associated with geographic origins of respective germplasm populations, but was not significantly associated with geographic distances between the populations.

Conclusions/Significance

This is the first report indicating that large genetic variation exists in the Chinese E. arundinaceus germplasm based on the SRAP molecular marker analysis of native populations. The genetic structure of populations in the species has been substantially affected by geographic landforms and environments. The diverse collection will be highly valuable in genetic improvement in the species per se and likely in sugarcane.     

Siberian wild rye (Elymus sibiricus L.): Genetic diversity of germplasm determined using DNA fingerprinting and SCoT markers

Elymus sibiricus is a perennial, self-pollinating, allotetraploid grass native to northern Asia. It is widely used in cultivated pastures and natural grassland due to excellent cold and drought tolerance, good forage quality, and adaptability to a variety of habitats. Information on the genetic diversity and variation among worldwide E. sibiricus germplasm is limited but necessary for germplasm collection, conservation and effective commercial use. In this study we ana lyzed genetic diversity and variation of 69 E. sibiricus accessions from the species range and constructed DNA fingerprinting profiles of 24 accessions using SCoT markers. A total of 173 bands were generated from 16 SCoT primers, 154 of which were polymorphic with 89.0% of polymorphic bands (PPB) occurring at the species level. The PPB within 8 geographical regions ranged from 2.3 to 54.3 %. Genetic variation was greater within geographical regions (57.9%) than between regions (42.1%). The 24 accessions from Qinghai-Tibet Plateau, Mongolia Plateau, Kazakhstan, and Russia were distinguished by their unique fingerprinting. This is the first report using SCoT markers for identifying cultivars and accessions of E. sibiricus. The DNA fingerprinting profiles of E. sibiricus were useful in germplasm collection and identification. The genetic diversity of worldwide E. sibiricus germplasm has been substantially affected by ecogeographical factors. Our results suggest that collecting and evaluating E. sibiricus germplasm from major geographic regions and unique environments broadens the available genetic base and illustrates the range of variation.     

Genetic Variability and Population Structure of Disanthus cercidifolius subsp. longipes (Hamamelidaceae) Based on AFLP Analysis

Disanthus cercidifolius subsp. longipes is an endangered species in China. Genetic diversity and structure analysis of this species was investigated using amplified fragments length polymorphism (AFLP) fingerprinting. Nei''s gene diversity ranged from 0.1290 to 0.1394. The AMOVA indicated that 75.06% of variation was distributed within populations, while the between-group component 5.04% was smaller than the between populations-within-group component 19.90%. Significant genetic differentiation was detected between populations. Genetic and geographical distances were not correlated. PCA and genetic structure analysis showed that populations from East China were together with those of the Nanling Range. These patterns of genetic diversity and levels of genetic variation may be the result of D. c. subsp. longipes restricted to several isolated habitats and “excess flowers production, but little fruit set”. It is necessary to protect all existing populations of D. c. subsp. longipes in order to preserve as much genetic variation as possible.     

Planchonella, first record of gynomonoecy for the family Sapotaceae

Inter-simple sequence repeat (ISSR) markers were used to investigate the levels and pattern of genetic variation within and among populations of Pteroceltis tatarinowii Maxim., an endangered plant endemic to China. Of the 76 primers screened, 11 produced highly reproducible ISSR bands. A total of 118 bands were presented from the 11 selected primers across all individuals of five natural populations, corresponding to an average of 10.73 bands per primer. The size of the ISSR bands ranged from 200 to 2,000 bp. The percentage of polymorphic loci at the population level ranged from 77.97 to 86.44%, with an average value of 82.54%. Genetic differentiation among populations was revealed based on Nei’s genetic diversity analysis (19.41%) and the nonparametric analysis of molecular variance (20.62%). The Mantel test showed a significant positive correlation between geographic distance and genetic distance (r = 0.7758, P < 0.05), indicating a role of geographic isolation in shaping the present population genetic structure of P. tatarinowii. The size of the natural populations of P. tatarinowii was noted in field observations to be very small, chiefly owing to habitat destruction and overexploitation in the past decades. Therefore, effective measures for preserving genetic diversity of this species at the population level are needed and should include protecting its natural habitats and increasing the numbers of individuals. To meet the commercial demand for this species, P. tatarinowii plantations and cultivation facilities should be established as an alternative source of raw materials.     

The extent of clonality and genetic diversity in the rare Caldesia grandis (Alismataceae): Comparative results for RAPD and ISSR markers

Genetic variation and clonal diversity of three natural populations of the rare, highly clonal marsh herb Caldesia grandis Samuelsson were investigated using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Both of the markers worked effectively in clone identification of C. grandis. RAPD markers detected more diversity than ISSR markers in the three populations examined. Of the 60 RAPD primers screened, seven produced highly reproducible bands. Using these primers, a total of 61 DNA fragments were generated with 52 (85.25%) being polymorphic indicating considerable genetic variation at the species level. Analysis of molecular variance (AMOVA) showed that a large proportion of genetic variation (81.5%) resided within populations, while only a small proportion (18.5%) resided among populations. With the use of 52 polymorphic RAPD markers, we were able to identify 127 genets among 342 samples from three populations. The proportion of distinguishable genets (PD: mean 0.37), Simpson's diversity index (D: mean 0.91), and evenness (E: mean 0.78) exhibited high levels of clonal diversity compared to other clonal plants. These results imply that sexual reproduction has played an important role at some time during the history of these populations. Nevertheless, the high level of diversity could have been also partially generated from somatic mutations, although this is unlikely to account for the high diversity generally found among C. grandis genets.     

Using SSR markers to evaluate the genetic diversity of Lentinula edodes’ natural germplasm in China

In this study, microsatellite markers were utilized to reveal the genetic diversity of 56 strains of Lentinula edodes grown in China. A total of 224 DNA bands were detected through 25 primer pairs, of which, 223 bands (99.6%) were polymorphic between two or more strains. The variation in SSR (Simple Sequence Repeat) DNA band patterns and average genetic similarity among the wild strains of L. edodes obtained from the same region uncovered a vast genetic diversity in the natural germplasm found in China. Compared with L. edodes strains from other areas, the genetic diversity of those from the Yunnan Plateau, Hengduanshan mountains, Taiwan, and south China was significantly greater. Based on cluster analysis and principal coordinate analysis, the results indicated that all L. edodes strains could be divided into three major groups. These results effectively displayed the differences between the strains from North and South China, and those from the same or adjoining regions could cluster preferentially into small groups in most cases, suggesting the positive correlation between the cluster results and the geographical origin for the natural germplasm of Chinese L. edodes. To our knowledge, this is a pioneering report on the utilization of the SSR marker technique in analyzing L. edodes’ genetic diversity.     

Genetic diversity and biogeography of the traditional Chinese medicine, Gardenia jasminoides, based on AFLP markers

Gardenia jasminoides Ellis is used in traditional Chinese medicine (TCM) in China. Levels of genetic variation and patterns of population structure within and among eight wild or cultivated populations of G. jasminoides Ellis in China were investigated using amplified fragment length polymorphism (AFLP) markers. Of the 11 primers screened, four produced highly reproducible AFLP bands. Using these primers, 244 discernible DNA fragments were generated with 165 bands (67.6%), were polymorphic, indicating considerable genetic variation at the species level. In contrast, there were relatively low levels of polymorphism at the population level with the percentage of polymorphic bands (PPB) ranging from 36.89% to 59.43%. Genetic diversity within populations ranged from 0.2086 to 0.3108, averaging 0.2392 at the species level. A high level of genetic differentiation among populations was detected based on Nei's genetic diversity analysis (76.59%), Shannon's index analysis (64.8%) and AMOVA analysis (72.75%). No significant statistical differences (analysis of molecular variance [AMOVA], p = 0.0639) in AFLP variation were found between regions. However, the variance among populations and within populations differed significantly (p < 0.001). An indirect estimate of historical levels of gene flow (N_m = 1.7448) was consistent with the high mean genetic identity (mean I = 0.9263) found among populations. There is an association between geographic and genetic distances between populations. Presently gene change exists between populations.     

Genetic Diversity Within and Among Lepidium draba Populations from Eastern Anatolia Based on RAPD Analysis

Genetic variation and structure of six natural populations of Lepidium draba L. from Eastern Anatolia were assessed using random amplified polymorphic DNA (RAPD) markers. For RAPD analysis, 12 primers generated 218 reproducible bands across the six populations analyzed, of which 73 bands (33.3%) were polymorphic. The mean Nei’s gene diversity value for all six populations was 0.1771. Shannon’s information index varied with population (0.2278–0.3082), averaging 0.2608. Analysis of molecular variance (AMOVA) showed that genetic diversity was greater within populations (58.66%) than among populations (30.68%). In addition, the variation between groups was 10.33%. The genetic differentiation among populations (G _ST) was 0.3210, indicating that most genetic diversity occurs within populations. Gene flow (Nm) was low, at only 0.5288.     

Genetic diversity and structure of the noxious alien grass Praxelis clematidea in southern China

Praxelis clematidea (Asteraceae), a plant species native to South America, is a noxious weed in southern China. We examined the genetic variation and population structure of 12 populations (76 individuals) of P. clematidea from Fujian, Guangdong, and Hainan Provinces in China using inter-simple sequence repeat (ISSR) analysis. From an initial set of 69 ISSR primers, 10 were selected which yielded 80 reproducible bands. Polymorphic bands (P) were 100%, Shannon's information index (I) was 0.4226, and Nei's gene diversity (H) was 0.2791. We infer that the high levels of genetic diversity exhibited by P. clematidea may have contributed to its invasiveness. Gene flow among populations was 2.4930, which has led to homogenization. The coefficient of population differentiation (Gst = 0.1671) indicated low levels of genetic variation among populations and high levels of genetic polymorphism within populations. There was a negative correlation between population elevation and genetic diversity, while there was a significant positive correlation between genetic distance and geographic distance based on a Mantel test (r = 0.5820, P < 0.01). Some populations from different provinces clustered together in principal coordinate and UPGMA analyses indicating that human-mediated events may have contributed to the dispersal of the species.     

Genetic Diversity of and Differentiation among Five Populations of Blunt Snout Bream (Megalobrama amblycephala) Revealed by SRAP Markers: Implications for Conservation and Management

The blunt snout bream (Megalobrama amblycephala) is an important freshwater aquaculture fish throughout China. Because of widespread introductions of this species to many regions, the genetic diversity of wild and natural populations is now threatened. In the present study, SRAP (sequence-related amplified polymorphism) markers were used to assess genetic diversity of blunt snout bream. Three natural populations (Liangzi Lake, Poyang Lake and Yuni Lake, one cultured population (Nanxian) and one genetic strain (‘Pujiang No. 1’) of blunt snout bream were screened with 88 SRAP primer combinations, of which 13 primer pairs produced stable and reproducible amplification patterns. In total, 172 bands were produced, of which 132 bands were polymorphic. Nei''s gene diversity (h) and Shannon''s information index (I) values provided evidence of differences in genetic diversity among the five populations (Poyang Lake>Liangzi Lake>Nanxian>‘Pujiang No. 1’>Yuni Lake). Based on cluster analysis conducted on genetic distance values, the five blunt snout bream populations were divided into three groups, Poyang Lake and Liangzi Lake (natural populations), Nanxian and ‘Pujiang No. 1’ (cultured population and genetically selected strain), and Yuni Lake (natural population). Significant genetic differentiation was found among the five populations using analysis of molecular variance (AMOVA), with more genetic divergence existing among populations (55.49%), than within populations (44.51%). This molecular marker technique is a simple and efficient method to quantify genetic diversity within and among fish populations, and is employed here to help manage and conserve germplasm variability of blunt snout bream and to support the ongoing selective breeding programme for this fish.     

Population genetic structure of Ceriops tagal (Rhizophoraceae) in Thailand and China

Knowledge of the amount and patterns of genetic variation within and among populations of mangrove trees is essential for devising optimum genetic management strategies for their conservation and sustainable utilization. Ceriops tagal is a widespread viviparous mangrove. Genetic diversity in the species was examined with inter-simple sequence repeat (ISSR). Nine natural populations were collected from Thailand and China. The estimates of genetic variation were extremely low (H_T = 0.0179 ± 0.005, H_S = 0.0084 ± 0.001), and only 47% of the total gene diversity was maintained within populations (G_ST = 0.529). The eastern coastal populations of Thailand were more similar to populations from China than to populations from the western coastline of Thailand. A high level of Nei's genetic identity exists between populations of C. tagal (I = 0.989), suggesting their common ancestry. The low levels of genetic diversity in the species may result from a series of genetic bottlenecks during several glacial epochs.     

Contrasting coarse and fine scale genetic structure among isolated relic populations of Kmeria septentrionalis

Trees of the Magnoliaceae family are of scientific, cultural and socio-economic importance. Kmeria septentrionalis Dandy (Magnoliaceae) is a dioecious tree, found in small, isolated, relic populations in Southern China, and is subject to extensive protection due to its rarity and high economic values. To improve conservation outcomes and in particular, germplasm collection guidelines, information on spatial genetic structure of the species is required. In this study, we investigated the spatial genetic structure and genetic diversity of 161 individuals of K. septentrionalis collected from five natural populations using AFLP molecular markers. Within-population genetic variation was measured, with percentage of polymorphic bands (PPB) ranged from 63% to 87%, while H _S (genetic diversity within population) varied from 0.185 to 0.244 with a mean of 0.215 ± 0.025. Significant genetic differentiations were revealed between pairwise populations, indicating each population existing as an independent evolutionarily significant unit. Mantel test results showed no pattern of isolation-by-distance among populations separated by large distance. Fine scale spatial patterns of genetic variation suggested significant effects of isolation-by-distance within population at distances of 22 m. The results of contrasting genetic structure at coarse and fine scale in K. septentrionalis may indicate restricted pollen flow and seed dispersal at fine scales, and separated evolution in isolated populations over long period of time at coarser scales. Finally, we make several suggestions for improved management practices that may assist in the conservation of this species.     

SRAP analysis of genetic diversity of nine native populations of wild sugarcane, Saccharum spontaneum, from Sichuan, China

Saccharum spontaneum is a wild sugarcane species that is native to and widely distributed in China. It has been extensively used in sugarcane breeding programs, and is being tested for the development of bioenergy cultivars. In order to provide basic information for the exploitation of this species, we analyzed genetic variation among and within native S. spontaneum populations collected from Sichuan, China. Eighty plants from nine native populations were sampled. Twenty-one sequence-related amplified polymorphism primer pairs generated 235 clearly scorable bands, of which 185 were polymorphic (78.7%). Nei's genetic diversity was 0.2801 and Shannon's information index was 0.4155 across the populations. Genetic diversity parameters, G(ST) value (0.2088) and N(m) value (1.8944), showed that the genetic variation within populations was greater than that among populations. In the cluster analysis, one major grouping was formed by populations from Ya'an and another one by populations from Sichuan basin; a population from Baoxing formed a single cluster. In order to fully comprehend the genetic diversity of cold-tolerant local germplasm in this species, germplasm should be collected from the heterogeneous environments along the northern regions of this species' distribution. The germplasm that we collected should be a valuable resource for Saccharum breeding.     

Genetic diversity of wild populations of Rheum tanguticum endemic to China as revealed by ISSR analysis

Rheum tanguticum is an important but endangered traditional Chinese medicine endemic to China. The wild resources have been declining. Establishing the genetic diversity of the species would assist in its conservation and breeding program. Inter-simple sequence repeats (ISSR) markers were used to assess the genetic diversity and population genetic structure in 13 wild populations of R. tanguticum from Qinghai Province. Thirteen selected primers produced 329 discernible bands, with 326 (92.94%) being polymorphic, indicating high genetic diversity at the species level. The Nei's gene diversity (He) was estimated to be 0.1724 within populations (range 0.1026–0.2104), and 0.2689 at the species level. Analysis of molecular variance (AMOVA) showed that the genetic variation was found mainly within populations (71.02%), but variance among populations was only 28.98%. In addition, Nei's differentiation coefficients (G_st) was found to be high (0.3585), confirming the relatively high level of genetic differentiation among populations. Mantel test revealed a significant correlation between genetic and geographic distances (r = 0.573, P = 0.002), and the unweighted pair-group method using arithmetic average (UPGMA) clustering and Principal coordinates analysis (PCoA) demonstrated similar results. Meanwhile, the genetic diversity of R. tanguticum positively correlated with altitude and annual mean precipitation, but negatively correlated with latitude and annual mean temperature. This result might be an explanation that the natural distribution of R. tanguticum is limited to alpine cold areas. We propose conservation strategy and breeding program for this plant.     

Genetic variation within the sand-fixation species Caragana microphylla (Leguminosae) in Horqin sandy land detected by inter-simple sequence repeats analysis

Caragana microphylla is the most dominant and constructive shrub species in the Horqin sandy land in the northeast of China. We evaluated it's the level of genetic variation within and among populations sampled from two different populations types in Horqin sandy land by using inter-simple sequence repeat polymorphism (ISSR) molecular markers. The results showed that eight ISSR primers generated 106 bands, of which 87 were polymorphic. At the species level, genetic diversity was relatively high (P = 82.08%, h = 0.2831, I = 0.4233). Genetic variation in natural populations (h = 0.2152, I = 0.3169) was more than that in plantation populations (h = 0.2021, I = 0.3040). Based on Nei's G_ST value, more genetic differentiation among plantation populations was detected (G_ST = 0.7787). Six populations of C. microphylla clustered into two clades. These results have important implications for restoring and managing the degraded ecosystem in arid and semi-arid areas.     

Genome and population dynamics under selection and neutrality: an example of S-allele diversity in wild cherry (Prunus avium L.)

Self-incompatibility, a common attribute of plant development, forms a classical paradigm of balancing selection in natural populations, in particular negative frequency-dependent selection. Under negative frequency-dependent selection population genetics theory predicts that the S-locus, being in command of self-incompatibility, keeps numerous alleles in equal frequencies demonstrating a wide allelic range. Moreover, while natural populations exhibit a higher within population genetic diversity, a reduction of population differentiation and increase of effective migration rate is expected in comparison to neutral loci. Allelic frequencies were investigated in terms of distribution and genetic structure at the gametophytic self-incompatibility locus in five wild cherry (Prunus avium L.) populations. Comparisons were also made between the differentiation at the S-locus and at the SSR loci. Theoretical expectations under balancing selection were congruent to the results observed. The S-locus showed broad multiplicity (16 S-alleles), high genetic diversity, and allelic isoplethy. Genetic structure at the self-incompatibility locus was almost four times lower than at 11 nSSR loci. Analysis of molecular variance revealed that only 5?% of the total genetic variation concerns differentiation among populations. In conclusion, the wealth of S-allelic diversity found in natural wild cherry populations in Greece is useful not only in advancing basic population genetics research of self-incompatibility systems in wild cherry but also in the development of breeding programs.     

Population structure and genetic diversity of Stipa grandis P. Smirn,a dominant species in the typical steppe of northern China

Random amplified polymorphic DNA (RAPD) markers were used to characterize genetic heterogeneity within and among five populations of Stipa grandis in the Xilingol Plateau. Estimates of the percentage of polymorphic bands, Shannon's diversity information index and Nei's gene diversity index were comparatively high in the five populations, and the Population GSM was found to have the highest genetic diversity among all populations. An analysis of molecular variance indicated that the majority of variation existed within populations (74.12%), and that there was significant differentiation among populations (Φ_ST = 25.88%, P < 0.001). Genetic distance (Φ_ST) ranged from 0.198 to 0.310 and the differentiation between pair-wise populations was significant when individual pairs of populations were compared. Based on the Φ_ST values, gene flow (Nm) was estimated and was found to vary from 0.556 to 1.013 between pair-wise populations and 0.7412 among populations. The results of UPGMA cluster analysis and nonmetric multi-dimensional scaling analysis indicated that most variation occurred within populations and that genetic differentiation had happened between populations. These findings are important for a better understanding of the adaptive strategy of S. grandis in northern China and will be useful for conservation managers to work out an effective strategy to protect this important species.     

Genetic Diversity and Population Structure of Miscanthus sinensis Germplasm in China

Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n = 2x = 38), as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei’s genetic diversity index (He) of 0.32 and polymorphism information content (PIC) of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83%) was substantially greater than the between-subpopulation variation (17%). Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits.     

Genetic variation within the endangered quillwort Isoëtes hypsophila (Isoetaceae) in China as evidenced by ISSR analysis

The genetic diversity of 56 individuals of Isoëtes hypsophila Hand.-Mazz. from China was investigated by ISSR. Twelve primers were screened from 65 primers, and a total of 119 DNA fragments were scored, of these, 82% were polymorphic bands, which indicated that high levels of genetic variation existed in the natural populations. Genetic diversity varied greatly among populations with the percentage of polymorphic band (PPB) values ranging from 8 to 35%. An analysis of molecular variance (AMOVA) was used to apportion the variation between regions, among populations within regions, and within populations. Results indicated that most of the variance (85%) occurred between Yunnan and Sichuan. The variances among populations within regions and within populations, however, were only 5 and 10%, respectively. In the among-population analysis, the larger part of genetic variation (77%) resided among populations, and less (23%) presented differences within populations. UPGMA cluster analysis showed that there was no distinct genetic differentiation between populations from Sichuan province. A number of causes including limited gene flow, genetic drift and inbreeding might have led to these observed genetic profiles of I. hypsophila.