Search

Understanding the molecular mechanisms and evolutionary process of plant adaptation to the heterogeneous environment caused by altitude gradients in plateau mountain ecosystems can provide novel insight into species' responses to global changes. Flower color is the most conspicuous and highly diverse trait in nature. Herein, the gene expression patterns, evolutionary adaptation and metabolites changes of different-colored flowers of alpine Rhododendron L. species along altitude gradients were investigated based on a combined analysis of transcriptomics and metabolomics. Differentially expressed genes were found to be related to the biosynthesis of carbohydrates, fatty acids, amino acids and flavonoids, suggesting their important roles in the altitude adaptability of Rhododendron species. The evolution rate of high-altitude species was faster than that of low-altitude species. Genes related to DNA repair, mitogen-activated protein kinase and ABA signal transduction, and lipoic acid and propanoate metabolism were positively selected in the flowers of high-altitude Rhododendron species and those associated with carotenoid biosynthesis pathway, ABA signal transduction and ethylene signal transduction were positively selected in low-altitude species. These results indicated that the genes with differentiated expressions or functions exhibit varying evolution during the adaptive divergence of heterogeneous environment caused by altitude gradients. Flower-color variation might be attributed to the significant differences in gene expression or metabolites related to sucrose, flavonoids and carotenoids at the transcription or metabolism levels of Rhododendron species. This work suggests that Rhododendron species have multiple molecular mechanisms in their adaptation to changing environments caused by altitude gradients.

Trachycarpus nanus is an endangered plant that is endemic to southwest of China. In the present study, the complete chloroplast genome of this species was assembled and characterized using whole genome next-generation sequencing. The complete chloroplast genome showed a circular genome of 158,713 bp size with 36.6% GC content. The genome is of typical structure and contain a pair of inverted repeat (IR) regions with 27,240 bp, separated by one large single-copy (LSC) with 86,395 bp, and one small single-copy (SSC) regions with 17,838 bp. The genome contained 132 genes, including 86 protein-coding genes, 8 rRNA genes and 38 tRNA genes. A phylogenetic tree reconstructed based on 21 chloroplast genomes reveals that Trachycarpus nanus is most related with Chamaerops humilis. The information provides important genetic basis for the species’ future studies on phylogenetic and utilization.

In this study, Cansjera rheedei J. F. Gmelin is an important role in the phylogeny and evolution of Opiliaceae plant. The chloroplast genome of C. rheedei is 144,306 bp in size, with an average GC content of 37.5%. The complete chloroplast genome has a typical quadripartite structure, including a large single copy (LSC) region (82,773 bp) and a small single copy (SSC) region (9745 bp), which were separated a pair of inverted repeats (IRs, 25,894 bp). This plastome contained 101 different genes, including 67 protein-coding genes (PCGs), 30 tRNA genes and four rRNA genes. The chloroplast genome of C. rheedei has completed that will be based on the phylogeny and genomic studies in the family Opiliaceae.

Cinnamomum chago is a woody species of the family Lauraceae endemic to Yunnan province, China, previously known from only one location, and categorized as a Plant Species with Extremely Small Population. We surveyed to determine the distribution and population size of C. chago, characterize its habitat, identify any threats, assess its conservation status, and provide guidelines for its management and conservation. During 2014–2017 we found only 64 mature C. chago, in five locations. These small, fragmented populations occur along Lancang River in Dali Prefecture at altitudes of 2,200–2,400 m. The species' extent of occurrence is c. 923 km2, with an area of occupancy of c. 60 km2. The habitat of the species has been degraded by expansion of pastoral activities and deforestation. We recommend categorization of C. chago as Endangered on the IUCN Red List, prevention of the collection of seeds and wood of the species, protection and monitoring, and ex situ propagation for future reintroductions.

Cinnamomum pittosporoides is an important timber plant endemic to southwest of China. In the present study, we sequenced the complete chloroplast genome of C. pittosporoides and used the data to reveal the species phylogenetic in Lauraceae. The complete chloroplast genome showed a circular genome of 152,730 bp size with 39.2% GC content. The genome is of typical structure and contains a pair of inverted repeat (IR) regions with 20,074 bp, separated by one large single-copy (LSC) with 93,722 bp and one small single-copy (SSC) regions with 18,860 bp. The genome contained 116 genes, including 82 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. A phylogenetic tree reconstructed based on 26 chloroplast genomes reveals that C. pittosporoides is most related with C. chago in Lauraceae.

As a species with restricted and fragmented distribution in Yunnan Province, Cinnamomum chago possesses high economic and phylogenetic values. Although this species has been categorized as an endangered plant in the IUCN Red List and has extremely small populations in China, the genetic information of C. chago has been rarely studied. In the present study, we used 4 pairs of DNA markers and 11 pairs of expressed sequence tag–simple sequence repeat markers to conduct a systematic and comprehensive assessment about the genetic diversity, genetic structure, and demographic history of 5 C. chago populations. A low genetic diversity but a significant genetic differentiation were detected (Na=2.509, Np=3.8, Ra=2.423, AE=1.635, HO=0.177, He=0.340). The five populations presented obvious inbreeding phenomenon given the high value of inbreeding coefficient (Fis=0.462) and low value of outcrossing rate (t = 0.365). Although the genetic distance and geographic distance were not correlated, geographical structures were detected in C. chago. Extremely low historical and contemporary gene flow was detected between pairwise populations of C. chago. Additionally, the remnant populations of C. chago experienced a recent historical bottleneck, but the neutrality tests and mismatch distribution analysis revealed that this species did not underwent a recent population expansion. In consideration of the above consequence, we advocate in situ conservation of natural habitats and remaining individuals of C. chago, as well as artificial breeding. This study not only provides important insights into the genetic characteristic but also emphasizes the relevance of the conservation of C. chago and other extremely endangered plants.

Yunnanopilia longistaminea (W.Z. Li) C.Y. Wu & D.Z. Li, which is a controversial species in Opiliaceae, is treated as a variety of Champereia manillana (Blume) Merrill in the Flora of China and morphological analysis has produced conflicting results regarding its affinity to Melientha and Champereia. To determine the systematic position of Yunnanopilia in Opiliaceae, we selected two nuclear regions (internal transcribed spacer [ITS4‐ITS5] and 18S rDNA) and four chloroplast regions (rbcL, matK, psbA‐trnH, and trnS‐trnG) to test the phylogenetics of the family Opiliaceae using maximum likelihood and Bayesian inference analysis. Morphological characteristics were also examined to clarify the similarities and differences among Y. longistaminea and two closely related species. Agonandra was located at the basal position in the family Opiliaceae; in the large clade including other remaining genera, two main clades were clearly identified and correlated with inflorescence morphological characteristics. All samples of Y. longistaminea formed a clade. Yunnanopilia, Melientha, and Champereia were more closely related than other genera of Opiliaceae. Yunnanopilia longistaminea was sister to M. suavis Pierre and was more closely related to M. suavis than to C. manillana. Morphological analysis also showed that differences in the inflorescences and flowers between Y. longistaminea and M. suavis were substantial enough to warrant the retention of Y. longistaminea in its current genus. Thus, we suggest that the monotypic Yunnanopilia be treated as a distinct genus and that the name Y. longistaminea should be adopted.

Big tree rhododendron ( Rhododendron protistum var. giganteum ) is an extremely endangered plant with only two remnant populations distributed in the Gaoligong Mountains of northwestern Yunnan Province, China. However, the genetic structure, demographic history, and the population dynamics of this species have been rarely described. In the present study, data from 14 polymorphic nuclear microsatellite loci were used to assess the levels of genetic diversity, genetic structure, and demographic history of big tree rhododendron remnant populations. Results suggested that renmants maintained a moderate level of genetic diversity ( N E = 2.86, A R = 5.726, H o = 0.510, H e = 0.602, I = 1.174) despite their small population. Bayesian clustering and principal coordinate analysis indicated that sampled individuals were clustered into two distinct genetic groups. Demographic history analysis revealed high historical and low contemporary gene flow between two remnant populations. BOTTLENECK analysis under a two-phase mutation model showed that the populations could have experienced a recent historical bottleneck. The effective population sizes of the two populations were smaller than 30. Therefore, in situ conservation of this species should be prioritized. Furtheremore, ex situ cultivation of field collected seeds and introduction of saplings into the source site might be considered for the future conservation and restoration of big tree rhododendron.

Champereia manillana (Bl.) Merr. is a vulnerable plant from the family Opiliaceae. The complete chloroplast genome (plastome) of Opiliaceae family was sequenced for the first time. The plastome of C. manillana was 147,461 bp in length. It was consisted of a large single copy (LSC) region (83,505 bp) and a small single copy (SSC) region (7,806 bp), which were separated by two inverted repeats (IRs, 28,075 bp). This plastome contained 101 different genes, including 67 protein-coding genes (PCGs), 30 tRNA genes and four rRNA genes. The overall GC content was 37.4%. Furthermore, phylogenetics analysis of 4 species in the Santalales was also conducted. The whole chloroplast genome of this species will be useful for the future plant evolutionary, phylogeny and genomic studies in the family Opiliaceae.

Typha orientalis is an important wetland macrophyte native to the eastern parts of Asia and Oceania. Herein, the complete chloroplast genome of this species was assembled and characterized using whole-genome next-generation sequencing. The complete chloroplast genome showed a circular genome of 160,969 bp size with 36.6% GC content. The genome is of typical structure and contains a pair of inverted repeat (IR) regions with 26,691 bp, separated by one large single-copy (LSC) with 89,118 bp, and one small single-copy (SSC) regions with 18,469 bp. The genome contained 132 genes, including 86 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. A phylogenetic tree reconstructed based on 15 chloroplast genomes reveals that T. orientalis is most related to Typha latifolia.

Cinnamomum chago, an endangered species endemic to Yunnan province, possesses large economic and phylogenetic values in Lauraceae. However, the genomic information of this species remains relatively unexplored. In this study, we used RNAseq technology to characterize and annotate the C. chago transcriptome and identify candidate genes involved in special metabolic pathways and gene-associated simple sequence repeats (SSRs) and single-nucleotide polymorphism (SNP). A total of 129,097 unigenes, with a mean length of 667 bp and an N50 length of 1,062 bp, were assembled. Among these genes, 56,887 (44.07%) unigenes were successfully annotated using at least one database. Furthermore, 47 and 46 candidate genes were identified in terpenoid biosynthesis and fatty acid biosynthesis, respectively. A total of 22 candidate genes participated in at least one abiotic stress response of C. chago. Additionally, a total of 25,654 SSRs and 640 SNPs were also identified. Based on these potential loci, 55 novel expressed sequence tag (EST)-SSR primers were successfully developed. This work provides comprehensive transcriptomic data that can be used to establish a valuable information platform for gene prediction, signaling pathway investigation, and molecular marker development for C. chago and other related species. Such a platform can facilitate further studies on germplasm conservation and utilization of Lauraceae species.

Cinnamomum pittosporoides is an important timber plant endemic to southwest of China. In the present study, we sequenced the complete chloroplast genome of C. pittosporoides and used the data to re...

Euryodendron excelsum H. T. Chang is a critically endangered plant from the family Theaceae that is endemic to China. It is now present in only one remnant population in a very narrow range and with a highly isolated and fragmented distribution pattern. The species is distributed close to the local villages and faces extinction because of the high level of anthropogenic disturbance. Thus, conservation and restoration of this species is urgent. The species reproduces by seed, but its germination requirements and seedling emergence are rarely understood. In this study, the germination requirements, desiccation tolerance and seedling emergence of the species were studied under controlled laboratory conditions. The results indicated that seeds of E. excelsum were non-dormant. Optimal temperatures for germination were 15°C to 25°C; the germination percentage decreased and the mean germination time increased at high temperature. Seed germination was inhibited in the dark, suggesting that the seeds were positive photoblastic. Water stress also significantly inhibited germination percentage; no seeds germinated at 15% polyethylene glycol 6000. The fresh seeds had moderate moisture content of 28.6% and showed strong tolerance of dehydration. Thus, the seeds of E. excelsum tended to be orthodox. Seeds on the soil surface had the highest emergence percentage, which declined with depth of burial. Soil types significantly affected seedling emergence; seeds had higher emergence percentage in sandy soil than in mixed soil and clayed soil. Our study demonstrated that ex situ conservation and reintroduction of E. excelsum using seedling propagation from seeds is feasible.

Big tree rhododendron, Rhododendron protistum var. giganteum (Ericaceae) is an endangered and important germplasm source with high ornamental value in China. To design appropriate germination and seedling establishment protocols for a species conservation and restoration program, we studied the effects of temperature, photoperiod, storage, and gibberellic acid (GA(3)) treatment on seed germination in a laboratory experiment. The effects of soil substrate and sowing depth on seedling emergence were studied in a greenhouse experiment. We hypothesized that photoperiod is a limiting factor for seed germination of big tree rhododendron, and soil type and sowing depth would affect seedling emergence. Results showed that seeds of big tree rhododendron were non-dormant, and temperature significantly affected germination percentages (GP) and mean germination time (MGT). The optimal temperatures for seed germination were relatively low (15 degrees C and 20 degrees C). High temperature negatively affected seed germination. The seeds had less than 5% of GP when incubated in complete darkness, suggesting that darkness significantly inhibits seed germination. Storage period and temperature had significant effect on GP and MGT of big tree rhododendron seeds, and the effect of their interaction on MGT was also significant. GA(3) treatment increased GP and germination speed. Soil substrates did not significantly affect seedling emergence, but native soil is beneficial to seedling growth. When the seeds were sown on the soil surface, seedling emergence was higher than 80%, but it decreased with increasing sowing depth, and no seedling emerged at 3 cm soil depth. We present some suggestions for the ex situ conservation and restoration program, including seed germination and seedling artificial propagation of big tree rhododendron based on the research results. (C) 2015 Elsevier GmbH. All rights reserved.

Cinnamomum chago, an endangered species endemic to Yunnan province, possesses large economic and phylogenetic values in Lauraceae. However, the genomic information of this species remains relatively unexplored. In this study, we used RNAseq technology to characterize and annotate the C. chago transcriptome and identify candidate genes involved in special metabolic pathways and gene-associated simple sequence repeats (SSRs) and single-nucleotide polymorphism (SNP). A total of 129,097 unigenes, with a mean length of 667 bp and an N50 length of 1,062 bp, were assembled. Among these genes, 56,887 (44.07%) unigenes were successfully annotated using at least one database. Furthermore, 47 and 46 candidate genes were identified in terpenoid biosynthesis and fatty acid biosynthesis, respectively. A total of 22 candidate genes participated in at least one abiotic stress response of C. chago. Additionally, a total of 25,654 SSRs and 640 SNPs were also identified. Based on these potential loci, 55 novel expressed sequence tag (EST)-SSR primers were successfully developed. This work provides comprehensive transcriptomic data that can be used to establish a valuable information platform for gene prediction, signaling pathway investigation, and molecular marker development for C. chago and other related species. Such a platform can facilitate further studies on germplasm conservation and utilization of Lauraceae species.

Transcriptome sequences generated by next-generation sequencing (NGS) technologies can be utilized to rapidly detect and characterize a large number of gene-based microsatellites from different plants. Rhododendron rex Lévl. is a perennial woody species from the family Ericaceae and an endangered plant with high ornamental value endemic to Southwestern China. Nevertheless, the genetic and genomic information of R. rex remain unknown. In this study, we performed transcriptome sequencing for R. rex leaf samples, and generated large transcript sequences for functional characterization and development gene-associated SSR markers. A total of 164,242 unigenes were assembled and 115,089 (70.07%) unigenes were successfully annotated in public databases. In addition, a total of 15,314 potential EST-SSRs were identified, and the frequency of SSRs in the R. rex unigenes was 9.32%, with an average of one EST-SSR per 5.65 kb. The most abundant type was repeated di-nucleotide (54.63%), followed by mono- (26.03%) and tri-nucleotide (18.51%) repeats. Based on the SSR-containing sequence, 100 primer pairs were randomly selected and synthesized and used for assessment of the polymorphism. Thirty-six primer pairs were polymorphic and revealed polymorphism among 20 individuals from four R. rex populations. A total of 197 alleles were identified, with an average of 5.472 alleles per locus. The Polymorphism Information Content ranged from 0.154 to 0.870, with a mean of 0.482. The newly developed EST-SSR markers exhibited high transferability (58.33–83.33%) among the six subgenera. Thus, these novel EST-SSR markers developed would provide valuable sequence resources for population structure, genetic diversity analysis, and genetic resource assessments of R. rex and its related species.

Yunnanopilia longistamineais an endangered monotypic species belonging to Opiliaceae. This edible plant is an important germplasm source with a high economic value in China if propagation were less difficult. Seed dormancy and germination of this species were investigated to improve propagation. Considering seeds have a fully developed embryo and mature and are dispersed in summer, and radicles and epicotyls emerge the following autumn and next spring, respectively, we hypothesized thatY. longistamineaseeds may undergo physiological epicotyl dormancy. Seed moisture content and viability decreased as dehydration occurred. Thus, the seeds may be recalcitrant. The seed germination of this species involves two stages: radicle emergence and epicotyl (shoot) emergence. The optimum temperature was 28 °C and 28 °C/20 °C to radicle emergence. The optimum GA3solution for the seeds undergoing shoot emergence was 100 mg L−1. The percentages of shoot emergence in seven and 14 days stratification at 5 °C were slightly higher than those in other groups. This study is the first to describe physiological epicotyl dormancy inY. longistamineaseeds. Under natural conditions, seeds are subjected toY. longistamineaa autumn → winter → spring temperature. Warm moist conditions and cold stratification can improve radicle emergence and alleviate epicotyl dormancy, respectively. The duration of cold stratification also significantly affects the epicotyl dormancy release ofY. longistaminea. Optimal dormancy breakage methods are warm (28 °C/20 °C) → cold (5 °C) → GA3(100 mg L−1) → warm (28 °C/20 °C).

Yunnanopilia longistaminea is an endangered monotypic species belonging to Opiliaceae. This edible plant is an important germplasm source with a high economic value in China. The seed dormancy and germination of Opiliaceae species have been rarely investigated. This study examined the effects of scarification, soaking in gibberellic acid, and dehydration on the seed germination of Y. longistaminea. Results indicated that the seed germination of this species involves two stages: radicle emergence and epicotyls (shoot) emergence. During radicle emergence, the optimum temperatures were 28 °C and 28 °C/20 °C. Seed moisture content and viability decreased as dehydration occurred. Thus, the seeds may be recalcitrant. The optimum GA3 solution for the seeds undergoing shoot emergence was 100 mg·L−1. The percentages of shoot emergence in 7 and 14 days of stratification at 5 °C were slightly higher than those in other groups. This study is the first to describe epicotyl dormancy in Y. longistaminea seeds. From the seed grow to the seedling of Y. longistaminea subjected to a autumn→winter→spring temperature process in nature conditions. Warm and cold stratification can alleviate radicle and epicotyl dormancy, respectively. The duration of cold stratification also significantly affects the epicotyl dormancy release of Y. longistaminea. The researches on the seeds breaking methods: warm(28°C/20°C)→cold(5°C)→GA3(100mg·L−1)→warm(28°C/20°C).

Apterosperma oblata H. T. Chang is an endangered species in the Theaceae, and although it reproduces by seed its germination requirements are not known. To provide basic information for conservation and restoration programs, we studied the effects of temperature, light, desiccation, and storage on the germination of A. oblata seeds under laboratory conditions. Optimal temperatures for seed germination were 15 and 20°C. Photoperiod greatly affected final germination percentage, and constant darkness inhibited seed germination. Fresh harvested seeds had a high moisture content (56.4%), and they gradually lost their germination ability as dehydration occurred, suggesting that the seeds may be recalcitrant. Although short-term (2 months) dry storage at 4°C increased the germination percentage, the overall trend was a considerable decline in germination percentage with an increase in storage duration at 4°C and 20°C. Since seeds are recalcitrant and easy to germinate at maturity, we recommend seedlings establishment rather than seeds for conservation and restoration programs of the species.

In the present study, the distribution, population size and structure, habitat and stand disturbance of a critically endangered plant Euryodendron excelsum H. T. Chang were examined using field investigations. A total of 179 individual plants, including 23 adult trees, were found. The population was distributed in 10 highly isolated and fragmented patches. Half of the 10 patches had less than 10 individual plants and two patches had only one remnant adult; there were no adult plants in two of the patches. Although the overall population structure trends to a reversed ‘J’ shape, two fragile stages of E. excelsum limit its natural recruitment and regeneration: seed germination and seedling growth toward adulthood. The major threats for the survival of this species are its specific small population size and the high frequency of anthropogenic destruction. Based on the results, some strategies were put forward for the conservation of E. excelsum populations.

This is the first study of the genetic diversity and structure of the big tree rhododendron, Rhododendron protistum var. giganteum, which is a highly endangered species with only two known endemic populations in a small area in the southern part of Yunnan Province in China. We detected moderate to high genetic diversity at the species level, but low genetic differentiation between the two extant populations. These results suggest that some rare and endangered species are able to maintain high levels of genetic diversity even at small population sizes., Comprehensive studies on the genetic diversity and structure of endangered species are urgently needed to promote effective conservation and management activities. The big tree rhododendron, Rhododendron protistum var. giganteum, is a highly endangered species with only two known endemic populations in a small area in the southern part of Yunnan Province in China. Unfortunately, limited information is available regarding the population genetics of this species. Therefore, we conducted amplified fragment length polymorphism (AFLP) analysis to characterize the genetic diversity and variation of this species within and between remaining populations. Twelve primer combinations of AFLP produced 447 unambiguous and repetitious bands. Among these bands, 298 (66.67 %) were polymorphic. We found high genetic diversity at the species level (percentage of polymorphic loci = 66.67 %, h = 0.240, I = 0.358) and low genetic differentiation (Gst = 0.110) between the two populations. Gene flow between populations (Nm) was relatively high at 4.065. Analysis of molecular variance results revealed that 22 % of the genetic variation was partitioned between populations and 78 % of the genetic variation was within populations. The presence of moderate to high genetic diversity and low genetic differentiation in the two populations can be explained by life history traits, pollen dispersal and high gene flow (Nm = 4.065). Bayesian structure and principal coordinate analysis revealed that 56 sampled trees were clustered into two groups. Our results suggest that some rare and endangered species are able to maintain high levels of genetic diversity even at small population sizes. These results will assist with the design of conservation and management programmes, such as in situ and ex situ conservation, seed collection for germplasm conservation and reintroduction.

The paper is aimed at studying the diversity of endophytic fungi community from Paris polyphylla var. yunnanensis, and to provide a scientific basis for the utilization value of the endophytic fungi as bioactive material resources. In the present study, endophytic fungi were isolated from roots, rhizomes and leaves of wild P. polyphylla var. yunnanensis collected from Baoshan, Heqing county and Songming city of Yunnan province, and identified and classified by morphological methods together with its ITS sequence analysis. Seven and forty-nine strains of endophytic fungi were isolated from P. polyphylla var. yunnanensis. They were identified belonging to 41 genus. In these 41 genus, 3 genus exist in root only, 12 genus only exist in rhizome and 8 genus only exist in leaf. There was difference in endophytic fungi isolated from different sample sites. Endophytic fungi diversity from rhizomes of Heqing site was the highest. Endophytic fungi similarity coefficient was low among different sites and tissues. Based on these results, it is reasonable to propose that endophytic fungi of P. polyphylla var. yannanensis from different tissue and different sample sites has a certain difference which is possibly relate to their different habitats, different structure and composition of each tissue.

It is increasingly evident that the mycorrhizal colonisation of endangered species is of major importance for their restoration. In the present study, the symbiosis of arbuscular mycorrhizal fungi (AMF) and endangered species Euryodendron excelsum was investigated in 10 patches of a remnant population in south China. The presence of arbuscules and vesicles indicates that E. excelsum is a typical arbuscular mycorrhizal plant. Five genera were identified in the rhizosphere of E. excelsum, and the most common and frequent genus was Glomus. Root total colonisation intensity is negatively correlated with the available soil phosphorus and potassium content in the soil. In addition, we find no significant relationship between spore density and soil characteristics, or between spore density and total colonisation intensity. Furthermore, a greenhouse experiment under two soil types (humus: native soil = 3 : 1 ST1; humus: native soil = 1 : 3 ST2) was conducted to evaluate the effects of AMF inoculation on seedling growth. The levels of plant mycorrhizal response of E. excelsum seedlings under the ST1 and ST2 soil types were 136 and 413%, respectively. Although a significant growth enhancement was found in the ST1 soil type, seedling growth and survival rate were improved after AMF colonisation under both soil types. The results suggest that AMF colonisation may have practical implications in establishing effective conservation and restoration strategies for this critically endangered plant.

Cinnamomum chago (family Lauraceae) is an essential source of timber and oil. This plant is narrowly distributed in the western part of the Yunnan Province. In this study, the distribution, habitat, and biological characteristics of C. chago were examined through field investigation. The genetic diversity and the variation of the remnant populations were also studied using the inter-simple sequence repeat technique. Results showed that C. chago is mainly distributed in the upstream tributary mountains of Lancang River in Yunlong County of Yunnan Province. The species distribution exhibited a fragmented pattern with five isolated populations and high-frequency anthropogenic interference. A combination of morphological features (opposite leaves, pinnate leaf veins, absence of glandular fossa, large drupe, small punch, and pollen surface with triangular spike grain, with cushion bumps at the base) indicated that C. chago is a key phylogenetic taxon between the two sections of Asian Cinnamomum plants (Sect. Camphora (Trew) Meissn. and Sect. Cinnamomum). Analysis of the genetic diversity of C. chago indicated that it has a moderately high level of genetic diversity at the population and species levels (populations level: Ne = 1.629, H = 0.348, I = 0.504, and PPB = 83.3%; species level: Ne = 1.864, H = 0.460, I = 0.652, and PPB = 100%). Analysis of molecular variance revealed that 17% of the genetic variation was divided between the populations, whereas 83% was observed within the populations. Based on these results, we suggest the inclusion of C. chago in the Wild Plants with Extremely Small Populations in China. Moreover, the species should be given special attention and protection. Some strategies were proposed for the conservation of the C. chago populations.