Biochemical and transcriptomic analyses of the symbiotic interaction between Cremastra appendiculata and the mycorrhizal fungus Coprinellus disseminatus.

BACKGROUND: Cremastra appendiculata is a rare terrestrial orchid with a high market value as an ornamental and medicinal plant. However, the species depends entirely on fungi for seed germination under natural conditions. In a previous study, we have successfully isolated and identified the mycorrhizal fungus Coprinellus disseminatus which was able to induce the germination of C. appendiculata seeds. We then speculated that C. disseminatus may do so by breaking the testa imposed dormancy of the seeds. In this study, biochemical and transcriptomic analyses were used to characterize the germination of C. appendiculata seeds, collected at different stages of germination, as affected by C. disseminatus. RESULTS: The lignocellulose in the seeds coat of C. appendiculata was degraded by the mycorrhizal fungus resulting in facilitated absorption of water. The rate of decline in lignin content was 67 and 73% at 6 and 12 days after sowing, respectively. The water content increased from 13 to 90% during symbiosis. A total of 15,382 genes showing significantly different levels of expression (log2 FPKM≥2.0, Qvalue≤0.05) were successfully identified among all libraries, where the highest number of DEGs was shared between 6 days versus 0 day after symbiotic germination. Gene annotation results suggested that 15 key genes related water-status, such as DHN gene family and Xero 1 were down-regulated. The genes zeaxanthin epoxidase ZEP, 9-cis-epoxycarotenoid dioxygenase NCED3 and ß-carotene hydroxylase involved in the biosynthesis of abscisic acid (ABA) were significantly down-regulated in 6 days as compared to 0 day after symbiotic germination. CONCLUSIONS: This work demonstrates that mycorrhizal fungus C. disseminatus can stimulate C. appendiculata seeds germination through a mechanism of breaking the testa imposed dormancy and inducing water absorption of the embryo.

Evaluation of in vitro cytotoxicity and in vivo potential toxicity of the extract from in vitro cultivated Anoectochilus roxburghii Lindl.

Anoectochilus roxburghii Lind. (A. roxburghii) has promising anti-oxidant, hyperglycemic, hepatoprotective, and immunomodulatory activities as well as anti-tumor effects. However, the pharmacological actions of in vitro cultured plants remain to be determined. Therefore, the objective of the study was to assess in vitro cytotoxicity and in vivo potential toxicity of an extract derived from in vitro cultivated A. roxburghii, termed as iARE. The total flavonoid content and predominant flavonoid compounds of extract were identified and quantitatively analyzed. The in vitro cytotoxicity of iARE was examined using several cancer and normal cell lines. The apoptotic activity and expression of apoptosis-associated genes were also examined in MCF7 cells to determine the underlying mechanisms related to anti-proliferative effects. In vivo potential toxicity of iARE was assessed following acute and subchronic oral administration in Sprague Dawley rats. Quercetin, kaempferol, and isorhamnetin were three flavonoid components identified in iARE. The extract exerted cytotoxic effects on various cancer cells but not normal fibroblasts. Apoptosis in MCF7 cells was induced by iARE in a concentration-dependent manner associated with increased Bax/Bcl-2 ratio and reduced mitochondrial membrane potential ΔΨm, leading to release of cytochrome c, activation of caspase-3/7 and caspase-9, and cleavage of PARP. In the acute oral toxicity study, no mortality or toxicological signs were observed in rats at 1000 or 5000 mg/kg. In a subchronic oral toxicity study, iARE at a dosage of up to 1000 mg/kg produced no mortality or treatment-related adverse effects on general behavior, food intake, body weight, relative organ weights. No apparent marked changes in the histopathology of the liver and kidney were detected. Data demonstrated that iARE induced in vitro cytotoxic effects in cancer cells are associated with lackof invivo toxicity. Thus, iARE was suggested to be considered as apotential therapeutic candidate for cancer treatment.

Comparative transcriptomic analyses of normal and peloric mutant flowers in Cymbidium goeringii Rchb.f identifies differentially expressed genes associated with floral development.

Cymbidium geringii has high ornamental and economic importance. Its traits, including flower shape, size, and color, are highly sought by orchid breeders. Gaining insights into the molecular basis of C. geringi flower development would accelerate genetic improvement of other orchids. Methods and Results: Here, C. goeringii RNA was purified from normal and peloric mutant flowers, and cDNA libraries constructed for Illumina sequencing. We generated 329,156,782 clean reads, integrated them, and then assembled into 236,811 unigenes averaging 595 bp long. A total of 11,992 differentially expressed genes s, of which 6119 were upregulated and 5873 downregulated, were uncovered in peloric mutant flower buds relative to normal flower buds. Kyoto Encyclopedia of Genes and Genomes enrichment assessments posited that these differentially expressed genes are associated with "Photosynthesis", "Linoleic acid metabolism", as well as "Plant hormone signal transduction" cascades. The DEGs were designated to 12 remarkably enriched GO terms, and 16 cell wall associated GO terms. The expression level of 16 determined genes were verified using RT-qPCR. Conclusions: Our gene expression data may be used to study the regulatory mechanism of flower organ development in C. geringi.

[Effect of cultivation substrate on growth and active component contents of Anoectochilus roburghii from three different origins].

Three different origins of Anoectochilus roburghii were used as experimental materials to study the effect of three different substrate( peat soil-river sand-peanut shell) radio on survival rate,plant height,stem diameter,plant fresh weight,root number,the longest root length,root diameter,and the contents of polysaccharide,flavonoids,and polyphenol. The results showed that when the substrate ratio was 4 ∶2 ∶2,the survival rate of A. roburghii from different origins was the highest,and the plant height,stem diameter,plant fresh weight,the longest root length and root diameter were also the largest. The cultivation substrate had no significant effect on the polysaccharide content of A. roxburghii and A. formosanus. When the substrate ratio was 4 ∶ 2 ∶ 2,the polysaccharide content of A.chapaensis was significantly lower than that of the other two combinations. When the substrate ratio was 4 ∶2 ∶1,the flavonoid content of A. formosanus was higher than that of the other two combinations. When the substrate ratio was 4 ∶2 ∶2,A. formosanus and A. chapaensis had higher polyphenol content.

Piriformospora indica promotes the growth of the in-vitro-raised Cymbidium aloifolium plantlet and their acclimatization.

Cymbidium aloifolium is known for its ornamental and medicinal values. It has been listed as threatened orchid species. In this study, in vitro propagated C. aloifolium plantlets were interacted with the Piriformospora indica. The growth assay was performed for 45 days; the plant growth pattern such as number and length of roots and shoots were measured. Microscopic study of the root section stained by trypan blue was done to detect the peloton formation. The methanol extracts of the fungal colonized plant as well as uncolonized (control) plant were prepared and various metabolites were identified by gas chromatography mass spectroscopy. Acclimatization was done in a substrate composition of coco peat: gravel: charcoal in ratio 2:2:1. P. indica-colonized plantlet showed the highest growth with the formation of clamdospore in the root section. The growth regulator such as auxin, ascorbic acid, andrographolide, hexadecanoic acid, and DL-proline were identified. After three months of field transfer, plantlet colonized by P. indica survived and remained healthy as compared to uncolonized control plantlet.

Phylogeography of the Neotropical epiphytic orchid, Brassavola nodosa: evidence for a secondary contact zone in northwestern Costa Rica.

Spatial patterns of genetic variation can reveal otherwise cryptic evolutionary and landscape processes. In northwestern Costa Rica, an approximately concordant genetic discontinuity occurs among populations of several plant species. We conducted phylogeographic analyses of an epiphytic orchid, Brassavola nodosa, to test for genetic discontinuity and to explore its underlying causes. We genotyped 18 populations with 19 nuclear loci and two non-coding chloroplast sequence regions. We estimated genetic diversity and structure, relative importance of pollen and seed dispersal, and divergence time to understand how genetic diversity was spatially partitioned. Nuclear genetic diversity was high with little differentiation among populations (GSTn = 0.065). In contrast, chloroplast haplotypes were highly structured (GSTc = 0.570) and reveal a discontinuity between northwestern and southeastern populations within Costa Rica. Haplotype differences suggest two formerly isolated lineages that diverged ~10,000-100,000 YBP. Haplotype mixing and greater genetic diversity occur in an intermediate transition zone. Patterns of nuclear and chloroplast data were consistent. Different levels of genetic differentiation for the two genomes reflect the relative effectiveness of biotic versus abiotic dispersers of pollen and seeds, respectively. Isolation of the two lineages likely resulted from the complex environmental and geophysical history of the region. Our results suggest a recent cryptic seed dispersal barrier and/or zone of secondary contact. We hypothesize that powerful northeasterly trade winds hinder movement of wind-borne seeds between the two regions, while the multi-directional dispersal of pollen by strong-flying sphinx moths resulted in lower differentiation of nuclear loci.

De Novo assembly, characterization and development of EST-SSRs from Bletilla striata transcriptomes profiled throughout the whole growing period.

Bletilla striata is an endangered orchid that has been used for millennia as a medicinal herb, in cosmetics and as a horticultural plant. To construct the first nucleotide database for this species and to develop abundant EST-SSR markers for facilitating further studies, various tissues and organs of plants in the main developmental stages were harvested for mRNA isolation and subsequent RNA sequencing. A total of 106,054,784 clean reads were generated by using Illumina paired-end sequencing technology. The reads were assembled into 127,261 unigenes by the Trinity package; the unigenes had an average length of 612 bp and an N50 of 957 bp. Of these unigenes, 67,494 (51.86%) were annotated in a series of databases. Of these annotated unigenes, 41,818 and 24,615 were assigned to gene ontology categories and clusters of orthologous groups, respectively. Additionally, 20,764 (15.96%) unigenes were mapped onto 275 pathways using the KEGG database. In addition, 25,935 high-quality EST-SSR primer pairs were developed from the 15,433 unigenes by MISA mining. To validate the accuracy of the newly designed markers, 87 of 100 randomly selected primers were effectively amplified; 63 of those yielded PCR products of the expected size, and 25 yielded products with significant amounts of polymorphism among the 4 landraces. Furthermore, the transferability test of the 25 polymorphic markers was performed in 6 individuals of two closely related genus Phalaenopsis and dendrobium. Which results showed a total of 5 markers can successfully amplified among these populations. This research provides a comprehensive nucleotide database and lays a solid foundation for functional gene mining and genomic research in B. striata. The developed EST-SSR primers could facilitate phylogenetic studies and breeding.

Induction and Characterization of Tetraploids from Seeds of Bletilla striata (Thunb.) Reichb.f.

Bletilla striata (Thunb.), an ornamental and medicinal plant, is on the list of endangered plants in China. Its pseudobulb is abundant in polysaccharide and has been used for centuries as a herbal remedy. However, a recent rise in demand has placed it at risk of extinction, and therefore, research on its propagation and genetic improvement is essential. Since polyploids tend to possess advantageous qualities, we incubated B. striata seeds with colchicine with the aim of creating tetraploid plantlets. Aseptic seeds treated with 0.1% colchicine for 7 days showed the highest tetraploid induction rate of 40.67 ± 0.89%. Compared with the wild-type, the tetraploids could be identified by their morphological characteristics including larger stomata at a lower density, larger leaf blades, and a thicker petiole. Contents of polysaccharide and phenolic compounds were also determined in the tetraploid pseudobulbs, revealing significantly higher values than in the wild-type. In vitro colchicine treatment can therefore be used to successfully produce B. striata tetraploids with superior pseudobulbs.

Host-specificity of symbiotic mycorrhizal fungi for enhancing seed germination, protocorm formation and seedling development of over-collected medicinal orchid, Dendrobium devonianum.

All orchids maintain an obligate relationship with mycorrhizal symbionts during seed germination. In most cases, germination-enhancing fungi have been isolated from roots of mature plants for conservation and cultivation purposes. To understand the germination biology of Dendrobium devonianum, an over-collected medicinal orchid, the seeds of D. devonianum were inoculated with a fungal strain (FDd1) isolated from naturally occurring protocorms of D. devonianum and two other germination-enhancing fungal strains (FDaI7 and FCb4) from D. aphyllum and Cymbidium mannii, respectively. The fungal strain was isolated from five protocorms of D. devonianum and identified as a species of the genus Epulorhiza. In germination trials, treatments with all of the three fungal strains showed a significant promoting effect on seed germination and protocorm formation, compared with the control treatment (no inoculation). However, FDd1 fungal strain showed the greatest effectiveness followed by FDaI7 and FCb4. For all inoculation and control treatments, seeds developed to protocorms regardless of the presence of illumination, whereas protocorms did not develop to seedlings unless illumination was provided. The results of our manipulative experiments confirmed the hypothesis that mycorrhizae associated with orchid seedlings are highly host-specific, and the degree of specificity may be life stagespecific under in vitro conditions. The specific mycorrhizal symbionts from protocorms can enhance restoration efforts and the conservation of orchids such as D. devonianum.

Effects of naphthalene acetic acid (NAA) on the plant growth and sugars effects on the cut flowers Mokara chark kuan orchid / Efeitos do ácido naftaleno acético (naa) sobre o crescimento das plantas e de açúcares sobre flores cortadas da orquídea Mokara chark kuan

A study was carried out to investigate the effects of Naphthalene Acetic Acid (NAA) and sugars on the plants and flowers quality of Mokara Chark Kuan orchid respectively. Parameters were monitored between November 2014 to March 2015, with the application of three concentrations of NAA at 25, 50 and 100 mg/L in the field. The application of 25 mg/L NAA significantly increases the plant height, number of roots and total soluble solid content of Mokara Chark Kuan orchid plants. But, there was no significant effect on the leaves number, chlorophyll content and number of flowers. In case of storage experiment, the cut Mokara Chark Kuan flowers were treated with 3 % and 6 % glucose and sucrose. Physiological parameters: fresh weight, water uptake, petal thickness, discoloration and vase life were evaluated. It can be concluded that spraying with 25 mg/L NAA enhanced the plant growth and development of Mokara Chark Kuan orchid. The study also showed that 6 % sucrose was the best treatment for maintaining the post-harvest quality as well as vase life of cut Mokara Chark Kuan orchid flowers.

Um estudo foi realizado para investigar os efeitos do ácido naftaleno ácido acético (NAA) no crescimento de e açúcares no plantas e na qualidade de flores da orquídea Mokara Chark Kuan . Os parâmetros foram monitorados entre novembro de 2014 e março 2015, com a aplicação de três concentrações de ANA em 25, 50 e 100 mg / L sob condições de campo. A aplicação de 25 mg / L de ANA aumentou significativamente a altura da planta, o número de raízes e o teor de sólidos solúveis totais de plantas de orquídeas Mokara Chark Kuan. Todavia, não houve nenhum efeito significativo sobre o número de folhas, o teor de clorofila e o número de flores. No caso do experimento de armazenamento, flores cortadas de Mokara Chark Kuan foram tratadas com 3% e 6% de glicose e de sacarose. Os parâmetros fisiológicos: peso fresco, absorção de água, espessura pétala, descoloração e vida de vaso foram avaliados. Pode concluir-se que a pulverização com 25 mg / L de NAA aumentou o crescimento e o desenvolvimento das plantas de orquídea Mokara Chark Kuan. O estudo também mostrou que 6% de sacarose foi o melhor tratamento para a manutenção da qualidade pós-colheita, bem como vida de vaso em flores de corte da orquídea Mokara Chark Kuan .

Population Genetic Structure and Marker Trait Associations Using Morphological, Phytochemical and Molecular Parameters in Habenaria edgeworthii-a Threatened Medicinal Orchid of West Himalaya, India.

Habenaria edgeworthii Hook. f. ex Collett is an important terrestrial orchid used in different Ayurvedic formulations. In the present study, variations among morphological, phytochemical and molecular markers were assessed. A significant difference was observed among populations using morphological traits. Inter-simple sequence repeat (ISSR) data revealed lower genetic diversity at population level (He = 0.207) as compared to species level (He = 0.334). Analysis of molecular variance (AMOVA) indicates 74 % variation among populations and 26 % within population. Tuber extracts showed significantly (p < 0.05) higher total phenolics and flavonoids among the populations. Antioxidant activity determined by 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays exhibited considerable antioxidant potential. Furthermore, the associations between molecular and morphological and phytochemical attributes were studied using multiple regression analysis (MRA). Several ISSR fragments were associated with some morphological and phytochemical traits. These ISSR fragments can be useful for breeding programme of the species when no other genetic information, such as linkage maps and quantitative trait loci, is available.

[Nontargeted metabolomic analysis of Anoectochilus roxburghii at different cultivation stages].

Anoectochilus roxburghii is a traditional Chinese medicine and natural health products. In the modern cultivation system, A. roxburghii is micropropagated in tissue culture, and the plants are transferred to soil cultivation for months. However, it remains unclear about the necessity of soil cultivation for the accumulation of health beneficial compounds. In this paper, we performed nontargeted metabolomic analysis using GC-TOF-MS and UPLC-Q-TOF-MS, on A. roxburghii plants at tissue culture stage or after 3 months of soil cultivation. The results showed that the primary metabolites such as alcohols and organic acids are abundant in the tissue culture plants. In contrast, polysaccharide, nucleoside, esters and secondary metabolites such as flavonoids, terpenoids were significantly accumulated in cultivated seedlings. Flavonoids and polysaccharides are considered as the principle effective components in A. roxburghii. Soil cultivation period is therefore essential for the accumulation of these metabolites.

Protocols for In Vitro Mass Multiplication and Analysis of Medicinally Important Phenolics of a Salep Orchid, Satyrium nepalense D.Don ("Salam Mishri").

Satyrium nepalense is a rare and threatened medicinal orchid, populations of which in its native habitats are dwindling because of indiscriminate collections and habitat destruction, thus necessitating the development of methods for its in situ and ex situ conservation. Because of non-endospermous nature of the seeds and the immature embryos at seed dispersal stage, orchids cannot be seed-propagated as other plants. Micropropagation, using plant tissue culture techniques, offers an effective method for the multiplication of orchids. In this chapter, a five-step efficient reproducible protocol for large-scale in vitro multiplication of Satyrium nepalense is described. The first step involves asymbiotic germination of seeds isolated from immature green pods and cultured on Mitra's medium (M) gelled with 0.8 % agar and supplemented with 2 % sucrose and 1 % peptone (hereafter referred to as basal medium, BM). On this medium, seeds start germinating after a week of culture. Protocorms developed from the seeds are sub-cultured on BM fortified with 4 µM kinetin (Kn) after 8 weeks, for shoot differentiation and multiplication. The shoots developed on Kn-supplemented medium are transferred to BM alone for their elongation for the same period. The elongated shoots are transferred to the rooting medium, comprising BM supplemented with 0.5 or 1.0 µM indole-3-butyric acid, for further 8 weeks. The regenerated plantlets are transferred to a potting mix of sand and vermiculite (1:1) for acclimatization. The tubers and leaves excised from both in vitro-developed plants and those from their native habitats are analyzed and compared for the contents and concentration of medicinally important phenolics using high-performance liquid chromatography (HPLC), details of which are provided in this chapter.

[Current researches and prospects of seedling propagation and cultivation modes of Jinxianlian].

In the wake of on-the-spot investigation into Chinese major production bases in Fujian, Zhejiang, Jiangxi, Taiwan, Guangxi and Yunnan provinces, and based on relevant literature, the paper systematically elaborates the current researches of botanical origin, major cultivation type, seedling propagation technique as well as cultivation mode of Jinxianlian. The way of seedling breeding mainly includes aseptic seed culture, in vitro propagation, artificial seed and bioreactor propagation, etc. And the planting model mainly includes protected cultivation modes, bionic wild cultivation modes and pot cultivation modes, etc. Further discussions have also been conducted to tackle significant problems existing in the production process of Jinxianlian, based on personal studies of the authors. It has made considerable contributions for the betterment of Jinxianlian's development and improvement.

[Current status and sustainable development countermeasures of Anoectochilus roxburghii].

The current status of the domestic manufacturing and sales markets of Anoectochilus roxburghii were investigated and analyzed in the study. Some problems in the A. roxburghii industry were revealed and a variety of sustainable development countermeasures were also proposed. The main problems of A. roxburghii industry are the lack of protection for wild resources, the lag in the speed of variety breeding, the insufficient research on the quality systems, the low level of industry and product innovation capability, as well as the relatively low market cognition and brand competence. Therefore, strengthening the protection for breeding resources, establishing a dynamic monitoring system, promoting the variety breeding, constructing a propagation system for improved varieties, enhancing the quality of medicinal herbs, accelerating the adjustment of product structure, upgrading the industry technology, strengthening brand competence and expanding the market, will be the effective methods to realize the sustainable development of A. roxburghii industry.

[Morphological and cytohistological observations of seed germination and protocorm development of Bletilla striata].

In order to investigate the mechanism of growth for Bletilla striata, which could be applied for rapid propagation, morphological and cytohistological of seed germination and protocorm development in vitro culture were observed using paraffin section techniques. In this study, we have found that the development of B. striata goes through four stages： embryo, protocorm, rhizome and pseudobulb. The end away from embryo suspensor is able to differentiate green buds after the seed of B. striata swelling, growing point. At the same time, the other end of embryo grows many white villous roots, with the green bud differentiating into cotyledon, the embryo breaking through seed coat and being protocorm. The shoot apical meristem of protocorm consists of tunica, corpus and leaf primordium, whose developmental flowing tunica-corpus theory. After more vascular bundle appeared from the leaf primordium, B. striata grows into the stage of rhizome. While in the stage of rhizome, the root primordium of tissue culture seedlings are differentia initially that derived from rhizome vascular bundle, belonging to internal origin. Subsequently, the pseudobulb forms by the inner meristem growing into mature parenchymatous tissue and the rhizome enlargement gradually.

[Pollen viability, stigma receptivity and fruiting characteristics of botanical origin of Jinxianlian].

The viability and life span of pollen were evaluated by TTC (2,3,5-triphenyl tetrazlium chloride) and the peroxidase solution, the stigma receptivity were estimated by benzidine-H2O2 method and the fruiting characteristics were investigated. The results showed that (1) Anoectochilus roxburghii and A. formosanus appeared the same up-and-down trend of the pollen viability, increased and then decreased. The storage temperature and storage time had significant impact on the pollen viability. With the extension of storage time, the pollen activity decreased. 4 degrees C refrigerator storage may be extended the pollen vitality. (2) The stigma had receptivity in 1st day and reached the highest level in the 4th day after blooming. A. roxburghii lost receptivity in the 8th day while A. formosanus lost receptivity in the 10th day after blooming. (3) The different pollination had significant impact on seed setting rate. The seed setting rate of artificial cross-pollination was higher than that of the artificial self-pollination. Collecting pollen in the 3rd day and carrying out artificial cross-pollination in the 4th day after blooming can significantly improve seed setting rate. The results provided technical assurance for A. roxburghii and A. formosanus breeding of new varieties and seed breeding.

In vitro regeneration and ploidy level analysis of Eulophia ochreata Lindl.

Various parameters including explant-type, medium compositions, use of phytohormones and additives were optimized for direct and indirect regeneration of E. ochreata, a medicinal orchid under threat. Protocorm-like-bodies (PLBs) proved to be the best explants for shoot initiation, proliferation and callus induction. Murashige and Skoog's (MS) medium containing 2.5 mg L(-1) 6-benzylaminopurine (BAP), 1.0 mg L(-1) kinetin (Kin) and additives (adenine sulfate, arginine, citric acid, 30 mg L(-1) each and 50 mg L(-1) ascorbic acid) was optimal for shoot multiplication (12.1 shoots and 7.1 PLBs per explant with synchronized growth), which also produced callus. Shoot number was further increased with three successive subcultures on same media and approximately 40 shoots per explant were achieved after 3 cycles of 30 days each. Additives and casein hydrolysate (CH) showed advantageous effects on indirect shoot regeneration via protocorm-derived callus. Optimum indirect regeneration was achieved on MS containing additives, 500 mg L(-1) CH, 2.5 mg L(-1) BAP and 1.0 mg L(-1) Kin with 30 PLBs and 6 shoots per callus mass (approximately 5 mm size). The shoots were rooted (70% frequency) on one by fourth-MS medium containing 2.0 mg L(-1) indole-3-butyric acid, 200 mg L(-1) activated charcoal and additives. The rooted plantlets were hardened and transferred to greenhouse with 63% survival rate. Flow-cytometry based DNA content analysis revealed that the ploidy levels were maintained in in vitro regenerated plants. This is the first report for in vitro plant regeneration in E. ochreata.

In vitro propagation and reintroduction of the endangered Renanthera imschootiana Rolfe.

Renanthera imschootiana Rolfe is an endangered tropical epiphytic orchid that is threatened with extinction due to over-collection and the loss of suitable habitats. In vitro propagation is a useful way to mass produce plants for re-establishment in the wild and for commercial propagation. Seeds collected 150 days after pollination (DAP) were the optimum stage for in vitro culture. Seed germination reached 93.1% on quarter-strength MS (i.e., MS containing a quarter of macro- and micronutrients) medium containing 0.5 mg l(-1) α-naphthaleneacetic acid (NAA), 20% coconut water (CW), 1.0 g l(-1) peptone, 10 g l(-1) sucrose and 1.0 g l(-1) activated charcoal (AC). Quarter-strength MS medium supplemented with 1.0 mg l(-1) BA, 0.5 mg l(-1) NAA, 1.0 g l(-1) peptone, 10 g l(-1) sucrose and 20% CW was suitable for the sub-culture of protocorm-like bodies (PLBs) in which the PLB proliferation ratio was 2.88. Quarter-strength MS medium containing 1.0 mg l(-1) NAA, 1.0 g l(-1) peptone, 100 g l(-1) banana homogenate (BH), and 1.0 g l(-1) AC was suitable for plantlet formation and 95.67% of plantlets developed from PLBs within 60 days of culture. Hyponex N016 medium supplemented with 0.5 mg l(-1) NAA, 1.0 g l(-1) peptone, 20 g l(-1) sucrose, 150 g l(-1) BH, and 1.0 g l(-1) AC was suitable for the in vitro growth of plantlets about 2-cm in height. Plantlets 3-cm in height or taller were transplanted to Chilean sphagnum moss, and 95% of plantlets survived after 60 days in a greenhouse. Three hundred transplanted of seedlings 360-days old were reintroduced into three natural habitats. Highest percentage survival (79.67%) was observed in Yuanjiang Nature Reserve two years after reintroduction, followed by Huolu Mountain forest park (71.33%). This protocol is an efficient means for the large-scale propagation and in vitro and in vivo germplasm conservation of R. imschootiana.

[Multiple analysis of relationship between morphologic traits and yield formation of Anoectochilus roxburghii].

Nine morphologic traits, plant height, ground diameter, leaf length, leaf width, leaf area of plant, leaf fresh weight, blades, length/width ratio, plant fresh weight of Anoectochilus roxburghii from 13 different areas were determined for correlation analysis, path analysis and principal components analysis. Different source of morphological trait variation coefficient of A. roxburghii was 2.96% -12.59%, plant fresh weight was significant positively correlated with ground diameter, plant height and leaf number, and positively correlated with leaf fresh weight. Path analysis showed that plant height had the largest positive direct effect on plant fresh weight, the leaf fresh weight and blades number had indirect effects on the plant fresh weight. Through principal component analysis, morphological traits of A. roxburghii can be divided into "Determinants of high-yielding morphology" and "Determinants of leaf production". In the actual process of production and breeding of A. roxburghii, we should pay attention to plant height, leaf fresh weight, blades numbers and other traits.