Population genetic structure of the endangered and endemic medicinal plant <Emphasis Type="Italic">Commiphora</Emphasis><Emphasis Type="Italic">wightii</Emphasis>

Commiphora wightii is a medicinally important endangered species endemic to the Thar Desert of Rajasthan, India and adjoining areas of Pakistan. The populations of this species are declining sharply because of its extensive use as a natural herb. Random amplified polymorphic DNA analysis was conducted to find the genetic variation among 7 populations of C. wightii. Of the 100 random primers screened, 44 primers yielded 220 loci. Statistical analysis indicated low genetic diversity (H _pop = 0.0958; I = 0.1498; mean polymorphic loci = 14.28%), and high genetic differentiation among the populations (G _ST = 0.3990; AMOVA Φ _ST of 0.3390; Bayesian θ ^(II) = 0.3002). The low genetic diversity may be due to geographic isolation and restricted gene flow (N _m = 0.7533) between the fragmented populations. Unsustainable utilization of the plant has fragmented the population continuum which served the purpose of genetic exchange between populations. Mantel’s test was performed which revealed a highly significant positive correlation between genetic and geographic distance (r ² = 0.614, P = 0.023) among the populations studied. Low variation can also be attributed to poor seed setting and the slow growth pattern of the species, which is also an apomict. In UPGMA dendrogram the Commiphora wightii samples were divided into two major and one minor cluster. These findings can serve as a guide to preserving the genetic resources of this medicinal plant species.     

The genetic structure of endangered indigenous populations of the amago salmon, <Emphasis Type="Italic">Oncorhynchus</Emphasis><Emphasis Type="Italic">masou</Emphasis><Emphasis Type="Italic">ishikawae</Emphasis>, in Japan

The amago salmon, Oncorhynchus masou ishikawae, is an endemic subspecies of O. masou in Japan. Owing to the extensive stocking of hatchery fish throughout Japan, indigenous populations of O. m. ishikawae are now on the verge of extinction. We examined the genetic effects of stocking hatchery fish on wild populations in the River Koza, Japan, using microsatellite and mitochondrial DNA (mtDNA) markers. For mtDNA, haplotype mt1, which is common in wild populations, was present exclusively in isolated wild populations assumed to be unaffected by previous stocking, while it was never observed in hatchery fish. Genetic diversity was much higher in wild populations in the stocked area, which shared many mtDNA haplotypes with hatchery fish, than in isolated wild populations with haplotype mt1. Pairwise F _ST estimates based on microsatellites showed significant differentiation among the isolated populations with many microsatellite loci monomorphic. Significant deviation from Hardy–Weinberg equilibrium was observed in wild populations in the area subject to stocking, where a Bayesian-based assignment test showed a high level of introgression with hatchery fish. These results suggest that wild populations with haplotype mt1, which became isolated through anthropogenic environmental change in the 1950–1960s, represent indigenous populations of O. m. ishikawae in the River Koza. They have low genetic diversity, most likely caused by genetic bottlenecks following damming and environmental deterioration, while stocking of hatchery fish over the past 30 years apparently had a large impact on the genetic structure of wild populations in the main channel of the River Koza.     

Assessment of genetic stability of <Emphasis Type="Italic">in vitro</Emphasis> grown <Emphasis Type="Italic">Dictyospermum ovalifolium</Emphasis>

In the present study, a polymerase chain reaction (PCR)-based method namely inter simple sequence repeat (ISSR) was employed to assess genetic stability in tissue culture-derived Dictyospermum ovalifolium plantlets. To study genomic stability of micropropagated plants, 14 individuals were randomly tagged among a population of 2500 regenerants and were compared with single donor mother plant. A total of 51 clear and reproducible bands ranging from 200 bp to 2.1 kb were scored corresponding to an average of 3.64 bands per primer. Two of the 51 bands were polymorphic (3.92 %) among 14 individuals, thus indicating the occurrence of low level genomic variation in the micropropagated plants. Cluster analysis indicates that genetic similarity values were 0.978 which allows classification of the plants to distinct groups. Further an attempt was made to reintroduce the micropropagated plants into their natural habitat. Over one thousand six hundred fifty plants were successfully established.     

<Emphasis Type="Italic">In vitro</Emphasis> regeneration of medicinal plant <Emphasis Type="Italic">Centella asiatica</Emphasis>

This paper describes multiple shoot regeneration from leaf and nodal segments of a medicinally important herb Centella asiatica L. on Murashige and Skoog’s (MS) medium supplemented with a range of growth regulators. The highest number of multiple shoots was observed on MS augmented with 3.0 mg dm⁻³ N⁶-benzylaminopurine (BAP) and 0.05 mg dm⁻³ α-naphthaleneacetic acid (NAA). Leaf explant showed maximum percentage of cultures regenerating shoots (81.6 %), with the highest shoot number (8.3 shoots per explant) and the shoot length (2.1 cm) whereas, nodal explant showed less number of shoots with callus formation at the base cut end. Successive shoot cultures were established by repeatedly sub-culturing the original explant on a fresh medium. Rooting of in vitro raised shoots was best induced on half strength MS supplemented with 0.5 mg dm⁻³ indole-3-butyric acid (IBA) with highest percentage of shoot regenerating roots (76.8 %) with 3–4 roots per shoot. Plantlets were acclimated in Vermi-compost and eventually established in soil. Contents of chlorophyll, total sugars, reducing sugars and proteins were estimated in leaf tissue from both in vivo and in vitro raised plants. Chlorophyll content was higher in in vivo plants, whereas other three components were higher in in vitro plants.     

Headspace-SPME of <Emphasis Type="Italic">in vitro</Emphasis> shoot-cultures and micropropagated plants of <Emphasis Type="Italic">Lavandula viridis</Emphasis>

In this work the volatiles emitted from in vitro shoot-cultures and micropropagated plants of Lavandula viridis L’Hér. were characterized and compared with those obtained from the field-grown mother-plant, using headspace solid phase micro-extraction following by capillary gas chromatography coupled to mass spectrometry (HS-SPME-GC/MS). The headspace composition consisted mainly in oxygenated monoterpenes (66.7–79.2 %), where the major constituents emitted by the mature field-grown mother-plant, in vitro shoot-cultures and micropropagated plants were 1,8-cineole (74.0, 51.9 and 57.8 %) and camphor (2.9, 15.3 and 8.7 %), respectively. The headspace of in vitro shoot-cultures and micropropagated plants showed greater amount of α-pinene, camphene, β-pinene, β-selinene and selina-3,7(11)-diene, when compared with the field-grown mother-plant.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of the medicinal plant <Emphasis Type="Italic">Centaurea montana</Emphasis>

An efficient transformation system was developed for Centaurea montana by co-cultivation of leaf explants with Agrobacterium tumefaciens strain AGL1 that contained a plasmid harboring the isopentenyl transferase gene under the control of the developmentally regulated Atmyb32 promoter of Arabidopsis thaliana and the gene encoding for hygromycin resistance under the control of the Cauliflower Mosaic Virus 35S (CaMV35S) promoter. A total of 990 explants were infected with Agrobacterium, and 18 shoots were regenerated resulting in an overall transformation efficiency of 1.8%. Molecular analyses, including PCR, Southern blotting and RT-PCR, were performed on T₀ and T₁ plants to confirm chromosomal integration and expression of the transgene in the phenotypically normal transformed plants. Transformation of C. montana was also performed using A. tumefaciens supervirulent strain EHA105 harboring the β-glucuronidase (GUS) reporter gene. Expression of the GUS gene in the putative transgenics was confirmed using a histochemical GUS assay.     

High genetic diversity in an endangered medicinal plant, <Emphasis Type="Italic">Saussurea involucrata</Emphasis> (<Emphasis Type="Italic">Saussurea</Emphasis>, Asteraceae), in western Tianshan Mountains,China

Saussurea involucrata (Asteraceae) is a medicinal and second-degree national priority endangered plant that is mainly distributed in the high latitude region of the western Tianshan Mountains. The population is fragmented and isolated, and extensive human impact merits a suitable and specific conservation strategy, which can be compiled based on the genetic diversity, population structure, and demographic history. Phylogeographic studies were conducted on a total of five natural populations and 150 individuals were sampled. Data from three cpDNA intergenic spacer regions (trnL-F, matK, and ndhF-rpl32) and nrDNA ITS sequences showed that twelve haplotypes in cpDNA and five haplotypes in nrDNA indicated high genetic diversity among populations sampled (H _T?=?0.820 and 0.756) and within populations sampled (H _S?=?0.792 and 0.721). Additionally, the high genetic diversity did not mirror genetic structure in either cpDNA (F _ST?=?0.03153, G _ST?>?N _ST, p?<?0.05) or nrDNA (F _ST?=?0.03666, meaningless G _ST and N _ST). Two groups (north and south) were determined for a SAMOVA analysis. Based on this analysis, the demographic history was conducted with a Bayesian Skyline Plot and Isolation with Migration analysis, which showed sustainable and stable extension without a marked bottleneck. Divergence time was indicated at c. 6.25 Mya (90%HPD: 15.30–0.22 Mya) in the Miocene, which is consistent with the formation of the Kelasu section of Tianshan. The southern populations in the Bayanbulak and Gonglu regions require additional attention and transplanting would be an effective way to restore rare cpDNA haplotypes, increase effective population size, and migration rate. Our results suggested that in situ conservation of S. involucrata in western Tianshan should be the main strategy for protection and recovery of the species.     

<Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>-mediated transformation of a medicinal plant <Emphasis Type="Italic">Taraxacum platycarpum</Emphasis>

Dandelion plants, the genus Taraxacum, are used in herbal medicine owing to their choleretic, diuretic and anti-carcinogenic activities and several medicinal compounds have been isolated from the roots of these plants. Metabolic manipulation of secondary metabolite biosynthesis is a potential strategy to improve the production of high-value secondary metabolites. The enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) is known to control a key regulatory step in the isoprenoid pathway. We report an efficient transformation protocol for stable introduction of HMGR into dandelion plants (Taraxacum platycarpum H. Dablstaed), which is essential for the biotechnological approach. The Agrobacterium tumefaciens strain EHA105 containing the binary vector, pCAMBIA1301, with GUS and HMGR genes, showed high transformation efficiency after 3–5 week hygromycin selection. Southern blotting, GUS staining and RT-PCR analyses demonstrated stable integration of one copy of the HMGR gene into the dandelion genome. Expression of the integrated genes was particularly eminent in root tissues of primary transformant plants. The establishment of an efficient transformation method may facilitate the improvement of medicinal plant in terms of the accumulation levels of secondary metabolites.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of <Emphasis Type="Italic">Decalepis arayalpathra</Emphasis>, a critically endangered ethnomedicinal plant

Summary This study reports a protocol for successful micropropagation of Decalepis arayalpathra (Joseph and Chandras) Venter. (Janakia arayalpathra Joseph and Chandrasekhran; Periplocaceae), a critically endangered and endemic ethnomedicinal plant in the southern forests of the Western Ghats which is overexploited for its tuberous medicinal roots by the local Kani tribes. Natural regeneration is rare and conventional propagation is difficult. Conservation of the species through micropropagation was attempted. The nodal explants of greenhouse-raised plants, were more desirable than cotyledonary nodal explants of aseptic seedlings. The basal nodes (73%) of 12–16-wk-old greenhouse-grown plants cultured in Murashige and Skoog (MS) medium containing 12.96 μM 6-benzyladenine (BA), 2.48 μM 2-isopentenyladenine (2-ip) and 2.68 μM α-naphthaleneacetic acid (NAA) formed 16–17 cm long unbranched robust solitary shoots in 8 wk. Cotyledonary nodal explants cultured in the same medium showed multiple shoot formation and axillary branching. But the shoots were thin, fragile and not suitable for mass propagation. Single nodes of a solitary shoot subcultured on MS medium containing 2.22 μM BA and 0.24 μM 2-ip together produced 9.8±0.3 nodes from 18.0±0.6 cm long shoots within 5–6 wk. The basal nodes of the shoots so formed were repeatedly subcultured to increase the stock of propagules while the 2.5–3.0 cm terminal cuttings were used for rooting. The best root induction (68%) and survival (86%) was achieved on half-strength MS medium supplemented with 1.07 μM NAA. Field-established plants showed uniform growth and phenotypic similarity to parental stock.     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

Development of expressed sequence tag-derived microsatellite markers for <Emphasis Type="Italic">Saccharina</Emphasis> (<Emphasis Type="Italic">Laminaria</Emphasis>) <Emphasis Type="Italic">japonica</Emphasis>

Expressed sequence tag-derived microsatellite markers (EST-SSR) were generated and characterized in Laminaria japonica using data mining from updated public EST databases and polymorphism testing. Fifty-eight of 578 ESTs (10.0%) containing various repeat motifs were used to design polymerase chain reaction (PCR) amplification primers. A total of 12 pairs of primer were generated and used in the PCR amplification. Alleles per locus ranged from two to ten (average of 5.7). The observed heterozygosities and expected heterozygosities were from 0.045 to 0.543 and from 0.056 to 0.814, respectively. All loci were in Hardy–Weinberg equilibrium and no linkage disequilibrium was detected. These robust, informative, and potentially transferable polymorphic markers appear suitable for population, genetic, parentage, and mapping studies of L. japonica.     

Genotype independent and efficient <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated genetic transformation of the medicinal plant <Emphasis Type="Italic">Withania somnifera</Emphasis> Dunal

Withania somnifera one of the most reputed Indian medicinal plant has been extensively used in traditional and modern medicines as active constituents. A high frequency genotype and chemotype independent Agrobacterium-mediated transformation protocol has been developed for W. somnifera by optimizing several factors which influence T-DNA delivery. Leaf and node explants of Withania chemotype was transformed with A. tumefaciens strain GV3101 harboring pIG121Hm plasmid containing the gusA gene encoding β-glucuronidase (GUS) as a reporter gene and the hptII and the nptII gene as selection markers. Various factors affecting transformation efficiency were optimized; as 2 days preconditioning of explants on MS basal supplemented with TDZ 1 μM, Agrobacterium density at OD₆₀₀ 0.4 with inclusion of 100 μM acetosyringone (As) for 20 min co-inoculation duration with 48 h of co-cultivation period at 22 °C using node explants was found optimal to improved the number of GUS foci per responding explant from 36?±?13.2 to 277.6?±?22.0, as determined by histochemical GUS assay. The PCR and Southern blot results showed the genomic integration of transgene in Withania genome. On average basis 11 T₀ transgenic plants were generated from 100 co-cultivated node explants, representing 10.6 % transformation frequency. Our results demonstrate high frequency, efficient and rapid transformation system for further genetic manipulation in Withania for producing engineered transgenic Withania shoots within very short duration of 3 months.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of <Emphasis Type="Italic">Cistus clusii</Emphasis> Dunal,an endangered plant in Italy

Shoot tips and nodes from a genotype of Cistus clusii were cultured on a medium containing Murashige and Skoog macronutrients, Nitsch and Nitsch micronutrients, sucrose, iron, thiamine, myoinositol, and agar. This establishment medium, enriched with growth regulators and the biocide substances Plant Preservative Mixture and Thiabendazole lactate, improved explant survival by 14–16% and reduced contamination late in culture. For the proliferation stage, the explants rapidly formed axillary buds on a culture medium containing 6-benzylaminopurine (0.5 mg l⁻¹). The best response for rooting was obtained on a culture medium with a 0.1 mg l⁻¹ indolebutyric acid supplement. Rooted plantlets were acclimatized to greenhouse conditions and then transferred to the field in order to evaluate their phenotypic homogeneity. Karyotyping showed that the in vitro propagated plantlets have the same chromosome numbers as the mother plants. The success of this work indicates that micropropagation can be a useful tool for the conservation of C. clusii Dunal, an endangered plant in Italy.     

High-frequency clonal propagation of <Emphasis Type="Italic">Curcuma angustifolia</Emphasis> ensuring genetic fidelity of micropropagated plants

A high-frequency clonal propagation protocol was developed for Curcuma angustifolia Roxb., a high valued traditional medicinal plant. Axillary bud explants of C. angustifolia were explanted on Murashige and Skoog (MS) medium fortified with 4.4–22.2 µM 6-benzyladenine (BA), 2.9–5.7 µM indole-3-acetic acid (IAA), 2.3–23.2 µM kinetin (Kin), 2.7–5.4 µM naphthalene acetic acid (NAA) and 67.8-271.5 µM adenine sulphate (Ads) in different combinations. The maximum number of shoots per explants (14.1?±?0.55) and roots per shoot (7.6?±?0.47) was achieved on media containing 13.3 µM BA, 5.7 µM IAA and 135.7 µM Ads. Stability in phytomedicinal yield potential of micropropagated plants was assessed through GC–MS and HPTLC. Gas chromatogram of essential oil of conventional and micropropagated plants of C. angustifolia had similar essential oil profile. HPTLC analysis of rhizome extracts of in vitro and field grown plants revealed no significant differences in the fingerprint pattern and in curcumin content. Genetic integrity of in vitro and field grown derived plants were evaluated with inter-simple sequence repeat (ISSR) primers and flow cytometry using Glycine max as an internal standard. A total of 1260 well resolved bands were generated by 12 ISSR primers showing monomorphic banding patterns across all plants analyzed. The mean 2C DNA content of conventionally and micropropagated plant was estimated to be 2.26 pg and 2.31 pg, respectively. As no somaclonal variations were detected in tissue culture plantlets, the present micropropagation protocol could be applied for in vitro conservation and large-scale production of C. angustifolia.     

Phylogenetic analyses of <Emphasis Type="Italic">Uromyces viciae-fabae</Emphasis> and its varieties on <Emphasis Type="Italic">Vicia</Emphasis>, <Emphasis Type="Italic">Lathyrus</Emphasis>, and <Emphasis Type="Italic">Pisum</Emphasis> in Japan

A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan     

<Emphasis Type="Italic">Galleria</Emphasis><Emphasis Type="Italic">mellonella</Emphasis> are Resistant to <Emphasis Type="Italic">Pneumocystis</Emphasis><Emphasis Type="Italic">murina</Emphasis> Infection

Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.     

Revision of the <Emphasis Type="Italic">Serrulati</Emphasis> species of <Emphasis Type="Italic">Penstemon</Emphasis> section <Emphasis Type="Italic">Saccanthera</Emphasis> subsection <Emphasis Type="Italic">Serrulati</Emphasis>

A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.     

<Emphasis Type="Italic">Agrobacterium</Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>-mediated transformation of callus cells of <Emphasis Type="Italic">Crataegus</Emphasis><Emphasis Type="Italic">aronia</Emphasis>

A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l⁻¹ Indole-3-butyric acid (IBA) and 0.5 mg l⁻¹ 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l⁻¹ kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l⁻¹ hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of an endangered plant species, <Emphasis Type="Italic">Thermopsis turcica</Emphasis> (Fabaceae)

This report deals with micropropagation of the critically endangered and endemic Turkish shrub, Thermopsis turcica using callus, root and cotyledonary explants. Callus cultures were initiated from root and cotyledon explants on MS medium supplemented with 0.5–20 μM NAA or 2,4-D. The root explants were found to be better in terms of quick responding and callusing percentages as compared to the cotyledons. Organogenic callus production with adventitious roots and shoots were obtained on MS medium with only NAA. The calli obtained with NAA, root and cotyledonary explants were cultured with BA and kinetin (2–8 μM) alone or in combination with a low level (0.5 μM) of 2,4-D or NAA. The best regeneration of shoots from root explants was observed on hormone-free MS medium. NAA with BA or kinetin in the medium improved shoot induction from the calli obtained with NAA. Maximum percentage of shoots (93.3%), maximum number of shoots (6.2) and maximun length of shoots (8.22 cm) were achieved from cotyledonary explants at 4 μM BA and 0.5 μM NAA. The presence of 0.5 μM or higher levels of 2,4-D in shoot induction medium inhibited the regeneration in T. turcica explants. 83% of in vitro rooting was attained on pulsed-IBA treated shoots. The regenerated plants with well developed shoots and roots were successfully acclimatized. Application of this study’s results has the potential to conserve T. turcica from extinction.     

Characterization of root-associated microbiota in medicinal plants <Emphasis Type="Italic">Astragalus membranaceus</Emphasis> and <Emphasis Type="Italic">Astragalus mongholicus</Emphasis>

Although the quality of herbal medicine is tightly associated with plant genotype and location, microbial traits of most herbs remain unclear. In this study, bacterial communities residing Astragali Radix, which is derived from Astragalus membranaceus and A. mongholicus roots, have been characterized by automated ribosomal intergenic spacer analysis (ARISA) and pyrosequencing of 16S rRNA amplicons. The samples were collected from four representive locations and differing in genotype and planting pattern. The spatial resolution study by ARISA firstly distinguished between the two anatomically-based parts, the periderm and secondary vascular tissue, demonstrating that microbial communities residing in the former were more diverse and clearly separated by host genotype and location as compared with those residing in the latter. Taxonomic coverage revealed that phyla of Proteobacteria, Planctomycetes and Bacteroidetes dominated the bacterial assemblages across the samples. The community diversity in A. mongholicus was more abundant than it was in A. membranaceus, especially A. mongholicus in Shanxi province of China. In addition, the conventional cultivation exerted consistently negative effects on microbiota complexity when compared with the planting pattern “imitating wild conditions”, which was regardless of the host genotype. With the focus on microbiota members in Shanxi, taxa associated with the genotype, geography and planting pattern were finally discriminated and used as indicators for the screening of endophytic bacteria that contain ACC deaminase. Taken together, microbiota should be an important trait of herbal medicines and the periderm should be a specialized niche for microbiota research in medicinal plants.