Endophytic fungi, host genotype, and their interaction influence the growth and production of key chemical components of Dendrobium catenatum.

To examine how host plant genotype, endophytic fungal species, and their interaction may affect growth and key chemical content and composition in an important orchid species, we assessed four Dendrobium catenatum cultivars co-cultured with three fungi previously isolated from D. catenatum. Fungal endophytes (Tulasnella sp.

[Study on tissue culture system of Polygonatum cyrtonema].

In order to accelerate the breeding of the excellent seedlings of Polygonatum cyrtonema,tissue culture system of P. cyrtonema was established through the comprehensive regulation of key factors( leaf age,leaf location,basic media and plant growth regulators) and cytological basis of callus formation and differentiation was analyzed through paraffin section. The results showed that the 30-day-old leaf base explanton medium MS+6-BA 1.

[Cloning and function analysis of promoter of DcCDPK8 from Dendrobium catenatum].

DcCDPK8 involved in abiotic stress such as low temperature and signal transduction of hormones ABA and MeJA,but the transcriptional regulation is still unclear. In order to study the core promoter region of DcCDPK8 gene in Dendrobium catenatum and explore its transcriptional regulation mechanism,the DcCDPK8 gene promoter sequence was cloned by PCR from D. catenatum.

Single-stranded DNA modified protonated graphitic carbon nitride nanosheets: A versatile ratiometric fluorescence platform for multiplex detection of various targets.

Facile and cost-effective detection of multiple targets is essential for a variety of applications ranging from life sciences to environmental monitoring. Here, we report a versatile ratiometric fluorescence platform for multiple detection of various targets based on the conjugation of single-stranded DNA (ssDNA) with protonated graphitic carbon nitride nanosheets (Pg-CN NSs). We demonstrate that intrinsic peroxidase-like activity of Pg-CN NSs is enhanced by conjugating with ssDNA, and thus the oxidation of substrate o-phenylenediamine (OPD) is promoted in the presence of HO.

Rapid and visual detection of aflatoxin B1 in foodstuffs using aptamer/G-quadruplex DNAzyme probe with low background noise.

Contamination of foods by aflatoxin B1 (AFB1) is a common serious problem. To improve the efficiency of AFB1 detection, this study aims to develop a sensitive aptasensor for detection of AFB1 in food samples based on the catalytic effect of aptamer/G-quadruplex DNAzyme probe. The resulting reassembly of this probe in the presence of hemin and K catalyzes the generation of fluorescent 2,3-diaminophenazine (DAP) from o-phenylenediamine (OPD).

[Effects of germplasm and host tree trunk on endophytic fungal communities in epiphytic Dendrobium catenatum].

In order to investigate the effects of germplasm and host tree trunk on endophytic fungal communities in epiphytic Dendrobium catenatum, a total of 3 835 isolates were recovered from roots, stems and leaves of four D. catenatum germplasms attached to one kind of host tree trunk and one germplasm attached to four kinds of epiphyte-host tree trunks. A total of 152 taxa were identified and classified based on the fungal cultural characteristics and phylogenetic analyses of ITS sequences.

[Effects of sampling time on polysaccharides of Dendrobium catenatum under temperature-controlled condition].

In order to reveal the accumulation trend of polysaccharides in Dendrobium catenatum and determine the effect of sampling time on polysaccharides, D. Catenatum D21 clone was harvested from January to December after culturing for 2 to 5 months in the growth chamber with constant temperature. Polysaccharides were determined by phenol-sulfuric acid method and the monosaccharide compositions were analyzed by pre-column derivative-UPLC.

[Effects of cultivation environments on Dendrobium catenatum].

The study was aimed to clarify the effect of three cultivation environments on the growth and metabolism of Dendrobium catenatum C13 group. There were three different cultivation conditions including rock epiphytic cultivation, pear epiphytic cultivation and pot cultivation. Morphological characteristics and agronomic characters of D.

[Dendrobium officinale cliff epiphytic cultivation method].

To solve the issues of costly planting of facility cultivation method and inferior efficacy than wild herbs of Dendrobium officinale, the cliff epiphytic cultivation method was studied. To research the growth, agronomic traits, yield, polysaccharide and alcohol-soluble extract contents were measured on the D. officinale from different water regulation and cliff slope gradients treatments.

[Comparison of different harvest ways of Dendrobium officinale].

To standardize the harvest ways of Dendrobium officinale and improve the quality and yield of D. officinale, a field experiment was carried out to study the effect of two kinds of harvest ways, which were keeping some of the axial shoot and harvesting all of the shoot by the end of the year. Then, the agronomic traits and yield were measured and the contents of polysaccharides and extractum were determined.

[Dendrobium officinale stereoscopic cultivation method].

The study is aimed to make the most of available space of Dendrobium officinale cultivation facility, reveal the yield and functional components variation of stereoscopic cultivated D. officinale, and improve quality, yield and efficiency. The agronomic traits and yield variation of stereoscopic cultivated D.

[Effect of ABA on transcriptionally active Ty1-copia retrotransposons in Dendrobium officinale].

Using universal primer Tyl-copia retrotransposon RT, the conserved reverse transcriptase domain of about 260 bp was amplified by RT-PCR from the Dendrobium officinale which induced by 100 micromol x L(-1) abscisic acid (ABA), indicating these retrotransposons activated by 100 micromol x L(-1) ABA. The amplicons were recovered and cloned,then sequenced and analyzed by related bioinformatics software. Forty-two Ty1-copia like retrotransposon RT transcriptionally activated were obtained with high heterogeneity.

[Cloning and analysis of reverse transcriptase(RT) of Ty1-copia retrotransposons in Dendrobium officinale].

Using universal primer Ty1-copia retrotransposon RT,43 Ty1-copia like retrotransposon RT with high heterogeneity, stop codon mutation and frameshift mutation were amplified by PCR from genomic DNA of Zhejiang Lin'an (C15) and Yunnan Guangnan (A39) of Dendrobium officinale. The length of these sequences varied from 260 to 266 bp, and was rich in AT and consistency ranged from 47.1% to 97.

[Cloning and expression analysis of HSP70 gene from Dendrobium officinale under low temperature stress].

Objective: To investigate HSP70 gene expression from Dendrobium officinale under low temperature stress, which will provide the molecular biological foundation for breeding the low temperature resistant strain.

Method: HSP70 gene full length cDNA was cloned by rapid amplification of cDNA ends (RACE) on the basis of HSP70 gene fragment sequences, and the structure and function of HSP70 gene were deduced. The expression of HSP70 under low temperature stress was detected by RT-PCR.

[Studies on agronomic traits of seedlings from different F1 generations of Dendrobium officinale].

Objective: To select superior mating combinations from different F1 generations of Dendrobium officinale.

Method: Twenty-six superior parents from four provenances were selected to make up 26 mating combinations. The agronomic traits of different F1 generation were measured, counted, and analyzed by DPS software.

[Special culture mediums of breeding clones of Dendrobium officinale].

The explants were obtained from stem segments of hybrid combination of Dendrobium officinale germplasms (Zhejiang Yandang Mountain x Yunnan Guangnan). The screened culture mediums for buds induction and multiplication, which were 1/2MS + IBA 1.0 mg x L(-1) +6-BA 1.

[Comparison study of different extraction methods of Sarcandra glabra].

Objective: To compare the different extraction methods of Sarcandra glabra (Thunb.) Nakai.

Methods: To compare the yield of extraction and determination content of extraction by 6 kinds of different extraction methods as cold-soaked extraction, percolation extraction, reflux extraction, continuous reflux extraction, ultrasonic extraction and microwave extraction, and the content of furmaric acid was determinated as index.

[Effects of storage time on magnolol and honokiol contents in bark of Magnolia officinalis].

Objective: To reveal the relationship between the storage time of the bark of Magnolia officinalis and the content of phenols in it, and lay a theoretical foundation for the harvest, processing, management and storage.

Method: The contents of magnolol and honokoiol in 15 bark samples, collected from the main producing areas in China, were determined in the time of freshly harvest and 3 and 10 years after respectively by HPLC method.

Result: It showed that within a certain period of time, bark storage was favorable to conversion and accumulation of phenols, that the content of magnolol tended to increase from year 0 to year 3, then followed by slight decrease with years on account of volatilization of phenols, but was still higher when the bark was stored for 10 years than that that when the bark was freshly harvested, and the content of honokoiol still tended to increase when the bark had been stored for 10 years.

[Study on tissue culture and rapid propagation of Atractylodes macrocephala].

A study was conducted by tissue culture on the explant of Atractylodes macrocephala Koidz.. The result showed that NAA was a leading factor for induction of callus from leaf blades and the petiole as well as bud differentiation.