Effect of polygonatum polysaccharide on the hypoxia-induced apoptosis and necrosis in in vitro cultured cerebral cortical neurons from neonatal rats

BACKGROUND： Cardiocerebrovascular diseases induced cerebral circulation insufficiency and senile vascular dementia can result in ischemic/hypoxic apoptosis of central neurons, which we should pay more attention to and prevent and treat as early as possible. Traditional Chinese medicine possesses the unique advantage in this field. Polygonatum, a Chinese herb for invigorating qi, may play a role against the hypoxic apoptosis of brain neurons. OBJECTIVE ： To observe the protective effect of polygonatum polysaccharide on hypoxia-induced apoptosis and necrosis in cerebral cortical neurons cultured in vitro. DESIGN： A comparative experiment.SETTING： Laboratory of Cell Biology, Institute of Basic Medical Sciences, Jiangxi Provincial Academy of Traditional Chinese Medicine. MATERIALS： The experiment was carried out in the Laboratory of Cell Biology, Institute of Basic Medical Sciences, Jiangxi Provincial Academy of Traditional Chinese Medicine from November 2003 to April 2005. Totally 218 Wistar rats （male or female） of clean degree within 24 hours after birth were purchased from the animal center of Jiangxi Medical College （certification number was 021-97-03）. METHODS：① Preparation of cerebral cortical neurons of rats： The cerebral cortical tissues were isolated from the Wistar rats within 24 hours after birth, and prepared to single cell suspension, and the cerebral cortical neurons of neonatal rats were in vitro cultured in serum free medium with Neurobasal plus B27 Supplement. ② Observation on the non-toxic dosage of polygonatum polysaccharide on neurons： After the neurons were cultured for 4 days, polygonatum polysaccharide of different dosages （1-20 g/L） was added for continuous culture for 48 hours, the toxicity and non-toxic dosage of polygonatum polysaccharide on neurons were observed and detected with trypan blue staining. ③Grouping： After hypoxia/reoxygenation, the cultured neurons were divided into normal control group, positive apoptotic group and polygonatum polysaccharide group. In the normal control group, the neurons were cultured at 37℃ in CO2 with the volume fraction of 0.05 under saturated humidity for 6 days. In the apoptotic positive group, the neurons were cultured with hypoxia for 12 hours after 4-day culture, and followed by reoxygenation for 48 hours. In the polygonatum polysaccharide group, polygonatum polysaccharide with the terminal concentration of 0.5, 1 and 1.5 g/L was added to some neurons at 10 hours before the hypoxia culture, and then the neurons were cultured with hypoxia for 12 hours, followed by reoxygenation for 48 hours; polygonatum polysaccharide with the terminal concentration of 0.5, 1 and 1.5 g/L was added to the other neurons at 12 hours after hypoxia followed by reoxygenation for 48 hours.④ The Hoechst33342 fluorescence staining, Annexin V/PI flow cytometer, appearance of DNA agarose gel electrophoresis gradient strap and immunohistochemical staining were used to observe the expressions of Bcl-2, Bax and Caspase-3 apoptotic and anti-apoptotic proteins and the ratio of Bcl-2/Bax, and observe the effect of polygonatum polysaccharide against the hypoxic apoptosis of cerebral cortical neurons of neonatal rats. MAIN OUTCOME MEASURES： ① Toxicity and non-toxic dosage of polygonatum polysaccharide on neurons;② Apoptotic rate of neurons detected with Hoechst33342 fluorescence staining;③ Early apoptotic rate and necrotic rate of neurons detected with Annexin V/PI flow cytometer; ④DNA agarose gel electrophoresis ladder-like strap appeared or not;⑤ Expressions of Bcl-2, Bax and Caspase-3 apoptotic and anti-apoptotic proteins and the ratio of Bcl-2/Bax. RESULTS：① Polygonatum polysaccharide within 6 g/L had no cytotoxicity on the normal cultured cerebral cortical neurons （P 〉 0.05）. ②The apoptotic rates of neurons detected with Hoechst33342 fluorescence staining had significant differences between the polygonatum polysaccharide groups and positive apoptosis group added to neurons at 10 hours before the hypoxia culture [（13.00±4.52）%,（12.72±2.15）%, （11.80±1.18）%,（38.03±1.05）%, P 〈 0.01], and had no significant differences between the polygonatum polysaccharide groups and positive apoptosis group added to neurons at 12 hours after the hypoxia culture （36.77±1.45）%, （36.60±1.61）%, （36.37±2.02）%, （38.03±1.05）%, P 〉 0.05].③ Annexin V/PI flow cytometer detected that the anti-necrotic effect was enhanced with the increased concentration of polygonatum polysaccharide within 0.5-1.5 g/L （P 〈 0.01）. Polygonatum polysaccharide of 0.5-1.5 g/L added before hypoxia could significantly decrease the apoptotic rate of neurons induced by hypoxia/reoxygenation （P 〈 0.01）. ④ No DNA agarose gel electrophoresis ladder-like strap appeared in the groups with polygonatum polysaccharide of 0.5-1.5 g/L added at 10 hours before hypoxia;⑤ After Polygonatum polysaccharide of 0.5-1.5 g/L was added before hypoxia, the expression of Bcl-2 protein of hypoxic neurons was increased （P 〈 0.01）, and those of Bax protein and Caspase-3 protein were reduced （P 〈 0.01）, and the ratio of Bcl-2/Bax was increased （P 〈 0.01）. CONCLUSION： Polygonatum polysaccharide within 6 g/L has no cytotoxicity on the normal cultured cerebral cortical neurons. Polygonatum polysaccharide of 0.5-1.5 g/L added before hypoxia plays a role agains necrosis of neurons induced by hypoxia. Polygonatum polysaccharide of 0.5-1.5 g/L can significantly reduce the apoptosis of neurons induced by hypoxia through up-regulating the expression of Bcl-2 protein, down-regulating the expressions of Bax protein and Caspase-3 protein, and increasing the ratio of Bcl-2/Bax.

Effects of brain-derived neurotrophic factor on synapsin expression in rat spinal cord anterior horn neurons cultured in vitro

Brain-derived neurotrophic factor （BDNF） promotes synaptic formation and functional maturation by upregulating synapsin expression in cortical and hippocampal neurons. However, it remains controversial whether BDNF affects synapsin expression in spinal cord anterior horn neurons. Wistar rat spinal cord anterior horn neurons were cultured in serum-supplemented medium containing BDNF, BDNF antibody, and Hank＇s solution for 3 days, and then synapsin I and synaptophysin protein and mRNA expression was detected. Under serum-supplemented conditions the number of surviving neurons in the spinal cord anterior horn was similar among BDNF, anti-BDNF, and control groups （P 〉 0.05）. Synapsin I and synaptophysin protein and mRNA expressions were increased in BDNF-treated neurons, but decreased in BDNF antibody-treated neurons （P 〈 0.01）. These results indicated that BDNF significantly promotes synapsin I and synaptophysin expression in in vitro-cultured rat spinal cord anterior horn neurons.

Effects of Estradiol on Cashmere Goat Primary Hair Follicles Cultured in vitro

[Objective] The aim of this study was to preliminarily explore the effects of estradiol on morphology and growth of cashmere goat primary hair follicles. [Method] Cashmere goat primary hair follicles were cultured in serum-free Williams E media supplemented with different doses of 17 β-E2 (0, 0.1, 1.0, 10.0, 100.0 nmol/L), and their growth rates and morphological changes were observed. [Result] The growth rate of 0.1 nmol/L 17 β-E2 group was quite comparable with that of the control group(0 nmol/L), but the 17 β-E2 with concentrations of 1.0, 10.0 and 100.0 nmol/L displayed different degrees of inhibition on the growth of hair follicles. Different morphological changes of hair follicles could also be discovered in different concentration treatments. [Conclusion] The study laid a certain foundation for exploring the regulation mechanism of estrogen on growth of cashmere goat hair follicles.

IGF-1 mRNA expression of adult rat thyroid cell cultured in vitro

Objective: To investigate the law of age-related changes of insulin-like growth factor-1 (IGF-1) expression of rat thyroid cells cultured in vitro. Methods: Rat thyroid of different age (10, 45, 65, 100, 150 weeks) was isolated and thyrocytes cultured. Total RNA was extracted in different rat age group when thyroid cells had been cultured for two weeks. mRNA IGF-1 expression was measured with reverse-transcription polymerase chain reaction( RT-PCR) in each group and compared. Results: Quantity of total RNA in thyroid cells decreased with ageing when the rat thyroid cells had been cultured for 2 weeks. There is significant difference among groups (P<0.05). Expression of IGF-1 mRNA could be detected in thyroid cells of different age cultured in vitro. Quantity of IGF-1 mRNA expression by RT-PCR analysis increased from 10 to 45 weeks old, and then decreased with ageing. Conclusion: Rat thyroid cells from different age cultured in vitro can express IGF-1 mRNA. Quantity of total RNA in thyroid cells cultured in vitro decreased with aging. IGF-1 mRNA expression was correlated to age (r=0.401, P<0.05).

Shine bright: considerations on the use of fluorescent substrates in living monoaminergic neurons in vitro

The biogenic monoamines dopamine （DA）, norepinephrine （NE） and serotonin （5-hydroxytryptamine, 5-HT） are major neuromodulators in the mammalian central nervous system （CNS）. DA containing neurons are found in i） the mesolimbic system in which cell bodies in the ventral tegmental area （VTA） project axons into the amygdala, cortex, hippocampus and the nucleus accumbens; and ii） the nigrostriatal system in which cell bodies located in the substantia nigra pars compacta send their axons into the dorsolateral parts of the striatum （Bjorklund and Dunnett, 2007）. The central noradrenergic neurons are concentrated in distinct brainstem nuclei with the locus coeruleus （LC） being the most prominent nucleus which projects a diffusely arborizing axonal network to most areas of the CNS （Szabadi, 2013）.

pFTAA: a high affinity oligothiophene probe that detects filamentous tau in vivo and in cultured neurons

Tauopathies describe a group of neurodegenerative diseases in which the protein tau,encoded by the gene MAPT,is aberrantly misfolded,leading to tau aggregation,neural dysfunction,and cell death（Spillantini and Goedert,2013）.In Alzheimer＇s disease（AD）,tau forms the characteristic intracellular neurofibrillary tangles（NFTs）,which are thought to be the major cause of neurodegeneration（Bloom,2014）.In other tauopathies,including frontotemporal dementia with Parkinsonism linked to chromo- some 17 （FTDP-17T）, corticobasal degeneration and progressive supranuclear palsy, there are specific forms of tau aggregates and filaments without any amyloid pathology, demonstrating tau＇s po- tent disease-causing potential （Spillantini and Goedert, 2013）. Tau is a microtubule （MT） binding protein, which becomes abnormally hyperphosphorylated on several residues prior/during the process of aggregation, thereby causing loss of its MT binding activity （Mandelkow and Mandelkow, 2012）.

A Preliminary Observation on the Development of Mouse Embryos Co-cultured with Human Oviductal Tissue or Conditioned Medium in Vitro

The present investigation has been carried out to examine the effect of human oviductaltissue co-culture system on the development of mouse embryos in vitro. Two-cell embryos collected from superovulated mouse were co-cultured with human oviductal tissue suspended inHam 's F10+10% Fetal Calf Serum(F10 FCS),or,in oviductal tissue conditioned medium andF10 FCS as control.The results showed that the proportion developed into blastocyst,proportion of hatchedand the velocity of embryo development were higher in both tissue co-culture and conditionedmedium as compared with F10 FCS control. Furthermore,the velocity and percentage ofembryomic development were higher in co-culture with ampullary tissue or its conditioned medium than that of isthmus.The effects of co-culture and conditioned medium on embryo development had no significant difference. All the embryos obtained from two co-culture systemscould cleave normally.This experimental observation indicated that human oviductalepithelium might secrete some factors to promote the embryonic development in vitro.

Quantitative detection and comparison of sulfate glycosaminoglycans content in extracellular matrix of in vitro cultured epiphyseal, articular and rib chondrocytes

Objective To establish a method for quantitative detection of the sulfate glycosaminoglycans ( GAG) content in extracellular matrix of in vitro cultured chondrocytes so as to evaluate the biological characteristics of epiphyseal, articular and rib chondrocytes. Methods Sulfate GAG content in extracellular matrix of three chondrocytes was measured by the modified dimethylmethylene blue (DMB) method. The changes of the toluidine blue (TB) stain of chondrocytes were observed by light microscope. Results Primary chondrocytes had the highest content of sulfate GAG in the extracellular matrix, ie, epiphyseal chondrocytes reached ( 70. 12 ± 7. 72 )μg/cm2, articular chondrocytes (92.00 ± 10.15) μg/cm2 and rib chondrocytes (80.61 ± 11. 40) μg/cm2, respectively. On the third pasage chondrocytes, epiphyceal chondrocytes decreased to (53.27 ± 9. 50 ) μg/cm2, articular chondrocytes to (63.88 ± 11.92) μg/cm2 and rib chondrocytes to (58.94 ±8.21) μg/cm2, respectively. The change of TB in every passage

Production of functional sperm from in vitro-cultured premeiotic spermatogonia in a marine fish

In vitro production of functional gametes can revolutionize reproduction by reducing generation intervals and accelerating genetic breeding in aquaculture,especially in fish with relatively long generations.Nevertheless,functional sperm production from in vitro-cultured spermatogonia remains a challenge in most aquaculture fish.In this study,we isolated and characterized premeiotic spermatogonia from marine four-eyed sleepers(Bostrychus sinensis),which are prone to ovotesticular or sterile testicular development,and induced the differentiation of the spermatogonia into flagellated sperm in a three-dimensional(3D)culture system.Artificial insemination indicated that the in vitro-derived sperm were capable of fertilizing mature oocytes to develop into normal larvae.Furthermore,melatonin significantly promoted spermatogonia proliferation and differentiation through the ERK1/2 signaling pathway,and thus increased the efficiency in functional sperm production.The 3D culture system and resulting functional sperm hold great promise for improving the genetic breeding of aquaculture fish.

Direct Regeneration of Plants Derived from in vitro Cultured Shoot Tips and Leaves of Poplar （Populus×euramericana ＇Neva＇）

The purpose of the present study was to establish a regeneration procedure for Populus × euramericana ＇Neva＇ by using in vitro shoots tips and leaves. For sterilization, 0.1% （w/v） mercuric chloride （HgCl2） solution for 8 to 10 min was the optimal treatment for this poplar cultivation. The effects of benzyladenine （BA） and α-naphthaleneacetic acid （NAA） added to Murashige and Skoog （MS） medium were tested on organogenesis. The highest regeneration rate and numbers of shoots/explant from shoot tips （96.7%, 9.8） and leaves （90.0%, 8.7） were obtained on the half-strength MS medium supplemented with 0.5 mg/L BA and 0.1 mg/L NAA. The optimal medium for in vitro rooting of shoots was on a half-strength MS medium containing 1 mg/L indolebutyric acid （IBA） with the highest rooting frequency （93.3%） and numbers of roots/explant （8.2）. For acclimatization, in vitro rooted plantlets were transferred to plastic cups containing vermiculite and peat （1： 1）. After acclimatization, transplanted plantlets grew well in a shade house. Therefore, we believe that this efficient plant regeneration protocol especially by leaf explants is very important for in vitro clonal propagation of Populus×euramericana ＇Neva＇.

Brain-derived neurotrophic factor induces neuron-like cellular differentiation of mesenchymal stem cells derived from human umbilical cord blood cells in vitro

Human umbilical cord blood was collected from full-term deliveries scheduled for cesarean section. Mononuclear cells were isolated, amplified and induced as mesenchymal stem cells. Isolated mesenchymal stem cells tested positive for the marker CD29, CD44 and CD105 and negative for typical hematopoietic and endothelial markers. Following treatment with neural induction medium containing brain-derived neurotrophic factor for 7 days, the adherent cells exhibited neuron-like cellular morphology. Immunohistochemical staining and reverse transcription-PCR revealed that the induced mesenchymal stem cells expressed the markers for neuron-specific enolase and neurofilament. The results demonstrated that human umbilical cord blood-derived mesenchymal stem cells can differentiate into neuron-like cells induced by brain-derived neurotrophic factor in vitro.

Culture Experiment in vitro of Eperythrozoon of Mustela lutreola

[Objective] The research aimed to make the culture experiment in vitro of eperythrozoon of Mustela lutreola. [Method] 30% newborn bovine serum or Mustela lutreola was added in RPMI-1640, DMEM, M-199 and HL culture solutions. Epery-throzoon of M. lutreola was cultured in vitro under the conditions of 37 ℃, 5% CO2. The culture solutions were replaced every 24 hours. Appropriate amount of healthy erythrocytes were supplemented to make subculture. [Result] The infection rate and infection intensity of eperythrozoon in RPMI-1640 and HL culture solutions were higher than that in DMEM and M-199 culture solutions. The infection rate and infec-tion intensity of eperythrozoon in RPMI-1640 and HL culture solutions with adding 30% serum of M. lutreola were higher than that with adding 30% newborn bovine serum. And the infection rate and infection intensity of eperythrozoon in RPMI-1640 culture solution were slightly higher than that in HL culture solution. The infection rate was over 80% after culturing 12 hours. 23 generations of subculture in vitro was made. [Conclusion] The research provided an effective approach for screening out the drugs that could effectively control eperythrozoon of M. lutreola, preparing diagnostic antigen and producing the relevant vaccine.

The Study of Influencing Factors on the Growth Characters of Sprague-Dawley Rat Retinal Neurons in Vitro

Purpose:To investigate the influencing factors in culturing Srague-Dawley(S-D) rats retinal neurons in order to lay foundation for further experimental research.Materials and Methods:Retinal cells were plated on plastic plates and coverslips coated with poly-lysine or ethylene imine polymer for primary culture.The cultured cells were divided into following groups:1.Culture medium changed every 2 tp 3 days vs changed only once;2.Cytosine arabinoside(Ara-C)added to the culture medium vs not added.The cells were observed and pictured under inverted phase contrast microscope.The cells were identified through immunocytochemistry.Results:The immunofluorescence showed that most of the cultured cells were neurons,among them were a few retinal ganglion cells.In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c,the neurons intended to aggregate into clusters with relatively straight neurites.In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c,the neurons grew dispersively with bent neurites.Both of them survived for 2 to 3 weeks.The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks.In the group of which medium changed several times,the survival time of neurons was shorter than that in the medium changed only once.Conclusions:The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth.It is not favorable for the growth of the neurons by changing culture medium many times.Ara-c may possibly have side effect on the growth of retinal neurons.

Embryonic Limb Buds Derived Neurotrophins on the Survival of Neurons and the Growth of Axons in Culture in Vitro

Bioactive proteins from SD rat limb buds were extracted and purified. Fractions of 22 ku, 34 ku and 95 ku were proved to have neurotrophic activity to neurons, and the combined activity of these three fractions was the highest. So they were combinedly added into the culture medium of sensor neurons in dorsal root ganglia and motor neurons of anterior spinal cord from 2-week-old embryonic rats, and PBS was added as control. Phase-contrast microscopic and electron microscopic observations, and true cholinesterase measurements were performed to evaluate the survival and changes in growth, function, and ultrastructure of these cultured neurons. In the experimental group, it was found that the AchE activity was higher (P<0. 01), ultrastructural changes in mitochondria,Gorgi's complex and other cell organs were milder than those in the control group. The results showed limb buds derived neurotrophins played an important role in maitaining the survival of the neurons and promoting the growth of axons. It was concluded that embryonic limb buds derived neurotrophins had high neurotrophic activities on neurons' survival and axon growth.

The effects of human genome DNA on spinal cord neurons of the embryonic mouse in vitro

objective: To study the effects of human genome DNA on the cultured spinal cord neurons of em bryonic mouse. Methods: The human genome DNA was added to the culture medium of the spinal cord neu rons of embryonic mouse. Eight days later, MTT assay, NSE immunocytochemical staining and image analy sis were proformed to examine the viabilities and the neurites lengths of the neurons. Results: The neurite length of the experimental group was significantly Ionger than that of the control group, but no marked dif ference was found between the viabilities of the neurons of the experimental groups and that of the control ones. Conclusiou: Human genome DNA has no effects on the viabilities of the cultured neurons but can pro mote the neurite growth.

EFFECT OF RADIX SALVIAE MILTIORRHIZAE ON GROWTH OF ISOLATED CELLS FROM EMBRYONIC CHICKEN FRONTAL BONE CULTURED IN VITRO (A HISTOCHEMICAL STUDY) Ⅱ.THE DEVELOPMENT AND MATURATION OF OSTEOBLAST-LIKE CELLS

The isolated osteoblast-like cells from embryonic chicken frontal bone werecultured in vitro and histochemical methods adopted to observe the effect of RadixSalviac Miltiorrhizae (RSM) on proliferation, differentiation, and osteogenic capacity ofthese cells. It was found that: 1. The mitosis and proliferation of the osteoblast-like cellscould be accelerated by RSM, resulting in increased density of the cells in RSM groupas compared with the control. 2. After 48 h, the pseudopodia stretched out and drew backactively in osteoblast-like cells in RSM group. Small particles produced in the cells weresecreted through exocytosis to the extracellular medium. However, in the control group,the capacity to form and secrete these particles was limited. These particles showed posi-tive Alcian blue staining in Alcian blue-Sirius red reaction, so they were acidmucopolysaccharide particles. 3. The osteoblast-like cells could secrete vesicular particles 3micra in diameter. These vesicular particles could be stained with Alcian blue in earlystage, then they could be stained with Sirius red, and finally by Alizarin red S. Thesevesicular particles could aggregate and fuse around the cell colonies, forming bonenodules and bone flakes. The quantity and volume of the bone nodules and flakes inRSM group were larger than in the control group. 4. The bone nodules and flakes couldbe labeled vitally with tetracycline, and show strong yellow fluorescence under thefluorescence microscope. Therefore, these substances were the newly formed bone sub-stances.

Culture in vitro and Cryopreservation of Shouguang Black Chicken Fibroblasts

[Objective] The aim of this study was to establish the in vitro culture system of chicken fibroblasts.[Method] Tissue explant method and enzymatic digestion method were used to separate and culture chicken skin fibroblasts respectively.The rate of cell growth,cryopreservation and recovery were compared.[Result] The primary chicken fibroblasts prepared by enzymatic digestion grew faster and converged together to form monolayer on 5 d post preparation;the passage cells prepared by these 2 methods grew at similar speed and formed monolayer within 2-3 d;homogeneous fibroblasts could be obtained by trypsin digestion and repeated attachment for 3-4 passages;there were 75%-80% of cells survived after cryopreservation and recovery;the growth curves of embryonic fibroblasts and skin fibroblasts were all normal and the two kind of cells still retained the normal number of chromosomes even at the twelfth passage.[Conclusion] The feeder layer cells needed for establishing ES cell lines could be obtained by culturing chicken fibroblasts through both tissue explant method and enzymatic digestion method.This study provided a basis for the successful establishment of ES cell lines.

Effects of Different Culture Condition in vitro on Growth of Cashmere Goat Primary Hair Follicles

[Objective] The aim of this study is to lay a foundation for illustrating the biological characteristics and growth regulation mechanism of hair follicles.[Method]Cashmere goat primary hair follicles were separated under aseptic condition and cultured in serum-free DMEM and serum-free Williams E media respectively;subsequently,the growth rate and morphological changes were observed under the inverted microscope.[Result]Hair follicles cultured in serum-free DMEM media showed a growth rate of 0.034 mm/d during the first 3 days,whose structure and morphological characteristics could maintian a stable status for a long time in the growth process.Hair follicles grew much faster in the serum-free Williams E media with a growth rate of 0.077 mm/d during the first 3 days.[Conclusion]There were significant differences(P<0.05)between the growth of cashmere goat hair follicles cultured in the 2 kinds of media.Serum-free Williams E medium was superior to serum-free DMEM medium.

Effects of Hormone Factors on the in vitro Culture Flowering Induction of Dendrobium officinate Kimura et Migo

[Objective]The aim was to select the suitable hormone factors for flowering induction in vitro culture of Dendrobium officinate Kimura et Migo.[Method]The test-tube plantlets from the stems of Dendrobium officinate Kimura et Migo were used as the experimental materials and MS medium as the basic medium.Comparative tests have been done between single-factor hormone treatments（different concentrations of PP333 or TDZ） and multi-factor hormone treatments（different combinations of PP333,TDZ,6-BA and NAA） to research the effects of hormone factors on the flowering induction of the plantlets.[Result]Among the single-factor hormone treatments,the suitable concentration and the rate of flower buds formation of PP333 treatment were 0.2 mg/L and 8.5%,the that of TDZ treatment were 0.06 mg/L and 15.5%;the effects of multi-factor hormone treatments on the flowering induction were ordered as follow：（PP333 ＋ 6-BA ＋ NAA ＋ TDZ）〉 （PP333 ＋ 6-BA ＋ NAA）〉 （PP333 ＋ 6-BA） and（PP333 ＋ NAA） ;the most suitable treatment was PP333 0.3 mg/L ＋ 6-BA 0.5 mg/L ＋ NAA 0.5 mg/L ＋ TDZ 0.06 mg/L,the rate of flower bud formation and the rate of the blossomed flower were respectly reached to 80.4% and 90.3%.[Conclusion]PP333 and TDZ showed the important effect on the flowering induction in vitro culture of Dendrobium officinate Kimura et Migo.The effect of TDZ was better than that of PP333.It is much more conducive to the flower bud formation,when using appropriate concentration of TDZ combined with other hormones properly.

Rapid Propagation of Chirita ophiopogoides in Vitro

A method for in vitro culture and rapid propagation of Chirita ophio- pogoides was developed using leaves as explants in this study, The results indicat- ed that the medium MS＋6-BA 0.1 mg/L＋NAA 0.1 mg/L was suitable for bud induc- tion and seedling regeneration from leaves in primary culture. The media MS＋0.5 mg/L 6-BA＋0,1 mg/L NAA＋10% banana＋5% potato and MS＋0.5 mg/L 6-BA＋0.5 mg/L NAA＋2% banana were very suitable for callus multiplication and seedling hardening in subculture, and the proliferation coefficients were 7,9 and 5.6 per 60 d respec- tively. The optimal rooting medium was MS and the rooting rate was 100% on day 30 of culture. The rooted plantlets of C. ophiopogoides were transplanted in green- house with humus soil and 92.5% survived. Theoretically, using the rapid propaga- tion system, about 20 176 seedlings can be reproduced from a sterile plantlet in a year.