RESUMEN
Desert teak (Tecomella undulata (Sm.) Seem) a multipurpose ornamental tree native to the arid and semi-arid tropics has entered the endangered plant category mainly as a result of the species' ineffective seed reproduction system. The tree usually reproduces through a few root suckers in old stands. Conventional methods of plants multiplication could not offer a viable practice for its mass multiplication. Low adventitious rooting of the cuttings has been the principal cause of failure in its vegetative propagation. Hence, the present research was planned and conducted to evaluate the feasibility of somatic embryogenesis in this species, the pathway that bypasses the need for rooting stage by developing bipolar embryos. Ovary explant was cultured in modified Murashigue & Skoog (MS) medium supplemented with different auxins and cytokinins. The results showed ?-naphthalene acetic acid (NAA) was superior in inducing embryogenic callus. NAA ranging 5.4-21.5 ?M could induce the highest embryogenic calli which exhibited developing pro-embryogenic masses (PEM) and globular somatic embryos. The calli which were induced by the use of 2,4-dichlorophenoxyacetic acid (2,4-D) were poor in quality and showed no morphogenesis potency. Individual application of Thidiazuron (TDZ) and N6-benzyladenine (BA) induced good callogenesis at low concentrations but the calli were non-embryogenic with both. The proliferation of embryogenic calli was the best in a hormone-free medium. However, the media containing 40.5 and 54 ?M NAA alone could induce somatic embryos along with callus proliferation. Low BA-contained medium (0.9-4.44 ?M) led to recurrent somatic embryogenesis. Neither BA and GA3, nor the elevating sucrose concentration could cause further development and maturation of the somatic embryos induced during previous stages (callogenesis and callus proliferation). More research is required to optimize the maturation stage. The findings of the present study can be useful for future studies in the micropropagation of this recalcitrant specieslationships in Indian mustard under heat stress and the differential remobilization efficiencies in the advanced breeding lines.
RESUMEN
Objective: To explore the research progress of the cell sources and related signaling pathways of the wound-induced hair follicle neogenesis (WIHN) in recent years. Methods: The literature related to WIHN in recent years was reviewed, and the cell sources and molecular mechanism were summarized and discussed. Results: Current research shows that WIHN is a rare regeneration phenomenon in the skin of adult mammals, with multiple cell origins, both hair follicle stem cells and epithelial stem cells around the wound. Its molecular mechanism is complicated, which is regulated by many signaling pathways. Besides, the process is closely related to the immune response, the immunocytes and their related cytokines provide suitable conditions for this process. Conclusion: There are still many unsolved problems on the cellular origins and molecular mechanisms of the WIHN. Further study on the mechanisms will enhance the understanding of adult mammals' hair follicle regeneration and may provide new strategy for functional healing of the human skin.
RESUMEN
Intensive exploitation of mahogany wood (Swietenia macrophylla, Meliaceae) has resulted in the loss of natural populations. Somatic embryogenesis offers an alternative to clonal propagation and conservation of mahogany. This study describes biochemical (carbohydrates, total phenols, total flavonoids, protein, and plant growth regulators content) and histological characteristics of the somatic embryogenesis process in mahogany. Calli were obtained by culturing cotyledons of seeds from immature fruits for six weeks on semi-solid MS medium supplemented with 1.0 mgL-1 of kinetin and 4.0 mgL-1 of 2, 4-D. Primary callus was cultured on half strength semi-solid MS medium supplemented with 1.0 mgl-1 6-BA (6-benzylaminopurine) and embryogenic structures were obtained. Embryo development from globular-shaped somatic embryos to the cotyledonary stage was confirmed by histology and scanning electron microscopy. Shoot initiation was observed after somatic embryos were transferred to germination and maturation medium. Endogenous concentrations of carbohydrates, total phenols, total flavonoids, protein, and plant growth regulators were determined in embryogenic (EC) and non-embryogenic (NEC) calli of mahogany. Embryogenic cultures contained significantly higher concentrations of IAA (indoleacetic acid), ABA (abscisic acid), and GAs (Gibberellins 1+3+20), whereas non-embryogenic calli contained more total phenols, flavonoids and resistant starch. Fructose and glucose were not present at detectable levels in EC or NEC, whereas soluble starch and sucrose were only detectable in EC. Concentrations of total proteins, Z/ZR (Zeatin/zeatin riboside) and iP/iPA (N6-(Δ2-isopentenyl) adenine and N6-(Δ2-isopentenyl) adenosine) were similar in EC and NEC.
La explotación intensiva de la madera de caoba (Swietenia macrophylla) ha provocado la pérdida de poblaciones naturales. La embriogénesis somática ofrece una alternativa a la propagación clonal y la conservación de esta especie. Este estudio describe las características bioquímicas (contenido de carbohidratos, fenoles totales, flavonoides totales, proteínas y reguladores del crecimiento) e histológicas del proceso de embriogénesis somática en caoba. Los callos se obtuvieron cultivando cotiledones de semillas de frutos inmaduros durante seis semanas en medio MS semisólido suplementado con 1.0 mgL-1 de kinetina y 4.0 mgL-1 de 2, 4-D. Luego se cultivó el callo primario en medio MS semisólido y un suplemento de 1.0 mgl-1 BA y se obtuvieron estructuras embriogénicas. El desarrollo de embriones somáticos de forma globular a la etapa cotiledonar se confirmó por histología y microscopía electrónica de barrido. La iniciación del brote se observó después de que los embriones somáticos se transfirieron a un medio de germinación y maduración. Se determinaron las concentraciones endógenas de carbohidratos, fenoles totales, flavonoides totales, proteínas y reguladores del crecimiento en callos embriogénicos (EC) y no embriogénicos (NEC) de caoba. Los cultivos embriogénicos contenían concentraciones significativamente más altas de IAA, ABA y GA, mientras que los callos no embriogénicos contenían más fenoles totales, flavonoides y almidón resistente. La fructosa y la glucosa no estaban presentes en niveles detectables en EC o NEC, mientras que el almidón soluble y la sacarosa solo se detectaron en el EC. Las concentraciones de proteínas totales, Z / ZR e iP / iPA fueron similares en EC y NEC.
RESUMEN
ABSTRACT: This study evaluated the effect of different concentrations of 2-isopentenyladenine (2-iP) on the direct somatic embryogenesis capacity of the Mundo Novo cultivar of Coffea arabica. Leaf explants were cultivated with half the MS salt concentration and the addition of sucrose (20gL-1) and 2-iP (0; 2.5; 5; 7.5 and 10µM). The 2-iP doses of 7.5 and 10µM produced the greatest responses with respect to the percentage of explants with embryogenic structures and the size of the embryogenic structures. However, the greatest production of somatic embryos occurred on the explants treated with 10µM of 2-iP, followed by 7.5µM, whereas their production was absent or reduced with 0 and 5µM, respectively.
RESUMO: Este estudo avaliou o efeito de diferentes concentrações de 2-isopentalinadenina (2-iP) na capacidade de embriogênese somática direta da cultivar Mundo Novo de Coffea arabica. Explantes foliares foram cultivados em meio com metade da concentração de sais de MS e adição de sacarose (20gL-1) e de 2-iP (0; 2,5; 5; 7,5 e 10µM). Os tratamentos com 7,5 e 10µM de 2-iP induziram respostas mais elevadas de porcentagem de explantes com estruturas embriogênicas e de tamanho de estrutura embriogênica. Porém, os explantes tratados 10µM de 2-iP tiveram maior produção de embriões somáticos, seguido de 7,5µM, enquanto nos tratamentos controle e com 5µM, as respostas foram respectivamente de ausência e de baixa formação destes.
RESUMEN
Abstract Catharanthus roseus (L.) G. Don, Apocynaceae, is an immensely important medicinal plant, produces a variety of anticancerous compounds. The yield of two most investigated alkaloids vinblastine and vincristine is unfortunately very low. A vast array of technologies including elicitation have recently been used to enrich Catharanthus alkaloid in culture. Yeast extract is a biotic elicitor, the polysaccharide and the peptide moiety have been recognized as a signalling element in enriching secondary metabolites. In this study, the yeast extract elicitation on vinblastine and vincristine was studied in various protoplast derived tissues and plantlets. Four different yeast extract treatments (T1 = 0.5 g/l, T2 = 1.0 g/l, T3 = 1.5 g/l and T4 = 2.0 g/l) were prepared and used. The alkaloid was quantified and a comparative account of yield were presented by the use of High performance thin layer chromatography. The yeast extract amendment in medium improved vinblastine and vincristine yield in cultivating tissues, maximum being in germinating embryos and in in vitro raised leaf. The highest yield was in T3 (1.5 mg/l) in which 22.74% vinblastine and 48.49% vincristine enrichment was noted in germinating embryos; the enhancement was however, treatment-specific. Antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase activities were investigated as addition of yeast extract caused cellular stress and had enriched level of alkaloids.
RESUMEN
Aims: The purpose of this experiment was to determine the artificial symbiosis interaction of Herbaspirillum seropedicae (Z78) on oil palm embryogenic calli. Methodology and results: For this purpose, symbiotic associations were established between Z78 and embryogenic calli of oil palm tissue cultured. A total of five treatments involved, in particular: i) + 3.0 mg/L 2,4-D + 100% N MS medium (control), ii) + Z78 pellet cells (1 mL) + 25% N MS medium, iii) + Z78 supernatant (1 mL) + 25% N MS medium, iv) + Z78 broth culture (1 mL) + 25% N MS medium, and v) + Z78 sonicated cells (1 mL) + 25% N MS medium. All treatments were supplied with minimal N sources (25% N), ammonium nitrate and potassium nitrate, while the control was treated with 100% N sources. Treated samples were harvested on D80 and observed for biomass and diameter increment (%), formation of embryoids, and Z78 colonization. The results showed embryogenic calli in the inoculated treatments that contained depleted N produced similar result to the control treatment which contained 100% N nutrients. Positive interactions occurred between the diazotroph and host plant tissues as viewed under FESEM and EFTEM. Among the treatments, Z78 sonicated cell showed better growth of embryogenic calli compared to others. Conclusion, significance and impact study: The in vitro nitrogen-depleted artificial symbiosis environment allowed the diazotroph (Z78) to be expressed and provide the nitrogen sources and indole-3-acetic acid for cell growth. This study represents beneficial co-culture interaction effects of different inocula of diazotrophic bacterial cells with in vitro embryogenic calli of oil palm.
RESUMEN
Aims: An efficient and reproducible In vitro regeneration protocol is vital for varietal improvement research. The current research was conducted to optimize the callus induction, shoot and root regeneration of three indica rice varieties. Place, Duration and Design of Study: The experiment was conducted in the tissue culture and biotechnology laboratory of the department of Genetics and Plant Breeding of Bangladesh Agricultural University using completely randomized experimental design. Methodology: Dehusked mature seeds of three indica rice varieties namely, BRRI dhan28, BRRI dhan29 and BINA dhan6 were cultured In vitro in MS medium supplemented with different concentrations and combinations of phytohormones. Results: The callus induction ranged from 14 - 84% which showed a general increasing trend with the increase in the concentration of 2,4-Dichlorophenoxyacetic acid (2,4-D) starting from 1.0 mg L-1 till 2.5 mg L-1. A further increase in the concentration of 2,4-D to 2.5 mg L-1, however, decreased the percentage of callus induction in all three varieties. MS medium supplemented with 2.5 mg L-1 2,4-D and 0.5 mg L-1 6-Benzylaminopurine (BAP) was better than any other composition for callus induction. For size of callus and nature of callus, however, MS medium supplemented with 2.0 mg L-1 2,4-D and 0.5 mg L-1 BAP was found to perfume best. The highest percentage of callus induction was observed in the variety BRRI dhan29 (84%) followed by BRRI dhan28 (74%). Almost all the varieties produced yellowish and compact calli except BINA dhan6 which produced creamy and friable calli. The desiccation treatment has shown to increase size but decrease the compactness of the callus. The differences are, however, not statistically significant. MS medium supplemented with 0.6 mg L-1 1-Naphthaleneacetic acid (NAA) and 6 mg L-1 Kinetin (Kn) showed highest shoot regeneration in BRRI dhan29 (85%) followed by BRRI dhan28 (60%). Higher frequency of root formation was observed in all three varieties using Indole-3-butyric acid (IBA). The survival rate of the plantlet in acclimatization chamber (96%) and in field condition (93.33%) was higher for BRRI dhan29. BINA dhan6 has shown the least regeneration potentiality for all the aforementioned traits. Conclusion: Of the three varieties, BRRI dhan29 and BRRI dhan28 has shown higher regeneration potentiality. This optimized protocol will thus be useful in genetic improvement of these varieties using biotechnological manipulations.
RESUMEN
Objective: To discuss the influence of several factors on the cryopreservation of embryogenic calli induced from Dioscorea bulbifera microtuber by droplet-vitrification and to test the genetic stability of the regenerated plantlets after freezing from the aspects of morphology, physiology, DNA content, as well as the photosynthetic characteristics and chlorophyll fluorescence parameters in this paper. Methods: Plant tissue culture (including microtuber induction and embryogenic callus induction), plant physiology index detection (including total chlorophyll, soluble protein, soluble sugar and superoxide dismutase enzyme and peroxide enzyme activity), and cell flow cytometry were applied. Results: The best cryopreservation conditions of embryogenic callus of D. bulbifera microtuber were as following: Embryogenic calli were precultured in liquid media of MS+KT 2 mg/L+NAA 0.5 mg/L+2, 4-D 0.5 mg/L+0.3 mol/L sucrose for 1 d and then treated in loading liquid (MS+2 mol/L glycerol+0.4 mol/L sucrose, pH 5.8) for 20 min. In order to dehydrate, embryogenic calli were transferred in 100% PVS2 at 0℃ for 40 min. After dehydration, the embryogenic calli were inoculated to PVS2 small drops in the aluminum foil strips and then dipped in liquid nitrogen (LN). Finally the aluminum foil strips were quickly transferred to freezing tube that filled with LN and then put into LN tank. After conserving for 1 d in LN, the aluminum foil strips were removed and the embryogenic calli were immersed into liquid washing media (MS+KT 2 mg/L+NAA 0.5 mg/L+2, 4-D 0.5 mg/L+1.2 mol/L sucrose, pH 5.8) preheated in 37℃ warm water. After separated from the aluminum foil strips, the embryogenic calli were washed with fresh liquid washing media at room temperature for there times, 10 min each time. After washing, the embryogenic calli were transferred onto differentiation medium (MS+KT 2 mg/L+NAA 0.5 mg/L+30 g/L sucrose+5 g/L agar), and cultured in dark for 2 d and then cultured in 12 h/d photoperiod, the cell survival rate reaches above 89%. The morphological and physiological indexes and the content of DNA of two kinds of plantlets, which regenerated from cryopreserved and non-cryopreserved embryogenic calli induced from D. bulbifera microtuber by droplet-vitrification, showed no significant difference (P>0.05). Conclusion: Cryopreservation technology system of embryogenic calli induced from D. bulbifera microtuber by droplet-vitrification is established and the regeneration plants have no genetic variation, which provides the theoretical basis and technical basis for the long-term preservation of germplasm resources in the plants of Dioscorea L.
RESUMEN
The goal of this study was to evaluate the effect of desiccation and chilling treatments on somatic embryogenesis of rough lemon (Citrus jambhiri Lush.). Styles were cultured on seven culture media (MS I-MS VII) containing Benzylaminopurine (BAP), Kinetin (KN) and Malt Extract for cell proliferation and somatic embryo development. Cell proliferation was maximum on MS IV media but maximum cultures showing somatic embryogenesis (52.08 %) was observed on MS VII media. Embryogenic callus proliferated on MS VII media was subjected to desiccation and chilling treatment for 24, 48, 72 and 96 hours. Embryogenic callus desiccated for 24 and 48 hours in sterile petriplates showed 58.33 and 56.94 % somatic embryogenesis respectively as compared to undesiccated callus (51.98%). Average number of cotyledonary embryos (6.80/culture) in embryogenic cultures from desiccated callus (48 hrs) was more as compared to untreated callus (2.26/culture). There was significantly less number of abnormal embryos (0.60-0.53/culture) in desiccated callus for 48, 72 and 96 hours as compared to untreated callus (7.20/culture). Chilling treatment also improves the average number of cotyledonary embryos and reduces the abnormal development of embryos. Among all the treatments desiccation of embryogenic callus for 48 hrs proved beneficial for improvement of somatic embryo development and germination.
RESUMEN
Mother axis of the infected suppressed ear-head of pearl-millet with embryoids was sliced (2-3 mm) and surface sterilized with 0.2 % Ethyl mercuric chloride followed by repeated washings with sterile antioxidant solution (50 mg/L citric acid, 25 mg/L ascorbic acid and 50 mg/L P.V.P). Sterilized slices were cultured on modified MS medium supplemented with 10 mg/L IAA, 0.5 mg/L Kinetin, 2.5 mg/L 2,4-D, 3.0 mg/L casein hydrolysate, 25 mg /L ascorbic acid and 150 mg/L coconut water. Two types of calli were formed after 10-15 days. Slow growing compact milky coloured was embryogenic and the other hyaline fast-growing was non-embryogenic. The fungus grew on the callus after 20-25 days of inoculation. It grew axenically on the surface of the medium after sometime. Slow growing embryogenic callus was subcultured to auxin free ¾ strength MS medium with 25 mg/L ascorbic acid, 100 ml/L coconut water and 0.5 mg/L Kinetin. Regeneration plantlets were transferred for rooting on ½ strength MS medium containing 1.5 mg/L IBA and 25 mg/L ascorbic acid. The regenerated plantlets with strong root system were transferred to 4 earthen pots. The plantlets raised were subjected for disease resistance by growing them on the medium containing different concentrations of the fungus filtrate. The plantlets showing resistance have been accepted as diseases resistant.
RESUMEN
El trabajo se realizó con el objetivo de obtener brotes in vitro vía organogénesis directa en sorgo variedad CIAP 2E-95, para la formación de callos con estructuras embriogénicas. Se tomaron semillas maduras de plantas que crecían en condiciones controladas, las que se desinfectaron y fueron colocadas a germinación en un medio de cultivo con las sales MS, mioinositol 100 mg L-1, sacarosa 3%, pH 5,7, Fitagel 2,5 g L-1. Para la multiplicación de los brotes, se estudiaron diferentes concentraciones de 6 Bencilaminopurina (6-BAP) y kinetina. El empleo en el medio de cultivo de multiplicación con las sales MS y 6- BAP 0,22 mg L-1, incrementó el número de brotes por explante y se observó la presencia de oxidación fenólica. La oxidación fenólica se contrarrestó con la adición al medio de cultivo de 50 mg L-1 de ácido ascórbico y se incrementó significativamente el número de brotes, altura y número de hojas. En la obtención de brotes in vitro de calidad para la formación de callos, estos fueron engrosados con las sales MS, sin reguladores de crecimiento, ácido ascórbico 50 mg L-1, Fitagel 2,5 g L-1, pH 5,7 y 40 g L-1 de sacarosa. La formación de callos con estructuras embriogénicas a partir del cilindro central de las hojas enrolladas del segmento más próximo a la base de los brotes engrosados se alcanzó a los 45 días de cultivo. Los segmentos del cilindro central de las hojas enrolladas constituyen una fuente segura y promisoria de explantes para la formación de callos embriogénicos.
The current work aimed to obtain in vitro shoots by direct organogenesis from sorghum variety CIAP 2E-95, for the formation of calluses with embryogenic structures. Mature seeds were collected from plants grown under controlled conditions, which were disinfected and were placed in a germination medium with MS salts, myo-inositol 100 mg L-1, 3% sucrose, pH 5.7, phytagel 2.5 g L-1. Different concentrations of 6-benzylaminopurine (6-BAP) and kinetin were studied for shoot multiplication. Using 6 - BAP 0.22 mg L-1 in the multiplication culture medium increased the number of shoots per explant, showing phenolic oxidation. Adding 50 mg L-1 of ascorbic acid to the culture medium resisted phenolic oxidation and the number of sprouts (5.0), height and number of leaves increased significantly. Quality in vitro buds for callus formation were obtained stimulating the thickening by using MS salts, without growth regulators, ascorbic acid 50 mg L-1, phytagel 2.5 g L-1 and pH 5.7 and 40 g L-1 of sucrose. The largest diameter of shoots, height, number of leaves and roots of in vitro plants, was achieved after 21 days of cultured in MS salts with 40 g L-1 sucrose. Calluses formation with embryogenic structures from the central cylinder of curled leaves of the nearest segment to the base of thickened shoots was achieved after 45 days of culture. Segments from the central cylinder of the curled leaves are a safe source for the formation of embryogenic calli.
Asunto(s)
Ácido Ascórbico , Plantas , Sorghum , Sacarosa , Reguladores del Crecimiento de las Plantas , QuininaRESUMEN
La embriogénesis somática representa una herramienta esencial en el mejoramiento genético y en la micropropagación clonal masiva de bananos mejorados. En el presente trabajo se analizaron los patrones morfológicos y anatómicos que ocurren durante la embriogénesis somática del banano Williams, dirigidos a conocer y mejorar este proceso. En la investigación se establecieron suspensiones celulares embriogénicas (SCE) a partir de callo embriogénico obtenido de manos florales inmaduras masculinas, las cuales originaron abundantes embriones que regeneraron plantas. Hacia los tres meses de cultivo se detectaron embriones somáticos (ES) primarios color blanco-crema en las manos florales de los nudos nueve a doce, contados a partir del ápice floral. Al cuarto mes estos ES primarios dieron origen al callo embriogénico, de color blanco crema, estructura granular, con abundantes ES torpedo en su periferia y con una organización celular en tres diferentes zonas. De este callo se cultivaron porciones pequeñas con ES torpedo en medio de multiplicación durante dos meses, dando origen a la SCE I. La misma se tamizó (250 µm) para establecer la SCE II. El sedimento de células y los agregados celulares embriogénicos de ambas SCE se trasladó a medio de maduración. Transcurridos dos meses los embriones maduros se transfirieron a medio de conversión de embriones, lográndose regenerar plantas completas a partir de las dos semanas. Las SCE produjeron numerosos embriones somáticos maduros y mostraron una buena conversión de embriones a plantas y regeneración de plantas. Este sistema de embriogénesis somática permitió la obtención de plantas funcionales en nueve meses.
Somatic embryogenesis represents an essential tool for the genetic improvement and for the mass clonal micropropagation of the improved banana plant. In this present work morphological and anatomical patterns were analyzed in the somatic embryogenesis of Williams banana, to know and enhance this process. In the investigation embryogenic cell suspensions (ECS) were established from embryogenic callus obtained from floral immature male hands, which gave rise to many somatic embryos that regenerated plants. Towards the three months of culture white-cream primary somatic embryos (SE) were detected in the floral hands of the nodes nine to twelve, counted from the floral apex. At the fourth month this primary SE gave origin to a creamy-white embryogenic callus, with granular structure and abundant SE torpedo on its periphery. Cell organization with three different zones was observed in callus. Small portions of this callus were cultivated in the multiplication medium for two months, to originate ECS I. This ECS was filtered through a mesh (250 µm pore size) to establish the ECS II. The sediment of embryogenic cells and cell clusters of the ECS were moved to maturation media. After two months the mature embryos were transferred to conversion medium, and two weeks later, whole plants were developed. The ECS produced numerous mature SE, which showed good conversion of embryos into plants and plant regeneration. This system of somatic embryogenesis permitted the mass production of functional plants in nine months.
Asunto(s)
Creación de Embriones para Investigación/métodos , Cultivo Primario de Células/métodos , Investigaciones con Embriones , Mejoramiento Genético/métodos , Técnicas de Cultivo de Embriones/instrumentación , Técnicas de Cultivo de Embriones/métodos , Producción de Cultivos , Desarrollo Embrionario , Medios de Cultivo/análisisRESUMEN
Objective To evaluate the influences of the genotypes,anther developmental stages,and cultural conditions on the efficiency of embryogenic callus induction and plant regeneration in the anthers culture of Bupleurum chinense.Methods The different effects such as four genotypes,plant growth regulators,and temperature condition were compared in the experiments.The histological study was performed with the process of the anther culture.Results The highest inducing rate of embryogenic calli were achieved for the genotypes Zhongcaiyihao(ZCYH),Z4,and Z5 at the early-to middle-uninucleate stages,except for genotype ZPM1 at the tetrad stage.Cold pretreatment increased the production of the embryogenic callus,in which 4-day cold pretreatment improved the production of embryogenic callus from 0% to 2.2% and 5.0% for genotypes ZPM1 and ZCYH,respectively.No embryogenic callus was induced in the medium containing less than 0.75 mg/L 2,4-dichlorophenoxyacetic acid(2,4-D).The highest regeneration rate (34.6%)was obtained in 1/2 MS salts regeneration medium supplemented with 0.1 mg/L 6-benzylmaminopurine (BA).The low concentration of BA was able to promote the embryogenic callus formation and subsequent plantlet regeneration via somatic embryogenesis.Chromosome counting of regenerated plantlets showed mostly diploid plant (2n = 12)with only one haploid plant(n = 6).Because of the low rate of microspore embryo formation,we only tracked the process of embryogenesis from the connective tissue,instead of microspore by histological observations.Conclusion This study establishes an efficient system for embryogenic callus induction and plant regeneration system.This is the first report on the haploid plantlet through the anther culture orB.chinense.
RESUMEN
The major progress on the study of etiology of the Hirschsprung's disease is the genetic factots and the aherations of microenvironment in primarily embryogenic period.The genetic factors comprise of RETGDNF system.EDNRB.EDN3 system,and many other genes involving in the formulation of the tormer two svstems.such as SOX10,NRG-1, FoxD3,PHOX2B,HOXB5,ZFHXIB,all of which file essencial for the migration and differentiation of neural crest cells(NCC).The alterations of microenvironment in primarily embryogenic period include interstitial ceLls of cajal(ICC),cell adhesion molecules(CAMLl),Ca2+ and so on.Definitely,CAML1 plays as the basis of NCC's migration and differentiation,and the decline of the Ca2+dependent channel's expression brings about the anolnaloug contraction of smooth muscle.
RESUMEN
Objective Using stem tip of Gymnadenia conopsea in this experiment to investigate somatic embryogenesis and plant regeneration in vitro.Methods Uniform dedign for the most suitable media for embryogenic callus induction and embryogenic cell complex,development of somatic embryo and plant regeneration were screened.Results The results showed that Chaturvedi and Mitra(CM)+6-BA 1.0 mg/L+IAA 2.0 mg/L+2,4-D 0.1 mg/L was fit for embryogenic callus and embryogenic cell complex induction.Percentage was 98%;The medium of development of somatic embryo and plant regeneration was CM+6-BA 1.00 mg/L+IAA 0.10 mg/L.Percentage was 100% and converted into plantlets with shoots and roots after 50 d culture on the same medium.Conclusion The observation of morphostructure and ultrastructure proves the process of somatic embryogenesis of G.conopsea.