首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
In vitro symbiotic seed germination is an important tool not only for the study of orchid-fungus specificity but also for the production of mycobiont-infected healthy seedlings that could be valuable for both horticultural and conservation purposes. The current study compared effectiveness of eight putative orchid mycorrhizal fungi obtained from mature orchids in the genera Paphiopedilum, Cymbidium and Dendrobium, in promoting in vitro seed germination and protocorm development of Grammatophyllum speciosum Blume and Dendrobium draconis Rchb. f., native Thai orchids. The developmental stages of seeds and protocorms cultured on Murashige and Skoog (MS) medium, oat meal agar (OMA), or OMA inoculated with one of the eight fungal isolates were evaluated weekly. Two isolates of Epulorhiza repens (Bernard) Moore (=anamorphic species of Tulasnella calospora (Boud.) Juel), Da-KP-0-1 and Pv-PC-1-1, were found to be the most effective fungi in promoting protocorm development of G. speciosum. At week 13, protocorms co-cultured with either one of these two fungal isolates, on the average, were significantly more advanced than those sown on OMA. Protocorms co-cultured with isolate Pv-PC-1-1 were also significantly more advanced than those cultured on MS medium. For D. draconis seed germination, three fungal isolates of different anamorphic species of Tulasnella, C1-DT-TC-1, Pv-PC-1-1, and C3-DT-TC-2, were found to be the most effective fungi in promoting protocorm development. However, none of these fungal isolates outperformed MS medium. Additionally, the compatibility between the fungal isolates tested and the two orchid species was discussed.  相似文献   

2.
The effects of different types of chitosan on seed germination and protocorm development were determined for two orchid species, Dendrobium bigibbum var. compactum and Dendrobium formosum. Six chitosan types derived from polymer or oligomer chitosan each with 70, 80 or 90% levels of deacetylation (P70, P80, P90, O70, O80 and O90, respectively), were evaluated as direct medium supplements at 0, 10, 20, 40 or 80 mg/L in modified VW medium by following seed germination and protocorm growth for 12 weeks. Chitosan of all six tested types and four concentrations were found to significantly enhance the proportion of D. formosum seeds that germinated, when compared to these germinated without chitosan. In contrast, chitosan caused no enhanced germination rate was noted for D. bigibbum var. compactum with all tested chitosans and doses tested. However, almost all types of chitosan at 10 mg/L, except O90, were able to significantly improve the growth of D. bigibbum var. compactum protocorms, whilst 10 or 20 mg/L of P70 chitosan was the best formula to enhance the growth of D. formosum protocorms. It is concluded that chitosan responses in seed germination and protocorm development were somewhat species and developmental stage dependent. Therefore, the appropriate chitosan application for each plant species should be evaluated first before use.  相似文献   

3.
The appropriate chitosan types and concentrations for enhancing the in vitro micropropagation of Dendrobium ‘Eiskul’ were studied using 70, 80 and 90% N-deacetylated polymeric (P-70, P-80 and P-90) and oligomeric (O-70, O-80 and O-90) forms of crab (Portunus pelagicus) chitosan. For the initial protocorm-like body (PLB) multiplication, the application of 10 mg/L of P-70 or 20 mg/L of P-90 was optimal, although 10 mg/L of P-80 and O-70 were also effective, and attained maximal PLB replication rates without increasing the detectable levels of somaclonal variation. However, during PLB-shoot induction, 10 or 20 mg/L of O-80 was the most appropriate chitosan and also induced further PLB formation. For plantlet regeneration, the addition of 10 mg/L of O-80 or P-80 gave the best quantity and quality, respectively, of plantlets. Finally, 20 mg/L of P-70 chitosan as a supplement during exflasking enhanced both the survival rate and the growth of the plantlets at one month after exflasking. Together, these data reveal a potentially beneficial and applicable protocol for commercial orchid micropropagation.  相似文献   

4.
Goldenseal (Hydrastis canadensis L.) is an endangered medicinal plant used to treat sore eyes and mouths, cold and flu and also as a dye. The objective of this study was to develop an efficient in vitro propagation protocol for goldenseal. Significantly more shoots (26 shoots per leaf explants) were induced on a medium containing 2.5 μM thidiazuron (TDZ) and 5.0 μM 1-naphthaleneacetic acid (NAA) than any other treatment. Sub-culturing regenerated shoots on a medium with 5.0 μM 6-benzylaminopurine (BA) induced the maximum rate of shoot multiplication. Growth of the regenerated shoots in a temporary immersion bioreactor resulted in significant increases in biomass, shoot height and shoot multiplication. The regenerated shoots from the temporary immersion bioreactor formed roots when transferred onto a medium with 1.0–2.0 μM indole-3-butyric acid (IBA). Regenerated whole plantlets were acclimatized and maintained in standard greenhouse conditions for further growth. The regeneration protocol developed in this study provides a basis for germplasm conservation and for further investigation of this rare, medicinally important species.  相似文献   

5.
Efficient protocols were established for in vitro seed germination, neo-formation of secondary (2°) protocorms from primary (1°) protocorms and multiple shoot buds and protocorm-like body (PLB) induction from pseudo-stem segments of in vitro-raised seedlings of Cymbidium giganteum. Four nutrient media, namely Murashige and Skoog (MS), Phytamax (PM), Mitra et al. (M), and Knudson ‘C’ (KC) were evaluated for seed germination and early protocorm development. In addition, the effects of peptone, activated charcoal (AC) and two plant growth regulators [6-benzylaminopurine (BAP) and 2,4-dichlorophenoxyacetic acid (2,4-D)] were also studied. Both M and PM supplemented with 2.0 g l−1 peptone or 1.0 mg l−1 BAP resulted in ∼100% seed germination. Media supplemented with 2.0 g l−1 AC could effectively induce large protocorms (1.6 ± 0.1 mm in diameter). Neo-formation of 2° protocorms from 1° protocorms was achieved in liquid and agar-solidified PM medium fortified with different concentrations and combinations of auxins (α-naphthalene acetic acid (NAA) and 2,4-D) and cytokinins [BAP and kinetin (KN)]. The highest number of 2° protocorms was obtained in liquid medium (10.7 ± 0.9/1° protocorm) supplemented with 2.0 mg l−1 BAP + 1.0 mg l−1 NAA. Although protocorms proliferated profusely in liquid medium, these did not develop further unless transferred to agar-solidified medium within 6–8 weeks. Multiple shoot buds and PLBs were induced from pseudo-stem segments on agar-solidified PM medium fortified with different concentrations and combinations of BAP and NAA and the maximum number of PLBs (6.00 ± 0.20) was recorded when BAP and NAA were applied at 2.0 mg l−1 each. A solid root system was induced from PLBs and shoot buds when these were transferred to half-strength PM or M media fortified with 0.5 mg l−1 indole-3-acetic acid. Well-rooted plants were transferred to the greenhouse with 95% survival.  相似文献   

6.
This study was conducted to determine the effects of coconut water (CW) and activated charcoal (AC) on multiplication of Phalaenopsis gigantea protocorms. The protocorms used for this study were obtained by germinating seeds in vitro. Protocorms with trimmed and untrimmed bases were cultured on XER basal medium containing 0, 10, 15 or 20% (v/v) CW; and 0, 1, 2 or 2.5 g AC l−1. Trimmed protocorms exhibited the highest percentage of proliferation on a medium containing 15% (v/v) CW and 2.5 g AC l−1 (56.82 ± 38.86%) with an average of 4.24 ± 2.89 protocorms formed per protocorm. Untrimmed protocorms cultured on a medium containing 20% (v/v) CW without AC produced the highest percentage of new protocorms (6.93 ± 6.28%) with an average of 0.72 ± 0.57 per protocorm. When CW was added to a medium singly, 10% (v/v) CW induced a higher degree of proliferation on trimmed protocorms (5.68 ± 10.14%) with an average 0.50 ± 0.84 new protocorms per protocorm. Untrimmed protocorms proliferate to a much lower extent (2.57 ± 2.74%) with an average of 0.72 ± 0.57 protocorms per protocorm when cultured on a similar medium. A high concentration of CW enhanced proliferation on untrimmed protocorms, but increased mortality of trimmed protocorms. The addition of CW with AC to media increased protocorm proliferation and survival of both trimmed and untrimmed protocorms. When cultured on all media, trimmed protocorms produced a higher number of new protocorms (an average 0.5–7.0) as compared to untrimmed protocorms (0.3–1.9). Comparative studies showed that trimmed protocorms produced up to 10 times more new protocorms than untrimmed ones. Altogether this study showed that trimmed protocorms cultured on a medium containing CW and AC can be used for high-frequency multiplication of P. gigantea seedlings.  相似文献   

7.
An in vitro plant regeneration protocol was successfully established in Satyrium nepalense, a terrestrial orchid by culturing immature seeds from unripe fruits. Seeds were germinated on Murashige and Skoog, Knudson C and Knudson C modified Morel medium. The germination of the seeds and development of protocorm was highest in MS medium (86.7%) followed by Knudson C modified Morel medium (74%) and Knudson C medium (61.2%). Among the cytokinins tried for multiple shoot induction from the protocorm, 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ) was found to be superior. Indole-3-butyric acid (IBA) was effective for inducing healthy roots. Well-developed plantlets were hardened in vermicompost (leaf litter + cow dung 1:1), sand and coconut husk (1:1:1).  相似文献   

8.
Lanzhou lily (Lilium davidii var. unicolor) is one of the best lilies which are edible in China but the efficient shoot regeneration system has not been developed. The purpose of the present study is to establish an efficient and reproducible protocol for induction of shoots in vitro from L. davidii var. unicolor leaves. Shoot regeneration from in vitro cultured leaves of L. davidii var. unicolor was tested on the 26 media based on NN [Nitsch, J.P., Nitsch, C., 1969. Haploid plants from pollen grains. Science 163, 85–87] basal medium, containing different concentrations of thidiazuron (TDZ) in combination with different concentrations of α-naphthaleneacetic acid (NAA). Shoot organogenesis occurred directly from the leaves without forming callus. Shoot regeneration mainly occurred from the cuts across the midvein and the base of the leaf explants. The highest frequency of regeneration (93.3%) and the largest number of shoots per leaf (3.83) were obtained on NN basal medium supplemented with 0.5 mg l−1 TDZ and 1.0 mg l−1 NAA. All the regenerated shoots formed complete plantlets on half-strength MS [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant 15, 473–497] basal medium containing 0.1–0.5 mg l−1 indole-3-butyric acid (IBA) with in 30 days, and 92% of the regenerated plantlets survived in the soil. This study will be useful for Agrobacterium-mediated transformation and exploitation of somaclonal variation of Lanzhou lily.  相似文献   

9.
A protocol for clonal propagation of Rosa clinophylla, a rare and endangered species but very important for breeding purposes had been standardized through in vitro axillary bud culture. Although cytokinins alone were able to induce shoot buds, but their proper growth and number could be increased only when they were used in combination with GA3. However, there was shoot tip necrosis and leaf fall in the proliferated shoots. AgNO3 at 58.85 μM proved effective to avoid shoot necrosis and yellowing of leaves. Activated charcoal (AC) at 250 mg l−1 was found necessary at all the stages of shoot multiplication as well as rooting. Ninety percent rooting could be achieved in 1/2 MS medium supplemented with 4.92 μM IBA and 250 mg l−1 AC. Rooted plantlets were hardened and transferred to the field successfully with 80% survival rate.  相似文献   

10.
The aim of this work was to study the effect of solid medium, developmental stage, embryonic age, cold treatment and additives to the medium on plant regeneration from microspore-derived embryos in four F1 hybrids of ornamental kale (Brassica oleracea L. var. acephala). The results showed that all of the cultivars responded best when the embryos were cultured in solidified B5 medium with 1% agar. Optimal regeneration was gained when cotyledonary embryos were cultured for 25 days. Cold treatment significantly improved plant regeneration with a frequency of up to 79.0% under 4 °C for 2 d or 5 d. The addition of 3.0 or 5.0 mg/L silver nitrate (AgNO3) increased the frequency of plant regeneration. In the Zhouyehongxin cultivar, the frequency of plantlet development reached 84.4%. The addition of activated charcoal reduced embryo hyperhydricity.  相似文献   

11.
In vitro seeds germination and plantlet establishment of Labisia pumila were studied in this report. The seeds obtained from the mature fruits of L. pumila were sterilized and cultured on Murashige and Skoog (MS) solid media supplemented with 1–3 μM of 6-benzylaminopurine (BAP) and 3% (w/v) sucrose. The presence of BAP in the medium significantly affects seeds germination. High percentage of seeds germination (up to 90%) was successfully achieved after 2 weeks of culture on medium supplemented with 2 μM BAP. Up to 70% of explants produced shoots through direct regeneration from newly emerged epicotyls after 5 weeks of culture. The average of 8.1 ± 1.0 shoots per explant obtained on media treated with 2 μM BAP. Seedlings were further transferred to growth media fortified with different types of cytokinin. Result observed after 12 weeks showed that medium supplemented with 1 μM zeatin (ZEA) promote the highest growth with an average of 2.9 ± 1.0 cm shoot length and 7.7 ± 3.2 leaves per explant after 12 weeks. In addition, medium added with 2 μM BAP and supplemented with 3–4% (w/v) of sucrose promote the best growth i.e., 3.0 ± 0.6 shoots per explant, 2.27 ± 0.2 cm length and 4.3 ± 0.5 leaves per explant.  相似文献   

12.
A novel micropropagation protocol was established for Capsicum frutescens L. cv. ‘Uchithi’, a pungent chilli cultivar, through induction of axillary shoot proliferation of in vitro raised plantlets by decapitation and using the axillary shoots as explants for multiple shoot bud induction. About 2–6 axillary shoots were induced within 2 weeks when 4-week-old in vitro raised plantlets were decapitated. The axillary shoot-tip explants produced multiple shoot buds when cultured on Murashige and Skoog's (MS) medium containing 8.8–44.4 μM 6-benzylaminopurine (BAP) or 9.3–46.7 μM kinetin alone or 8.8–44.4 μM BAP with 4.6 μM kinetin or 5.7 and 28.5 μM indole-3-acetic acid (IAA). Maximum number of shoots (5.6) were induced on medium containing 22.2 μM BAP in combination with 4.65 μM kinetin. The separated shoots rooted and elongated on medium containing 2.8 μM IAA or 2.4–4.9 μM indole-3-butyric acid (IBA). Rooted plantlets were successfully established in the soil. Efficient mass multiplication of this important food crop was achieved.  相似文献   

13.
An effective protocol was developed for in vitro regeneration of Psoralea corylifolia through enriched cotton moistened-liquid (CML) and solid culture systems. Prolific adventitious shoot buds were achieved from hypocotyl explants of 2-week-old cultures on enriched CML Phillips and Collins (L2) medium supplemented with different concentrations and combinations of thidiazuron (TDZ), benzyladenine (BA), kinetin (KIN), naphthalene acetic acid (NAA), indole-3-acetic acid (IAA) and bavistin (BVN). Combination of 2 μM TDZ, 0.5 μM BA, 100 mg l−1 BVN and 2 μM NAA produced a greater number of adventitious shoots per explant (93.5) when transferred to half-strength enriched solid L2 medium. Regenerated shoots (40–50 mm in length) were exposed simultaneously for rooting as well as hardening in moistened (1/8-L2 basal salt solution with 5 μM IBA and 100 mg l−1 BVN) soil mixture and vermiculite (3:1, v/v). The plants were subsequently established in the field. The survival percentage differed with seasonal variations.  相似文献   

14.
The effects of sodium hypochlorite treatment and growth medium on in vitro seed germination and seedling growth of the leopard orchid (Ansellia africana Lindl.) were investigated. Forty minutes treatment of seeds with 1.75% sodium hypochlorite stimulated germination (70.6%) and seedling development when measured at Stage 5 (emergence of first leaf) on P668 medium after 8 weeks of culture. The growth medium played a significant role in determining the germination response of A. africana seeds. Dark pretreatment of seed cultures significantly enhanced the germination percentage and the growth of rhizoids on the protocorms. Leaf growth in terms of length was substantially enhanced on P668 medium. It was significantly reduced in modified Knudson C medium after 16 weeks of culture. Seedlings developed on P668 medium showed a significantly better growth performance in relation to leaf length, leaf number, root length, fresh and dry weights per plant in vermiculite after 12 weeks of ex vitro growth in a mist house with 90% relative humidity. Further studies developing a suitable method for in vitro symbiotic germination could assist in reintroduction of this threatened orchid species into the wild.  相似文献   

15.
Effects of banana extract (BE) and 6-benzylaminopurine (BAP) were evaluated on asymbiotic seed germination and an early differentiation of protocorms and plant regeneration of Dendrobium lituiflorum Lindl. High percentage germination was achieved by culturing seeds on modified Knudson C medium supplemented with 10% (v/v) BE. Rapid regeneration was observed within 60 days of culture on 10% (v/v) BE supplemented KC medium where maximum percentage propagules showed development of leaves and root formation. Propagules on BAP supplemented KC medium showed no further development beyond one leaf stage. In another experiment, culture of shoots on 12.5% (v/v) BE supplemented KC medium led to multiplication, shoot elongation as well as vigorous rooting. Shoots cultured on 10 μM BAP supplemented MS medium showed maximum multiplication but these were stunted. Plants with well expanded deep green leaves and elongated roots from BE media were first hardened in vitro followed by ex vitro hardening on cocopeat:perlite (9:1) in the greenhouse conditions and exhibited 90% survival. The study emphasizes the role of BE as a natural additive at different stages of development from seed germination to plant regeneration.  相似文献   

16.
In vitro propagation of Epimedium alpinum L. was carried out using immature seed explants. The effects of various concentrations of thidiazuron (TDZ) and 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU), on the induction of organogenic callus, were evaluated. Organogenesis occurred most efficiently when explants were transiently exposed (48 h) to 20 μM CPPU or 80 μM TDZ followed by culture on hormone-free woody-plant medium (WPM). Organogenic callus consisting of white, compact clumps of tissue proliferated slowly on hormone-free WPM. To promote adventitious shoot induction, the effects of different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA) were investigated. The highest per cent shoot regeneration, 66.7% of explants, and the maximum mean number of shoots, 2.6 per explant, were obtained on WPM containing 1.1 μM 2,4-D and 22 μM BA. Shoots were rooted on hormone-free WPM and well-developed plantlets were successfully transferred to soil.  相似文献   

17.
Vriesea reitzii Leme & Costa is an endemic bromeliad from the Atlantic Forest in South Brazil. The devastation of this biome threatens the extinction of this species that besides its role in the ecosystem has an ornamental value. Tissue culture techniques are important tools for the mass propagation of threatened bromeliad species. In the present work we established an in vitro regenerative protocol for the large-scale propagation, and improvement of this species. Young basal leaves used as explants showed 90.6% induction rate of nodule clusters in MS culture medium supplemented with 20.0 μM 2,4-D and 1.0 μM Kin. The subculture of these nodule clusters to MS medium with BAP, Kin and 2-iP resulted in a regeneration rate of 60 shoots/g nodule clusters. Subsequent subculture to MS media supplemented with 2.5 μM 2-iP and 0.5 μM NAA and then to MS medium free of PGR enhanced the full development of plantlets. Plantlets longer than 3 cm were successfully acclimatized showing a survival rate of 90%.  相似文献   

18.
An efficient plant regeneration protocol via somatic embyogenesis by leaf base culture of in vitro grown Iris pumila shoots was developed. Induction of embryogenic calli was achieved on MS media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin (4.5 μM, each) and some additives (L-proline, casein hydrolysate, adenine sulphate and tyrosine). Further differentiation of embryogenic calli was achieved on MS hormone-free media, and on media supplemented with either BAP (4.5 μM) or BAP + zeatin (4.5 and 0.2 μM, respectively), which allowed somatic embryos, as well as shoot-like structures to form. Fully developed somatic embryos germinated on an MS hormone-free medium. An anatomical study confirmed that shoot-like structures represented early germinating stages of somatic embryos. Acclimatization of plants derived from somatic embryos was 64% after 1 year and no morphological variation was observed.  相似文献   

19.
The genus Ptilotus has immense potential for ornamental horticulture but its commercial development has been hindered by propagation limitations. Poor seed quality and germination are reported. Cutting propagation is limited by cutting supply as the juvenile phase of Ptilotus is short. Micropropagation has been used in an attempt to overcome these difficulties but explants become floral in vitro and this causes plantlets to elongate. Ethephon has been used to control flowering of stock plants of many ornamental species. This study investigated the effect of ethephon applied to young (3-week-old, deflasked from tissue culture) and mature (1-year-old) Ptilotus plants in a greenhouse. A system of applying gaseous ethylene at 0, 100, 200 and 300 mg l−1 to the headspace of in vitro plantlets in glass jars was developed and the response of in vitro plantlets to ethylene studied. One-year-old Ptilotus plants were treated with 500 mg l−1 ethephon 2 days before pruning or 1 or 2 weeks after pruning. Ethephon application 2 days before pruning decreased the number of inflorescences and increased the number of shoots (compared to the control) but was phytotoxic. Ethephon applications of 150 or 300 mg l−1 applied weekly or fortnightly to 3-week-old plants deflasked from tissue culture reduced plant height and number of inflorescences and at low concentrations increased the number of new shoots. A fortnightly application at 150 mg l−1 is recommended. Previous reports on the effects of ethylene on inflorescence production on plantlets in vitro are limited. Our study showed that exposure of in vitro plantlets of P. nobilis to ethylene gas at 100 mg l−1 for 1 h significantly increased the number of shoots and plant height but this did not occur for plantlets of P. spicatus. Plantlets of P. spicatus exposed to transient ethylene at 200 and 300 mg l−1 showed significantly greater rooting (52.4%) than the control (13.6%).  相似文献   

20.
Protocols are outlined for the regeneration of Curcuma soloensis, an attractive tropical ornamental plant, from young vegetative bud explants. We used both direct and callus-mediated regeneration techniques to produce material suitable for mass propagation and the development of transgenic plants. During direct plantlet propagation, the presence of thidiazuron (TDZ) in the growing medium induced more than three times as many shoots as 6-benzylaminopurine (BA), with a mean of 18.7 shoots per explant on MS medium containing 2.5 μM TDZ compared to 5.0 shoots with 40 μM BA. Subsequently, the shoots rooted readily on MS basal medium that was free of plant growth regulators. During indirect plantlet regeneration, TDZ combined with BA and 2,4-dichlorophenoxyacetic acid (2,4-D) had significant effects on embryogenic callus induction and multiplication. The frequency of callus formation was 91.1% for explants cultured on MS basal medium supplemented with 2.5 μM TDZ, 2.0 μM BA and 1.2 μM 2,4-D. On average 7.1 shoots were produced per callus mass cultured on MS medium supplemented with 2.5 μM TDZ, 9.0 μM BA and 1.2 μM naphthaleneacetic acid (NAA). Regenerated shoots were transferred to MS medium supplemented with 2.5 μM TDZ, to produce multiple shoots. In vitro cultured plantlets readily acclimatized to greenhouse conditions, showing 100% survival rates in a sphagnum, perlite and sand (1:1:1) medium. These plants were transplanted into pots or planted in the field. The ex vitro acclimated plants grew vigorously and produced showy inflorescences 5–6 months after planting. The high-frequency of shoot multiplication and rapid flowering of tissue-cultured plants indicate that C. soloensis has great potential in the floricultural market.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号