共查询到20条相似文献,搜索用时 31 毫秒
1.
Ampullary organs of Euristhmus lepturus occur in high densities along the head and in four parallel pathways along the trunk of the body. Large ampullary pores (125–130 μm)
are easily distinguishable from other sensory epithelial pores due to the differences in size and the presence of a collar-like
structure. Simple, singular ampullary organs of the head region consist of an ampullary pore connected to a long canal with
a diameter of 115–175 μm before terminating as a simple ampulla with an external diameter of 390–480 μm. The ampullary canal
is composed of 1–2 layers of flattened squamous epithelial cells, the basement membrane and an interlocking collagen sheath.
The innermost cells lining the canal wall are adjoined via tight junctions and numerous desmosomes, as are those of the receptor
and supportive cells. Canal wall tissue gives rise to a sensory epithelium containing between 242 and 285 total receptor cells,
with an average diameter of 11.7 ± 5.3 μm, intermixed with medially nucleated supportive cells. Each receptor cell (21.38 ± 4.41 μm,
height) has an apically positioned nucleus and a luminal surface covered with numerous microvilli. Neural terminals abut the
basal region of receptor cells opposite multiple presynaptic bodies and dense mitochondria. Supportive cells extend from the
ampullary lumen to the basement membrane, which is adjacent to the complex system of collagen fibres. 相似文献
2.
Federica Villa Lucia Giacomucci Andrea Polo Pamela Principi Lucia Toniolo Marienella Levi Stefano Turri Francesca Cappitelli 《Biotechnology letters》2009,31(9):1407-1413
The potential on N-vanillylnonanamide (NVN) in preventing the attachment of Pseudomonas stutzeri and a Bacillus cereus-group strain was investigated. NVN up to 852 μM was not toxic, nor was it an energy source for either organism. Microbial
attachment assays were carried out on glass and polylysine slides. with NVN being dispersed in or applied to the surfaces
using a polyurethane coating. NVN at 205 μM inhibited Bacillus adhesion on glass slides by 48% and the percentage did not significantly increase at 852 μM. NVN blended into or sprayed
onto the coating at 205 μmol/kg did not prevent adhesion. The compound is therefore not useful as an antifouling product under
the tested coating conditions. 相似文献
3.
Kittisak Chawawisit Monthon Lertcanawanichakul 《World journal of microbiology & biotechnology》2008,24(10):2199-2204
Secondary metabolites, particularly bioactive compounds, from probiotic bacteria, are good candidates for replacing antibiotics
to which bacteria have become resistant. In order to compare bioactive crude material from strain SA14 of Brevibacillus laterosporus with two antibiotics, the MICs of this bioactive crude and those of antibiotics vancomycin and oxacillin, against methicillin-resistant
Staphylococcus aureus (MRSA), were determined. The result indicated that the MIC (3.6–19.2 μg/ml) of bioactive crude was higher than vancomycin
(MIC = 1.28–2.56 μg/ml) when tested against MRSA. Interestingly, all tested strains of MRSA were susceptible to bioactive
crude and were approximately 5.2-fold more potent than oxacillin (MIC > 100 μg/ml). Its activity against MRSA gives support
for further evaluation, and the development of this substance for therapeutic use. 相似文献
4.
C. Douglas Boyette Mark A. Weaver Robert E. Hoagland Kenneth C. Stetina 《World journal of microbiology & biotechnology》2008,24(11):2721-2726
A mycelial formulation of the fungus Myrothecium verrucaria (IMI 361690) containing 0.20% Silwet L-77 surfactant was found to be highly efficacious in controlling the exotic invasive
weed kudzu. The mycelium can be rapidly (48–72 h) produced in several media, including an inexpensive soy flour–corn meal
medium. Mycelial yields were 2, 10, and 25 g dry weight l−1 in Czapek-Dox, Richard’s V-8, and soy flour–corn meal media, respectively. Scale-up production in soy flour–corn meal medium
using laboratory fermenters (10–25 l), resulted in a mycelial formulation that caused 90% mortality of naturally-occurring
mature (0.9–1.0 m in height) kudzu within 48 h after application in field experiments. HPLC analyses revealed that the mycelium
produced in this liquid culture contained no detectable amounts of the trichothecene mycotoxins roridin A and verrucarin A
(limit of detection 2 μg ml−1). This has resulted in a safer, yet effective bioherbicidal product. We anticipate that these findings should improve the
probability of EPA registration and subsequent commercial development of this bioherbicide. 相似文献
5.
Milne MA Townsend VJ Smelser P Felgenhauer BE Moore MK Smyth FJ 《Experimental & applied acarology》2009,47(1):19-33
We collected 22,769 adult female mosquitoes, representing 27 species, from light traps in Norfolk, Virginia (2006–2007) and
examined them to assess infestation by larval mites. Mosquitoes were parasitized by two species of aquatic (Acari: Arrenuridae:
Arrenurus) and three species of terrestrial mites (Acari: Erythraeidae). The prevalence of infestation varied from 0.55% (2006) to
0.17% (2007). The mean intensity of parasitism ranged from 3.6 mites per host (2006) to 1.8 mites per host (2007). The most
common host species for aquatic mites was Culex erraticus, while the most common host for terrestrial mites was Anopheles quadrimaculatus. Relationships between biotic and abiotic factors were investigated in an attempt to provide insight into temporal, spatial,
and interspecific variation in mite–mosquito interactions. Scanning electron microscopy was used to examine the mode of attachment
for larval mites. While the prevalence of aquatic mite parasitism was correlated for Culex erraticus, the invasive mosquito, Aedes albopictus, was never parasitized through the duration of the study.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
Ruixiang Zhao Junliang Sun Peter Torley Dahong Wang Shengyang Niu 《World journal of microbiology & biotechnology》2008,24(8):1349-1354
Lactobacillus acidophilus, as a probiotic, is widely used in many functional food products. Microencapsulation not only increases the survival rate
of L. acidophilus during storage and extends the shelf-life of its products, but also optimal size microcapsule makes L. acidophilus have an excellent dispersability in final products. In this paper, L. acidophilus was microencapsulated using spray drying (inlet air temperature of 170°C; outlet air temperature of 85–90°C). The wall materials
used in this study were β-cyclodextrin and acacia gum in the proportion of 9:1 (w/w), and microcapsules were prepared at four
levels of wall materials (15, 20, 25 and 30% [w/v]) with a core material concentration of 6% (v/v). The microcapsule diameters
were measured by Malvern’s Mastersizer-2000 particle size analyzer. The results showed that the particle diameters of microcapsule
were mostly within 6.607 μm and 60.256 μm and varied with 2.884–120.226 μm (the standard smaller microcapsule designated as
<350 μm). Through comparison of microcapsule size and uniformity with different concentration of wall materials, we concluded
that the optimal concentration of wall material was 20% (w/v), which gave microcapsule with a relatively uniform size (averaging
22.153 μm), and the number of surviving encapsulated L. acidophilus was 1.50 × 109 c.f.u./ml. After 8 weeks storage at 4°C, the live bacterial number was above 107 c.f.u./ml, compared with unencapsulated L. acidophilus, 104–105 c.f.u./ml. Through the observation of scanning electron microscopy, we found that the shapes of microcapsule were round and
oval, and L. acidophilus cells located in the centre of microcapsule. 相似文献
7.
The relationship between the particle size of an inert silica dust, its up-take from different surfaces and the grooming behaviour
of males, gravid females, and fifth and sixth instar nymphs of the German cockroachBlattella germanica (Dictyoptera: Blattellidae) (L.) was investigated. The normal grooming behaviour of gravid females, nymphs and males differed
according to sex and age. The gravid females and nymphs exhibited greater grooming activity than the males, especially of
the antennae and the legs. Gravid females, nymphs, and adult males exhibited increased grooming activity after exposure to
dust in the size range 0.5–63 μm, but there was no significant difference in grooming behaviour from the control when cockroaches
were exposed to dust sizes greater than 70 μm. Antennal grooming by males was greater than leg grooming when exposed to all
dust sizes, except size particles ranging 4.5–7.5 μm. A dust pick-up experiment indicated that the average amount of dust
transferred toB. germanica is affected by particle size, the porosity of the treated surface, and the sex and age of the cockroaches. Gravid females
picked up greater amounts of dust than fifth and sixth instar nymphs, which in turn picked up more dust than males. Silica
dust particles (0.5–7.5 μm) were picked up more effectively than larger particle sizes, by all three categories, males, females
and fifth and sixth instar nymphs of cockroach on all three test surfaces plastic, ceramic and unpainted plywood. Plywood
was the least effective surface for transfer of dust, of all sizes, to males, females and nymphs. 相似文献
8.
Raulio M Pore V Areva S Ritala M Leskelä M Lindén M Rosenholm JB Lounatmaa K Salkinoja-Salonen M 《Journal of industrial microbiology & biotechnology》2006,33(4):261-268
The aim of the present work was to explore possibilities of photocatalytic TiO2 coating for reducing biofilms on non-living surfaces. The model organism, Deinococcus geothermalis, known to initiate growth of durable, colored biofilms on machine surfaces in the paper industry, was allowed to form biofilms
on stainless steel, glass and TiO2 film coated glass or titanium. Field emission electron microscopy revealed that the cells in the biofilm formed at 45°C under
vigorous shaking were connected to the surface by means of numerous adhesion threads of 0.1--0.3 μm in length. Adjacent cells
were connected to one another by threads of 0.5--1 μm in length. An ultrastructural analysis gave no indication for the involvement
of amorphous extracellular materials (e.g., slime) in the biofilm. When biofilms on photocatalytic TiO2 surfaces, submerged in water, were exposed to 20 W h m−2 of 360 nm light, both kinds of adhesion threads were completely destroyed and the D. geothermalis cells were extensively removed (from >107 down to below 106 cells cm−2). TiO2 films prepared by the sol-gel technique were slightly more effective than those prepared by the ALD technique. Doping of
the TiO2 with sulfur did not enhance its biofilm-destroying capacity. The results show that photocatalytic TiO2 surfaces have potential as a self-cleaning technology for warm water using industries. 相似文献
9.
María del Socorro Santos Díaz Candy Carranza Álvarez 《In vitro cellular & developmental biology. Plant》2009,45(2):162-170
Two procedures for the in vitro propagation of Encyclia mariae, a threatened Mexican orchid, were developed. In the first procedure, leaves from in vitro germinated seedlings were cultured on Murashige and Skoog medium (MS) supplemented with the range of 2.21–4.4 μM 6-benzylaminopurine
(BA) in combination with 2.69–10.74 μM naphthalene acetic (NAA), 2.07–8.29 μM indole-3-butyric (IBA), or 2.85–11.42 μM indole-3-acetic
acid (IAA) to determine the best medium for the induction of shooting. Maximum direct shoot formation from leaves was observed
on MS containing 22.21 μM BA and 10.74 μM NAA (25 shoots/explant). The second procedure began with the culture of protocorms
on media containing NAA, IBA, or IAA, which induced callus formation with high regenerative potential in the form of protocorm-like-bodies
(PLBs) that eventually differentiated into shoots. The optimal response was attained when these structures were cultured on
medium with 4.14 μM IBA (30 shoots/PLB). To promote the elongation of shoots derived from PLBs, the material was subcultured
onto MS medium containing 22.21 μM BA and 5.37 μM NAA. Through the exploration of the effects of auxins and matrix on the
rooting of shoots, it was determined that the optimal rooting occurred on media supplemented either with 5.71 μM IAA or 4.14 μM
IBA either on agar-gelled medium or in liquid media with coir as the matrix. Rooting was found to be 20% higher in liquid
media than in agar-gelled medium. 相似文献
10.
The distribution of dry Douglas-fir forests in western North America is expected to shift northward with climate change and
disappear from the grassland interface in the southern interior of British Columbia. This shift may be accentuated by clearcutting,
a common harvesting practice that aims to reduce the competitive effects of residual mature trees on new regeneration, but
in so doing, ignores their facilitative effects. In this study, we investigated the net effects of competition from and facilitation
by mature trees retained on harvested sites on seedling establishment in the dry interface Douglas-fir forests. We demonstrate
that access to a mycorrhizal network (MN) and proximity to trees have important influences on seedling performance. On six
sites, we established trenched plots around 24 mature Pseudotsuga menziesii var. glauca (Douglas-fir) trees, then planted Douglas-fir seedlings into four mesh treatments that served to restrict MN access (i.e.,
planted into mesh bags with 0.5-, 35-, or 250-μm pores, or without mesh) or into impermeable bags (grown in isolation) at
four distances (0.5, 1.0, 2.5, or 5.0 m). Seedling survival tended to be greater and water stress lower where seedlings had
full access to the MN. Seedling height, shoot biomass, needle biomass, and nutrient uptake peaked at 2.5–5.0 m from mature
trees. Seedlings 0.5 m from mature trees had lower CO2 assimilation rates and wood δ13C compared to seedlings 5.0 m away. Competition for soil resources was highest near mature trees but facilitation was relatively
greater at further distances, resulting in a zone of net benefit for seedlings. These results show that intraspecific tree-seedling
interactions are both competitive and facilitative in dry Douglas-fir forests, and that they are spatially dependent. After
disturbance, maintaining residual mature trees may be important for their beneficial regeneration zones.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
11.
Montane conifers of western North America commonly colonize mineral surfaces resulting from landslides, lahars, mudflows,
and rock avalanches. This colonization can include shade-tolerant conifers that may eventually dominate the forest in a pattern
termed “direct” succession. Documenting examples of this long-term successional process are useful for identifying alternative
successional trajectories and indicating potential controlling mechanisms for subsequent experimental analysis. This study
(1) analyzes the 1992 status of the conifer colonization on the coarse-textured surface of a 1650 AD rock avalanche in northern
California and (2) measures individual growth and survivorship in permanent plots between 1992 and 2003. Increment cores of
large trees indicated initial conifer colonization before 1700 AD with continuous subsequent colonization. Mean conifer density
in 1992 was 725 (SD = 747) ha−1 with densities increasing with decreasing rock sizes. Densities were not correlated with distances to possible seed sources.
Median heights were <1 m, and the mean proportional height growth rate for healthy individuals was 0.0166 year−1. The mortality rate for individuals ≥0.1-m tall was <0.007 year−1. The conifers were more numerous than shrubs, and there was little apparent evidence of facilitation or inhibition of conifers.
The species assemblage is mostly (89%) Abies concolor, Pinus monticola, and Pinus ponderosa individuals dispersed across an elevation range of 1870–2040 m a. s. l. This is an atypical species mix for these elevations
in this location, and this mix is not readily predicted from species properties such as seed mass, seed flight distance, or
drought tolerance. 相似文献
12.
Makoto Mizuno 《Journal of plant research》1982,95(4):349-357
Cocconeis scutellum var.ornata Grun. from three localities of Japan was studied. The striation density in 10 μm showed a marked tendency to increase with
the decrease of the valve length in both raphe and rapheless valves, and this tendency did not vary with locality or environmental
condition. The striation densities of rapheless valves were 4–6 in 10 μm for a valve length of 40μm, 4–6.5 for 30 μm, 6–9
for 20μm and 6.5–11 for 15μm. Those of raphe valves were 10–11 in 10μm for a valve length of 40μm, 10–12 for 30μm, 11–14.5
for 20μm and 12.5–17 for 15μm.
According to the range of changing value in striation density obtained by the present study,C. scutellum var.schmidti Frenguelli andC. japonica Schmidt are identical withC. scutellum var.ornata.
Dedicated to Prof. Munenao Kurogi on the occasion of his academic retirement.
Culture experiment in the present study was undertaken at the Institute of Algological Research, Faculty of Science, Hokkaido
University at Muroran. 相似文献
13.
C. S. Jeong H. N. Murthy E. J. Hahn H. L. Lee K. Y. Paek 《Acta Physiologiae Plantarum》2009,31(1):219-222
The effect of the root-inoculum size and axuin concentration on growth of adventitious roots and accumulation of ginsenosides
were studied during suspension cultures of ginseng (Panax ginseng C.A. Meyer). Of the various concentrations of indole-3-butyric acid (IBA) and γ-naphthaleneacetic acid (NAA) used as supplementary
growth regulators along with Murashige and Skoog medium, 25 μM IBA was found suitable for lateral root induction and growth,
as well as accumulation of ginsenosides. Inoculum size of 5 g L−1 was found suitable for optimal biomass (10.5 g L−1 dry biomass) and ginsenosides (5.4 mg g−1 DW) accumulation. Of the various length of root inocula tested (chopped to 1–3, 4–6, 7–10 mm and un-chopped), root inocula
of 7–10 mm was found suitable for biomass and ginsenoside accumulation. 相似文献
14.
We have characterized cytochromes P450, CYP710A13, and CYP710A14, as the sterol C22-desaturase in the moss Physcomitrella patens. GC–MS analyses demonstrated that P. patens accumulated stigmasterol as the major sterol (56–60% of total sterol) and sitosterol to a lesser extent (8–12%); this sterol
profile contrasts with those in higher plants accumulating stigmasterol as a minor component. Recombinant CYP710A13 and CYP710A14
proteins prepared using a baculovirus/insect cell system exhibited the C22-desaturase activity with β-sitosterol to produce
stigmasterol, while campesterol and 24-epi-campesterol were not accepted as the substrates. The K
m values for β-sitosterol of CYP710A13 (1.0 ± 0.043 μM) and CYP710A14 (2.1 ± 0.17 μM) were at comparable levels of those reported
with higher plant CYP710A proteins. In Arabidopsis T87 cells over-expressing CYP710A14, stigmasterol contents reached a level 20- to 72-fold higher than those in the basal
level of T87 cells, confirming the C22-desaturase activity of this P450 enzyme. The occurrence of the end-products together
with the enzymes involved in the last step of the pathway substantiated the presence of an entire sterol biosynthetic pathway
in P. patens, providing evidence for the conservation of the sterol biosynthetic pathway through the evolutionary process of land plants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
Okeke BC 《Journal of industrial microbiology & biotechnology》2008,35(12):1571-1579
Pollution of terrestrial surfaces and aquatic systems by hexavalent chromium, Cr(VI), is a worldwide public health problem.
A chromium resistant bacterial isolate identified as Exiguobacterium sp. GS1 by 16S rRNA gene sequencing displayed high rate of removal of Cr(VI) from water. Exiguobacterium sp. GS1 is 99% identical to Exiguobacterium acetylicum. The isolate significantly removed Cr(VI) at both high and low concentrations (1–200 μg mL−1) within 12 h. The Michaelis–Menten K
m
and V
max for Cr(VI) bioremoval were calculated to be 141.92 μg mL−1 and 13.22 μg mL−1 h−1, respectively. Growth of Exiguobacterium sp. GS1 was indifferent at 1–75 μg mL−1 Cr(VI) in 12 h. At initial concentration of 8,000 μg L−1, Exiguobacterium sp. GS1 displayed rapid bioremoval of Cr(VI) with over 50% bioremoval in 3 h and 91% bioremoval in 8 h. Kinetic analysis
of Cr(VI) bioremoval rate revealed zero-order in 8 h. Exiguobacterium sp. GS1 grew and significantly reduced Cr(VI) in cultures containing 1–9% salt indicating high salt tolerance. Similarly
the isolate substantially reduced Cr(VI) over a wide range of temperature (18–45 °C) and initial pH (6.0–9.0). The T
opt and initial pHopt were 35–40 °C and 7–8, respectively. Exiguobacterium sp. GS1 displayed a great potential for bioremediation of Cr(VI) in diverse complex environments. 相似文献
16.
Nitrogen deposition effects on soil organic matter chemistry are linked to variation in enzymes,ecosystems and size fractions 总被引:2,自引:0,他引:2
A. Stuart Grandy Robert L. Sinsabaugh Jason C. Neff Martina Stursova Donald R. Zak 《Biogeochemistry》2008,91(1):37-49
Recent research has dramatically advanced our understanding of soil organic matter chemistry and the role of N in some organic
matter transformations, but the effects of N deposition on soil C dynamics remain difficult to anticipate. We examined soil
organic matter chemistry and enzyme kinetics in three size fractions (>250 μm, 63–250 μm, and <63 μm) following 6 years of
simulated atmospheric N deposition in two ecosystems with contrasting litter biochemistry (sugar maple, Acer saccharum—basswood, Tilia americana and black oak, Quercus velutina—white oak, Q. alba). Ambient and simulated (80-kg NO3
−–N ha−1 year−1) atmospheric N deposition were studied in three replicate stands in each ecosystem. We found striking, ecosystem-specific
effects of N deposition on soil organic matter chemistry using pyrolysis gas chromatography/mass spectrometry. First, furfural,
the dominant pyrolysis product of polysaccharides, was significantly decreased by simulated N deposition in the sugar maple–basswood
ecosystem (15.9 vs. 5.0%) but was increased by N deposition in the black oak–white oak ecosystem (8.8 vs. 24.0%). Second,
simulated atmospheric N deposition increased the ratio of total lignin derivatives to total polysaccharides in the >250 μm
fraction of the sugar maple–basswood ecosystem from 0.9 to 3.3 but there were no changes in other size classes or in the black
oak–white oak ecosystem. Third, simulated N deposition increased the ratio of lignin derivatives to N-bearing compounds in
the 63–250 and >250 μm fractions in both ecosystems but not in the <63 μm fraction. Relationships between enzyme kinetics
and organic matter chemistry were strongest in the particulate fractions (>63 μm) where there were multiple correlations between
oxidative enzyme activities and concentrations of lignin derivatives and between glycanolytic enzyme activities and concentrations
of carbohydrates. Within silt-clay fractions (<63 μm), these enzyme-substrate correlations were attenuated by interactions
with particle surfaces. Our results demonstrate that variation in enzyme activity resulting from atmospheric N deposition
is directly linked to changes in soil organic matter chemistry, particularly those that occur within coarse soil size fractions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Multiple shoot induction and callus regeneration in Sarcostemma brevistigma Wight & Arnott, a rare medicinal plant 总被引:1,自引:0,他引:1
An efficient micropropagation protocol based on multiple shoot induction and callus regeneration has been standardized in
Sarcostemma brevistigma, a rare medicinal plant. The nodal cuttings were cultured on MS medium supplemented with BA (0.5–8 μM) or Kn (0.5–8 μM) alone
or in combination with NAA (0.5–1.5 μM). Maximum multiple shoot induction was observed on MS medium supplemented with 4 μM
BA. On this medium, 100% cultures responded with an average number of 11.3 shoots per explant. However, the average shoot
length was limited to only 0.9 cm on this medium. The addition of 1 μM NAA along with 4 μM BA gave rise to an average number
of 10.9 shoots with an average shoot length of 1.8 cm. Luxuriantly growing callus was obtained on MS medium supplemented with
BA (5 μM) and 2,4-D (2 μM). The callus was subcultured on MS medium supplemented with BA (2–15 μM) or Kn (2–15 μM) alone or
in combination with NAA (0.5–2 μM) for shoot organogenesis. Optimum callus regeneration was obtained on MS medium supplemented
with 10 μM BA and 1 μM NAA. On this medium, 100% cultures responded with an average number of 13.4 shoots per culture. The
shoots obtained via multiple shoot induction and organogenesis were rooted on half-strength MS medium supplemented with NAA
(1–7 μM) or IBA (1–7 μM). IBA was better than NAA in terms of both the percentage of cultures that responded and the average
number of roots per explant. The rooted shoots were successfully transplanted to soil with 86% success. This standardized
protocol will help to conserve this rare medicinal plant. 相似文献
18.
Rhizobial strains, rescued from the root nodules of Robinia pseudoacacia growing in Japan and Poland, were characterized for the phenotypic properties, genomic diversity as well as phylogeny and
compared with the reference strains representing different species and genera of nodule bacteria. They had a moderately slow
growth rate, a low tolerance to antibiotics, a moderate resistance to NaCl and produced acid in yeast mannitol agar. Cluster
analysis based on the phenotypic features divided all bacteria involved in this study into four phena, comprising: (1) Rhizobium sp. + Sinorhizobium sp., (2) Bradyrhizobium sp., (3) R. pseudoacacia microsymbionts + Mesorhizobium sp., and (4) Rhizobium galegae strains at similarity coefficient of 74%. R. pseudoacacia nodule isolates and Mesorhizobium species were placed on a single branch clearly distinct from other rhizobium genera lineages. Strains representing R. pseudoacacia microsymbionts shared 98–99% 16S rDNA sequence identity with Mesorhizobium species and in 16S rDNA phylogenetic tree all these bacteria formed common cluster. The rhizobia tested are genomically heterogeneous
as indicated by the AFLP (Amplified Fragment Length Polymorphism) method. The bacteria studied exhibited high degree of specificity for nodulation. Nitrogenase structural genes
in these strains were located on 771–961 kb megaplasmids.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
S. C. Debnath 《In vitro cellular & developmental biology. Plant》2009,45(2):122-128
An efficient system to regenerate shoots on excised leaves of greenhouse-grown wild lowbush blueberry (Vaccinium angustifolium Ait.) was developed in vitro. The effect of thidiazuron (TDZ) on adventitious bud and shoot formation from apical, medial, and basal segments of the leaves
was tested. Leaf cultures produced multiple buds and shoots with or without an intermediary callus phase on 2.3–4.5 μM TDZ
within 6 wk of culture initiation. The greatest shoot regeneration came from young expanding basal leaf segments positioned
with the adaxial side touching the culture medium and maintained for 2 wk in darkness. Callus development and shoot regeneration
depended not only on the polarity of the explants but also on the genotype of the clone that supplied the explant material.
TDZ-initiated cultures were transferred to medium containing 2.3–4.6 μM zeatin and produced usable shoots after one additional
subculture. Elongated shoots were dipped in 39.4 mM indole-3-butyric acid powder and planted on a peat:perlite soilless medium
at a ratio of 3:2 (v/v), which yielded an 80–90% rooting efficiency. The plantlets were acclimatized and eventually established in the greenhouse
with 75–85% survival. 相似文献
20.
Sclerocarya birrea (marula) is an indigenous South African tree with highly valued medicinal and nutritional properties. Induction of nodular
meristemoids from leaf explants was achieved on Murashige and Skoog (MS) and woody plant medium (WPM) supplemented with 6-benzyladenine
(BA) in combination with naphthalene acetic acid (NAA), indole-3-butryric acid (IBA) and indole-3-acetic acid (IAA). Induction
of nodular meristemoids from 86% of the leaf cultures was achieved on MS medium with 4.0 μM BA and 1.0 μM NAA. High levels
(78–100%) of induction were also achieved on WPM with different concentrations of BA (1.0–4.0 μM) and IBA (1.0–4.0 μM). The
highest conversion of meristemoids into shoots was only 22% for 4.0 μM BA and 1.0 μM NAA on MS initiation medium. This was
improved to 62% when nodular clusters were cultured in a MS liquid medium. Histological studies revealed the globular stage
of the nodular meristemoids. This protocol has potential for application in mass micropropagation and plant breeding of S. birrea. 相似文献