Maximum Average Length Research Articles

In vitro propagation of Cuphea procumbens Orteg. and Evaluation of genetic fidelity in plantlets using RAPD marker

An efficient, rapid and reproducible plant regeneration protocol was successfully developed for Cuphea procumbens Orteg. using cotyledonary node explants excised from 15 days old aseptic seedlings. A range of cytokinins were investigated for multiple shoot regeneration. Of the three cytokinins, 6-benzyladenine (BA), Kinetin (Kin) and 2-isopentenyl adenine (2-iP) evaluated as supplement to Murashige and Skoog (MS) medium, BA at a concentration of 2.5 μM was effective in inducing multiple shoots. The highest number of multiple shoots (9.33 ± 0.60) and maximum average shoot length (4.16 ± 0.44 cm) was standardized on MS medium supplemented with 2.5 μM BA alongwith 0.5 μM NAA. Addition of 200 mg/l Casein hydrolysate (CH) to the shoot induction medium enhanced the growth of regenerants. Rooting of in vitro regenerated shoots was best achieved on 1/2 strength MS medium. The in vitro raised plantlets with well developed shoots and roots were hardened, successfully established in earthen pots containing garden soil and maintained in greenhouse with 80% survival rate. Randomly Amplified Polymorphic DNA (RAPD) markers were used to evaluate the genetic stability among in vitro regenerated progenies. All RAPD profiles from the micropropagated plants were monomorphic and similar to control plant. These results suggests that the culture conditions used for the axillary bud proliferation are appropriate for clonal propagation of this medicinally important plant as they do not appear to interfere with genetic integrity of in vitro regenerated plants. The described method can be successfully employed for large-scale multiplication and in vitro conservation of C. procumbens.

English

An efficient protocol was described for the rapid in vitro multiplication of an endangered medicinal plant, Caralluma bhupenderiana Sarkaria, via enhanced axillary bud proliferation from nodal explants collected from young shoots of six-months-old plant.  The physiological effects of growth regulators [6-Benzyladenine (BA), kinetin (Kn), 2-Isopentyl adenine (2iP), zeatin (Zn), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA)], different strengths of Murashige and Skoog (MS) medium and various pH levels on in vitro morphogenesis were investigated. The highest number (8.40 + 0.50) of shoots and the maximum average shoot length (3.2 ± 0.31 cm) were recorded on MS medium supplemented with BA (8.87 µM) at pH 5.8. Rooting was best achieved on half-strength MS medium augmented with NAA (2.69 µM). The plantlets regenerated in vitro with well-developed shoot and roots were successfully established in pots containing peat mass and garden manure in 1:1 ratio and grown in a greenhouse with 80% survival rate. The regenerated plants did not show any immediate detectable phenotypic variation.    Key words: Apocynaceae, asclepiadoideae, conservation, micro-propagation, endangered, Caralluma bhupenderiana.

Effects of Annealing on Sn Whisker Formation Under Temperature Cycling and Isothermal Storage Conditions

The global move toward reducing the usage of lead in electronics manufacturing industry is driving the industry to switch from tin-lead alloys to pure tin (Sn) for its component plating process. This transition has resulted in a reliability concern due to the formation of conductive Sn whiskers, which can grow from the component after the plating process within a few hours to months, with their length ranging from 10 micrometers up to several millimeters. The conductive Sn whiskers may cause current leakage or short circuits, leading to catastrophic failure in the field. This paper presents the results of an experimental study on Sn whisker formation based on the effects of annealing for 1 h at 150°C and environmental test conditions from the joint electron devices engineering council standards. This paper consisted of one temperature cycling test and two isothermal storage tests. The characterization results obtained confirm that temperature cycling and isothermal storage favor the formation of whiskers on Sn-plated copper lead frames. The average maximum length of the whiskers increased with the number of temperature cycles and duration of isothermal storage. It is also shown that annealing for 1 h at 150°C of the samples is effective in reducing the average maximum length of whiskers. Growth mechanisms of the Sn whiskers due to the effects of annealing and without annealing are also discussed.

Effect of Different Strength of Medium on Organogenesis, Phenolic Accumulation and Antioxidant Activity of Spearmint (Mentha spicata l.)

We investigated the effect of inorganic salt concentration on the in vitro organogenesis of spearmint (Mentha spicata L.) by using Murashige and Skoog culture medium of different strength (full, half- and quarter strength). The highest number of shoots and roots induced per explant (3.5 and 10, respectively), as well as the maximum average shoot length (16 cm) was observed on half strength medium. The maximum leaf number (35 per explant) and average root length (7 cm) were associated with regeneration on full medium. The highest average phenolic content was observed on shoot extracts (7.20 mg/g f.w.) and root extracts (5.93 mg/g f.w.) cultured onto quarter and half strength medium, respectively. The strength of the culture medium was inversely correlated with the antioxidant activity of plant extracts. Therefore, for spearmint organogenesis, half strength MS medium offers a compromise between optimum growth in vitro and antioxidant phenolic accumulation.

Age-based demographic assessment of fished stocks of Lethrinus nebulosus in the Gascoyne Bioregion of Western Australia

Abstract Age-based demographic analyses were undertaken to assess the current status of fished stocks of spangled emperor, Lethrinus nebulosus (Forsskål) in the Gascoyne Bioregion of Western Australia. Differences in age and growth characteristics were detected for samples collected from different assessment zones, with North Gascoyne fish observed to grow faster and reach a shorter average maximum length and younger average age than South Gascoyne fish. A significant difference in North Gascoyne catch-at-age data from different time periods demonstrated historical effects of fishing on population age structure. Instantaneous rates of fishing mortality (F) from catch-curve analyses of age–frequency data sampled for the North Gascoyne stock from recreational fishing catches from April 2007 to March 2008 were beyond the limit reference point compared with estimated instantaneous rates of natural mortality (M) (i.e. F > 1.5M), indicating that there is currently a risk to the sustainability of that stock.

Variability in growth, development and reproduction of the non-native seaweed Sargassum muticum (Phaeophyceae) on the Irish west coast

This study compared seasonal growth, development and reproduction of the invasive brown macroalga Sargassum muticum in habitats with different wave exposure on the Irish west coast. Three field sites with different degrees of wave exposure were chosen for monthly observations to reflect different habitats that were characteristic of the Irish west coast. Growth and receptacle development differed considerably between sites. Growth and receptacle development was lower at the most sheltered site. Here, S. muticum showed signs of early fragmentation in April/May during the two years of investigation (2007 and 2008), whilst the population at an exposed site developed normally and plants grew to a maximum average length of 163 cm by July, with the onset of fragmentation in August. Sargassum muticum in a tide pool exhibited a similar seasonal growth cycle as plants at the exposed open shore site. Overall growth however was stunted, with plants reaching a maximum length of only 30–40 cm in July. Receptacle development was also inhibited at the sheltered site, with a maximum of only 10% of plants found to be fertile during spring and summer 2008, while plants at the exposed site and the tide pool exhibited 100% plant fertility by August. An extensive occurrence of the native epiphyte Pylaiella littoralis on S. muticum was noticed during field sampling at the sheltered study site which may have contributed to inhibited development of S. muticum observed in this area. Seasonal biomass production, photosynthetic activity and plant/frond ratio development were contrasted between Sargassum muticum at the open shore and the tide pool. Sargassum muticum biomass production in the tide pool was 3.5 times lower than that of plants on the open shore. Receptacle development and seasonal photosynthetic activity were similar for tide pool and open shore plants, irrespective of morphological differences. Highest photosynthetic rates (fluorescence yield, Y o) were measured during active growth in February and lowest values during development of reproductive tissue and senescence. Numbers of S. muticum plants on the open shore decreased significantly during the year, whilst frond number per plant increased, possibly suggesting self-thinning through shading processes. The high variability in Sargassum muticum productivity and reproductive development between habitats suggests that the degree of competition and impact on native flora could be site-specific, and their local effect on displacements will require further investigations.

Three-dimensional Model of Human Platelet Integrin αIIbβ3 in Solution Obtained by Small Angle Neutron Scattering

Integrin alphaIIbbeta3 is the major membrane protein and adhesion receptor at the surface of blood platelets, which after activation plays a key role in platelet plug formation in hemostasis and thrombosis. Small angle neutron scattering (SANS) and shape reconstruction algorithms allowed formation of a low resolution three-dimensional model of whole alphaIIb beta3 in Ca(2+)/detergent solutions. Model projections after 90 degrees rotation along its long axis show an elongated and "arched" form (135 degrees) not observed before and a "handgun" form. This 20-nm-long structure is well defined, despite alphaIIb beta3 multidomain nature and expected segmental flexibility, with the largest region at the top, followed by two narrower and smaller regions at the bottom. Docking of this SANS envelope into the high resolution structure of alphaIIb beta3, reconstructed from crystallographic and NMR data, shows that the solution structure is less constrained, allows tentative assignment of the disposition of the alphaIIb and beta3 subunits and their domains within the model, and points out the structural analogies and differences of the SANS model with the crystallographic models of the recombinant ectodomains of alphaIIb beta3 and alphaV beta3 and with the cryo-electron microscopy model of whole alphaIIb beta3. The ectodomain is in the bent configuration at the top of the model, where alphaIIb and beta3 occupy the concave and convex sides, respectively, at the arched projection, with their bent knees at its apex. It follows the narrower transmembrane region and the cytoplasmic domains at the bottom end. AlphaIIb beta3 aggregated in Mn(2+)/detergent solutions, which impeded to get its SANS model.

Comparisons of the 2007 National Survey of Mental Health and Wellbeing and the 2003–2004 New Zealand Mental Health Survey

Probably only those involved with a major survey understand the extensive commitment required for such a survey to be prepared, run, analysed and written up. Congratulations are in order to all who played a role in the Australian 2007 National Survey of Mental Health and Wellbeing (NSMHWB), particularly to the Advisory Group for the survey, the Australian Bureau of Statistics, who actually ran the survey and performed the field work, and the researchers who have put together the suite of papers for this issue of theAustralian and New Zealand Journal of Psychiatry. It is good to see, even at this early stage in the analysis, that policy implications have been drawn, where possible. This editorial sets out to compare the findings from the Australian 2007 NSMHWB and the New Zealand Mental Health Survey (NZMHS), which was carried out in late 2003 and 2004. Both have resulted in an issue of the Australian and New Zealand Journal of Psychiatry: the October 2006 issue for the NZMHS [1 11] and this issue for the 2007 NZMHWB [12 17], which allows readers to obtain an overview of the main findings all at once instead of having to track papers across multiple journals as they are published. Of course there will be many more papers from each survey but to have the core descriptive papers presented together in one issue is a bonus not available to many of the other countries that have also participated in the World Mental Health Survey Initiative. Before comparing the findings it is necessary to set the context by describing the similarities and differences between the two surveys. The major features of the surveys were the same: they were both crosssectional surveys with national stratified multistage probability samples, they both interviewed participants face to face using a computer-assisted personal interview, and both used the English-language version of the Composite International Diagnostic Interview (CIDI 3.0), a fully structured interview that can be administered by trained lay interviewers, making it possible to obtain large samples. The common features make these two surveys comparable with each other and with other surveys in the World Mental Health Consortium (www.hcp.med.harvard. edu/wmh/). There are, however, some important differences between the 2007 Australian NSMHWB and the New Zealand NZMHS. Although the CIDI 3.0 was used in both countries, different approaches were taken to meet the common goal of having an interview with an average completion time of 90 min, the maximum average length thought to be acceptable to potential participants in the absence of remuneration. Certain diagnostic and demographic sections were omitted from both surveys but only the New Zealand survey retained the Part 1/Part 2 structure whereby a subset of participants completed some sections. This enabled more sections to be included in New Zealand but at the expense of the sample size for those included in Part 2. In Australia all participants entered or at least were screened for all sections included in the interview. The second major difference is that diagnoses reported so far from the NZMHS are DSM-IV J. Elisabeth Wells, Associate Professor

Biodiversity of North Sea fish: why do the politicians care but marine scientists appear oblivious to this issue?

AbstractGreenstreet, S. P. R. 2008. Biodiversity of North Sea fish: why do the politicians care but marine scientists appear oblivious to this issue? – ICES Journal of Marine Science, 65: 1515–1519. Political drivers underpinning the development of an Ecosystem Approach to Marine Management (EAMM) focus on conserving and restoring biodiversity. However, the Element of Ecological Quality for Fish Communities that emerged from the 2002 Bergen North Sea Ministerial Conference relates to “Changes in the proportion of large fish and hence the average weight and average maximum length of the fish community”. How did this apparent change in direction arise? Responding to advice requests from OSPAR, ICES established seven criteria for identifying “state” indicators capable of supporting indicator-based management. Application of these criteria underlined the merits of indicators of fish size, whereas diversity indices performed poorly against four of the criteria. These difficulties are examined here. Far from being oblivious to the issue of biodiversity, marine scientists recognized that they were not in a position to recommend Ecological Quality Objectives (EcoQOs) for fish biodiversity that would have relied on the use of biodiversity indicators. The use of indicators of size structure, for which the theoretical foundation was better developed, allowed the continued development of an EAMM in the short term. However, if the issue of biodiversity is to be addressed in the longer term, then shortcomings associated with the use of biodiversity indicators need to be addressed.

Lower esophageal palisade vessels and the definition of Barrett's esophagus

The designated area of the columnar-lined esophagus (CLE) is anatomically defined by the distal limit of the lower esophageal palisade vessels (LEPV) and the term 'Barrett's esophagus' is equally used along with the name CLE in Japan. The aim of this study was to investigate the actual prevalence of CLE based on the Japanese criteria and to evaluate the criteria per se. A total of 42 esophagi consecutively resected at this institute were included. All subjects underwent a surgical resection for squamous cell carcinoma of the esophagus. The position of the LEPV, squamocolumnar junction, the prevalence of CLE and intestinal metaplasia were investigated both pre- and postoperatively. Preoperative endoscopy revealed CLE based on the Japanese criteria in half of all patients. In the resected specimens the distal limit of LEPV was lower than the squamocolumnar junction in 95.2%. In other words, almost all cases had CLE (equivalent to Barrett's mucosa in Japanese criteria). However, most of the CLE areas were very short and their average maximum length was only about 5 mm. In addition, no intestinal metaplasia was observed in any of the CLE cases. Almost all individuals might therefore be diagnosed to have CLE or Barrett's mucosa based on precise endoscopic observations in Japan. The CLE located in a small area, e.g. less than 5 mm, defined according to the LEPV criteria without any other factor concerning typical Barrett's esophagus such as signs of gastroesophageal reflux should therefore be excluded from consideration as a high-risk mucosa.

Effect of diphenylsiloxane unit content on aggregation structure of poly(dimethylsiloxane‐co‐diphenylsiloxane)

AbstractA series of poly(dimethylsiloxane‐co‐diphenylsiloxane)s with different molar content of diphenylsiloxane unit (from 0.91 to 9.07 mol %) were synthesized and characterized by use of 1H NMR, gel permeation chromatography (GPC), the differential scanning calorimetry (DSC) and wide angle X‐ray diffraction (WAXD). The presence of diphenylsiloxane unit results in a decrease in the “orderness” of the crystal phase and aggrandizement in degree of lattice distortion. By calculating the sequence length of dimethylsiloxane unit of the random copolymer, it can be concluded that the maximum average sequence length of dimethylsiloxane units required for the copolymer to be amorphous is 11, and increasing the dimethylsiloxane sequence length will favour crystallization. The reduction in sequence length of dimethylsiloxane unit leads to that the three‐dimensional crystal shape is destroyed and crystal shape transforms into two‐dimensional or one‐dimensional, and finally disappeared. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 72–79, 2008

An efficient micropropagation system for Tylophora indica: an endangered, medicinally important plant

An efficient protocol is described for the rapid in vitro multiplication of an endangered medicinal plant, Tylophora indica (Burm. f.) Merrill, via enhanced axillary bud proliferation from nodal explants collected from young shoots of a two-year-old plant. The physiological effects of growth regulators [6-benzyladenine (BA), kinetin (Kin) thidiazuron (TDZ), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) or α-naphthalene acetic acid (NAA)], ascorbic acid (AA), different strengths of Murashige and Skoog (MS) medium and various pH levels on in vitro morphogenesis were investigated. The highest number (8.6 ± 0.71) of shoots and the maximum average shoot length (5.2 ± 0.31 cm) were recorded on MS medium supplemented with 2.5 μM BA, 0.5 μM NAA and 100 mg/l AA at pH 5.8. Rooting was best achieved on half-strength MS medium augmented with 0.5 μM IBA. The plantlets regenerated in vitro with well-developed shoot and roots were successfully established in pots containing garden soil and grown in a greenhouse with a 90% survival rate. The regenerated plants did not show any immediate detectable phenotypic variation. The described method can be successfully employed for large-scale multiplication and long-term in vitro conservation of T. indica.

In vitro rapid regeneration of plantlets from nodal explants of Mucuna pruriens– a valuable medicinal plant

AbstractA rapid and efficient protocol for the large‐scale propagation of a potential medicinal plant, Mucuna pruriens, through in vitro culture of nodal segment explants obtained from 15‐day‐old aseptic seedlings is described. Of the three different cytokinins, 6‐benzyladenine (BA), kinetin (Kin) and 2‐isopentenyl adenine (2‐iP) evaluated as supplements to Murashige and Skoog (MS) medium, BA at an optimal concentration of 5.0 μM was effective in inducing multiple shoots. Strength of the basal media also influenced the efficiency of shoot regeneration. The frequency of shoot regeneration tended to increase when the salt concentration in the basal media was reduced. Highest number of multiple shoots (23.3) and maximum average length (5.6 cm) were standardised on half‐strength MS medium supplemented with 5.0 μM BA along with 0.5 μM α‐naphthalene acetic acid (NAA) at pH 5.8. Rooting was best induced in shoots excised from proliferated shoot cultures on MS medium augmented with an optimal concentration of 1.0 μM indole‐3‐butyric acid (IBA). The in vitro‐raised plantlets with well‐developed shoots and roots were successfully established in earthen pots containing garden soil and were grown in greenhouse with 90% survival rate. The results of this study provide the first report on in vitro plant regeneration of M. pruriens.

High frequency in vitro regeneration of Lathyrus sativus L.

A simple and efficient protocol for high frequency plant regeneration of a grain legume grasspea (Lathyrus sativus L.) is described. Of different explant types tested epicotyl segments were most responsive. Murashige and Skoog's (1962) medium augmented with 17.76 µM 6-benzyladenine + 10.74 µM α-naphthaleneacetic acid showed the highest percentage of direct shoot regeneration. Among cultivars IC-120487 showed the highest regeneration frequency (80 %) with maximum shoot numbers (8.2 shoots per explant) and maximum average shoot length (4.1 cm). About 78 % of the regenerated shoots were rooted in half-strength MS medium containing 2.85 µM indole-3-acetic acid. After primary hardening the plantlets were established in soil with a survival rate of 75 %.

The variations of stable carbon isotope ratio of land plant-derived n-alkanes in deep-sea sediments from the Bering Sea and the North Pacific Ocean during the last 250,000 years

Two piston cores, one located far from the continents (The North Pacific Ocean: ES core), and another located comparatively closer to the continents (The Bering Sea: BOW-8a core) were investigated to reconstruct environmental changes on source land areas. The results show significant contribution of terrestrial organic matter to sediments in both cores. The δ 13C values of n-C 27, n-C 29, and n-C 31 alkanes in sediments from the North Pacific ES core show significant glacial to interglacial variation whereas those from the Bering Sea core do not. Variations of δ 13C values of land plant n-alkanes are related to the environmental or vegetational changes in the source land areas. Environmental changes, especially, aridity, rainfall, and pCO 2 during glacial/interglacial transitional periods can affect vegetation, and therefore C 3 / C 4 plant ratios, resulting in δ 13C changes in the preserved land plant biomarkers. Maximum values of δ 13C as well as maximum average chain length values of long chain n-alkanes in the ES core occur mostly at the interglacial to glacial transition zones reflecting a time lag related to incorporation of living organic matter into soil and transportation into ocean basins via wind and/or ability of C 4 plants to adapt for a longer period before being replaced by C 3 plants when subjected to gradual climatic changes. Irregular variations with no clear glacial to interglacial trends in the BOW-8a core may result from complex mixture of aerosols from westerly winds and riverine organic matter from the Bering Sea catchments. In addition, terrestrial organic matter entering the Bering Sea could originate from multiple pathways including eolian, riverine, and ice rafted debris, and possibly be disturbed by turbidity and other local currents which can induce re-suspension and re-sedimentation causing an obliterated time relation in the Bering Sea biomarker records.

Urodynamic evaluation of lower urinary tract function in relation to total abdominal hysterectomy

This study was performed to evaluate lower urinary tract functions in asymptomatic patients by urodynamic measurements after total abdominal hysterectomy and bilateral salpingo–oophorectomy. Twenty asymptomatic patients who had undergone hysterectomy for benign diseases were included in the study and urodynamic measurements were performed before and 6 weeks after total abdominal hysterectomy and bilateral salpingo–oophorectomy. There was no postoperative difference in first urge, normal urge, urgency and maximum bladder capacity but average urethral length, functional urethral length and maximum urethral closing pressure were decreased and also bladder discharging time was increased. Voided volume and residual urine volume were unchanged. It was concluded that total abdominal hysterectomy and bilateral salpingo–oophorectomy did not change the postoperative bladder loading functions in asymptomatic patients but that significant changes occurred in urethral functions.

Morphological and physiological parameters of beech leaves (Fagus sylvatica L.) in research demonstration object Poľana

Observations of the beech assimilatory apparatus in different levels of a model tree were realised from 1993 to 1999 in a research demonstration plot situated in Poľana. Different observations of the natural ecosystem condition were carried out. A model beech tree was chosen and marked as No. 228 for the above-mentioned analyses. The different ecophysiological and morphological characteristics of beech leaves were analysed in three (or two) tree crown levels. The results confirmed significant differences in these characteristics in dependence on three crown levels of mature beech tree. The differences in the mentioned characteristics were also shown in the course of particular years of research. In this paper we have presented the results of analysed beech leaves, their average maximum length, width, their average area, thickness, chlorophyll fluorescence during the research period.

Self-avoiding walks on scale-free networks

Several kinds of walks on complex networks are currently used to analyze search and navigation in different systems. Many analytical and computational results are known for random walks on such networks. Self-avoiding walks (SAW's) are expected to be more suitable than unrestricted random walks to explore various kinds of real-life networks. Here we study long-range properties of random SAW's on scale-free networks, characterized by a degree distribution P(k) approximately k(-gamma). In the limit of large networks (system size N-->infinity), the average number sn of SAW's starting from a generic site increases as mu(n) , with mu = k2/k-1 . For finite N, sn is reduced due to the presence of loops in the network, which causes the emergence of attrition of the paths. For kinetic growth walks, the average maximum length L increases as a power of the system size: L approximately Nalpha, with an exponent alpha increasing as the parameter gamma is raised. We discuss the dependence of alpha on the minimum allowed degree in the network. A similar power-law dependence is found for the mean self-intersection length of nonreversal random walks. Simulation results support our approximate analytical calculations.

Estratégias reprodutivas do dourado, Salminus maxillosus e do curimbatá, Prochilodus lineatus no Rio Mogi Guaçu, Estado de São Paulo, com ênfase nos parâmetros matemáticos da dinâmica populacional

The present work deals with the situation of curimbata, Prochilodus lineatus and dourado, Salminus maxillosus populations’ in Mogi Guacu River, through the analysis of populations dynamics parameters. Data were analysed according to previous results for the same species of that ecosystem. The analysed parameters were: size and age of first gonadal maturation, maximum average length of the specimens, minimum length of adult specimens captured, growth rate and sexual proportion. Results indicate that these specimens show reproductive strategies which are responsible for the survival and maintenance of the population balance, despite the intense overfishing and abiotic adversities they are being submitted to

Air method measurements of apple vessel length distributions with improved apparatus and theory.

Studies showing that rootstock dwarfing potential is related to plant hydraulic conductance led to the hypothesis that xylem properties are also related. Vessel length distribution and other properties of apple wood from a series of varieties were measured using the 'air method' in order to test this hypothesis. Apparatus was built to measure and monitor conductivity to air of fresh wood segments of different lengths. Theory for determining vessel length distribution was improved to give a single parameter uni-modal vessel length probability density function. The function, derived by combining the exponential extinction (with extinction coefficient k) of wood conductivity to air (C) as wood length (x) increases (i.e. C=Co exp (-kx)) with the differential double difference formula, is Px=xxk2 exp (-kx), where Px is the fraction of vessels of length x. The main parameter of the distribution, k, was found to be the inverse of the mode of the distribution, i.e. the most common vessel length, Lo. Lo for ten apple rootstock and scion varieties varied from 5.6+/-0.1 cm (+/-SE) for MM.111 to 9.0+/-1.0 for Prunifolia (P <0.05). Average maximum vessel length was approximately 50 cm, and differences were not significant. Effective vessel radii ranged from 14 for Prunifolia to 24.3+/-0.7 micro m for M.26, with standard errors less than 12% of the mean. Specific conductivity of a 15 cm wood segment ranged from 2x109-4) to 1.6+/-0.2x10(-2) dm3 s(-1) kPa(-1) m(-1) for maruba and M.26, respectively, with standard errors up to 63% of the mean. Vessel density at the air entry point ranged from 18+/-3 to 42+/-6 vessels mm-2 for M.26 and MM.106, respectively, with standard errors as high as 89% of the mean. It was concluded that there is no general relationship between the wood properties investigated and rootstock size class, and that plasticity increases from vessel lengths to radii to specific conductivity and vessel densities.