A comparative study of extraction methods reveals preferred solvents for cystine knot peptide isolation from Momordica cochinchinensis seeds

MCoTI-I and MCoTI-II (short for Momordica cochinchinensis Trypsin Inhibitor-I and -II, respectively) are attractive candidates for developing novel intracellular-targeting drugs because both are exceptionally stable and can internalize into cells. These seed-derived cystine knot peptides are examples of how natural product discovery efforts can lead to biomedical applications. However, discovery efforts are sometimes hampered by the limited availability of seed materials, highlighting the need for efficient extraction methods. In this study, we assessed five extraction methods using M. cochinchinensis seeds, a source of well-characterized cystine knot peptides. The most efficient extraction of nine known cystine knot peptides was achieved by a method based on acetonitrile/water/formic acid (25:24:1), followed by methods based on sodium acetate (20 mM, pH 5.0), ammonium bicarbonate (5 mM, pH 8.0), and boiling water. On average, the yields obtained by these four methods were more than 250-fold higher than that obtained using dichloromethane/methanol (1:1) extraction, a previously applied standard method. Extraction using acetonitrile/water/formic acid (25:24:1) yielded the highest number of reconstructed masses within the majority of plant-derived cystine knot peptide mass range but only accounted for around 50% of the total number of masses, indicating that any single method may result in under-sampling. Applying acetonitrile/water/formic acid (25:24:1), boiling water, and ammonium bicarbonate (5 mM, pH 8.0) extractions either successively or discretely significantly increased the sampling number. Overall, acetonitrile/water/formic acid (25:24:1) can facilitate efficient extraction of cystine-knot peptides from M. cochinchinensis seeds but for discovery purposes the use of a combination of extraction methods is recommended where practical.     

A comparison between three different methods of measuring knot parameters in picea abies

Both foresters and sawmillers are interested in the knot structure of trees; in particular, position and number of knots, knot diameter, knot length and dead knot border. For research purposes, it is possible today to carry out non‐destructive measurements using computer tomography (CT) and image analysis. The aim of this study was to measure knot parameters on Norway spruce (Picea abies (L.) Karst.) using a non‐destructive method developed for Scots pine (Pinus sylvestris L.), and to compare the results of this method with the results of two different destructive methods. In order to do this, two Norway spruce stems were scanned by CT. Then five logs from one stem were cut into flitches 20 mm thick and the defects on the sawn surfaces were scanned manually. The other stem was cut just above every whorl and then each knot was split through its centre and the knot parameters were measured manually. The study showed that the CT method compares well with the destructive methods. It is a reasonably fast, non‐destructive method which measures position and diameter of knots and detects larger knots with acceptable accuracy. The study also showed that a large number of smaller knots were not found by the CT method and that the CT method measured knot length and dead knot border with low accuracy. This means that the CT method has to be adjusted to Norway spruce in order to improve its ability to measure knot length and dead knot border and to detect smaller knots.     

Shape and distribution of knots in a sample of picea abies logs

In an attempt to develop a better understanding of the effect of knottiness on the yield of logs for sawn timber products, the present study examines the position and geometrical characteristics of 429 knots found in seven Norway spruce (Picea abies (L.) Karst) middle logs from southern Finland. The raw data used in this study were in the form of coordinates of points located on the knot surface recorded in a cylindrical (R, L, T) reference frame. The data were smoothed using a non linear three‐dimensional model. A curvature analysis of the knot pith was used to differentiate the curved and straight portions of the knots. This analysis made possible calculation of knot angles, symmetry, ovality and volume. The major finding of this study is the uneven distribution of knots around the log circumference. Nearly 50% of the total knot volume was concentrated in one‐third of the log facing the south‐east. Knots were also more prominent in higher portions of the logs studied. These observations support the argument that the uneven distribution of knots offers potential for improving the grade yield of timber sawn from trees harvested in high‐latitude countries.     

Response of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) to some different fertilizers applied at planting

Four fertilization at planting experiments were conducted with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) on eastern Vancouver Island. In experiment 1 Agriform (20-10-5, AGR) and Osmocote (17-7-12, OSM) supplied N at 0, 4.2, 8.4, 16.8 or 33.6 g/tree either broadcast, within 15 cm of the tree, or in a hole 15 cm from the tree (adjacent). In experiment 2 AGR, diammonium phosphate (21-55-0, DAP), ammonium sulphate (21-0-0, AMS), sulphur coated urea (35-0-0, SCU) supplied N at 0, 8.4, 16.8 and 25.2 g/tree. Triple superphosphate (0-45-0, TSP) supplied P at the same levels as DAP: 0, 9.6, 19.2 and 28.8 g/tree. In experiment 3 AGR and SCU (32-0-0) supplied N at 0, 8.4 and 16.8 g/tree. In experiment 4 DAP was used to fertilize trees on five different dates, between March and October, and each treatment supplied 16 g N/tree. Two-year old, bare root, planting stock was used except in experiment 3, where container stock was compared with bare root stock.Little growth response was obtained after one year, but height growth responses of 12 to 31% were measured after 3 to 6 years with fertilizers supply 8.4 to 16.8 g N per tree. Growth responses were little affected by the type of fertilizer and were primarily due to N, with release rate having no marked effect. The exception to this was TSP which did not increase growth but did increase survival. Survival was reduced by AMS and to a lesser extent by AGR. Container seedlings responded more to fertilization at planting than bare root seedlings.Seedling N, P and K concentrations and contents declined following planting for 6 months and only started to recover after July. Application of fertilizer caused a small increase in seedling nutrient concentration regardless of date, but this had no detectable effect on dry weight measured six weeks later.     

Development of an economic selection index for Australian tea tree

This study has developed the first formal breeding objective for the Australian tea tree plantation industry. Significant gains in profitability of Australian tea tree (Melaleuca alternifolia) could be made through selection for biomass and oil yield, while maintaining oil quality at acceptable levels. Economic values or weights (EWs), for breeding-objective traits were estimated based on a bio-economic model of a typical production system in Australia. Sensitivity of EWs to the production-system parameters was analysed by what-if scenarios. Selection indices and genetic responses were derived and sensitivity of selection index coefficients to variation in EWs and genetic parameters were analysed by Monte Carlo simulation. The EW for average leaf biomass (LB) and oil content (OC) had the net present value of AU29.53/kg and AU29.53/kg and AU2059 per mg/g, respectively. Among the production system parameters studied, discount rate and oil price had large impact on the two EWs, while operating costs changed the EW of LB but did not affect the that of OC. Using optimal selection index, positive expected responses in objective traits LB (36.2 kg/ha/year), OC (4.64 mg/g), and in all selection traits (i.e. juvenile OC, height, leafiness, and 1,8-cineole) were obtained except for terpinen-4-ol, at a 10% selection intensity (i = 1.76). Use of restricted selection index resulted in zero change in either 1,8-cineole or terpinen-4-ol content, but also in an opportunity cost especially in OC. The most important factor affecting the sensitivity of the selection index was the EW for OC.     

Aboveground nutrient components of Eucalyptus camaldulensis and E. grandis in semiarid Brazil under the nature and the mycorrhizal inoculation conditions

A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grandis plantations in the semiarid region (15° 09′ S 43° 49′ W) in the north of the State of Minas Gerais in Brazil. Results show that the total above-ground biomass (dry matter) was 33.6 Mg·ha⁻¹ for E. camaldulensis and 53.1 Mg·ha⁻¹ for E. grandis. The biomass of the stem wood, leaves, branches, and stem bark for E. camaldulensis accounted for 64.4%, 19.6%, 15.4%, and 0.6% of the total biomass, respectively (Table 2); meanwhile a similar partition of the total above-ground biomass was also found for E. grandis. The dry matter of leaves and branches of E. camaldulensis accounted for 35% of total biomass, and the contents of N, P, K, Ca, Mg, and S in leaves and branches accounted for 15.5%, 0.7%, 12.3%, 22.6%, 1.9%, and 1.4% of those in total above-ground biomass, respectively. In the trunk (bark and wood), nutrient accumulation in general was lower. Nutrient content of E. grandis presented little variation compared with that of E. camaldulensis. Wood localized in superior parts of trunk presented a higher concentration of P and bark contained significant amounts of nutrients, especially in E. grandis. This indicated that leaving vegetal waste is of importance on the site in reducing the loss of tree productivity in this semi-arid region. The two species showed mycotrophy.     

Predicting knottiness of Pinus sylvestris for use in tree bucking procedures

Abstract

The quality and accompanying value of Scots pine (Pinus sylvestris L.) lumber varies markedly in the Nordic countries. Consequently, tree bucking has a great impact on the economic result. The objectives of this study were (1) to analyse which knot characteristics usually reduce pine lumber sawn from the butt-logs to the next quality grade, (2) to determine the most appropriate characteristics that could be used in predicting lumber quality, and (3) to develop models that could be used in practice for predicting the probability of certain quality grades. The study was based on field experiments and test sawing data on 100 Scots pine stems from south-western Finland. Since the results showed that the maximum dead knot is the most crucial knot characteristic when the first cross-cutting point is determined, models were created that predict the height of the first dead knot that lowers grade A to B (B-grade dead knot). Both early growth rate and dead branch height should be measured to predict pine butt-log quality. Early growth rate seems to be appropriate in predicting between-stand variation, while dead branch height is appropriate for predicting within-stand variation.     

封山育林对小兴安岭东部地区蒙古栎林主要乔木种群径级结构的影响

在黑龙江省小兴安岭东部地区(东经444-4726 N?北纬2633-13141? 海拔400-1000 m), 对不同封育时间、不同坡向的蒙古栎林中的主要乔木树种径级结构进行分析。在阳坡,针对封育5年 16年和24年蒙古栎种群, 分别选择6个重复样地。在阴坡,也同样分别选择6块样地。每块样地的面积为20 m×20 m。在每块样地中, 测量各树的胸高直径,树高和冠幅直径。结果表明:在封育5年样地内,蒙古栎、糠椴和黄榆种群的数量均随着径级的增加而单调下降,表明均为增长型种群;在封育16年以后,由于林内乔木层的盖度较大,糠椴和黄榆种群均呈不同程度的衰退,已经成为蒙古栎种群的伴生种群;封育24年样地中,蒙古栎种群明显成为优势树种。在阳坡随封育时间延长乔木层盖度增长较快,而阴坡乔木层盖度增长较慢;糠椴和黄榆种群随封育时间延长逐步衰退的现象在阳坡比阴坡表现明显。图2表1参8。     

Cattle grazing under Pinus caribaea

An analysis is made of the animal stocking rate used in commercial Pinus caribaea plantations 2.5–8.5 yr old. Pines were planted at 2.5 × 2.5 m and programmed for clear-cut harvest at 10 yr rotations (pulpwood). Cattle grazing was introduced to reduce weeding costs.Stocking rate in 1983–1985 was 0.67 AU/ha/yr (AU = animal units 350 kg live weight). A quadratic model calculated using 1984 data (S = 0.0108 + 0.385A–0.0418A²) describes the relationship between animal stocking rate (S) and stand age (A 9.5 in yr).The model predicts a maximum of 0.89 AU/ha/yr at plantation age 4.5 yr. Grazing started at plantation ages 2.5 yr; no plantations older than 9.5 yr are grazed.     

Effects of pruning on radial growth and biomass increment of trees growing in homegardens of Kerala, India

To evaluate the effects of pruning on stem radial growth increment and leaf and twig biomass production, an experiment with four pruning intensities (0, 50, 75 and 90%) on ten locally important tree species (Ailanthus triphysa, Albizia odoratissima, Artocarpus hirsutus, Bombax malabarica, Bridelia crenulata, Erythrina indica, Grewia tiliifolia, Macaranga peltata, Terminalia paniculata and Xylia xylocarpa ), was carried out. The results did not support the contention that a certain level of pruning promotes stem growth in trees. Instead, all species have a level of pruning that reduces annual increment in stem diameter. In Ailanthus triphysa and Artocarpus hirsutus trees subjected to different pruning intensities showed a decline in the annual increment in stem diameter while in other species diameter increment reduced when the pruning intensity was 75% and 90%. Response to pruning in terms of biomass production also varied from species to species. In Erythrina indica, Macaranga peltata and Terminalia paniculata annual foliage and branch production in pruned trees was significantly more than that of the un-pruned trees. However, in Ailanthus triphysa, Albizia odoratissima, Artocarpus hirsutus, Bridelia crenulata, Grewia tiliifolia and Xylia xylocarpa pruned trees produced comparatively more amount of foliage and branches produced annually than that by the un-pruned trees when the pruning was carried out once in 2 years. Based on these observations it is recommended that trees of Erythrina indica, Macaranga peltata and Terminalia paniculata may be pruned at 50% level annually while the trees of Ailanthus triphysa, Albizia odoratissima, Artocarpus hirsutus, Bridelia crenulata, Grewia tiliifolia and Xylia xylocarpa may be pruned at the same pruning intensity once in 2 years.     

Quantification of knots in dimension lumber using a single-pass X-ray radiation

The knot depth ratio (KDR) evaluation method was designed to quantitatively evaluate the amount of knot in dimension lumber by a single-pass X-ray radiation. To verify the proposed method, KDR values for 38-mm-thick specimens were predicted, and they were compared with the actual measured KDR values. The knot is surrounded by the transition zone, and the density of the knot and the transition zone is higher than the clear wood. Because the average density of the transition zone was similar to the knot density, it was found that the proposed method gives the KDR values for the knot area including the transition zone. The coefficients of determination between the predicted and measured KDR values were 0.87 and 0.83 for Japanese larch and red pine specimens, respectively. Using the KDR information, the ratio of knot area including transition zone to cross-sectional area was calculated. The presence of latewood and earlywood in the same path of the X-ray radiation caused discrepancies in the estimation of KDR values because the density of latewood is much higher than that of earlywood. Fortunately, latewood and earlywood are repeated in a cross section, so the amount of overestimation and underestimation was expected to be nearly identical. As expected, the relationship between the predicted area ratio and the real area ratio of knot and transition zone was strong with R ² values of 0.89 and 0.93 for Japanese larch and red pine specimens, respectively.     

Interactions amongst trees and crops in <Emphasis Type="Italic">taungya</Emphasis> systems of western Kenya

Lack of empirical data on the effects of the taungya system on establishment and early growth of softwood plantations have partly contributed to controversial decisions regarding the continued suitability of the system for plantation establishment in Kenya. This study examined effectiveness of taungya systems of forest plantation establishment using Cupressus lusitanica and Pinus patula trees with Zea mays (maize) as a test intercrop on two contrasting site types (deep and shallow soils) in Mt. Elgon forest, western Kenya . Four treatments were evaluated in each site: trees with or without weed control, trees intercropped with maize, and sole maize. Results showed that tree survival, growth and nutrient uptake, and maize growth and yield were higher in the deep soil site than the shallow site. The t aungya system improved tree survival and growth, effects being greater in the deep than the shallow soil site. Both Cupressus lusitanica and Pinus patula trees had the same effects on maize growth and yield, reducing maize growth by 41–48% in the deep soil sites, and by 16–26% in the shallow site. Vector nutrient analysis and vector competition analysis of the treatment effects on growth and nutrient uptake of the trees and the maize crop suggested competition for N on the deep soils, but competition for K and P on the shallow soils. The study has demonstrated the applicability of graphical vector competition analysis in diagnosing tree–crop interactions in agroforestry.     

Models of Internal Knot Diameter for Pinus sylvestris

The objective of this investigation was to develop models describing the vertical variation in internal knot size of Scots pine (Pinus sylvestris L.) stems. The sawlog portion of 198 mature trees was scanned using computed tomography in order to measure internal knot size. The variation in knot diameter at the sound/loose knot border was described in terms of a non-linear segmented (hyperbolic-quadratic-quadratic) model, and as a function of stand variables, tree variables and height above ground. A second, simpler (hyperbolic-quadratic) model which was deemed easier to implement was also presented. Although no validation data set was available, the models performed adequately for trees with different growth rates, growing on different sites and being at different stages of development. These results are intended to be integrated in a model system for conversion simulation studies applicable to mature trees.     

Genetic diversity of the hyperparasite Sphaerellopsis filum on Melampsora willow rusts

The non‐specific rust hyperparasite Sphaerellopsis filum occurs naturally on Melampsora rusts of many species of the genus Salix as well as on a large range of other rust genera worldwide. To study the genetic diversity of the hyperparasitic fungus 77 S. filum isolates collected from rusts on willow clones from plantations, clone collections and natural habitats of different sites were investigated using polymerase chain reaction ‐ restriction fragment length polymorphism (PCR‐RFLP) analysis of the rDNA internal transcribed spacer regions including 5.8S rDNA and sequence analysis. Additionally, strains from Melampsora poplar rusts (4) and strains of Puccinia abrupta from Parthenium hysterophorus (5) and of P. obscura from Bellis perennis (1) were used for comparisons. Results of genetic analysis demonstrated distinct variation within the S. filum isolates. Two main groups with more than 32% difference between their nucleotide sequences were distinguished, indicating two taxa within S. filum. Within the first main group three profiles (I, II, III) were detected. The differences between these profiles were about 12%. The variation within each profile was very low (less than 2%). The second main group comprised two profiles (IV, V), which differed in 12 to 16% of their nucleotide positions. The isolates of group IV possessed a higher variation (up to 5%) within the group than those of the first main group (I, II, III). Group V was only represented by a single isolate. Neither interrelations between the S. filum profiles and the Melampsora genotypes nor a spatial distribution could be detected. It is remarkable that the six strains of S. filum from Puccinia rusts belong to one subgroup.     

Seasonal dependence of rooting success in cuttings from natural forest trees in Madagascar

Four ligneous species from the tropical forest in the east of Madagascar, with a proven or potentially high economic value, were subject to ‘low-tech’ vegetative propagation tests from stem cuttings. The species concerned were Aphloia theiformis, Ilex mitis, Prunus africana and Ravensara aromatica. The cuttings were three-node segments of stems on which one leaf was retained. All the species proved amenable to rooting. The maximum percentage of rooting ranged from 33% for P. africana to 60% for I. mitis. Rooting success was dependant on the season of cutting (high in the hot season, from October to May, and null in cold season). This study is the first successful attempt at propagating cuttings from Malagasy forest species. This result is of particular importance to P. africana, threatened by destructive exploitation in Madagascar. It goes a step further in the domestication of this species by demonstrating the ability of cutting from 10 year old ortets collected in natural forest to root as it offers the possibility of a reliable and effective method of reintroduction for the species in overexploited zones.     

Increased planting density as a means for improving Pinus elliottii lumber stiffness

Faster growth and reduced harvesting ages are causing a reduction in the stiffness of lumber from South African grown pine plantations. The objective of this study was to determine whether increased planting densities of Pinus elliottii would result in improved stiffness of its sawn lumber and whether it would affect other relevant lumber properties. Four planting density treatments (403, 1 097, 1 808, and 2 981 stems ha^?1) of a 12-year-old experimental spacing trial were processed into lumber. The static modulus of elasticity (MOE_stat), modulus of rupture (MOR), warp, knot properties and density of the lumber were measured for 172 boards. Results showed that the planting density had a significant effect on the MOE_stat of the lumber. The higher mean MOE_stat (up to 27% increases) of lumber from densely planted trees seems to be the result of the higher slenderness and the slower diameter growth of these trees. Planting density also had a significant effect on the twist, knot area ratio and the number of knots per board. The magnitude of the effect on each of these properties, however, was relatively low.     

Allometric models to estimate foliage biomass of Tamarindus indica in Burkina Faso

Tamarindus indica L. is a multi-purpose tropical species. In West Africa the local people use its leaves daily as a source of food, medicine and income. To prevent the over-exploitation of this species for its use for non-timber forest products, the estimation of foliage production needs to be adressed. This study aimed to (1) assess the effects of distribution zone and tree size on foliage production of T. indica in Burkina Faso, and (2) develop allometric equations to estimate foliage biomass of this species. A semi-destructive method was used to assess foliage biomass of 120 trees over six stem-diameter size classes within two distribution zones (Sub-Sahelian and North-Sudanian). A two-way ANOVA was perfomed to test the effect of distribution zone and tree size class on foliage production. Allometric equations were fitted with 80% of the sample trees randomly selected and 20% were used for model validation. The results showed that between the two factors, tree size class exhibited a significant effect on foliage production of T. indica both in the Sub-Sahelian and North-Sudanian zones. Allometric equations to predict the foliage biomass of T. indica were similar for its distribution zones in Burkina Faso. Therefore, a general model is adequate for the prediction of foliage biomass of T. indica at a larger scale including a variety of ecological conditions. Stem diameter at 1.3 m aboveground was the most accurate predictor variable (adjusted R² = 0.81) with a prediction error of ?2.76%. This study opens up new potentials to develop and use allometric equations for West African trees of high socio-economic value in their effective and sustainable use for non-timber forest products.     

Knots in trees: strain distribution in a naturally optimised structure

Electronic speckle pattern interferometry was applied to directly measure the distribution of longitudinal, tangential, and shear strains in small boards of Norway spruce (Picea abies (L.) Karst.) exposed to tensile load in longitudinal direction. A sample with a central intergrown knot and one with an equivalent loose knot were compared with reference samples made of clear wood with an artificial central circular or square hole, respectively. The observed measurements were compared with a finite element (FE) simulation. The FE model was based on a geometric model to quantify the local fibre orientation and a micromechanical model to estimate elastic constants of clear wood and knot tissue. Both the measurements and simulation clearly illustrate a rather homogenous strain distribution around the intergrown knot. In comparison, the natural optimisation of dispersing strain peaks is less efficient in the case of loose knots. The artificial circular and square holes in samples with parallel fibre orientation lead to high gradients in the strain field and peak values in vicinity of the disturbance.     

Anatomical observations of Pseudomonas savastanoi on Rhamnus alaternus

Buckthorn (Rhamnus alaternus) was recently reported as a new host of Pseudomonas savastanoi. The main symptom on buckthorn is the formation of knots on stems, branches and occasionally on leaves. Knot formation and anatomical changes in host tissues induced by P. savastanoi were studied macroscopically and by light microscopy. Inoculation of buckthorn shoots with P. savastanoi initiated small green swellings that developed into normal size knots. The pathogen invades intercellular spaces of parenchyma tissues degrading cell walls and resulting in extensive cavities filled with bacterial cells. Many host cells contiguous to such cavities were plasmolysed and necrotic. Depending on the depth of the inoculation wound, parenchyma, cambium, ray parenchyma, and pith cells close to bacterial cavities enlarge and proliferate forming the fully grown knots. At later stages of knot development, the cambium appears dispersed in the knot and forms unoriented vascular tissues. Periderm surrounds bacterial cavities and outer layers of knots. These findings on buckthorn are compared with those reported to be caused by the same pathogen on ash, oleander and olive.     

Relationship between branch-scar parameters and knot features of oriental beech (Fagus orientalis Libsky)

The classification of roundwood is inextricably linked to the measurement of a particular single wood defect. The appearance, location, and number of defects are important in the quality evaluation of logs and sawn timber, and the most important defects are knots. The purpose of this study was to investigate the relationship between the appearance of branch scars and features of the related knot inside oriental beech logs, and to model the relationship between well-defined branch-scar and knot parameters. One hundred and fifty knots in 15 stems of oriental beech trees were studied. Image analysis software was used to measure the branch-scar and knot features. The results showed a significant positive correlation between the branch-scar parameter “moustache length” and the knot length. The ratio of branch-seal length to width was found to be a good estimator of the stem diameter at the time of knot occlusion and the amount of clear wood between the knot occlusion and the bark. The relationship obtained for the oriental beech stem radius at time of knot occlusion confirms relationship reported for European beech (Fagus sylvatica L.).