Genetic parameter estimates in a clonally replicated progeny test of teak (Tectona grandis Linn. f.)

Teak (Tectona grandis Linn. f.) has been planted extensively in the tropics for its highly valued timber. We analysed data from a 3.5-year-old teak progeny test with clonal replication located in northern Australia. Additive and non-additive genetic variances were estimated for commercially important traits. Trees originating from seedlings were on average 2% taller and 4% straighter than those of the same genotype originating from cuttings. Non-additive genetic variance represented 35–50% of total genetic variance for growth traits and 63% of total genetic variance for incidence of flowering. Narrow-sense heritability was 0.22 for diameter, 0.18 for height and volume, 0.07 for stem straightness, 0.05 for insect defoliation, 0.03 for epicormic sprouts and 0.30 for incidence of flowering (estimated on an assumed underlying continuous scale). Broad-sense heritability was 0.37 for diameter, 0.28 for height, 0.35 for volume, 0.12 for stem straightness, 0.06 for insect defoliation, 0.12 for epicormic sprouts and 0.71 for incidence of flowering. Positive correlations were found between tree volume and flowering and between tree volume and stem straightness. The presence of sizeable non-additive variance supports the selection and deployment of clones to capture the full extent of genetic variation in commercially important traits.     

Variations in pith eccentricity and ring width in teak (Tectona grandis L. F.)

Summary Wood samples were collected from a teak (Tectona grandis) plantation established in Gambari Forest Reserve (Dry Forest) near Ibadan in south-western Nigeria. Values of percentage pith eccentricity (PPE) of bole cross-sections were computed using appropriate geometrical methods. Also the growth rings of the cross-sections were identified and their widths measured. Pith eccentricity and ring width did not vary significantly between plots on the site. Variations in pith eccentricity and ring width between trees on plots were very highly significant (at 0.1% probability level). Pith eccentricity and ring width varied along tree boles: the effect of height above the ground was very highly significant in each case. On average, pith eccentricity was highest at the base and top of the merchantable bole. The magnitudes of variations in both pith eccentricity and ring width along the bole differed between the plots: plots x levels interaction effect was very highly significant in each case. A decrease in ring width corresponded with an increase in the age of the vascular cambium. Only small proportions of the variation in pith eccentricity could be estimated from concomitant variations in radial growth rate (ring width), bole form factor and crown depth; the values of r ² were 11%, 10% and 11% respectively.     

Resistance of Scots pine wood to Brown-rot fungi after long-term forest fertilization

The susceptibility of Scots pine (Pinus sylvestris L.) sap- and heartwood against the wood decaying brown-rot fungus (Coniophora puteana) was investigated after long-term forest fertilization at three different sites in central Finland. Different wood properties: wood extractives, wood chemistry, and wood anatomy were used to explain sap- and heartwood decay. Scots pine sapwood was more susceptible to decay than its heartwood. In one site, sapwood seemed to be more resistant to wood decay after forest fertilization whereas the susceptibility of heartwood increased. Significant changes in the sapwood chemistry were found between treatment and sites, however, no relationship between wood chemistry and wood decay was observed in the factor analysis. The results of this study show that there was an inconsistent relationship between decay susceptibility and fertilization and the measured physical and chemical attributes of the wood were not consistently correlated with the decay rate.     

Reconstruction of June–September precipitation based on tree-ring data of teak (Tectona grandis L.) from Hoshangabad, Madhya Pradesh, India

An attempt has been made to explore dendroclimatological potentiality of teak (Tectona grandis L.) towards the reconstruction of climate from a new geographical region. Growth of this tree has been found to be limited by the low monsoon precipitation. Based on ring-width data of teak, mean monsoon precipitation of June–September has been reconstructed back to AD 1835. The reconstructed climate records show several alternating periods of high and low monsoon episodes. Many of these low monsoon years have been recorded to coincide with most of the known principal drought years of India.     

Wood stimulates the demethoxylation of [O14CH3]-labeled lignin model compounds by the white-rot fungi Phanerochaete chrysosporium and Phlebia radiata

Mineralization of polymeric wood lignin and its substructures is a result of complex reactions involving oxidizing and reducing enzymes and radicals. The degradation of methoxyl groups is an essential part of this process. The presence of wood greatly stimulates the demethoxylation of a non-phenolic lignin model compound (a [O¹⁴CH₃]-labeled β-O-4 dimer) by the lignin-degrading white-rot fungi Phlebia radiata and Phanerochaete chrysosporium. When grown on wood, both fungi produced up to 47 and 40% ¹⁴CO₂ of the applied ¹⁴C activity, respectively, under air and oxygen in 8 weeks. Without wood, the demethoxylation of the dimer by both fungi was lower, varying between 0.5 and 35%. Addition of nutrient nitrogen together with glucose decreased demethoxylation when the fungi were grown on spruce wood under air. Because the evolution of ¹⁴CO₂ in the absence of wood was poor, the fungi may have preferably used wood as a carbon and nitrogen source. The amount of fungal mycelium, as determined by the ergosterol assay, did not show connection to demethoxylation. P. radiata also showed a high demethoxylation of [O¹⁴CH₃]-labeled vanillic acid in the presence of birch wood. The degradation of lignin and lignin-related substances should be studied in the presence of wood, the natural substrate for white-rot fungi.     

Biodegradation of Pinus radiata softwood by white- and brown-rot fungi

The weight and component losses of Pinus radiata wood after decay by six species of white-rot and two species of brown-rot fungi for periods varying from 30 to 360 days were evaluated. Three groups of decayed wood samples were identified based on the principal component analysis (PCA) of the data on their weight and component losses. Selective lignin degradation was produced by Ceriporiopsis subvermispora and Punctularia atropurpurascens within different periods, the longest one lasting 90 days, and also by Merulius tremellosus after 90 days of biodegradation. Comparing the data on biodegradation of P. radiata by Trametes versicolor with the ones reported for biodegradation of Eucalyptus globulus and E. grandis indicated that P. radiata is as susceptible to wood decay by this white-rot fungus as the two types of hardwood.     

Dry weight loss and changes in chemical composition of pine (Pinus kesiya Royle) needles and teak (Tectona grandis L.) leaves during processing in a freshwater lake

The dry weight loss and chemical changes during the process of decomposition of two types of litters viz.; pine (Pinus kesiya Royle) needles and teak (Tectona grandis L.) leaves have been studied in a small freshwater lake using plastic net (1 mm pore size) bags. The results reveal that type of litter and depth of water were the most important factors regulating the rate of decomposition. The percentage composition of cellulose and hemicellulose showed little variation and only a minor fall was noted in their values towards the end of the study period. The lignin percentage increased steadily at all the stations except the deepest station. The sugar and amino acid concentration dropped appreciably during the initial phase and stabilised during later periods. The general trend of change in nitrogen percentage was initial fall - increase - fall - stabilisation at a near original value. The rate of decomposition was faster when compared with similar studies in Canada and Europe.     

Stock-plant etiolation causes drifts in total soluble sugars and anthraquinones, and promotes adventitious root formation in teak (Tectona grandis L. f.) coppice shoots

The effects of stock-plant etiolation on coppice-shoot growth, drifts in total soluble sugars and anthraquinones (AQs; C₁₄H₈O₂), and rooting potentiality of shoot cuttings were examined in Tectona grandis L. f. (clone FG1). When seedlings were one-year-old, they were coppiced and maintained in the dark for etiolation, with a parallel set kept under natural light in an open environment. Coppice shoots were made into single-node leafy cuttings (SNCs), which were cultured under intermittent mist for rooting. These SNCs were treated with different concentrations of NAA (0, 2000 and 3000 mg l⁻¹). Etiolation significantly increased the coppice-shoot length, internode length, number of coppice shoots, number of leaves, number of nodes and total soluble sugars. The HPTLC analysis showed qualitative and quantitative differences in AQs in coppice shoots obtained from etiolated and non-etiolated stock plants. The study showed that AQs could be used as a marker for maturity and juvenility in teak. Stock-plant etiolation caused a significant increase in percent rooting and sprouting, shoot length, number of shoots and number of leaves per SNC, but a decrease in callusing at the base of the SNC. NAA at 2000 and 3000 mg l⁻¹ had inhibitory effects on rooting and sprouting of SNCs. The result showed that stock-plant etiolation fostered rooting by rejuvenating the coppice shoots.     

Evaluation of the white-rot fungi Ganoderma australe and Ceriporiopsis subvermispora in biotechnological applications

Ganoderma australe is a white-rot fungus that causes a selective wood biodelignification in some hardwoods found in the Chilean rainforest. Ceriporiopsis subvermispora is also a lignin-degrading fungus used in several biopulping studies. The enzymatic system responsible for lignin degradation in wood can also be used to degrade recalcitrant organic pollutants in liquid effluents. In this work, two strains of G. australe and one strain of C. subvermipora were comparatively evaluated in the biodegradation of ABTS and the dye Poly R-478 in liquid medium, and in the pretreatment of Eucalyptus globulus wood chips for further kraft biopulping. Laccase was detected in liquid and wood cultures with G. australe. Ceriporiopsis subvermispora produce laccase and manganese peroxidase when grown in liquid medium and only manganese peroxidase was detected during wood decay. ABTS was totally depleted by all strains after 8 days of incubation while Poly R-478 was degraded up to 40% with G. australe strains and up to 62% by C. subvermispora after 22 days of incubation. Eucalyptus globulus wood chips decayed for 15 days presented 1–6% of lignin loss and less than 2% of glucan loss. Kraft pulps with kappa number 15 were produced from biotreated wood chips with 2% less active alkali, with up to 3% increase in pulp yield and up to 20% less hexenuronic acids than pulps from undecayed control. Results showed that G. australe strains evaluated were not as efficient as C. subvermispora for dye and wood biodegradation, but could be used as a feasible alternative in biotechnological processes such as bioremediation and biopulping.     

Demethoxylation of [O14CH3]-labelled lignin model compounds by the brown-rot fungi Gloeophyllum trabeum and Poria (Postia) placenta

Demethoxylation reactions in the cultures of the brown-rot fungi Gloeophyllum trabeum and Poria placenta were studied by determining the evolution of (14)CO(2) from a non-phenolic lignin model, beta-O-4 dimer, [O(14)CH(3)]-labelled at position 4 in the A ring (model I), and from [O(14)CH(3)]-labelled vanillic acid (model II). The fungi were grown under oxygen or air atmosphere on an agar medium with or without spruce sapwood blocks. The dimeric model (I) was impregnated onto agar or wood block in cultures to clarify the possible effect of wood as growth substrate. In the case of vanillic acid (model II), birch wood was used. The effect of supplemented nutrient nitrogen (2 mM N) and glucose (0.1 or 1.0% w/v) on demethoxylation was also studied. G. trabeum enhanced the production of (14)CO(2) from the dimer in the presence of spruce wood blocks. It released (14)CO(2) from the methoxyl groups giving 30-60% of the applied activity in 8 weeks. P. placenta produced almost 30% (14)CO(2 )from vanillic acid (model II) in 9 weeks under oxygen, but from the methoxyl group of the dimer only 3% of (14)CO(2) was evolved in 4 weeks. The biomasses determined as ergosterol assay showed variation from 14 to 226 microg g(-1) dry weight of agar, and 2 to 9 microg g(-1 )of wood, but they did not correlate with the production of (14)CO(2). The results indicate that these brown-rot fungi possess different mechanisms for demethoxylation.     

Endophytic fungi of teak leaves Tectona grandis L. and rain tree leaves Samanea saman Merr.

Summary In order to study the foliar endophytes from teak (Tectona grandis L.) and rain tree (Samanea saman Merr.) growing in the campus of Chulalongkorn University, healthy leaves were collected at two-monthly intervals during January to December. The number of genera and species, together with their colonization frequency (CF%) in mature teak and rain tree leaves were greater than those in the young leaves. More endophytic isolates in the leaves of both trees were recovered during the rainy season. The fungal genera found in both young and mature teak leaves were Alternaria, Colletotrichum, Nigrospora, Phomopsis and mycelia sterilia. Phomopsis was the dominant genus in both young (newly emerged) and mature leaves. Fusarium, Penicillium, Schizophyllum commune and members of the Xylariaceae were found only in mature leaves. For the rain tree leaves, species of Phomopsis and mycelia sterilia were found in both young newly emerged and mature leaves. Colletotrichum and Penicillium were found only in mature leaves, whereas Nigrospora was found only in young newly emerged leaves. In this study, Phomopsis was the dominant genus in the leaves of both tree species. A total of 37 isolates of endophytic fungi isolated from teak and rain tree leaves were tested for the production of antimicrobial activities. Out of these, 18 isolates could produce inhibitory substances effective against Bacillus subtilis, Staphylococcus aureus and Escherichia coli and 3 isolates inhibited growth of Candida albicans in vitro.     

不同光源对柚木组培苗生长发育的影响

该研究采用不同光源处理柚木组培继代苗,通过测定株高、叶宽、叶鲜重、全株干重、叶绿素含量和观察叶片上下表皮结构,研究不同光源对柚木组培苗生长发育的影响,并筛选适宜其快速生长发育的光环境。结果表明:不同光照下顶芽培养的植株高生长顺序为H_(FL)﹥H_(1RB)﹥H_S﹥H_(2RB)﹥H_(3RB)﹥H_D,茎段培养的腋芽高生长顺序为h_(FL)﹥h_S﹥h_D﹥h_(1RB)﹥h_(2RB)﹥h_(3RB)。LED红蓝组合灯(2RB、3RB)处理下植株最大叶宽显著大于荧光灯(FL)、全光谱灯(S)和无补光设备(D)处理,并随RB光强增加,最大叶宽及叶鲜重显著增加。全株干重以D和S光照处理显著低于其它光照处理。RB系列和S光照处理下的叶绿素总含量高于对照FL和D处理组。2RB和3RB光照处理下叶片的上表皮细胞不规则多角形,相互镶嵌排列,其它光照处理下上表皮细胞呈圆形。下表皮气孔数量在有补光设备处理(S、RB、FL)时是无补光设备处理(D)的1.5倍以上,2RB和3RB光照处理下气孔张开度大于对照FL和D处理组,且保卫细胞呈井型突起。参试光源中,柚木组培苗增殖阶段选择荧光灯或全光谱灯为好,高生长显著,腋芽分化和生长快,有利于提高增殖率;而RB红蓝组合灯(3RB、2RB)适合壮苗培养,叶大苗壮,全株生物量大,且叶表面结构发育成熟,有利于提高光合作用。     

Fluctuations of cambial activity in relation to precipitation result in annual rings and intra-annual growth zones of xylem and phloem in teak (Tectona grandis) in Ivory Coast

Background and Aims Teak forms xylem rings that potentially carry records of carbon sequestration and climate in the tropics. These records are only useful when the structural variations of tree rings and their periodicity of formation are known. Methods The seasonality of ring formation in mature teak trees was examined via correlative analysis of cambial activity, xylem and phloem formation, and climate throughout 1·5 years. Xylem and phloem differentiation were visualized by light microscopy and scanning electron microscopy. Key Results A 3 month dry season resulted in semi-deciduousness, cambial dormancy and formation of annual xylem growth rings (AXGRs). Intra-annual xylem and phloem growth was characterized by variable intensity. Morphometric features of cambium such as cambium thickness and differentiating xylem layers were positively correlated. Cambium thickness was strongly correlated with monthly rainfall (R(2) = 0·7535). In all sampled trees, xylem growth zones (XGZs) were formed within the AXGRs during the seasonal development of new foliage. When trees achieved full leaf, the xylem in the new XGZs appeared completely differentiated and functional for water transport. Two phloem growth rings were formed in one growing season. Conclusions The seasonal formation pattern and microstructure of teak xylem suggest that AXGRs and XGZs can be used as proxies for analyses of the tree history and climate at annual and intra-annual resolution.     

Optimisation of physical factors on the production of active metabolites by Bacillus subtilis 355 against wood surface contaminant fungi

A Surface Response Model was used to study the effect of pH, temperature and agitation on growth, sporulation and production of antifungal metabolites by Bacillus subtilis CCMI 355.Strong agitation, temperature between 27 and 34 °C and pH 6 favoured cell growth. Alkaline pH, strong agitation and temperature between 28 and 34 °C favoured spore formation. No relationship was found between sporulation and the production of antifungal metabolites. According to the model, pH 8, 37 °C and the absence of agitation were the optimal conditions for the production of broad-spectrum antifungal metabolites against Botrytis cinerea, Penicillium expansum, Trichoderma sp, Trichoderma harzianum, Trichoderma koningii and Trichoderma virgatum.In situ assays using green wood impregnated with Bacillus subtilis CCMI 355 inoculated in Yeast Extract Glucose Broth medium in the conditions above, displayed an efficient protection against wood surface contaminant fungi.     

Wood anatomy of theSarraceniaceae; ecological and evolutionary implications

The wood of theSarraceniaceae has a considerable number of primitive features including scalariform perforation plates, long and oblique end walls, scalariform lateral wall pitting, solitary vessels, tracheids with scalariform pitting, and diffuse axial parenchyma. Vessel elements in the genusHeliamphora have the greatest number of primitive features, while vessel elements inDarlingtonia andSarracenia appear to have modifications relating to temperate climates. The wood anatomy suggests thatHeliamphora is growing in a habitat more similar to the original habitat for the family thanDarlingtonia andSarracenia. The wood of theSarraceniaceae is similar to the wood of theTheales.     

Effect of Water Stress on Photosynthesis and Growth in Two Teak Phenotypes

Two teak (Tectona grandis L.f.) phenotypes differing in their leaf length/breadth ratios were subjected to water stress by withholding water supply for three weeks. Growth rates of whole plants, developing leaves (1^st and 2^nd from shoot apices), and 2^nd and 3^rd internodes were higher in broad leaved (BL) phenotype than in narrow leaved (NL) phenotype before and after imposing water stress treatment. However, the effect of water stress on these parameters was higher in the BL phenotype than in the NL one. Diurnal course of net photosynthetic rate (P _N) of 3^rd or 4^th leaves from shoot apices measured under well-watered conditions was higher for the NL than BL phenotype. P _N, stomatal conductance (g _s), and transpiration rate (E) in both phenotypes were negatively affected by water stress and their decline under water stress was significantly higher in the BL than NL plants. This revised version was published online in June 2006 with corrections to the Cover Date.     

Antifungal activity of <Emphasis Type="Italic">Bacillus subtilis</Emphasis> 355 against wood-surface contaminant fungi

A strain of Bacillus subtilis was examined for antifungal activity against phytopathogenic and wood-surface contaminant fungi. The bacterium was grown in five culture media with different incubation times in order to study cell development, sporulation, and the production of metabolites with antifungal activity. The anti-sapstain and anti-mould activity of the bacterium grown in yeast extract glucose broth (YGB) medium in wood was also evaluated. In YGB, the bacterium inhibited the growth of several fungi and displayed a broader spectrum of activity than in the other media tested. A relationship between bacterial spore production and the formation of metabolites with antifungal activity was detected. YGB medium displayed effective control in wood block tests. YGB medium was extracted with solvents of increasing polarity and the dry residues were applied to silicagel plates, resolved with the appropriate solvent and sprayed with different solutions, detecting the presence, of amines, and higher alcohols. The bioautographic method revealed the presence of at least two active compounds against the blue-stain fungus Cladosporium cucumerinum.     

Trichomes: their Diversity,Distribution and Density in Acclimatization of Teak (Tectona grandis L.) Plants Grown in vitro

Diversity, distribution and density of trichomes were studied in relation to other morphological and physiological parameters of in vivo and in vitro teak (Tectona grandis L.) plants with the objective to understand their role in hardening and acclimatization of micropropagated plants. Less diversity and scanty distribution of trichomes of in vitro leaves in comparison to the in vivo ones were correlated with water loss of the former plants leading to low rate of survival after transplantation. The probable cause for absence of certain types of trichome in in vitro plants was also discussed.     

Effect of enzyme extracts isolated from white-rot fungi on chemical composition and in vitro digestibility of wheat straw

A series of in vitro experiments were completed to evaluate the potential of enzyme extracts, obtained from the white-rot fungi Trametes versicolor (TV1, TV2), Bjerkandera adusta (BA) and Fomes fomentarius (FF), to increase degradation of cell wall components of wheat straw. The studies were conducted as a completely randomized design and analysed using one-way ANOVA. Enzyme activities of the extracts, previously obtained from a liquid culture medium, were characterized in terms of laccase and peroxidase for ligninolytic activity. Carboxymethyl cellulase (CMCase) and avicell digesting cellulase (Avicelase) were used for cellulolytic enzyme assays. Wheat straw samples were incubated with enzyme extracts in a citrate buffer (pH 5.0) in a forced air oven at 25 °C for 6 days. In vitro NDF digestibility (IVNDFD), and the rate and extent of NDF fermentation, without and after incubation with the white-rot enzyme extracts, were determined using a gravimetric microbiological method and a gas production technique, respectively. Results from cell wall chemical composition showed that TV2 and BA enzyme extracts decreased NDF concentration (P<0.05) and that TV1 had higher activity (P<0.05) towards cellulose. There was an increase in IVNDFD (P<0.05), resulting from treatment of wheat straw with enzyme extracts from BA, TV1 and TV2, reaching a difference of 13% for TV2 (P<0.05), versus the non-treated straw control. Treatment with enzyme extract from TV2 caused increased gas production (P<0.05) after the first 20 h of incubation, and also increased the maximum rate of gas production, thus enhancing fermentation kinetics. This study indicates that enzyme extracts from white-rot fungi can be used to develop new approaches to overcome low digestibility of some plant cell walls. Utilization of different substrates to produce enzyme extracts can lead to production of viable ligninolytic complexes which could improve the nutritive value of fibrous feeds.     

Pathogenicity, formulation and storage of insect pathogenic hyphomycetous fungi tested against Diabrotica speciosa

Studies were conducted tosearch for fungal strains with potentialpathogenicity against Diabrotica speciosa(Germar) (Coleoptera: Chrysomelidae).Among sixteen fungal isolates screenedthe most virulent was a Beauveria bassiana(Balsamo) Vuillemin isolate (FHD13) thatcaused 70% mortality of D. speciosathird instar larvae. The LC₅₀ value ofB. bassiana isolate FHD13 was3.48 × 10¹⁰ conidia/ml.Different temperatures (4, 17 and 26 °C)and vegetable oils (corn, sunflower and canola)used for storage did not significantly affectviability of conidia. A pathogenicity trialagainst D. speciosa larvae performed withthe corn oil formulation (1 × 10⁸ conidia/mlof oil) caused 65% of mortality.