Variation in Shoot Anatomy and Rooting Behaviour of Stem Cuttings in Relation to Age of Donor Plants in Teak (Tectona grandis Linn. f.)

Shoot anatomical features viz., number of vessel elements, width and length of vessel and fibre elements were studied in relation to juvenility/maturity of teak (Tectona grandis Linn. f.). The findings show significant differences in these features, which indicates that variation in shoot anatomy can be used as a reliable indicator of juvenility/maturity in teak. The effect of age of donor plants and application of auxins on adventitious root formation in single noded leafy stem cuttings of teak was also investigated. Aging of donor trees suppressed rooting and sprouting of cuttings, but increased callus formation at the base of cuttings. Per cent rooting and per cent sprouting in cuttings decreased as age of donor plants increased from 2-months to 15-years and up to 30-years. IBA treatment promoted per cent rooting as well as per cent sprouting, NAA promoted only rooting and it suppressed sprouting. The effect of auxin treatment on rooting and sprouting of teak stem cuttings varied with the age of donor plants. Auxin and its concentration, which suppressed rooting and sprouting in cuttings of younger donor plants, actually promoted rooting when cuttings were taken from more mature donor plants. It appears that the auxin requirement for causing and promoting rooting in teak cuttings increased with increasing age of donor plants. The higher auxin requirement for causing and promoting rooting in cuttings of older trees may be due to a decrease in the content on endogenous auxins or decreased sensitivity of aging tissues to rooting promoters and /or accumulation of inhibitory substances which inhibit rooting.     

Influence of Microbial Inoculants on Seedling Production in Teak (Tectona grandis L.f.)

Abstract

An experiment was conducted in forest college campus, Mettupalayam, India with an objective of studying the influence of microbial inoculants on seedling growth of teak. The fruits were collected from the seed production area in top slip (Tamil Nadu) from 63-year mother trees. The microbial inoculants viz., Azospirillum, Azotobacter, phosphobacteria, AMF, Azospirillum + AMF, Azotobacter+ AMF, phosphobacteria + AMF and an uninoculated control formed the treatments. The inoculants were mixed sand and red soil at 1:1:3 ratio, respectively, for preparing nursery mixture for filling the poly pots. The seeds were sown into the poly pots @ two seeds per pot. The experiment was set up in a randomized Block Design with three replications. Biometric observations on various growth attributes were recorded six months after treatment and also their survival in the main field-tested for one year. Azotobacter gave best performance with respect to shoot length, shoot weight and leaf area and combined inoculation of phosphobacteria and AMF gave higher root length and biomass, dry matter production and fine root weight. The survival was better in seedlings that were inoculated with phosphobacteria and AMF. However, below ground biomass and out planting survival during early phase are critical in any tree species. Hence it is concluded that inoculation of phosphobacteria and AMF conjointly be done for better survival and growth of teak seedlings.     

柚木寒害调查及抗寒无性系选择

抗寒育种是柚木研究的重点方向,本文是在大田测定的基础上,调查分析了两个柚木无性系试验林的寒害结果,结果表明,两个试验点不同柚木无性系间的保存株数都达到极显著差异,广西博白试验点保存率为0～91.67%,贵州罗甸试验点保存率为8.33～86.17%。初步筛选出了抗寒性强的柚木无性系有7514、7509、7531、Z408、7559、8301和7029,两个试验点的保存率都在80％以上。参试柚木缅甸种源抗寒性优于印度种源。     

Variation in the natural termite resistance of teak (Tectona grandis Linn. fil.) wood as a function of tree age

? Tree age is one of the most important factors to affect the natural durability of wood.

? The purpose of this study was to determine the natural termite resistance of heartwood and sapwood of teak (Tectona grandis Linn. fil.) for trees aged 8, 30 and 51 years. Reticulitermes speratus Kolbe was employed as a test termite using a no-choice feeding method.

? The heartwood and sapwood of all of the trees tested exhibited antitermitic activity. Based on the mean mass loss due to termite activity, the sapwood and heartwood regions of 8-year-old trees are the most susceptible to termites while the heartwood regions of the 30-year-old trees showed termite resistance similar to the termite resistance of 51-year-old trees.

? The mass loss is moderately correlated with n-hexane extractive content, total extractive content, brightness and redness of the wood.

     

Characterization of Lasiodiplodia theobromae (Pat.) Griffon & Maubl causing stem canker on Teak (Tectona grandis L.) in Ecuador

Teak is a very important tropical timber in Ecuador. In 2017, teak samples displaying stem canker symptoms were collected in two provinces of Ecuador. From 11 symptomatic trees, 11 isolates resembling a species of Lasiodiplodia were obtained. All isolates obtained induced stem canker on teak plants after artificial inoculation, confirming them as the cause of the observed canker symptoms. Bayesian inference with concatenated sequences of complete ITS and partial TEF-α and β-TUB gene sequences from two representative isolates clustered teak isolates with other sequences of Lasiodiplodia theobromae available in Genbank. This is the first report of L. theobromae causing stem canker on teak plants in Ecuador.     

Evaluation of early growth performance of 41 clones of teak(Tectona grandis Linn. f.) at four microsites in Purwakarta,Indonesia

Teak(Tectona grandis Linn. f.), one of the mostvalued tree species in the world, is slow-growing with a long period until it can be harvested;therefore, ensuring that only high-quality seedlings or clones are selected for planting is critical. The main objective was to determine performance and repeatability of selected clones in terms of growth and survival rates in different micro-environments. A 2-year clonal trial using 41 clones and a local seedling of teak as a control were grown at 4 microsites differing in spacing, soil fertility and alley crops to assess tree height, diameter and survival rate that was evaluated in Purwakarta, West Java, Indonesia using a randomized complete block design with four replicates of each clone at each microsite. Teak growth was influenced by clone(p < 0.01), microsite(p < 0.05) and clone 9 micrositeinteraction(p<0.01). The interaction clone 9 microsite resulted in several potential superior clones that differed in terms of growth rates at each microsite. On the basis of diameter only, superior clones(nos. 14, 18, 24, 30 and 37)were identified. Repeatability estimated was Rc2= 0.84 for diameter and Rc2= 0.77 for height. Growth performance of teak trees varied among microsites. Repeatability values for diameter and height characters were high. The effect of variable growth on each clone was influenced by genetic factors, environmental factors and the interaction of genetics 9 environment. Microsite significantly affected growth of teak clones. Clone 9 microsite interaction significantly affected growth of clones and led to the growth of superior clones at each microsite.     

False ring formation in teak (Tectona grandis L.f.) and the influence of environmental factors

Seedling anatomy and cross sectional discs of 8- and 12-year-old (juvenile) teak trees were examined for tree ring analysis and determination of environmental factors responsible for false ring formation in teak. Based on the anatomy and location within the true annual rings, four types of false rings were identified. The results from both cross-dating of plantation grown trees and controlled experiments, including induced drought, showed that rainfall during dry period, drought during active growing season, (container) polybag/field transplantation of seedlings and juvenility are the important causative factors of frequent false rings in teak. No definite relationship could be established between insect defoliation and the incidence of false rings. False ring formation in teak appears to be mainly a resultant feature of tree ring responses to different environmental and physical factors.     

粗枝云杉无性系种子园生长性状变异和无性系选择初步研究

该粗枝云杉初级无性系种子园面积4.6 hm2,4个大区共保留87个无性系。1区无性系胸径、树高和冠幅的均值分别为8.52 cm、4.36 m和3.11 m;2区无性系胸径、树高和冠幅的均值分别为8.90 cm、5.50 m和3.60 m;3区无性系胸径、树高和冠幅的均值分别为8.89 cm、5.21 m和3.54 m;4区无性系胸径、树高和冠幅的均值分别为10.13 cm、6.50 m和4.17 m。方差分析表明,1区无性系胸径、树高和冠幅无性系间(内)差异极显著;2区无性系胸径、树高和冠幅无性系间(内)差异不显著;3区无性系胸径无性系间(内)差异极显著,树高无性系间(内)差异极显著和差异显著,冠幅无性系间差异极显著,无性系内差异不显著;4区无性系胸径、树高和冠幅无性系间(内)差异极显著。无性系内的生长量平均数变异较无性系间的小得多,初步说明生长性状主要受遗传控制。立地条件对无性系树高影响差异极显著,对胸径影响差异显著,对冠幅影响差异不显著,立地×无性系交互作用对无性系胸径、树高的影响差异极显著。依据各区无性系的树高的多重比较对各区无性系的生长性状进行排序。对种子园的经营管理和利用途径进行了探讨。     

Comparative study on growth,wood quality and financial returns of teak (Tectona grandis L.f.) managed under three different agroforestry practices

Growth, wood quality parameters and productivity estimations of 12-year-old teak (Tectona grandis L.f.) grown under three agroforestry systems, namely unmanaged block (B_um), unmanaged line on the farm boundary (L_um) and intensively managed block (B_im) plantations are studied. Mean annual increment (MAI) of 0.020, 0.006 and 0.016 m³ tree^?1 year^?1 was recorded in L_um, B_um and B_im, respectively. Overall growth performance of teak raised in L_um, plantation appears to be better than two block plantations (B_um and B_im). For evaluating various wood quality parameters, tree logs from each plantation were tested for different physical and mechanical properties according to the standard procedures. The wood quality of B_um was found to be comparatively superior to B_im and much better than those of L_um. The 12-year-old farm teak trees from three systems exhibited lower average values of different wood quality parameters compared to mature forest teak. Since physical and strength properties of B_um were inferior compared to L_um and B_im, its exploitation is not advisable at this stage. Line plantation, however, releases land for cultivation of arable crops and does not demand any special silvicultural management as required by B_im. Although, total extractable volume of teak wood available after 12-years of age from B_um was much smaller compared to B_im or L_um, its commercial exploitation at an early age may be preferred over other two practices due to better wood quality and lower management cost. For optimum economic utilization and mechanical maturity of wood, harvesting of block plantation may be delayed for about 10-15 years because growth volume and strength properties are expected to improve with age of tree.     

Morphological parameters and genetic diversity of progenies from seed production areas and unimproved stands of teak (Tectona grandis L.f.) in India

We compared morphological and genetic attributes of prog-eny obtained from three seed production areas (SPAs) and three corre-sponding unimproved stands (UIS) of teak (Tectona grandis L.f) at three bro...     

Seasonal variation in the biomass and non-structural carbohydrate content of fine roots of teak (Tectona grandis L. f.) plantations in a dry tropical region

Seasonal variation in the biomass and total non-structural carbohydrate content (TNC) of fine roots of teak (Tectona grandis L. f.) were studied in 19- and 29-year-old plantations in a dry tropical region. Fine root TNC content was highest during the dry summer (May), and lowest in the early part of the rainy season (July). Generally, seasonal trends in TNC content were the opposite of those in fine root biomass. The TNC concentration of roots increased with diameter and decreased with soil depth. In the 19-year-old plantation, fine root TNC content was approximately 12% higher than in the 29-year-old plantation.     

Diversity of arbuscular mycorrhizal fungi in <Emphasis Type="Italic">Tectona grandis</Emphasis> Linn.f. plantations and their effects on growth of micropropagated plantlets

Regeneration of stands of valuable tropical hardwood tree species for sustainable harvest requires production of seedlings with high probabilities of survival. One way to enhance the vigor of plants for outplanting is pre-colonization of roots by arbuscular mycorrhizal (AM) fungi. We pursued the strategy that the most promising AM fungus candidates for inoculation would be those associated with the tree of interest in the field. AM fungus communities were assessed in five plantations of Tectona grandis Linn.f. A total of 18 AM fungal morphotypes were found, representing four families: Glomeraceae (49.6%), Acaulosporaceae (24.9%), Claroideoglomeraceae (20.8%), and Gigasporaceae (4.8%). AM fungus spore density was negatively correlated with soil organic carbon. Some of these AM fungi, plus Rhizophagus irregularis, were established in pot culture and in vitro with transformed carrot roots, and subsequently used to inoculate micropropagated plantlets of T. grandis. Tectona grandis plantlets inoculated in vitro were successfully colonized by all AM fungi studied. Plants inoculated with Funneliformis mosseae were taller than uninoculated plants. Tectona grandis plantlets inoculated with the AM fungus Claroideoglomus etunicatum PBT03 were taller than uninoculated controls in ex vitro experiments. This study provides early insight for the targeted use of the AM symbiosis in production of important tree species in future greenhouse studies and reforestation.     

杉木改良代无性系种子园子代测定林营建与评价

以阳新县七峰山林场杉木改良代无性系种子园自由授粉子代半同胞家系为研究对象,分析其树高、胸径、材积等生长性状,发现家系间存在极显著差异,说明杉木改良代无性种子园半同胞家系,经初级种子园子代测定林的选择,仍存在着较为丰富的变异,具选育潜力。其树高、胸径和材积间呈紧密相关关系。树高、胸径和材积的家系遗传力分别是0.4187、0.3315、0.4988,单株遗传力分别是0.2113、0.1329、0.2494,均为材积>树高>胸径,具有较强遗传力。按照33.3%的入选率,树高、胸径和材积入选10个家系均相同,其遗传增益分别是6.15%、7.21%、26.06%,可作为营建高世代种子园和进行人工交配进行全同胞测定的优良家系。     

Effect of auxins on axillary and de novo shoot regeneration from in vitro shoot cultures derived from forced epicormic buds of teak (Tectona grandis L.)

In this presentation,we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term,from cultures of Tectona grandis L.Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenic shoot-culture establishment.Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N 6-benzyleadenine (BA,8.8 μmol L-1) and indole-3-butyric acid (IBA,2 μmol L-1) for 24 months.Vigorously growing shoot tips (2 3 cm long) were inoculated on the MS basal medium supplemented with different concentrations (0,1,2,4,6,8 or 10 μmol L-1) of either IBA or α-naphthaleneacetic acid (NAA) for rooting.Axillary and de novo shoots were developed from axillary and cut basal ends of shoots,respectively.Shoots growing on auxins were further sub-cultured (every 15 days) and maintained for 45 days.The greatest number of de novo (5.06) as well as axillary shoots (2.85) was observed on the MS medium supplemented with 10 μmol L-1 NAA or 8 μmol L-1 IBA,respectively,after 45 days.The combinations of both IBA (μmol L-1) + NAA (μmol L-1) were tested at different concentrations (4 + 4,6 + 6,8 + 8) supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots.Rooting from non-decapitated de novo shoots was highest (93.33%) with a mean number of roots of 4.61 on this medium,supplemented with 6 μmol L-1 IBA + 6 μmol L-1 NAA,after 36 days of initial culture.Individual auxin,however,was not effective for root induction.Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.     

Diversity and genetic structure of teak (<Emphasis Type="Italic">Tectona grandis</Emphasis> L.f) in its natural range using DNA microsatellite markers

Teak (Tectona grandis L.f.) is considered to be an extraordinarily durable building timber with a worldwide reputation. Its widespread use has entailed the over-exploitation of natural forests and a large reduction in natural diversity. Fifteen microsatellite markers were used to study the genetic variability and structure of 166 teak trees distributed over the whole natural area of teak. Analysis showed that in the teak natural area there were four main centers of genetic variability. Two clusters were in India and could be considered as main centers of genetic diversity in teak. The third cluster mainly consisting of populations in Thailand and Laos was genetically very distinct from the Indian populations but presented only half as much allelic variability. A fourth cluster from Central Laos showed even less genetic variability. The use of SSR markers for conservation of teak forest diversity is discussed.     

Metabolic changes during adventitious root primordium development in <Emphasis Type="Italic">Tectona grandis</Emphasis> Linn. f. (teak) cuttings as affected by age of donor plants and auxin (IBA and NAA) treatment

Aging of the donor tree decreased adventitious root formation in shoot cuttings of Tectona grandis Linn. f. (teak). Exogenous application of auxins, i.e., α-naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA) has a significant positive effect on the percentage of rooting. The maximum percent rooting was obtained with 4,000 ppm IBA as compared to other treatment. Significant increase in root number was recorded in shoot cuttings treated with 4,000 ppm NAA. The overall rooting response was better in the treatment with IBA rather than with NAA. Further periodic samples (0, 10, 20, and 30 days) were taken to assess the total soluble sugar, starch, protein, and peroxidase (PER) activity in the rooting zone of shoot cuttings of teak during adventitious root formation. Application NAA and IBA to shoot cuttings resulted in an increase in the level of total soluble sugar, starch, protein, and PER-activity in the rooting zone. The stored carbohydrates were utilized during adventitious root formation. Hence, total soluble sugar and starch contents of cuttings, irrespective of age of donor plants, decreased with the passage of time in cuttings planted for rooting. Significant fluctuations were observed in the protein content of cuttings during the time of root induction. There was an increase in the protein content with the passage of time from the day of planting up to its 20th day, followed by a sharp decline in the protein content of cuttings at the 30th day of planting, irrespective of the age of donor plants or the treatment of cuttings with auxins. Irrespective of donor plant age, PER-activity in the cuttings increased from the day of their planting for rooting up to the 20th day, and then declined at its 30th day of planting. It was interesting to note that PER-activity remained higher at all stages in the cuttings of 2-month-old seedlings which rooted profusely as compared to the cuttings of 15- and 30-year-old donor plants those rooted poorly. This study suggested that the exogenously applied NAA and IBA at different concentration seems to activate sugar metabolism for release of energy, protein and PER-activity which are necessary for cellular division and differentiation during adventitious root primordium initiation or development in the rooting zone of shoot cuttings.     

日本落叶松种子园改扩建技术研究初报

笔者分析了日本落叶松种子园的现状、存在的问题,提出了相应的技术措施,通过日本落叶松种子园改扩建技术,以加速中国亚热带亚高山区日本落叶松良种化进程。     

黄金梨在岗丘瘠薄地优质高效生产综合因素研究

南阳市东大岗是典型的岗丘瘠薄地,通过为期5a的无公害黄金梨优质生产技术试验,研究证明:株行距2m×3m的栽植密度在岗丘瘠薄地最为合适;研究选出了黄金梨低干矮冠疏层分散形丰产树形。     

DRIS evaluation of teak (Tectona grandis L.f.) mineral nutrition and effects of nutrition and site quality on teak growth in West Africa

The objective of the investigation was to study the site variables controlling teak yield (Tectona grandis Linn.fil.) and to establish guidelines for the selection of high productivity sites in Benin, Côte d'Ivoire, Liberia, Nigeria and Togo. Depending on stand age, soil and region, between 70 and 90% of the variation in tree growth (site index, SI) could be explained by the supply of nitrogen, the root-available soil depth and precipitation. Diagnostic foliar analysis for a broad range of elements was carried out in all plantations with the exception of Nigeria. This showed that in 20% of the stands, various deficiency symptoms occur, and in an additional 40%, hidden demand of at least one nutrient is apparent. According to the Diagnosis and Recommendation Integrated System (DRIS), the most deficient nutrients besides N are Ca and P, while in 45% of all stands there is a relative Al excess. Recommendations for the evaluation and classification of site quality and the number of trees sampled for foliar analysis are given.