Inter simple sequence repeats (ISSR) constitute a powerful dominant DNA molecular marker system used for diversity analysis, which is indispensable for making estimates of genetic base and demarcation of populations for undertaking conservation and improvement program offorest tree species. Twenty nine populations of teak (Tectona grandis L.f.) were collected from central and peninsular India for analysis of genetic diversity and structure. Genomic DNA from ten randomly selected individuals of each population was extracted and amplified using five ISSR primers (UBC-801, 834, 880, 899 and 900). The primers showed 100% polymorphism. UBC-900 recorded the highest Nei's genetic diversity (0.32 to 0.40) and UBC-899 had the highest Shannon's Information Index (0.49 to 0.59). AMOVA revealed a very high intra-population genetic diversity (91%), in comparison to inter-population genetic diversity among states (6.17%) and within states (2.77%), were also indirectly confirmed by large standard deviations associated with genetic diversity estimates for individual population, as well as poor bootstrapping values for most of the cluster nodes. However, UPGMA dendrogram revealed several clusters, with populations from central India being present almost in each cluster, making groups with populations of adjoining states and distant states. Nevertheless, the cluster analysis distinguished the drier teak populations of central India from the moist teak populations of south India, which was also confirmed by Principle Coordinate Analysis. The findings advocates the need not only for enhancing selection intensity for large number of plus trees, but also for laying out more number of in situ conservation plots within natural populations of each cluster for germplasm conservation of teak aimed at improving the teak productivity and quality in future. 

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Oriental beech (Fagus orientalis Lipsky) is a dominant tree species in the Caspian forests, where occupies approximately 18% of the forested area and produce more than 35% of the total wood stock volume in this region. However, little information is available about its variation along the Caspian forests of Northern Iran. This work studied the morphological variation of five native oriental beech populations grown in the western Caspian region in Guilan province (Astara, Asalem, Fuman, Chere, Shenrud). Eight leaf morphological traits, including leaf length, leaf width, petiole length, leaf area, leaf dry mass per unit leaf area, leaf thickness, leaf density were measured in 200 trees. The results showed that all measured leaf morphological traits were remarkably different among the populations, with the exception of distance between veins. A hierarchical classification of all populations led to the formation of three major groups: (i) Astara, (ii) Asalem, (iii) the rest of populations. Leaf morphological dissimilarities are possibly attributed to the genetic variations, developed as a result of adaptation to diverse environmental conditions. However, multisite common garden experiments would be needed in order to completely separate environmental and genetic factors explaining the observed level of natural variability. 

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One of the important aspects of hybridization is to understand the interaction between hybrid plants and the pests and diseases of the parental taxa. The foliar chemical attributes were compared between the hybrid of Eucalyptus citriodora and E. torelliana and its parental taxa. The fungus, Cylindrocladium quinqueseptatum, to which the hybrid and one parent E. torelliana have been observed resistant in the field, was used to examine patterns of resistance in relation to foliar constituents found active in labo-ratory bioassays. Concentration of active constituents of the hybrid was higher (monoterpenes- a-pinene, ß-pinene and citronellal, and total phenolics) than either parent or equivalent (ursolic acid) to parent E. torelliana thus suggesting an resistance pattern of hybrid. Beta-pinene, ursolic acid and total phenolics were found to be heritable. The findings suggest a chemical basis for fungal resistance and also indicate that the constituents could be used for screening of the disease resistant progeny in this tree system. 

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Fruit gathering from Ficus roxburghii Wall., a multipurpose tree, hinders its regeneration through seed. The present study was undertaken to propagate this species using branch cuttings treated with different hormones in two different seasons: rainy-July and spring-March. In both seasons (rainy and spring), large sized (1.25-2.5 cm diameter) cuttings resulted in statistically higher growth of all the studied parameters than that of small sized (< 1.25 cm diameter) cuttings, except the number of shoots in both the seasons and number of lateral roots in rainy season. The effect of hormonal treatments (Indole-acetic acid, Indole-butyric acid and Naphthyl-acetic acid) was also significant on all the studied parameters in both the study seasons except in the case of number of shoots in rainy season where the influence was not-significant. The interaction large size x IBA 100 ppm resulted in significantly better growth of the studied parameters in both seasons except for the number of lateral roots, number of shoots, shoot length and number of leaves in rainy season. This study implies that species is amenable to cloning with different hormonal treatments. In general, it was observed that growth and development of cuttings was better in spring than the rainy season. Therefore, for the successful propagation of Ficus roxburghii, large sized cuttings are to be treated with IBA 100 ppm and be planted in spring. 

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To understand the co-existence mechanisms of related species, the recruitment processes of Fagus crenata and F. japonica were censused during 3 and 4 years from emergence, respectively, in a cool-temperate forest in Japan. The distributional properties and the growth traits were compared between two Fagus species. To evaluate the distributional properties, the spatial abundance of seedlings was estimated by a generalized linear model (GLM), with explanatory variables such as topographic variables, light conditions, the presence of dwarf bamboo, and the abundance of the overstory. To evaluate the growth traits under herbivory pressure, both the elongated shoot length and the proportion of recovery from predation (re-growth) were also compared. No spatial segregation and no species-specific differences were detected by GLM, which was consistent throughout the census period. Only F. japonica exhibited a slope-related distribution, while F. crenata exhibited no topographical dependence, indicates the distributional overlaps. For the growth traits, contrasting trends were detected, F. crenata was superior in shoot growth, whereas the proportion of re-growth was higher in F. japonica than F. crenata. We concluded that co-dominance of these species was not attributed to the spatial segregation but to the trade-off between growth and resistance to herbivory.

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We investigated the temporal variability of intra-annual wood density variations in European beech (Fagus sylvatica L.) in a valley in southwestern Germany. Samples were collected from 11 beech trees growing at north-west (NW) and south-west (SW) exposed slopes. High-frequency densitometry was used to obtain wood density profiles. We converted radial positions within these profiles to a seasonal time scale over automatic point dendrometer data for the period 2001-2006. Temporally resolved wood density data was analyzed both visually and statistically, using correlation analysis and multiple linear regressions. Water availability was found to be of major importance for wood formation. Further, our results suggest that climatic forcing of wood density is not necessarily restricted to the late growing season only, but that strong associations may exist during a major part of the growing season. Combining wood property data with point dendrometer measurements was demonstrated to be valuable for increasing the understanding on the effects of changing environmental conditions on wood formation.

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