Advanced biotechnological approaches and gene manipulation in Populus species

The biotechnology of plant tissue culture has been developed as an applied science for micropropagation, tree improvement, and basic physiology studies. Biotechnological approaches in forest science are advanced as a desirable tool to obtain superior genotypes and to screen for insect resistance. As a basic technique, in vitro cloning is a powerful tool using different explant types such as immature ovules or stem nodes for tree improvement. Typically, plants can be regenerated in vitro by apical or vascular cambial meristems. Genetic transformation is another option to improve the variable lines by genetic modification in host genetic materials with desirable traits. In addition to cloning and gene transfer, in vitro screening methods are applicable for early selection with modified plantlets;In this advanced biotechnology program, several aspects were addressed with Populus species: (1) light and scanning electron microscope study of shoot formation in developing ovules of cottonwood (Populus deltoides), (2) evaluation of shoot proliferation from alternative in vitro nodal cultures of a cottonwood hybrid (Populus deltoides X P. nigra), (3) investigation of morphological in vitro shoot abnormalities in hybrid aspen (Populus alba L. X P. grandidentata Michx.), and (4) early screening of resistance to the cottonwood leaf beetle (Coleoptera: Chrysomelidae) in transgenic poplar (Populus deltoides X P. nigra);Immature ovule cultures can provide early cloning from zygotes that are composed of diverse genetic sources and the explant of immature ovules can be a desirable target for genetic transformation. Therefore, the culture system was developed and shoot formation from immature embryos was investigated via electron and light microscopes. The regeneration frequency was increased substantially by treatment with zeatin;Ordinarily, an intact node is used as explant material in plant tissue culture. However, shoot production was significantly enhanced by using internode and modified stem segment explants in this study. Besides the apical or vascular cambial meristems, shoots could be produced from the phellogen (lenticel) which is an organ for secondary growth in bark. Therefore, shoot formation from lenticel area was investigated through stereo and light microscopy;Even though the development of in vitro systems is important in biotechnological research, abnormal plantlets need to be studied to overcome in vitro problems. The cells and structure of normal and vitrified leaves of hybrid aspen were investigated with scanning electron and light microscopy. Vitrified leaves had more circular, larger stomata; an absence of palisade parenchyma; and large, vacuolated spongy mesophyll cells. Chloroplasts in vitrified leaves were less developed than in normal leaves;Finally, an in vitro system was integrated with entomological knowledge to screen for resistance to the cottonwood leaf beetle. This study was conducted to evaluate the potential of the proteinase inhibitor gene II (pin 2). The in vitro system provided a quick, highly controlled method to screen the transgenic poplar in an in situ condition directly

Phytoremediation and Physiological Effects of Mixed Heavy Metals on Poplar Hybrids

The effects of mixed heavy metals differ not only in different plants but also on the hybrids exposed. In this chapter, we focus on phytoremediation and the physiological effects of mixed heavy metals on four poplar hybrids. According to the results obtained from greenhouse pot experiments with mixed heavy metals, the photosynthetic and transpiration rates were affected by increased heavy metal concentrations. The concentration of heavy metals copper, chromium, cadmium, and zinc in the plant roots, stem and leaves varied with the concentration of mixed heavy metal as well as individual heavy metals. Based on the phytoextraction potential; hybrid 1 (Eco 28) was deduced as the best candidate for phytoremediation in mixed heavy metal contamination treatment. The results obtained are valuable in understanding how specific hybrids respond to mixed heavy metal stress especially when using them as bioindicators for phytoremediation experiments in multi-metal contaminated sites. Selection of new plants along with field trials over extended periods will increase the possibility of further enhancing and establishing phytoremediation technology in the future

Advanced biotechnological approaches and gene manipulation in Populus species

The biotechnology of plant tissue culture has been developed as an applied science for micropropagation, tree improvement, and basic physiology studies. Biotechnological approaches in forest science are advanced as a desirable tool to obtain superior genotypes and to screen for insect resistance. As a basic technique, in vitro cloning is a powerful tool using different explant types such as immature ovules or stem nodes for tree improvement. Typically, plants can be regenerated in vitro by apical or vascular cambial meristems. Genetic transformation is another option to improve the variable lines by genetic modification in host genetic materials with desirable traits. In addition to cloning and gene transfer, in vitro screening methods are applicable for early selection with modified plantlets;In this advanced biotechnology program, several aspects were addressed with Populus species: (1) light and scanning electron microscope study of shoot formation in developing ovules of cottonwood (Populus deltoides), (2) evaluation of shoot proliferation from alternative in vitro nodal cultures of a cottonwood hybrid (Populus deltoides X P. nigra), (3) investigation of morphological in vitro shoot abnormalities in hybrid aspen (Populus alba L. X P. grandidentata Michx.), and (4) early screening of resistance to the cottonwood leaf beetle (Coleoptera: Chrysomelidae) in transgenic poplar (Populus deltoides X P. nigra);Immature ovule cultures can provide early cloning from zygotes that are composed of diverse genetic sources and the explant of immature ovules can be a desirable target for genetic transformation. Therefore, the culture system was developed and shoot formation from immature embryos was investigated via electron and light microscopes. The regeneration frequency was increased substantially by treatment with zeatin;Ordinarily, an intact node is used as explant material in plant tissue culture. However, shoot production was significantly enhanced by using internode and modified stem segment explants in this study. Besides the apical or vascular cambial meristems, shoots could be produced from the phellogen (lenticel) which is an organ for secondary growth in bark. Therefore, shoot formation from lenticel area was investigated through stereo and light microscopy;Even though the development of in vitro systems is important in biotechnological research, abnormal plantlets need to be studied to overcome in vitro problems. The cells and structure of normal and vitrified leaves of hybrid aspen were investigated with scanning electron and light microscopy. Vitrified leaves had more circular, larger stomata; an absence of palisade parenchyma; and large, vacuolated spongy mesophyll cells. Chloroplasts in vitrified leaves were less developed than in normal leaves;Finally, an in vitro system was integrated with entomological knowledge to screen for resistance to the cottonwood leaf beetle. This study was conducted to evaluate the potential of the proteinase inhibitor gene II (pin 2). The in vitro system provided a quick, highly controlled method to screen the transgenic poplar in an in situ condition directly.</p

Forest Management In Mongolia – A Review Of Challenges And Lessons Learned With Special Reference To Degradation And Deforestation

The natural conditions, climate change and socio-economic challenges related to the transformation from a socialistic society towards a market-driven system make the implementation of sustainable land management practices in Mongolia especially complicated. Forests play an important role in land management. In addition to providing resources and ecosystem functions, Mongolian forests protect against land degradation.We conducted a literature review of the status of forest management in Mongolia and lessons learned, with special consideration to halting deforestation and degradation. We grouped our review into seven challenges relevant to developing regionally adapted forest management systems that both safeguard forest health and consider socio-economic needs. In our review, we found that current forest management in Mongolia is not always sustainable, and that some practices lack scientific grounding. An overwhelming number of sources noticed a decrease in forest area and quality during the last decades, although afforestation initiatives are reported to have increased. We found that they have had, with few exceptions, only limited success. During our review, however, we found a number of case studies that presented or proposed promising approaches to (re-)establishing and managing forests. These studies are further supported by a body of literature that examines how forest administration, and local participation can be modified to better support sustainable forestry. Based on our review, we conclude that it is necessary to integrate capacity development and forest research into holistic initiatives. A special focus should be given to the linkages between vegetation cover and the hydrological regime

Activation of Pathogenesis-related Genes by the Rhizobacterium, Bacillus sp. JS, Which Induces Systemic Resistance in Tobacco Plants

Plant growth promoting rhizobacteria (PGPR) are known to confer disease resistance to plants. Bacillus sp. JS demonstrated antifungal activities against five fungal pathogens in in vitro assays. To verify whether the volatiles of Bacillus sp. JS confer disease resistance, tobacco leaves pre-treated with the volatiles were damaged by the fungal pathogen, Rhizoctonia solani and oomycete Phytophthora nicotianae. Pre-treated tobacco leaves had smaller lesion than the control plant leaves. In pathogenesis-related (PR) gene expression analysis, volatiles of Bacillus sp. JS caused the up-regulation of PR-2 encoding β-1,3-glucanase and acidic PR-3 encoding chitinase. Expression of acidic PR-4 encoding chitinase and acidic PR-9 encoding peroxidase increased gradually after exposure of the volatiles to Bacillus sp. JS. Basic PR-14 encoding lipid transfer protein was also increased. However, PR-1 genes, as markers of salicylic acid (SA) induced resistance, were not expressed. These results suggested that the volatiles of Bacillus sp. JS confer disease resistance against fungal and oomycete pathogens through PR genes expression

Effects of Oxidized Brown Coal Humic Acid Fertilizer on the Relative Height Growth Rate of Three Tree Species

This study aimed to identify the effects of oxidized brown coal humic acid fertilizer on the relative growth rate of several tree species intended for reforestation. Field experiments were carried out during 2011&ndash;2014 at the Research and Experimental Center for Combating Desertification located at the Elsen Tasarkhai station in central Mongolia. The trees studied were Populus sibirica Tausch., Salix ledebouriana Trautv., and Acer tataricum L. The experiment was conducted with concentrations of 2000, 10,000, and 20,000 mg L&minus;1 of humic acid fertilization treatment. Measurement of the relative height growth rate (RHGR) was undertaken for a period of four years. The results demonstrated significant differences between the humic fertilizer concentrations, which varied depending on the species. Compared to monthly RHGR over the study period, the treatment using fertilizers yielded significantly better tree growth. P. sibirica, when treated with 2000 mg L&minus;1 and 10,000 mg L&minus;1 humic acid fertilizers, had significant height growth rates. S. ledebouriana with 20,000 mg L&minus;1 of humic acid fertilzers treatments showed the highest RHGR. In addition, when the humic acid treatments were compared to the control, results showed that oxidized brown coal humic acid fertilizers as an organic fertilizer can have a significant effect on the growth of A. tataricum. The results equally showed that the soil chemical properties EC, CO2, NO3, and K2O were significant among all the treatments compared to control. The effect on P2O5 significantly increased in all the treatments; however, there was no significant effect on pH and Mg among all treatments. Combining the results obtained with reforestation and sustainable land-management practices can help to improve soil organics in degraded sandy soil regions

Species Diversity, Stand Structure, and Species Distribution across a Precipitation Gradient in Tropical Forests in Myanmar

An understanding of how species diversity, structural pattern, and species distribution vary across different environmental regions is crucially important for tropical ecology. In this study, we explored how these ecological parameters vary across various rainfall regions in the tropics with annual rainfall levels ranging from 843 to 2035 mm. Diversity, similarity, structure, and forest classification, and their correspondence with rainfall regions were tested. We found that species diversity, site class, and structural complexity increased with rainfall, with differences of 1000 mm having significant effects on diversity. The structure and heterogeneity of forests were higher in the high rainfall regions than the low rainfall regions. The forest structure was significantly correlated with rainfall, and the structure differed substantially where annual rainfall differed among sites by approximately 200 or 400 mm. Forests could be classified into two types according to whether they had high annual rainfall (1411–2035 mm) or low annual rainfall (843–1029 mm). In addition, the dominance of species changed noticeably from high- to low-rainfall regions, with Tectona hamiltoniana and Terminalia oliveri only being abundant in the low rainfall region. Species diversity and richness were significantly correlated with rainfall and average temperature. These findings will provide invaluable information for forest management and ecological phytogeography