The fully sequenced genomes of Arabidopsis, rice, tomato, potato, maize, wheat, and soybean offer large amounts of information about cellular and developmental biology. It is a central challenge of genomics to use this information in discovering the function of proteins and identifying developmentally important genes. Although classical genetic approaches to gene identification which rely on disruption of a gene leading to a recognizable phenotype continues to be an extremely successful one, T-DNA mediated gene trap tagging which has been developed that utilize random integration of reporter gene constructs has also proven to be an extremely powerful tool in plant cellular developmental biology. In this review, how gene trap tagging, promoter trap tagging, and enhancer trap tagging detection systems have been applied to plant biology is described and these gene identification techniques could be useful to the plant molecular biology and plant biotechnology community.
Basic structure and algorithm of leaf mechanism photosynthesis model were described in first part of this study based on former researcher results. Then, considering some environmental factors influencing on leaf photosynthesis, three numerical sensitivity experiments were carried out. We simulated the single leaf net CO2 assimilation, which acts as a function of different light, carbon dioxide and temperature conditions. The relationships between leaf net photosynthetic rate of C3 and C4 plant with CO2 concentration intercellular, leaf temperature, and photosynthetic active radiation (PAR) were presented, respectively. The results show the numerical experiment may indicate the main characteristic of plant photosynthesis in C3 and C4 plant, and further can be used to integrate with the regional climate model and act as land surface process scheme, and better understand the interaction between vegetation and atmosphere.
Aboveground vertical profiles of N2O concentrations were measured within two natural coniferous-deciduous mixed forests of 1998 and 1999 in Changbal Mountain. Significant high N2O concentrations were found in six profiles out of twelve profiles. The results showed that high concentrations were 3.03% to 64.9% higher than the “normal concentrations” in these six profiles. Differences between the high concentrations and the “normal concentrations” were statistically significant. The simultaneous occurrence of high concentrations at/nearby the canopy height and normal concentrations at the trunk space height indicated an efflux of N2O from portant source of atmospheric N2O in a forest ecosystem.
A comparison study was made for the characteristics of pH value, organic matter content, nutrient element N, P and K contents in rhizosphere soils of pure and mixed plantations of Manchurian walnut and Dahurian larch and in bulk soils. The results show that the pH values of rhizosphere soil for all the plantations except the pure walnut stand, which was slightly higher, were lower than those of bulk soils, while the organic matter contents in the rhizosphere soil for all the plantations except the mixed plantation, which was slightly lower, were higher than that in bulk soil. There exists a relative nitrogen accumulation in the rhizosphere and the extent to which the nitrogen accumulates is closely related to tree species and mixed pattern. As far as the total P and K contents are considered, there exists a deficient tendency in rhizosphere in comparison with bulk soil. The element N, P and K are all mobilized in the rhizosphere of the pure or mixed plantation, characterized by the higher contents of the available N, P and K in the rhizosphere. The available N content in the rhizosphere of the larch in mixed plantation was obviously higher than that of its pure plantation, whereas the available P and K contents in the rhizosphere of walnut in the mixed plantation, on the other hand, were significantly higher than those of its pure plantation.
Paulownia tomentosa, P. fargesii, P. lamprorhylla, P. albiphloea, P. australis, P. fortunei, P. elongata, P. elongata f. alba andP. albiphloea varchenggtuensis were classified into three groups:P. fortunei group (P. fortunei andP. elongata f. alba);P. australis group (P. australis andP. albiphloea varchenggtuensis) andP. tomentasa group (P. tomentasa, P. fargesii, P. albiprhlaca, P. lamproprhylia andP. elongata) accordance to the results of the single and two-dimensional SDS-PAGE of protein in thePaulownia tree leaves. The result could lay a foundation for classifying the GenusPaulownia plants.
Xishuangbanna harbors valuable tropical rainforests with abundant biodiversity and it is acknowledged as a treasure house of wildlife. By describing the characteristics of its physical geography, the authors analyzed the habitat complex. The major vegetation types and rare wildlife were systematically studied to indicate the major elements and great value of the biodiversity. The present status of general biodiversity conservation was briefly appraised to reveal the potential crises and problems in the conservation practice. Based on the theories and experience borrowed from modern conservation biology and innovations at home and abroad, 4 primary strategies were accordingly suggested to establish a beneficial mutual-improvement mechanism for the better conservation so that the biodiversity conservation and utilization can be properly integrated, the local people’s livelihood effectively uplifted and their over-dependence on the resources relatively lessened.
Through five years (1996–2000), experiment, the growth characteristics and resistance to insect and cold of the seven poplar varieties includingP. popularis, P. opera, P: pseudo-simonii, P. beijinensis, P. bolleana, P. x euramericana andP. simonii, which were planted in loess hilly land in northwest Shanxi Province, were tested under different planting densities and site conditions. A randomized block design and three times repetition were adopted in the test. Based on the test results in arid and cold area of the northwest Shanxi, the hybrid poplar trees takingPopulus cathaysna as their female parent could be selected for afforestation, such asP. popularis andP. opera, and the growing space of single plant should be larger than 20 m2.P. bolleana as an introduced tree species grows well in this area, but its growth is likely affected by, ground water condition. On the site with relatively abundant soil water,P. bolleana usually suffer from frost crack at its trunk base. As a result,P. bolleara is suited to planting in the site where is short of soil water.P. x euramericana is not suitable for large-scale afforestation, especially in arid slopes and ridges of loess hilly land.
The dry-hot valleys (DHV) are located mainly in the deeply incised valleys along the upper streams of several international and domestically rivers, like Yangtz, Zhu, Lanchang, Hong, and Nu rivers. This paper briefly described the reasons of formation of DHV from view of climate and geographical conditions, and by referring to great deal of documents, analyzed the historical case and present status of the vegetations in DHV. The environment in DHV is facing the serious vulnerable period in the history due to its nature situation of half-year dry period, fragile geological structure and shallow soil, and its social situation, of over dense population and over farming. The primary vegetation is broad leaf forest and it was denuded in the history. The current local vegetation is the degraded secondary vegetation: savanna and succulent thorny shrub. Since, the environmental situation in valley influenced directly the water body of river, the soil erosion control and re-vegetation in DHV is the most urgent task in the process of environmental harness along the rivers. Quite a few pilot research projects have been carried out on demonstrating new silviculture techniques for re-vegetation in DHV, but there still exist great difficulties in carrying cut large-scale afforestation engineering.
The Random Amplified Polymorphism DNA (RAPD) markers were used to study the intra-specific diversity and regional differentiation of the Chinese forest frogs (Rana chensinensis), which were sampled from the fields of 8 regions in, Heilongjiang Province. Totally 78 polymorphic DNA loci were amplified by 10 RAPD primers. By genetic distance analysis and phylogenetic tree reconstruction with the Neighbor-Joining (NJ) method the results showed that the populations of Chinese forest frogs distributed in 8 regions existed great differentiation (Average Fst=0.347, SD=0.235) while, there was the paradox between geographic distances and genetic distances. Based on geographic and geological data, a hypothesis was posed that it is very possible that the hilly lands in the downstream of the Songhua River and the Heilong River were the center of the origin of the Chinese forest frogs in Heilongjiang Province. And mainly through the Songhua River system, the Chinese forest frogs dispersed into the Songneng Plain from the Sanjiang Plain whereas the Fangzheng region became a sub-center for the western dispersion.
In this paper, the theoretical expressions of wood thermal conductivity in the choral and radical direction are derived from the micro-structure of wood by applying some basic principles in physical mechanics. The thermal conductivities of about twenty species of trees were calculated by means of the expressions and compared with its experimental values under the same condition. The average relative error is about 5% so the calculation result is satisfactory.
Based on the growth rates of population, Gross Domestic Products (GDP) and agriculture productivity, the areas of deforestation were predicted in Jutpani Village, Chitwan district, Nepal by Area Production Model (APM). Through the APM simulation in this study, all of forestland will be transferred into agricultural land in 2030 at the rate of 24% per year on the current productivity. And if the productivity of subsistence food crop is assumed to increase at the rate of 1%, the productivity of market crop and export crop increase at the rate of 2% annually, deforestation rate will decrease to 17% per year, but only 124 hm2 forest land will be left till 2038. The agriculture productivity is a very important factor for the deforestation, so intensification of agriculture management is more important.
Bacillus thuringiensis is a major microbial insecticide and a source of genes encoding several proteins toxic to insects. In this paper the authors give a brief summary ofBacillus thuringiensis used on the integrated pest management in forestry. The derivatives of Bt strain HD1 subspkurstaki have been widely used to control the forest pests such as the gypsy moth (Lymantria dispar), spruce budworm (Choristoneura fumiferana), the pine processionary moth (Thaumetopoea pityocampa), the European pine shoot moth (Rhyacionia buoliana) and the nun moth (Lymantria monacha). Some progresses of transferring and expressing Bt toxin gene in forest trees are offered with a discussion on the limits and future prospects of using Bt products in forestry.
Microsatellite loci distributing on genome randomly act as effective genetic markers. To date, about 200 microsatellite loci were found in cervids by transferring microsatellite PCR primers derived in bovine, ovine to cervids, as well as a few loci derived directly from deer microsatellite library. These loci have been used in parentage determination, genetic diversity and population structure, population introgression, as genetic marker gestation length and wintering survivalet al. However, microsatellite loci presently found are untouchable to the demand of application. Future work should include: 1) isolating a large number of cervine microsatellite loci, 2) constructing genetic and physical maps of microsatellite loci. So that microsatelites have a strong base for advanced applications in deer.
The endangered giant panda (Ailuropoda melanoleuca) is endemic to the mountains of Sichuan, Gansu and Shaanxi Provinces in China. The species had numbered over 2000 animals in early 1970s, but declined to no more than 1,000 animals fragmented into perhaps 32 subpopulations in late 1990s as the result of numerous detrimental forces such as habitat shrinking, poaching and bamboo flowering. The mass flowering and followed die-off of bamboo played key roles in the declination of panda population in the past three decades. It trigged the starvation and following high mortality of giant pandas in 1970s over Min Mountains and in 1980s across Qionglai Mountains in Sichuan Province. The situation of survivorship is made worse by the fact that the panda habitat is fragmented into many small “islands”, each containing only a few pandas. Such small, isolated panda populations are rendered even more volnerable to extinction form threats such as habitat degradation, natural disaster, disease, and the deleterious effects of inbreeding. So restoring the panda habitat and reintroduction pandas to their historical habitat might be an important issue for protecting the giant panda in wild.
In this paper ecogeographical characteristics of forest soil animal in mountainous districts of the eastern China was analyzed, and results show that soil fauna was very rich in diversified forest habitat, moreover, as times and spaces varied, their compositions and abundance changed obviously too. Forest soil animal decreased gradually in taxa and individual number from the tropics to cold-temperature zone, and they are higher in zonal forest habitat than in other ones on the same mountain. Forest soil animal also got gradually less with increasing of depth in soil layer, and distributed principally in surface layer. The activities of human had strong affection on faunal composition and diversity of soil animal. On the tropics and subtropics mountains, forest soil animal are less in spring-summer than in autumn-winter, whereas they are more in summer-autumn than in winter-spring from warm-temperate zone to cold-temperate zone.
Urban peripheral green space (UPGS) plays more and more important role in sustaining urban physical and ecological environments. In this paper, a preliminary classification of UPGS was presented for seven types and quantity index of UPGS was discussed tentatively. The quantity and layout problems in urban peripheral green space, and the several principles were mainly discussed in urban ventilation and sanitation, recreational opportunity and landscape ecological structure.
Based on the analysis of forest inner mechanism, forest benefit in reducing flood disaster is defined. Through the characteristic analysis of forest benefit in reducing flood disaster, it is suggested that it is impossible to adopt the microanalysis method for studying the forest benefit in reducing flood, the macro analysis is the only method to be adopted. With the special case of disaster flooding of Changjiang River happened in 1998, the forest benefit in reducing flood disaster was scientifically assessed. The estimated results of forest benefit in reducting flood shows that forest vegetation establishment is the radical, way to control flood, but it only equals to 5 percent of the total benefits of water conservancy facilities.
Forest Potential Productivity (FPP) of 8 counties in Tianshan was calculated, and the potential timber output of these counties was analyzed with Miami Model and Thornthwaite Memorial Model. Research results showed that annual average output of present stand in Tianshan Forest Region was 3.7 m3/(hm2.a), which reached only 49% of average FPP.