Advanced Materials Research Vols. 864-867

Abstract: The 87 strains actinomycetes were separated and purificated from soil by dilution plate separation method, with pepper anthracnose (Colletotrichum gloeosporioides) as indicator pathogens, these actinomycetes had primary and secondary screening screened by cross method and mycelial growth inhibition method respectively, finally, three actinomycetes had obvious antimicrobial activity separated.

Abstract: The virus-induced mosaic Camellia reticulata cultivars in southwest China were identified, and evaluated for their ornamental value and bio-security in landscape. The results show that 11 virus-induced mosaic Camellia reticulata cultivars are found. The virus in mosaic leaves is spherical, with 30-50 nm in diameter. For the mosaic leaves, the chloroplasts are degraded in the yellow macular region, and the content of chlorophyll is significantly decreased. However, the virus-induced mosaic Camellia reticulata grow normally, and with significantly improved of visual appeal due to mosaic leaves. Further, the virus-induced mosaic Camellia reticulata have no bio-security threats to the main crops and other landscape plants. Thus, the virus-induced mosaic Camellia reticulata can be cultivated normally in the landscape in southwest China.

Abstract: In order to study the characteristic of soil seed bank in saline wetlands,samples from different land-use types of wetlands were selected.After the germination test,the results showed that the reserves of SSB in the four plots are huge,but the species composition is uncomplicated,the germinated seedlings are all coastal indicating halophytes.The differences between the four plots are obvious, P-value is almost less than 0.05.Artificial landscape wetlands have the largest variance coefficient.Compared with artificial wetlands,natural conservation wetlands show unique characteristic,it has the highest species richness,it has the stablest vegetation community structure,but the density of SSB is lowest for the low interference.Natural conservation wetlands have played important role in maintaining biodiversity.Therefore, the wetland ecosystem services should be fully taken into consideration when using wetlands.Appropriate protection of wetlands are needed,for it can helps to improve the ability of SSB in vegetation recovery.

Abstract: This paper mainly indicates the pest-control problem by using the biological control and the pesticide control. Firstly, it analyzed the continuous changing population of the three species-plants, plant pest and natural enemy-and the pesticides’ effects to establish a three-species model of the pests’ integrated control. Secondly, the pest equilibrium points with the natural enemy and that without natural enemy were obtained. We discussed the stability of the equilibrium points by the Hurwitz theorem and the first approximation method of stability and got the sufficient conditions for asymptotic stability. Finally, numerical simulations were performed by Matlab to analyze and verify the integrated control of plant pests in the situations with some natural enemies and without enemy. Moreover, the effects of spraying pesticides which have different killing rates on enemy and plant pest were analyzed.

Abstract: The appearance of agriculture roughly 10,000 years ago disrupted the ecological balance of numerous systems. Fortunately, the process of domesticating plants and animals and the spread of agriculture were slow enough to allow a new equilibrium to emerge. Plant genetic resources include primitive forms of cultivated plant species and landraces, modern cultivars, obsolete cultivars, breeding lines and genetic stocks, weedy types and related wild species, which provide the building blocks that allow classical plant breeders and biotechnologists to develop new commercial varieties and other biological products. Therefore, it is obviously very important to manage plant genetic resources for sustainable development in all of country. This article describes the management of plant genetic resources from conservation to utilization, introduces the status of international cooperation for sustainable development and perspectives that the significant plant genetic resources management for sustainable development in the future.

Abstract: The effects of oil-contaminated soil on plant growth are the focus study area all over the world. In this paper, two kinds of local plant seeds germination and seedlings growth in oil-contaminated soil were studied by germination experiment. Five different oil concentration gradients (0g/kg, 0.2g/kg, 5g/kg, 20g/kg, 40g/kg) were set up in this experiment, and the seed germination rates and bud length of wheat and rice cultivated in thermostat were observed and recorded. The results showed that crude oil took negative effects on wheat seed germination and germinability. With the oil concentration increasing, the germination rate of wheat seed and germinability decreased respectively. Crude oil impacted the seeding growth obviously, even under low oil concentration (20g/kg). Seedling growth almost stopped under high oil concentration such as 40 g/kg. Crude oil promoted germination and germinability of rice seed. The germination rates and germinabilities of three Oil concentrations (0.2 g/kg, 5 g/kg, 20 g/kg, 40 g/kg) were all higher than that in pure soil, further, the higher the oil concentration was, the germination rates and germinabilities were higher. Oil also accelerated the rice seedling growth under three different concentrations.

Abstract: For at least the last 10,000 years humans have been selecting plants that performed better for them across a wide range of criteria including fruit size, number of fruit per plant, adaptation to specific environments, resistance to certain pests, and many other characteristics. As the demand for agricultural productivity continues to rise, there is an increasing pressure on plant breeders to develop new varieties that are higher yielding and able to produce in more challenging environments. In recent years, there has been a significant increase in the application of molecular genetic methods for assessing the conservation and use of plant genetic resources that provides the new ways for plant breeding, for example, the high-throughput sequencing technology provides the possibility of analysing high numbers of samples over smaller periods of time. Currently, molecular breeding is standard practice in many crops, and a diverse collection of plant genetic resources and these resources remain accessible to breeders is important.This article describes the exploitation of plant genetic resources and modern plant breeding, introduces the application of molecular techniques in plant breeding and perspectives the significant of development and utilization of plant genetic resources for plant breeding.

Abstract: Soil moisture and soil seed bank are primary dependent factors during the vegetation natural regenerations in semi-arid sand areas. But the binary correlation analysis between seedling density and soil seed bank density as well soil moisture in transition zones between the windword slope of active dune and interdune lowland indicated that the correlation between seedling density and soil seed bank density was not significant (P>0.05) in the plant growing season; but the one between seedling density and soil moisture was significant and positive (P<0.05). The conclusions revealed that soil moisture was a primary dependent factor during seedling emergence and establishment in the transition zone

Abstract: Based on the soil water balance theory, soil water dynamics and evapotranspiration (ET) of artificial sand-fixing Caragana microphylla and Caragana korshinskii shrubs with three different densities were researched in Horqin sandy land during the growing season. Results showed that mean soil water content of three shrub densities changed with time, different density caused spatial changes of soil water content in the deep soil horizon, but brought little influence on soil water temporal trends. The annual ET/P ratio varied between 83.21% and 99.6% for three shrub densities and the ET was not continually increased along with increase in shrub density. Based on the comprehensive analysis of soil water content, ET, and plant coverage for three shrub densities, the optimum density of C. microphylla and C. korshinskii shrubs (20 years old) in the study area could be about 1000 trees/ha. The findings were helpful for vegetation restoration in Horqin sandy land of China.

Abstract: This research investigates the interaction between vegetation growth and water erosion by a new dynamic model. According to the theoretical and numerical analysis of the research, there are three cases of equilibrium distribution and their dynamics over time. And the dynamics between vegetation and erosion is disparate under the condition of different parameters. Every equilibrium point also has a unique distribution under every set of parameters. When there are two interior equilibriums, a critical curve exists and divides the system into two areas, one is coexistence area and another is dominated by vegetation or erosion.