鸡胚成纤维细胞感染IBDV后SOD活性的变化

鸡胚成纤维细胞用传染性囊病病毒感染后,采用邻苯三酚自氧化法测定细胞超氧化物歧化酶的活性。ＣＥＦｓ感染ＩＢＤＶ后８ｈ,细胞ＳＯＤ活性有所上升。之后,随着时间的延长,细胞ＳＯＤ活性逐渐下降。试验结果表明,ＳＯＤ活性降低是ＣＥＦｓ感染ＩＢＤＶ之后发生的重要生化变化,在ＩＢＤＶ诱导细胞凋亡的过程中可能起关键作用。     

Detection of genetic variation among seed and seedlings ofChamaecyparis obtusa using allozyme markers

The effects of nursery practices on genetic composition and structure were studied inChamaecyparis obtusa by analyzing seeds and one-, two-, and three-year-old seedlings. Enzyme polymorphisms of the6Pgd-2, G6pd, Got, Gk, Shd-2, Pod, Dia-1, andPgm loci were used. OnlyDia-1 indicated significantly different allelic frequencies between seeds and three-year-old seedlings. Most of the genetic diversity of the parental clones in this seed orchard could be transferred to the offsprings. Genetic diversity on the basis of an average expected heterozygosity did not differ between seeds and seedlings. A slight excess of homozygotes in seeds and a significant excess of heterozygotes in seedlings of different ages to the expected panmictic proportions were found. Most of the differences in genotypic distributions among the seed and seedling stages, probably resulted from viability selection favoring outcrosses, and selective removal of inbred offsprings including self-fertilized ones prior to their transplantation in the nursery. A part of this paper was orally presented at the 107th Annual Meeting of the Japanese Forestry Society (1996).     

Effects of growing leafy daikon (Raphanus sativus) on populations of Plasmodiophora brassicae (clubroot)

Control of some soilborne pathogens may be achieved by use of decoy or catch crops. These stimulate the germination of resting spores, resulting in limited expression of disease symptoms. Results achieved using this approach are reported here using leafy daikon (radish, Raphanus sativus var. longipinnatus ) for control of Plasmodiophora brassicae , the cause of clubroot disease of Brassicaceae. Disease indices of Chinese cabbage plants grown in pots that had previously contained leafy daikon were lower compared with pots where no plants had been grown before (control pots). Numbers of resting spores of P. brassicae in soil in pots after cultivation with leafy daikon were reduced by 71% compared with control pots when resting spores were recovered and counted directly. In a field experiment, numbers of resting spores were reduced by 94% compared with the start of the experiment when leafy daikon was grown in advance of Chinese cabbage, but there was no reduction in disease severity in the Chinese cabbage. Plasmodiophora brassicae infected the root hairs of leafy daikon and those of Chinese cabbage, but no clubs were found on leafy daikon roots. The results from pot trials indicate that leafy daikon may be useful as a decoy crop for the control of clubroot disease in field crops.     

Comparison of the disease incidences of Finnish Ayrshire and Finnish Black and White dairy cows

Finnish Ayrshire and Finnish Black and White cows were compared regarding the incidences of early and late mastitis, parturient paresis, ketosis, ovarian disorders, metritis and the risk of having a test-day somatic-cell count >200,000 cells ml⁻¹ at any of the first three monthly test days in lactation. In a retrospective cohort study 101,793 cows from 5844 tie stalls and 11,811 cows from 437 loose-housing systems from all over Finland were followed from calving in 2000 until the end of lactation. The observed incidences of those cows were then analysed using generalised linear mixed models. Finnish Black and White cows had higher incidences of all diseases except ovarian disorders. Although the differences were statistically significant in all models except metritis and early mastitis in loose-housing systems, they were, in our view, only important on the national level (for the breeding organisations), and of little importance for the farmers.     

土壤消毒在辽宁省设施蔬菜土传病害上的应用

设施蔬菜生产面积不断扩大,由于农民过分追求产量和效益,对土壤过度消耗,导致设施蔬菜生产中土传病害越来越严重.解决土传病害成了设施蔬菜生产中的一大难题,选择抗病品种、农业防治、土壤消毒等方法都是解决土传病害的重要途径.该文详细介绍了土壤消毒技术的作用原理、操作方法,科学分析了土壤消毒技术在实际应用中存在的问题以及正确使用...     

论天气系统下云的观测

在地面气象观测工作中,云的观测是一项最基本的观测要素,它既是现在天气的重要判定依据,也是未来天气预测的重要指标,所以做好云的观测是观测工作的重中之重.地面气象观测中只有把云和与它相对应的天气系统联系起来,借助天气形势的分析判断,把地面气象观测和天气系统的分析判断有机结合起来,用天气学的原理和方法来指导我们的地面气象观测.     

Comparing water-vegetative indices for rice (Oryza sativa L.)-wheat (Triticum aestivum L.) drought assessment

Drought indices (DI) are an useful tool for assessing different sectarian droughts. Standardized Precipitation Index (SPI) has been used worldwide to assess/monitor the onset, active phase, cessation and severity of drought. Normalized Difference Vegetation Index (NDVI) provides a comprehensive vegetation dynamics, which directly linked with rainfall received in a particular region. Indo-Gangetic Region (IGR), providing employment and livelihood to tens of millions of rural families directly or indirectly and rice (Oryza sativa L.)-wheat (Triticum aestivum L.) (RW) system of the Indo-Gangetic Plains (IGP) contributes 80% of the total cereal production and is critical to food security of the region. This study tries to verify the applicability of water-vegetative indices viz., SPI, Rainfall Index (RI) and NDVI for drought assessment of rice-wheat system productivity over IGR-India. The relationship between monsoon rainfall and NDVI shows that at around 1100 mm rainfall, the NDVI reached saturation point and no further significant increase in NDVI with increase of rainfall is noticed. Even though, there was a positive correlation of seasonal monsoon rainfall and average NDVI, conflicting results are noticed between monthly distribution of rainfall and monthly anomaly of NDVI over IGR States. It is noticed that June dif NDVI (actual NDVI-mean NDVI) contributes more to rice productivity followed by July. However, the combined effect of June, July and August, explains 15% of the variation of Kharif Rice Productivity Index (KRPI). As far as wheat is concerned, statistically significant relation was found between Wheat Productivity Index (WPI) and anomaly NDVI during December-March. This explains 35% of the variability in WPI.     

Efficient management of transportation logistics related to animal disease outbreaks

Vehicle routing is a key instrument to manage and control animal disease outbreaks. This paper focuses on an efficient, user-friendly and automatic procedure to manage transportation logistics to and between farms in the case of an outbreak. This procedure can be embedded into a veterinary geographical information system for the management and control of disease outbreaks. The transportation logistics for the problem at hand can be divided into two main transportation categories: (i) round itineraries, which are special cases of the travelling salesman problem, and (ii) one-to-one itineraries. Attention is given to the use of user-friendly, heuristic yet efficient algorithms for the determination of these itineraries. It is furthermore shown that the procedure is developed in such a way that the identified routes meet both national and international regulations in force during disease outbreaks.     

Visual Programming of Stochastic Weather Generator and Future Applications on Agroecological Study

Based on former studies on weather simulator modules in IPMist laboratory, study on visual programming of stochastic weather generator (VS-WGEN) was continued. In this study, Marlkov Chain,Monte Carlo, Fourier Series, and weak stationary process were used to generate the daily weather data in software Matlab 6.0, with the data input from 40 years' weather data recorded by Beijing Weather Station. The generated data includes daily maximum temperature, minimum temperature, precipitation and solar radiation. It has been verified that the weather data generated by the VS-WGEN were more accurate than that by the old WGEN, when twenty new model parameters were included. VS-WGEN bas wide software applications,such as pest risk analysis, pest forecast and management. It can be implemented in hardware development as well, such as weather control in weather chamber and greenhouse for researches on ecological adaptation of crop varieties to a given location over time and space. Overall, VS-WGEN is a very useful tool for studies on theoretical and applied ecology.     

《黑龙江八一农垦大学学报》的社会地位及影响力分析

采取文献计量法,对黑龙江八一农垦大学学报近年的引证数据进行了统计分析,明晰了黑龙江八一农垦大学学报的进展情况及在同类期刊中所处的地位。在此基础上,提出了学报未来的发展方向和具体举措。