越南和平水电站库区不同农林复合模式的环境效益比较

为了找出最适宜于越南中部山区、预期综合环境效益最佳的、更利于生态平衡的农林复合模式,该研究以越南和平水电站库区4种主要农林复合模式：马占相思树（Acacia mangium）-玉米（Zea mays）、马占相思树-木薯（Manihot esculenta crantz）、赤桉树（Eucalyptus camandulensis）-旱稻（Oraza sativa）和马占相思树-木薯-玉米为研究对象,采用盖度、土壤理化性质、土壤蓄水能力、水土保持能力等指标进行环境效益的比较,最后得出的结论为：在4种农林复合模式中,马占相思树-木薯-玉米复合模式具有最高的水土保持效益和综合环境效益;赤桉树-旱稻复合模式的水土保持效益和综合环境效益均最低;实践中应该增加前者的种植面积,限制和减小后者的种植面积。在马占相思树-木薯-玉米复合模式的基础上加以改进,提出了预期综合环境效益更好的马占相思树-木薯-玉米-肉桂（Cinnamomum cassia）复合模式,为农林复合系统在和平水电站库区的应用提供更好的选择,同时也为世界上有类似气候环境条件的地区农林复合模式的采用提供参考。     

Atmospheric measurements of nitrogen dioxide with a sensitive luminol instrument

A highly sensitive, lightweight, portable instrument has been developed for continuous monitoring of N0₂ in air. It operates by detecting the chemiluminescence produced when N0₂ encounters a surface wetted with a specially formulated solution containing luminol. Unlike other chemiluminescent instruments it measures N0₂ directly and does not require prior conversion of N0₂ to NO. It does not respond to H₂0₂, NO, HNO₃, NH₃, CO, C0₂, S0₂ or organic nitrates. The only interferences encountered to date are from 0₃ and PAN with the response to 0₃ being less than 0.2% of its response to N0₂. The response time of the instrument is less than 1 s and its sensitivity is better than 5 pptv. The instrument shows a negative temperature dependence of about 2% °C^?1 which is compensated electronically. Measurements have been made with the instrument during a number of field missions in polluted urban and relatively clean rural air. The relative influences of photochemistry and transport from local sources has been observed. Simultaneous measurements made with this instrument and the unequivocal tunable diode laser absorption spectroscopy method have shown excellent agreement.     

Differential staining of mitotic chromosomes from inbred lines and hybrids ofZea mays L.

Summary The Giemsa banding patterns of four inbred lines (DB1113, DB1116, WIR44 and WIR27) ofZea mays and their hybrids have been compared. The polymorphism of knob heterochromatin of 4 chromosome pairs allowed to distinguish the 4 inbred lines on the basis of their banding patterns, reflected the evolutionary distance of the inbred lines and provided evidence as to the origin of these chromosomes in hybrids.Sister chromatid differentiation by means of BrdUrd incorporation prior to fluorescence plus Giemsa(FPG)-technique revealed 3.7 SCEs per cell for the hybrid BEKOS 251. Individualization of chromosomes on the basis of their replication patterns or asymmetric bands after application of the same technique was impossible.

---

Differentialfärbung mitotischer Chromosomen von Inzuchtlinien und deren Hybriden beiZea mays L.

Zusammenfassung Die Giemsabandenmuster der vier Inzuchtlinien des Maises DB1113, DB1116 (convar.vulgaris) und WIR27, WIR44 (convar.dentiformis) sowie der daraus entstandenen Hybriden SU 10, Kappa und BEKOS 251 wurden untereinander verglichen. Polymorphismen des Knob-Heterochromatins auf vier Chromosomenpaaren (I, VI, VII, VIII) erlaubten die Unterscheidung der vier Inzuchtlinien anhand ihrer Bandenmuster, widerspiegelten den jeweiligen Verwandtschaftsgrad zwischen den Inzuchtlinien und ermöglichten für einige Chromosomen der Hybriden den Herkunftsnachweis.Schwesterchromatidendifferenzierung nach BrdUrd-Einbau und FPG-Färbung ergaben für die Doppelhybride BEKOS 251 3.7 SCEs/Zelle. Die Erfassung von Replikationsmustern oder asymmetrischen Banden zur Charakterisierung individueller Chromosomen war mit dieser Methode nicht möglich.

---

Zea mays L.

, , DB1113, DB1116 (convar.vulgaris) WIR27, WIR44 (convar.dentiformis), SU 10, Kappa BEKOS 251. - (I, VI, VII, VIII) , . BrdUrd FPG BEKOS 251 3,7 . .

     

RAPD variability in rice (Oryza sativa L.) plants derived from desiccation-tolerant calli

Genetic modification from selfed progenies of 18 rice (Oryza sativa L.) plants regenerated from callus tissues which survived desiccation, were investigated at the DNA level using the random amplified polymorphic DNA (RAPD) method. Twelve 10-mer random primers were used to amplify DNA of progenies from the regenerated plants, and a total of 228 PCR products and 1780 DNA fragments were obtained by primers, generating between four to thirteen major bands. The size of the amplified fragments ranged from 0.2 to 2.55 kb. The results showed that 10 out of 12 primers produced polymorphic bands, two primers (RA31 and RA185) showed no polymorphism among plants tested. A dendrogram of the genetic distance was constructed based on their polymorphism, demonstrating that somaclonal variation exists in rice plants regenerated from callus which survived the desiccation treatment. Part of this variation can be useful in rice breeding. This revised version was published online in August 2006 with corrections to the Cover Date.     

越南对抗角斑病棉花品种的选育（英）

I Introduction Bacterial Blight (Xanthomonas malvacearum ,BB) was probably originated in India, although the disease was first reported in the USA by Atkinson (1891), who gave the names angular leaf spot, blackarm and bacterial boll rot to the various stages in the syndrome of the disease. The first programme to breed for cultivar resistance to the disease was initiated in Sudan by research officers with the Cotton Research Corporation. Methods adopted there were soon implemented in Uganda and most of the early resistant varieties grown in many African countries were derived from the Uganda programme.     

Varietal Differences in Allelopathic Potential of Alfalfa

Alfalfa ( Medicago sativa L.) plants were found to contain water-soluble substances that inhibited the germination and seedling growth of alfalfa ( Chung and Miller 1990, Agron. J. 87, 762—767 ). Tsuzuki et al. (1999, Rep. Kyushu Branch Crop Sci. Soc. Japan 65, 39—40 ) discovered allelochemicals in alfalfa plants that could have adverse effects on the growth of some lowland weeds. This study was conducted to investigate varietal differences in allelopathic potential in alfalfa plants. Eight common varieties of Japanese alfalfa ( Medicago sativa L.), namely Batasu, Hisawakaba, Kitawakaba, Makiwakaba, Natsuwakaba, Lucerne, Tachiwakaba and Yuba, were grown by conventional methods in the Experimental Field of the Crop Science Laboratory, Faculty of Agriculture, Miyazaki University. Aqueous extracts of both fresh and dried material of alfalfa plants of all varieties significantly inhibited both germination and growth of lettuce ( Lactuca sativa L.). Leachates from germinating seeds of almost all alfalfa varieties inhibited elongation of the radicle but produced a negligible increase in germination and only slightly inhibited elongation of the hypocotyl of lettuce plants. Results demonstrated that the degree of inhibition of germination and growth of lettuce varied with the variety of alfalfa. In particular, Lucerne was identified as having the strongest allelopathic potential of the varieties studied. The results suggested that the allelopathic potential of alfalfa might be relating to a gene.     

The phenotypic characteristics and relational database for Vietnamese native pig populations

Although there are a number of Vietnamese native pig (VnP) populations, some are on the verge of extinction, and therefore adequate management and conservation are necessary. In this study, we conducted a field survey of VnP populations and analyzed interrelationships among their characteristics. We also established a relational database for management of field data on these populations. For data collection, we conducted interviews with farmers and visual inspection of 32 VnP populations in 22 provinces of Vietnam, as well as taking photographs of individual animals. Data on the characteristics of VnP populations were subjected to multiple correspondence analysis (MCA). For establishment of the database, normalization and table partitioning were performed to eliminate redundancy and ensure consistency of the collected data items. Passport data, characteristics data, and image data were collected from a total of 1,918 VnPs and entered as a normalized table. Upon MCA, most of the populations were not separated from each other, but the Mong Cai, O Lam, and Chu Prong populations were separated from the other populations. Thus, we have constructed a relational database from comprehensive information on the characteristics of VnP populations.     

Increasing cyst yields in Artemia culture ponds in Vietnam: the multi-cycle system

In this study, one-cycle and multi-cycle culture systems for Artemia in seasonal salt ponds are compared. In one-cycle systems, Artemia is inoculated only once per season, while in multicycle systems ponds are drained and re-stocked several times per season. In Vietnam, three-cycle systems gave significantly higher cyst yields than did the one-cycle system. However, after two cycles, systems were not significantly different. Food limitation probably caused the steady decline in cyst yields, as observed in the one-cycle ponds. In these ponds, females have smaller broods (from the second cycle onwards) and during the last cycle the number of adult females is lower than in multi-cycle ponds.     

Use of GIS and machine learning to predict disease in shrimp farmed on the east coast of the Mekong Delta,Vietnam

Diseases in shrimp farms in the Mekong Delta of Vietnam cause significant crop losses and are therefore of great concern to producers. Once a pond becomes infected, it is difficult to prevent spread of the disease to nearby shrimp farming areas. Thus, predicting the occurrence of disease is an essential part of reducing the risk for shrimp farmers. In this study, we applied an integrated geographic information system and machine learning system to predict three serious diseases of shrimp, namely, acute hepatopancreatic necrosis, white spot syndrome disease, and Enterocytozoon hepatopenaei infection, based on data collected from shrimp farms in the Tra Vinh, Bac Lieu, Soc Trang, and Ca Mau provinces of Vietnam. We first constructed a map showing the distribution of these diseases using the locations of affected farms, and then we conducted spatial analysis to acquire the geographical features of the affected locations. This latter information was combined with environmental factors and clinical signs to form the set of independent variables affecting the outbreak of diseases. The neural network model outperformed the logistic regression, random forest, and gradient boosting methods in terms of predicting infection to estimate the probability of disease occurrence in farmed areas. Acute hepatopancreatic necrosis disease infected farms downstream of the Co Chien and Hau Rivers of Tra Vinh and west of Ca Mau. Enterocytozoon hepatopenaei infection is distributed in Soc Trang Province, while white spot syndrome virus has spread to the coastal districts of Soc Trang and Bac Lieu Provinces, where it is highly associated to water from a complex canal system.

     

虚拟现实技术在测绘中的应用

虚拟现实技术是门新兴的科学技术,是多门学科交叉的产物,将虚拟现实技术引入到测绘领域,实现地理信息的三维可视化与虚拟再现,为测绘学的发展指明了新的方向.本文介绍了虚拟现实的概念及特征,分析了虚拟现实实现的关键技术以及虚拟现实系统的分类,并就虚拟现实技术在测绘领域中应用提出观点.