禽白血病病毒亚群重组囊膜蛋白基因的表达效果

用ELISA法测定了重组杆状病毒rBac-4817env感染的Sf9细胞中重组囊膜蛋白基因的表达效果。用特异性抗禽白血病病毒J型群（ALV-J）单克隆抗体JE9荧光染色证明了重组病毒能够在感染的Sf9细胞中表达ALV-J的env基因；糖基化抑制试验的结果表明，Sf9细胞表达的env基因产物是一种糖基化蛋白。不同量的重组病毒感染细胞与基因产物的表达产量无正相关，然而当每个细胞感染的病毒量2-800个时，表达产量相对较好。表达产物以感染后72-96h较高，并随着感染时间的延长，分泌到细胞外的重组基因产物有所增加，但在120h后，表达产物分解增加。研究结果对今后获取大量的基因的产物，并对其特性进一步研究奠定了基础。     

Primary lymphoedema in a dog—a case report

Primary lymphoedema is a swelling of a part or parts of the body due to a congenital defect in the lymphatic system. This report describes our experience with a case in a Rough Collie.     

荔枝农药残留的初步调查

本文对广东省一些荔枝园进行抽样调查,结果初步显示按常规方式生产的荔枝有三氯杀螨醇、氯氰菊酯以及甲胺磷农药残留,而经权威认证机构认证的有机荔枝园生产的有机荔枝未检测出农药残留。有机荔枝的出现解决了食品安全问题,是未来荔枝市场发展的必然趋势。     

Physiological basis for antagonism induced by mixtures of quizalofop-ethyl and bromoxynil in maize (Zea mays)

In this study, the physiological basis for antagonism induced by mixtures of quizalofop‐ethyl and bromoxynil was investigated in maize seedlings. In sequential applications, antagonism was observed when bromoxynil was applied before quizalofop‐ethyl or in a mixture with quizalofop‐ethyl, but was minimal when bromoxynil was applied afterwards. The degree of antagonism differed with application rates of bromoxynil and with the timing of the treatment. When test herbicides were applied locally to the second leaf, the inhibition of photosystem II (PS‐II) in the herbicide‐treated leaf was higher with the mixture than with bromoxynil or quizalofop‐ethyl alone. Subsequent growth of the untreated third leaf inhibited by quizalofop‐ethyl alone then recovered, depending on the dose of bromoxynil. There was no evidence that bromoxynil affected absorption of quizalofop‐ethyl. In local applications at different positions on the second leaf, antagonism was only observed when quizalofop‐ethyl was applied to the distal part of the leaf and bromoxynil applied to the proximal part. The antagonism of bromoxynil + quizalofop‐ethyl did not occur at the level of acetyl CoA carboxylase and Hill reaction, as revealed by in vitro assays. These results suggest that bromoxynil inhibits the phloem transport of quizalofop‐ethyl and thus antagonises its whole‐plant activity in maize.     

大穗看麦娘化学防控田间效果评价

大穗看麦娘在欧洲是一种分布广泛、危害巨大的禾本科杂草,在我国仅在台湾有报道分布,但目前在我国黄淮海区域已经有分布,为新的入侵危害杂草,其化学防控技术未见系统报道。本研究特选择小麦田常用防除禾本科杂草的8种除草剂,于2013-2014年度在大穗看麦娘为优势杂草的冬小麦田,分别于冬前、冬季低温及春季小麦返青初期3个时期施药,以期明确各除草剂对大穗看麦娘的田间防除效果、最佳使用时间及对冬小麦的安全性。试验结果表明,啶磺草胺不同时期施药,对大穗看麦娘均有很好的防控效果,鲜重防效达到97.1%~100.0%;甲基二磺隆在不同时期施药也有很好的效果,在80.1%~98.6%之间;唑啉草酯冬前施药效果优,但冬季低温和春季返青初期施药效果较差,3次施药鲜重防效分别在99.3%~99.9%,74.1%~88.9%和46.2%~75.8%之间;炔草酯、精噁唑禾草灵于冬前施药和冬后返青初期施药效果均较好,效果在81.1%~96.8%之间,但冬季低温施药效果差,防效在41.4%~76.0%之间;其他几种药剂氟唑磺隆、肟草酮、异丙隆3次时期施药对大穗看麦娘效果均较差。     

Development of real-time onion disease monitoring system using image acquisition

In this study, real-time disease monitoring was conducted on onion which is the most representative crop in Republic of Korea, using an image acquisition system newly developed for the mobile measurement of phenotype. The purpose of this study was to improve the accuracy of prediction of disease and state variables by processing images acquired from monitoring. The image acquisition system was consisted of two parts, a motorized driving system and a PTZ (pan, tilt and zoom) camera to take images of the plants. The acquired images were processed as follows. Noise was removed through an image filter and RGB (red, green and blue) colors were converted to HSV (hue, saturation and value), which enabled thresholding of areas with different colors and properties for image binarization by comparing the color of onion leaf with ambient areas. Four objects with the most significant browning in the onion leaf to the naked eye were selected as the samples for data acquired. The thresholding method with image processing was found to be superior to the naked eye in identifying accurate disease areas. In addition, it was found that the incidence of disease was different in each disease area ratio. As a result, the use of image acquisition system in image processing analysis will enable more prompt detection of any changes in the onion and monitoring of disease outbreaks during the crop lifecycle.     

Feature extraction of hyperspectral images for detecting immature green citrus fruit

At an early immature growth stage of citrus, a hyperspectral camera of 369–1042 nm was employed to acquire 30 hyperspectral images in order to detect immature green fruit within citrus trees under natural illumination conditions. First, successive projections algorithm (SPA) were implemented to select 677, 804, 563, 962, and 405 nm wavebands and to construct multispectral images from the original hyperspectral images for further processing. Then, histogram threshold segmentation using NDVI of 804 and 677 nm was implemented to remove image backgrounds. Three slope parameters, calculated from the pairs 405 and 563 nm, 563 and 677 nm, and 804 and 962 nm were used to construct a classifier to identify the potential citrus fruit. Then, a marker-controlled watershed segmentation based on wavelet transform was applied to obtain potential fruit areas. Finally, a green fruit detection model was constructed according to Grey Level Co-occurrence Matrix (GLCM) texture features of the independent areas. Three supervised classifiers, logistic regression, random forest and support vector machine (SVM) were developed using texture features. The detection accuracies were 79%, 75%, and 86% for the logistic regression, random forest, and SVM models, respectively. The developed algorithm showed a great potential for identifying immature green citrus for an early yield estimation.     

Contribution of forest floor fractions to carbon storage and abundance patterns of arbuscular mycorrhizal fungal colonisation in a tropical montane forest

Forest floor carbon stocks, which include different components of litter, hemic and sapric materials, have not been empirically quantified in tropical montane forest, although they influence soil carbon (C) pools. To date, the contribution of arbuscular mycorrhizae in C sequestration potentials in tropical montane forests have not been clearly investigated. This study determined the amount of C stocks in the different decomposing layers of forest floor, mainly litter, hemic and sapric materials. The abundance of arbuscular mycorrhizal root colonisation differed among forest floor fractions. Forest floor was measured for depth, area density, dry mass and carbon fraction separately in Sungai Kial Forest Reserve, Pahang, Malaysia to calculate C stocks. Percentages of root colonisation in the hemic and sapric materials were investigated. The results showed that forest floor C stocks were significantly higher in hemic (5 Mg C ha^?1) and sapric (7.7 Mg C ha^?1) compared with the litter fragments (1.5 Mg C ha^?1). Mycorrhizal root colonisation was significantly higher (75%) in the toeslope compared with the summit area in the hemic materials. Segregation of forest floor layers provided greater accuracy in forest floor C stocks reporting.     

Productivity and energy partition of late lactation dairy cows during heat exposure

Three late-lactation Holstein cows were used to determine the effects of environmental temperature on performance and energy partitioning. Each cow was housed in a respiratory chamber for 30 consecutive days and exposed to three different conditions of environmental temperature: (i) 20°C and 20°C (20°C), (ii) 25°C and 20°C (25°C), (iii) 30°C and 25°C (30°C) during the day and night, respectively. The temperature was switched in an interval of 10 days. Humidity in the chamber was maintained at 55–65% through the entire experimental period. The daily mean as well as morning and evening rectal temperatures of Holstein cows increased linearly ( P  < 0.05) as chamber temperature increased. There was a significant linear reduction in dry matter (DM) intake ( P  < 0.05) and an increase in DM digestibility ( P  < 0.05). The response in milk yield, however, was not affected by heat stress. There were no significant differences among treatments for intake energy, heat production, net energy for lactation and net energy for gain. This results of this study disagreed with the assumption that late lactation cows gave priority to increasing body tissue at the expense of milk production under thermal stress.     

长江下游地区部分优质粳稻品种与越光稻米支链淀粉结构特征及品质性状比较

为探讨具有优异食味品质的日本粳稻品种越光与中国长江下游地区食味品质好的水稻品种稻米的支链淀粉链长分布和主要品质特征差异,以期为中国优质水稻育种提供理论依据,选用长江下游地区公认的食味品质好的5个粳型水稻品种稻米和日本新泻地区生产的越光稻米为材料,分析支链淀粉链长分布、稻米RVA谱、直链淀粉含量、蛋白质含量、TOYO味度值等主要品质特性的差异及其相关性。越光的稻米支链淀粉链长分布和直链淀粉含量等主要品质指标与长江下游地区食味品质好的品种没有明显差异,支链淀粉长链部分(Fb3)和蛋白质含量显著低于长江下游地区食味品质好的品种,支链淀粉短/长链比(Fa/Fb3)显著高于长江下游地区食味品质好的品种。越光稻米中Mg、K含量以及淀粉谱特性中最高黏度、崩解值均显著高于长江下游地区食味品质好的品种。支链淀粉的短链部分(5≤DP≤12)所占比率与最高黏度值和崩解值呈显著正相关,Fa/Fb3与最高黏度和崩解值均呈显著正相关。由此认为,通过育种手段改善稻米的支链淀粉理化特性,并在栽培措施上通过降低氮肥施用量来降低稻米中蛋白质含量,是提高长江下游地区水稻品种食味品质的有效途径。