杨树人工林不同栽培模式碳储量研究

通过对赤峰市敖汉旗平缓固定沙地杨树人工林纯林、杨树与樟子松混交林、杨树与柠条混交林3种营林模式的不同树种的标准木生物量、碳含量进行测定,估算出不同模式单位面积生物量和碳储量。结果表明:相同林龄(20年生)不同营林模式碳储量差异较显著,其中杨树人工纯林碳储量最大为41.04 t/hm2,杨树与柠条混交林碳储量较小为21.6110 t/hm2,杨树与樟子松混交林碳储量最小为20.607 t/hm2。     

赤峰地区杨树人工林碳储量研究

以赤峰市杨树人工林为研究对象,对不同立地、不同林龄、不同林种杨树生物量、碳储量进行研究,结果表明:杨树人工林生物量随着树龄、胸径、树高的增长而增加,各个器官的生物量也不相同,干的生物量最大,叶的生物量最小,生物量依次顺序为:干根枝叶。树干的平均碳含量最大,为471.00 g/kg,根为461.14 g/kg,枝为468.00 g/kg,叶最小,为446.20 g/kg,不同器官的含碳率大小排序为树干树根树枝树叶。杨树人工林胸径与单株碳储量,树高、胸径与生物量、单株碳储量模型均符合乘幂模型,模型拟合率均大于80%。杨树人工林乔木层平均碳储量为37.783 t/hm2,赤峰地区杨树人工林乔木层碳储总量为26 539 627.38 t。     

Changes induced by osmotic stress in the morphology,biochemistry, physiology,anatomy and stomatal parameters of almond species （Prunus L. spp.） grown in vitro

We investigated the influence of different levels of osmotic stress on growth and development in selected wild almond species(eight Prunus spp.) grown in vitro. The study, while endorsing the efficacy of in vitro screening of auxiliary buds of wild almond for osmotic stress tolerance, showed species variability in its response to osmotic stress. Osmotic stress reduced growth and development of all the species. However, the putative tolerant Prunus spp. showed better performance than the putative susceptible genotypes. On average there was an 80% decrease in shoot dry weight at-1.2 MPa. Reduction in shoot weight was more common in osmotic stress-susceptible species in the section labeled ‘Euamygdalus'. The tolerant Prunus species produced smaller changes in biochemical responses than the sensitive cultivars for malondialdehyde content, catalase activity, relative permeability of protoplast membranes, and net photosynthetic rate. The tolerant species maintained cell integrity better than drought sensitive species. Wild almond species in the section labeled ‘Spartioides'(Prunus arabica(Olivier) Neikle, Prunus glauca (Browicz) A.E. Murray, Prunus scoparia Spach) and ‘Lycioides'(Prunus lycioides Spach, Prunus reuteri Bossi. et Bushe) were best adapted to osmotic stress. Increase in chlorophyll concentration and leaf thickness under high osmotic stress can be considered as preliminary selection parameters for osmotic stress tolerance in Prunus spp. The study confirmed the efficacy of the in vitro method for screening of large number of genotypes for osmotic stress tolerance in wild almond species.     

广东适生樱花及其园林应用

在对樱花作系统调查、引种、筛选和试种的基础上,推介适合广东地区种植的‘中国红’、‘广州’樱、和‘富贵’樱等5种适应性强、观赏价值高的樱花品种,重点介绍其品种特征、生态习性、观赏特性、繁殖栽培及园林应用。     

Bacterial flora associated with the giant freshwater prawn Macrobrachium rosenbergii, in the hatchery system

The objective of this study was to understand the microbial flora associated with the hatchery system of giant fresh water prawn, Macrobrachium rosenbergii during an entire rearing cycle. Bacteriological and physico-chemical analysis was done for different samples of water, larvae, and Artemia. The total bacterial load in well water, seawater and inlet water varied from 10¹ to 10⁵ cfu ml^− 1 with higher counts seen in larval rearing tank (LRT) water. The Vibrio count ranged between 10¹ to 10³ cfu ml^− 1. Larval samples harboured a bacterial load of 10⁶ to 10⁷ cfu/10 larvae. The bacterial load in Artemia hatching water ranged from 4.90 × 10⁴ to 5.63 × 10⁶ cfu ml^− 1 while Artemia had a load ranging from 1.08 × 10⁷ to 2.09 × 10⁹ cfu g^− 1. Vibrio count in the LRT water ranged from 10¹-10³ cfu ml^− 1 while the count in larvae ranged from 10² to 10⁴ cfu/10 larvae. The bacterial genera were predominantly Gram-negative and comprised of Aeromonas spp., Pseudomonas spp., Vibrio spp. and Bacillus spp. and non-spore formers (NSF) were the dominant Gram-positive bacteria. This study documents the bacterial flora associated with Macrobrachium hatchery system during a regular normal run. Knowledge of the qualitative and quantitative aspects of bacterial flora in the hatchery would help to understand disturbances, if any, brought about during disease outbreaks.     

鹤蕉种质资源抗寒性和农艺性状的鉴定与评价

针对抗寒性、花期和观赏特性等几个农艺性状,对引进的67个鹤蕉品种进行了连续3年的大田圃鉴定与评价,筛选出适合在海南不同区域栽培的8个有应用价值的品种。旨在为鹤蕉的品种改良、栽培和开发利用提供参考。     

甘肃甘南野生羊肚菌rDNA的ITS序列分析

根据形态学特征挑选了7株采自甘肃甘南境内的野生羊肚菌,应用rDNA-ITS序列进行了比对技术分析。结果表明,7株野生羊肚菌归属为4个种：粗柄羊肚菌Morchellav crassipes、羊肚菌M.esculenta、黑脉羊肚菌M.angusticeps和高羊肚菌M.elata。根据分子系统树发现,粗柄羊肚菌和羊肚菌属于黄羊肚菌类群,而黑脉羊肚菌和高羊肚菌属于黑羊肚菌类群。     

桉树栽培紫芝及营养成分分析

为探讨桉树栽培紫芝的可行性,笔者于2012年-2013年利用当地5年～6年树龄的尾叶桉为菌材,开展了桉树栽培紫芝对比试验,并对其灵芝产品营养成分送样检测。结果表明,利用桉树栽培紫芝是可行的,其菌丝生长速度快于米槠（CK）菌材,当年平均产量（早晚季合计）25．42kg·m^-3,比对照提高2．67％,差异不显著;氨基酸、粗多糖等营养成分经福建省分析测试中心检测,桉树早季灵芝总氨基酸含量（TAA）6．05g/100g,晚季灵芝总氨基酸含量（TAA）7．31g/100g,早季粗多糖含量0．52g/100g,晚季粗多糖含量0．67g/100g,比米槠（CK）栽培粗多糖含量0．59g/100g高13．56‰     

Clonal Spread of Salmonella enterica Serovar Infantis in Serbia: Acquisition of Mutations in the Topoisomerase Genes gyrA and parC Leads to Increased Resistance to Fluoroquinolones

Quinolone‐resistant Salmonella Infantis (n = 64) isolated from human stool samples, food and poultry during the years 2006–2011 were analysed for their resistance phenotypes, macrorestriction patterns and molecular mechanisms of decreased susceptibility to fluoroquinolones. Minimum inhibitory concentrations (MICs) of nalidixic acid (NAL) and ciprofloxacin (CIP) were determined by the agar dilution procedure, and the susceptibility to additional antimicrobial agents was determined by the disc diffusion method. To assess the influence of enhanced efflux activity, MICs were determined in the presence and absence of the inhibitor PAβN. The results of pulsed‐field gel electrophoresis (PFGE) typing revealed that quinolone‐resistant S. Infantis in Serbia had similar or indistinguishable PFGE profiles, suggesting a clonal spread. All S. Infantis showed combined resistance to NAL and tetracycline, whereas multiple drug resistance to three or more antibiotic classes was rare (2 isolates of human origin). The MICs ranged between 512 and 1024 μg/mL for NAL and 0.125–2 μg/mL for CIP. A single‐point mutation in the gene gyrA leading to a Ser83→Tyr exchange was detected in all isolates, and a second exchange (Ser80→Arg) in the gene parC was only present in eight S. Infantis isolates exhibiting slightly higher MICs of CIP (2 μg/mL). The inhibitor PAβN decreased the MIC values of CIP by two dilution steps and of NAL by at minimum 3–6 dilution steps, indicating that enhanced efflux plays an important role in quinolone resistance in these isolates. The plasmid‐mediated genes qnr, aac(6′)‐lb‐cr and qepA were not detected by PCR assays.