编线工艺对渔用高强度聚乙烯编织线拉伸性能的影响

2007年3月~2008年12月在东海水产研究所开展了编线工艺对渔用高强度聚乙烯(HSPE)编织线拉伸性能的影响研究。结果表明,在试验捻距范围(公称直径3.0 mm和3.9 mm编织线的试验捻距范围分别为11.1~29.2 mm、16.4~48.5 mm)内,若其它条件(包括线股结构、线芯用丝数量和线芯结构等)相同,则以不同捻距编织的相同公称直径渔用HSPE编织线的断裂强力及单线结强力均随捻距的增加而增加,而断裂伸长率及线密度则随捻距的增加而减小;多项式回归方程显示,断裂强力与捻距、单线结强力与捻距均显示较好的相关性(R2≥0.987 7)。在线芯用丝数量范围(公称直径3.0 mm和3.9 mm编织线的试验用线芯用丝数量范围分别为0~36、0~64)内,若其它条件(包括线股结构、捻距和线芯结构等)相同,则以不同线芯用丝数量编织的相同公称直径渔用HSPE编织线的断裂强力、单线结强力及线密度均随线芯用丝数量的增多而增加,而断裂伸长率则随线芯用丝数量的增加而减小;多项式回归方程显示,断裂强力与线芯用丝数量、单线结强力与线芯用丝数量均显示较好的相关性(R2≥0.969 5)。若其它条件(包括线股结构、捻距和线芯用丝数量等)相同,则将线芯结构由不加捻的平行丝束改为捻度为32 T/m的线股后,公称直径2.5 mm渔用HSPE编织线的断裂强力、单线结强力、断裂伸长率和线密度均有一定的增加。捻距、线芯用丝数量及线芯结构对渔用HSPE编织线拉伸性能的影响较大。     

Identification of domestic cat hepadnavirus from a cat blood sample in Japan

The hepatitis B virus (Hepadnaviridae) induces chronic hepatitis and hepatic cancer in humans. A novel domestic cat hepadnavirus (DCH) was recently identified in several countries, however, the DCH infection status of cats in Japan is unknown. Therefore, we investigated the DCH infection rate of 139 cat samples collected in Japan. We identified one positive blood sample (0.78%) from a 17-year-old female cat with chronically elevated alanine aminotransferase. Phylogenetic analysis demonstrated that the DCH strain identified in this study is genetically different from strains in other countries. Further investigations are required to elucidate the evolution of DCH and the impact of DCH infection on hepatic diseases in domestic cats.     

陇川坝水稻德优8号(香型)品种优质高产栽培技术

通过云南陇川引进水稻德优8号(香型)品种的示范种植,初步提出了德优8号(香型)在陇川坝的优质高产栽培技术措施。     

Turbidity‐induced changes in emergent effects of multiple predators with different foraging strategies

Abstract – In natural systems, prey frequently interact with multiple predators and the outcome often cannot be predicted by summing the effects of individual predator species. Multiple predator interactions can create emergent effects for prey, but how those change across environmental gradients is poorly understood. Turbidity is an environmental factor in aquatic systems that may influence multiple predator effects on prey. Interactions between a cruising predator (largemouth bass Micropterus salmoides) and an ambush predator (muskellunge Esox masquinongy) and their combination foraging on a shared prey (bluegill Lepomis macrochirus) were examined across a turbidity gradient. Turbidity modified multiple predator effects on prey. In clear water, combined predators consumed in total more prey than expected from individual predator treatments, suggesting risk enhancement for prey. In moderately turbid water, the predators consumed fewer prey together than expected, suggesting a risk reduction for prey. At high turbidity, there were no apparent emergent effects; however, the cruising predator consumed more prey than the ambush predator, suggesting an advantage for this predator. Understanding multiple predator traits across a gradient of turbidity increases our understanding of how complex natural systems function.     

苹果砧木M26试管苗不定根发育过程中蛋白质的变化

为进一步了解木本植物不定根发生、发育的机理,对苹果砧木M26试管苗不定根的发生、发育过程进行解剖观察,利用十二烷基磺酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)对M26试管苗在接入生根培养基前后,不同时期表达的蛋白进行了研究。结果发现:在不定根原基形成和发育的阶段性过程中,茎基部蛋白质的种类和数量出现明显差异。生根培养后,在继代苗茎基部表达的5条蛋白条带减弱或消失,其分子量分别为26.8 kDa、37kDa、40.3 kDa、43 kDa和66 kDa;明显表达了4条新的蛋白条带,其分子量分别为26 kDa、27.7 kDa、32.5 kDa、和45 kDa,同时有4条蛋白条带(38.5 kDa、42 kDa、53.2 kDa和55.5 kDa)其表达丰度提高。多种蛋白条带的消失和出现,可作为M26试管苗不定根产生的生化标志。在不定根原基逐步形成发育的同时,有3条蛋白条带的表达丰度也逐步提高,可作为不定根形成过程表达的特异标记蛋白带。     

Molecular characterization and PCR detection of a nitrogen-fixing Pseudomonas strain promoting rice growth

Nitrogen-fixing plant growth-promoting rhizobacteria (PGPR) from the genus Pseudomonas have received little attention so far. In the present study, a nitrogen-fixing phytohormone-producing bacterial isolate from kallar grass (strain K1) was identified as Pseudomonas sp. by rrs (16S ribosomal RNA gene) sequence analysis. rrs identity level was high with an uncharacterized marine bacterium (99%), Pseudomonas sp. PCP2 (98%), uncultured bacteria (98%), and Pseudomonas alcaligenes (97%). Partial nifH gene amplified from strain K1 showed 93% and 91% sequence similarities to those of Azotobacter chroococcum and Pseudomonas stutzeri, respectively. The effect of Pseudomonas strain K1 on rice varieties Super Basmati and Basmati 385 was compared with those of three non-Pseudomonas nitrogen-fixing PGPR (Azospirillum brasilense strain Wb3, Azospirillum lipoferum strain N4 and Zoogloea strain Ky1) used as single-strain inoculants. Pseudomonas sp. K1 was detected in the rhizosphere of inoculated plants by enrichment culture in nitrogen-free growth medium, which was followed by observation under the microscope as well as by PCR using a rrs-specific primer. For both rice varieties, an increase in shoot biomass and/or grain yield over that of noninoculated control plants was recorded in each inoculated treatment. The effect of Pseudomonas strain K1 on grain yield was comparable to those of A. brasilense Wb3 and Zoogloea sp. Ky1 for both rice varieties. These results show that nitrogen-fixing pseudomonads deserve attention as potential PGPR inoculants for rice.     

橡胶产业升级与关键技术调研——橡胶树采胶及病虫害防控

通过对我国海南、云南、广东三大植胶区橡胶产业发展情况的调研,简要阐述橡胶采胶及病虫害防控方面的现状。探讨分析橡胶采胶及病虫害方面所面临的采胶技术管理执行不够好,橡胶树割面干涸病防控技术仍未获得突破,橡胶树常规病虫危害日趋严重及新病虫害不断涌现,橡胶栽培技术经济合理性研究不够等问题。提出通过切实做好采胶技术管理,割面干涸病防控技术研发,高效安全的采胶技术及新型刺激剂复方的研发,橡胶树突发病虫害监测预报及应急防控技术,橡胶树根病综合防控及植保药物技术研发等建议,发展提升橡胶产业整体水平。     

中间偃麦草、长穗偃麦草及其杂种F1代同工酶研究

通过对过氧化物酶(POD)、酯酶(EST)、超氧化物歧化酶(SOD)和多酚氧化酶(PPO)同工酶谱的分析,探讨中间偃麦草(Elytrigia elongata(Host)Nevski)、长穗偃麦草(E.intermedia(Host)Nevski)及其杂种F₁代的酶谱特征和亲缘关系。结果表明:亲本同工酶酶带数目、迁移率、着色程度等差异不大,二者亲缘关系较近。与亲本相比,杂种F₁代存在POD、SOD、PPO酶带丢失现象,但正、反交植株中均产生了一些亲本没有的新生带。杂种F₁代EST酶谱与亲本基本相同,仅着色程度略有差异。杂种F₁代植株的POD、PPO酶谱特征有偏向中间偃麦草的倾向,而SOD酶谱特征倾向于长穗偃麦草。杂种F₁代同工酶具有多态性,可作为遗传标记用于杂种鉴定和后代株系目标性状的选择。     

蛹虫草菌种复壮方法比较

蛹虫草菌种退化是蛹虫草栽培的关键问题。本试验采用子囊孢子分离复壮法、分生孢子分离复壮法、蚕蛹回接复壮法、基内菌丝分离复壮法等4种复壮方法,通过比较不同复壮方法后代菌丝生长速度、转色速度及子实体形成情况,初步判定子囊孢子分离复壮法和蚕蛹回接复壮法都有明显复壮效果。     

聚丙烯酸钠对黄土坡面产流产沙的影响研究

通过野外模拟降雨试验,研究了施用SP对黄土坡面产流、产沙的影响,并对实验数据进行数学模拟,建立了SP施用量与产流、产沙强度间的关系模型.结果表明:SP施用量与产流时间、平均产流强度呈二次函数相关关系,与产沙强度呈线性负相关关系.SP用量在0～2.42 g/m\+2之间时,能够延缓坡面产流,用量为1.21 g/m\+2时延缓产流效果最明显;用量介于0～3.31 g/m2之间时,能够增加土壤入渗,减少坡面产流量,用量1.65 g/m2的增渗减流效果最佳;施用SP后,能够减少坡面输沙强度,且用量越大,减沙效果越明显.SP可影响坡面产流过程,用量1.8 g/m2时,能够减小产流初期径流强度增幅,用量为3.6 g/m2时,其产流过程线与对照极接近,而施用量增加到5.4 g/m2时,产流强度明显增大.SP对坡面产沙过程的影响表现为:随施用量增大,产沙强度峰值呈逐步减小的变化趋势.