甘肃南部襀翅目昆虫研究初报

甘肃南部地区，地形地貌复杂，属大陆性中亚热带季风湿润气候，昆虫资源十分丰富，首次报道了这一地区襀翅目的种类和分布。结果表明共有襀翅目昆虫16科12属19种，其中包括甘肃省新纪录10种。     

Production of Spotless Allotriploids from Female Non-Spotted Rainbow Trout (Houraimasu), Oncorhynchus mykiss,and Male Amago Salmon,O. rhodurus

ABSTRACT

A new phenotype, spotless allotriploids, was introduced into the aquaculture industry. Spotless allotriploids were produced from female non-spotted rainbow trout, Oncorhynchus mykiss, and male ama-go salmon, landlocked type of O. rhodurus. These allotriploids combine the favorable characteristics of the good flavor of amago salmon, faster growth (compared to that of amago salmon), and absence of spots, preferred by the market. The relationship between the non-spot character (gene) and the external appearance of the allotriploids was traced by analyzing the erythrocyte major axis, the allozymes, and the progeny test in each maternal genotype. Results indicate that spotless allotriploids can be produced by using female dominant homozygotic (hh) non-spotted rainbow trout. When females are heterozygotic (hn) non-spotted rainbow trout, the offspring produced are both spotted and spotless allotriploids in approximately equal proportions.     

Comparison of the lipid properties of healthy and pansteatitis‐affected African sharptooth catfish,Clarias gariepinus (Burchell), and the role of diet in pansteatitis outbreaks in the Olifants River in the Kruger National Park,South Africa

Pansteatitis has been identified in wild populations of sharptooth catfish, Clarias gariepinus (Burchell), and Nile crocodiles, Crocodylus niloticus Laurenti, inhabiting the same waters in the Olifants River Gorge in the Kruger National Park, South Africa. Mesenteric and pectoral fat tissue was investigated microscopically and by fatty acid analysis in healthy and pansteatitis‐affected catfish from both captive and wild populations. Variation in fatty acid composition between pectoral and mesenteric fat was noted. Composition of mesenteric fat differed between fish from various localities as a result of differences in diet. Pansteatitis in the captive population, resulting from ingestion of high amounts of dietary oxidized fat, reflected higher levels of unsaturated fatty acids within the mesenteric fat. Mesenteric fat of pansteatitis‐affected wild catfish was characterized by an increase in moisture content, a decrease in fat content and a decrease in stearic and linoleic acids. The n‐3 to n‐6 fatty acid ratio of mesenteric fat was higher in pansteatitis‐affected wild catfish than in healthy catfish from the same locality, reflecting higher polyunsaturated fat intake by pansteatitis‐affected fish. The possible role of alien, invasive, phytoplankton‐feeding silver carp, Hypophthalmichthys molitrix (Valenciennes), in the aetiology of pansteatitis in both catfish and crocodiles in the Olifants Gorge is discussed.     

Movement patterns of southern redbelly dace,Chrosomus erythrogaster,in a headwater reach of an Ozark stream

Previous research on fish movement has focused primarily on recreationally important fishes in perennial streams; however, fewer studies have examined movement patterns of small‐bodied fishes in intermittent streams where abiotic and biotic conditions can be extreme compared with perennial systems. Using mark–recapture, we examined movement patterns of southern redbelly dace, Chrosomus erythrogaster, in an intermittent Ozark stream having both permanently connected and temporally isolated sections. Juvenile (60–88%) and adult (55–83%) residency rates were not significantly different for any mark–recapture sample, and movement was primarily within a section for both groups. Ontogenetic differences were detected for kurtosis, distance moved and population spread, with adults exhibiting greater variability in movement, moving more often and further. When considering only adults, there was a significantly higher number of individuals that exhibited intermovement from isolated sections compared with connected sections. In addition, a higher proportion of adults exhibiting intermovement moved to connected stream sections in May and July compared to January and March. Dace exhibited upstream bias in July, with 76% of emigrates moving to an upstream connected section. Although there were no statistically significant associations between the proportion of intermovers from connected and isolated sections and measured water quality and habitat variables, noteworthy trends were observed, and these trends were always stronger for connected sections. Understanding the factors that influence population dynamics in headwater streams is important for the survival and persistence of stream fish populations, especially considering the anticipated expansion of intermittent headwater streams as a result of future climatic changes.     

川南浅丘区旱地三熟新模式“菜-粱-粱”技术

通过对川南浅丘区气候和旱地耕作特点的分析，探讨适应当前生产的“菜-粱-粱”新旱三熟模式栽培技术要点。     

清代晋南乡镇演变研究

清代晋南乡镇类型多样,商贸性质的乡镇占据主体,反映出区域经济发展的总体状况;乡镇在布局上主要集中于谷地、河流两岸、驿路与孔道沿线,各乡镇与府县城市的城市间距适中,体现了乡镇据点在地域上的规律性;到清代后期,晋南乡镇的总体数量有所增加,尤以商贸和驿递性质的乡镇为主,这与当地的自然、人文环境密切相关。     

滇南高海拔地区桉树优良无性系的选择及其制浆造纸性能研究

通过对所引种培育的10个桉树无性系的测定和选择,杂交桉树(尾巨桉)在造林中表现优异,4年生时有三个品系年均蓄积增长量在30m3.hm-2以上,在对比试验林中生长较好的无性系,在大面积示范种植中也显示其生长优势,推广种植的两年生桉树年平均生长量均为33m3.hm-2以上,第一年至第二年的净生长量为48m3.hm-2以上。通过对生长表现较好的四个桉树优良无性系制浆造纸应用进行评价研究,它们的化学成分抽出物含量偏低,纤维素及综纤维素含量偏高,对纸浆得率的提高有利,纤维形态属于桉木中的中等水平,LH110和LH107的硫酸盐浆得率能达到52%-53%;硫酸盐浆的粘度都在1430ml.g-1以上,LH110的则在1500ml.g-1以上,从四个无性系漂白硫酸盐浆所表现出来的强度指标来看,可划为阔叶硫酸盐浆中的高强度纸浆;白度指标值高达94.8%-97.6%,完全可以进入超高白度纸浆的应用市场,表现出更高的附加值。     

“南水北调”西线工程与中国西北开发和生态环境的改善

我国是个水资源既丰富又贫乏的国家 ,总量有 2 .8万亿 m3,但人均仅 2 2 60 m3,处于缺水的上、下限之间。北中国人均只有 1 1 2 7m3,接近缺水的下限 ,华北地区更少 ,仅 556m3。随着北中国社会经济的发展 ,缺水问题日益严重 ,不仅制约了社会经济的进一步发展 ,更造成了地下水资源破坏、黄河断流、土地荒漠化等一系列生态环境恶化问题。据估算 ,2 1世纪 50年代 ,北中国将缺水 2 0 0 0亿 m3,解决的根本途径是“南水北调”。今天考虑的“南水北调”,进到北方的水量仅 60 0亿 m3左右 ,只能是“解渴”工程 ,如要“重整河山 ,再造中国”,彻底解决北中国缺水和土地荒漠化问题 ,必须考虑和启动“大时空南水北调”,调除长江水外的西南诸水。这是一项“利在当代 ,功在千秋”的大业 ,更需要全民族不懈地努力和奋斗     

植酸酶对斑点叉尾鮰生长性能、营养物质表观消化率及氮、磷排泄的影响

本试验旨在研究植酸酶对斑点叉尾鮰生长性能、营养物质表观消化率及氮、磷排泄的影响,以确定植酸酶在斑点叉尾鮰饲料中的适宜添加量.选取初始均重为(1.74±0.02)g的斑点叉尾鮰幼鱼540尾,随机分成6个组,每组3个重复,每个重复放养30尾鱼.对照组饲喂基础饲料,试验组分别饲喂在基础饲料中添加300、500、1 000、l...