优良玉米自交系"87-1"穗部性状的配合力分析及其杂优类群的划分

以自选系87-1,87-3及14个国内常用的优良玉米自交系为亲本按griffing4双列杂交模式设计,组配成120个单交组合,采用格子方排列进行试验,对产量、穗长、穗粗等6个穗部性状的一般配合力和特殊配合力进行了分析.结果表明,在这16个自交系中,87-1和87-3两自交系产量的一般配合力值处于中等水平,但穗粗性状的一般配合力值最为突出,居于各自交系之首.就产量性状而言,在87-1所组配的杂交组合中,该系与HZ32和综3的特殊配合力效应值最高,对照优势分别达13.31%和9.85%.聚类分析结果表明,自交系87-1与外杂选亚群的许178和P138的关系最近,可聚为一类.     

松嫩草原的植被类型及主要饲用植物类群

简要介绍了松嫩草原的自然概况．讨论了该区域的植被类型，同时根据该区域的植被状况和生态条件，将草场植被资源划分为三大类型，即草原、草甸和沼泽．讨论了该区域所含的各种植物类群．并根据其产草量和营养特点，给预评价．     

Attitudes,beliefs, and prevalence of dumpster diving as a means to obtain food by Midwestern,low-income,urban dwellers

Dumpster diving is a term generally used for obtaining items, in this case food for consumption, from dumpsters. This study evaluates the prevalence of dumpster diving in two low-income urban communities in Minneapolis, Minnesota. Additionally, attitudes and beliefs of adults who engage in this behavior are reported. Surveys (n=396) were used to collect data including individual dumpster diving behavior, food security, health, and demographic data. Nearly one-fifth of those surveyed had used dumpster diving as a means to obtain food. Focus groups (n=17) were conducted to further evaluate dumpster divers attitudes and beliefs about dumpster diving, use of food assistance programs including benefits and barriers, and other strategies used to obtain food such as stealing. Focus group participants were primarily homeless and most were high school educated. Ways to improve delivery of food assistance are suggested. In conclusion, more research on the use of dumpsters as a source of food is needed. Utilizing more of the 96 billion pounds of food wasted each year in the US through food recovery and donation programs could help to provide socially acceptable means for low-income urban dwellers to obtain food.     

庞泉沟自然保护区周边农田甲虫群落调查

2006年6~8月,在山西庞泉沟国家自然保护区(111°22'~111°33'E,37°45'~37°55'N)周边的农田(海拔1 600~1 640m),包括玉米田、马铃薯田、莜麦田、胡麻田、大豆田、退耕还林地和荒地,利用巴氏罐诱法,并结合网筛、扫网等采集方法对甲虫群落进行了初步调查,共获标本1980号,隶属13科。优势类群为步甲科Carabi-dae,占总捕获量的74.04%。并结合该地区的农田耕作方式对不同功能类群的种类及数量分布进行分析。     

葛藤主要节肢动物种群种间协变的研究

研究了葛藤节肢动物中10个主要种群的相互关系。采用Pearson积矩相关分析的结果表明：有9个种对呈极显著相关，有3个种对呈显著相关。以叶蝉类和豆突眼长蝽种对间的关联程度最高，为-0．781，二者均取食叶片，存在着激烈的竞争关系；隐翅虫类和叶甲类种对，其相关系数为0．737，两者之间为极显著的正协变，即随着一个种群的数量上升另一个种群的数量也会跟着上升，二者之间表现为捕食关系。采用Spearman秩相关分析的结果表明：有7个种对问呈极显著相关，2个种对呈显著相关。以叶蝉类和豆突眼长蝽种对间的接相关系数最高，为-0．728，积矩相关分析的结论一致；豆突眼长蝽和筛豆龟蝽之间存在着显著的正协变，相关系数为0．408，二者具有某种程度上的依存关系。     

浅议弱势群体报道中人文关怀的表面化倾向

当下,在对弱势群体的报道中坚持"三贴近"原则、体现人文关怀已经成为新闻媒体的普遍共识。但是,在具体操作过程中,由于多方面的原因,这种人文关怀在很大程度上仅仅流于表面形式。本文旨在指出弱势群体报道中人文关怀的种种表面化现象,并就如何对弱势群体进行真正的人文关怀提出建议。     

CIMMYT亚热带优质蛋白玉米自交系的配合力和杂种优势群分析

 采用NCII设计，以齐205、CA375和CA339为测验种，与22个来自于CIMMYT的亚热带QPM自交系配制66个测交组合，经过两年完全区组田间试验，分析22个CIMMYT自交系的配合力和杂种优势群。结果表明，CML181、CML182、CML194、CML179、CML193产量一般配合力较高，在我国的QPM种质改良中有较大的应用价值。来源于群体Pool32、UWO417、WOMTA、CYO和Pool33的自交系与CA375、CA339之间的亲缘关系较近，可划在同一个杂种优势群，定为QA群。来源于群体Pool34和UYO的自交系与齐205的亲缘关系较近，可划在同一杂种优势群，定为QB群。     

栽培种南瓜的品种群研究

作者建议在葫芦科专家Whitaker划分的品种群(cultivar groups)分类基础上,按照果实形状及果形指数为主要指标,结合其他亲缘关系,将3个栽培种南瓜Cucurbita moschata,C.pepo,C.maxima划分成18个品种群,其中2个(C.pepo的观赏瓜品种群,C.maxima的板栗瓜品种群)是作者新划分的。     

陕西玉米杂种优势群划分和杂优模式研究

通过对陕西19个自育玉米品种的种质杂种优势群和杂交优势利用模式的综合分析,结果表明:陕西玉米的种质基础过于狭窄,改良Reid群×塘四平头群和塘四平头群×Mo17亚群是近20年陕西利用的主要杂交优势模式,应继续加强研究和利用,要注意自330亚群,旅大红骨群和其它种群的改良利用,并重新研究改良Reid群×旅大红骨群,塘四平头群×外杂选亚群和塘四平头群×旅大红骨群这三个杂优模式,以突破现有的杂交优势利用模式,才可能使陕西玉米育种水平上一个新台阶。     

Changes in the content of free sulphydryl groups during postharvest wheat and flour maturation and their influence on technological quality

The main aim of this study was to determine the changes in free sulphydryl content during postharvest wheat and flour maturation. The content of free sulphydryl groups was determined from wet gluten over 50 days of wheat postharvest maturation and over 14 days of flour maturation by varying incubation temperatures (30 and 37 °C) and incubation times (0, 45, 90 and 135 min). The amount of free sulphydryl groups increased during postharvest wheat and flour maturation as well as with the increase in temperature and gluten incubation time. The additional aim of this study was to find the interrelation between the content of free sulphydryl groups and selected parameters of technological quality by means of Principal Component Analysis. During wheat/flour maturation, the strengthening of protein structure was observed manifested by the increase in gluten index and Mixolab protein network weakening (C2), and changes in dough resistance as well. The incubation temperature of 37 °C affected the weakening of protein structure manifested by the decrease in gluten index and resistance, and increase in extensibility. Strong differentiation of examined varieties in terms of selected quality indicators was observed upon pre-defined maturation period, probably due to the expression of their intrinsic properties.