基因型与环境对小麦粗脂肪含量的影响及其稳定性分析

针对生产上小麦粗脂肪含量变化很大的问题,选用参加2005~2006年山东省小麦高肥1组区域试验的11个材料,进行粗脂肪含量及其稳定性分析试验。结果表明:不同品种、不同地点间小麦籽粒粗脂肪含量变幅为1.6%~2.7%,变异系数为4.55~13.28;利用主效可加互作可乘模型(AMMI)对其进行稳定性分析,得知粗脂肪含量存在显著的品种和地点间的互作效应,其中品种的固定效应导致的变异最大,品种和地点互作次之,地点(含重复)效应较小;但不同品种与不同试点的交互作用不同,每个品种(系)对试点都有其特殊的适应性。因此,在小麦产业化种植时,要获得粗脂肪达到标准的商品粮食,既要选准适宜的品种又要注意适宜的种植区域。     

土地利用变化与经济发展关系的理论探讨——以陕北黄土高原为例

目前国际土地利用/覆被变化的研究趋势是强调土地利用变化的综合性研究和土地利用变化与人类活动的协同演进研究。文章统地分析了土地利用变化与产业经济发展之间关系的研究现状、土地利用变化与产业经济发展之间相互作用的理论机制,并以陕北黄土高原为例做了实证分析。可以看出随着社会经济的发展,土地利用目标、利用方式和开发水平的变化以及各产业部门间对土地利用的特殊要求和比较经济效益的差异,导致土地资源在不同产业部门间流转和重分配,从而引起土地利用变化,反之,土地利用变化又会影响区域经济发展水平、经济产业结构、产业布局的演进和变化,二者是一种协同、互动的演进关系。在陕北产业经济类型的转变过程中,土地利用变化的主导机制也由国家计划调配主导型转变为土地利用的经济效益竞争机制主导型、经济效益最优机制及各种政策主导型、经济效益和生态效益最优机制主导型,土地利用变化表现出显著的阶段性特征。     

不同地区小麦梭条花叶病病毒致病力的差异

为了研究小麦梭条花叶病病毒的致病力及其与品种(系)抗病性的互作关系,应用采集自江苏苏州、江宁、兴化、宜兴和六合五个不同地区的小麦梭条花叶病病土,测定了30个小麦品种(系)在上述病土中的发病情况.结果表明,30个小麦品种(系)对梭条花叶病毒的抗性表现为3种类型即广谱抗型、部分抗型和广谱感型;小麦梭条花叶病毒致病力有明显的区域性差异,存在着显著的致病力分化现象;病毒致病力和品种(系)间存在互作效应.     

烟草对复合污染土壤中镉的吸收运转及改良的研究

[目的]研究烟草对重金属镉的吸收运转规律,改良剂对重金属的改良效果,为最终实现人工调控镉活性提供科学依据。[方法]采用盆栽试验,研究了在复合污染的土壤中烟草对重金属镉的吸收规律,5种改良剂对重金属的改良效果以及烟草体内镉与鲜重和其他重金属的相互关系。[结果]烟草对镉的转移系数在2.28～4.60,向上迁移镉元素能力强。烟草属于镉元素耐性作物,随生育期推移不同部位的镉含量呈下降趋势。加入修复剂在不同程度上减少了烟株体内的镉含量。不同部位的镉含量与其鲜重呈显著负相关。在复合污染的条件下,烟株体内镉的含量与其他重金属(Pb、As和Hg)存在着显著正相关关系。[结论]修复剂在减少烟草镉含量的同时也降低了其他重金属的含量,提高了烟草的生物学产量,达到了提高烟草安全品质和产量的双重功效。     

大豆(Glycine max) GmDREB5互作蛋白GmGβ1的筛选及鉴定

从大豆(Glycine max)中克隆了一个与抗逆相关的DREB (Dehydration Responsive Element Binding Protein) 基因GmDREB5。功能分析证明, GmDREB5基因能够显著提高烟草的抗旱性和耐盐性。为了筛选GmDREB5的互作蛋白, 采用酵母双杂交系统以GmDREB5蛋白73~226位氨基酸区段为诱饵筛选干旱处理的大豆cDNA文库, 发现一个互作蛋白含有保守的WD40结构域, 与棉花(Gossypium hirsutum)和水稻(Oryza sativa)的G蛋白β亚基分别具有61%和52%的同源性, 说明蛋白可能是一类新的大豆G蛋白β亚基, 将其定名为GmGβ1。将GmDREB5与GmGβ1共转化酵母菌株AH109, 转化的酵母能够在四营养缺陷型培养基上(SD/ trp- leu- his- ade-)正常生长, 而对照不能生长; 同时, 共转化的酵母能够激活LacZ报告基因的表达, 证明GmGβ1与GmDREB5之间存在相互作用。表达特性分析表明, GmGβ1基因受干旱、低温、高盐等胁迫和激素ABA处理的诱导而表达, 证明GmGβ1不仅参与植物对非生物胁迫的响应, 同时参与对GmDREB5蛋白水平的调控。     

水稻条纹病毒编码蛋白在灰飞虱体内的检测及其与CP体外结合研究

 【目的】检测灰飞虱体内由水稻条纹病毒（RSV）编码的外壳蛋白（CP）、病害特异性蛋白（SP）,以及非结构蛋白NS2、NS3和NSvc4等5种蛋白以及病毒粒子CP与SP、NS2、NS3、NSvc4的体外结合,为进一步研究水稻条纹病毒与其介体昆虫互作提供有用信息。【方法】提取高带毒灰飞虱（Q家系）总蛋白,用免疫方法检测昆虫体内CP、SP、NS2、NS3和NSvc4等5种重要蛋白的表达以及病毒粒子CP与SP、NS2、NS3、NSvc4的体外结合情况。【结果】结果表明在带毒灰飞虱体内以上5种蛋白都能检测到,而且CP含量最高,NSvc4、SP、NS3、NS2含量依次降低;用体外原核表达后纯化的蛋白进行了RSV粒子CP与SP、NS2、NS3、NSvc4的体外结合实验,实验结果表明病毒粒子CP与SP、NSvc4之间存在体外结合关系。【结论】检测结果为灰飞虱作为RSV的昆虫寄主并且可以在其体内增殖的结论提供了支持,表达差异表明病毒编码蛋白在介体灰飞虱体内可能存在着一定的协调关系;病毒粒子与SP的结合为前人关于CP与SP可能共同作用于叶绿体进而影响症状的严重度的报道又提供了一个新的证据,病毒粒子与NSvc4之间存在体外结合关系,也为NSvc4可能作为运动蛋白通过与CP的互作以及诱导病毒在胞间运动需要CP的辅助提供了佐证。     

小麦磷效率相关性状配合力与环境互作分析

为了研究小麦磷效率相关性状的配合力与环境互作,随机选用8个亲本,组配成28个双列杂 交组合在两种环境条件下进行试验。结果表明,所有4个性状的一般配合力与环境互作和特殊配合 力与环境互作均达极显著水平;子粒全磷含量以环境效应的作用最大,非加性效应与环境互作次之; 叶片和茎秆磷含量以及磷素利用效率以非加性效应与环境互作为主,非加性效应次之;除子粒全磷 含量外,其它3个性状的一般配合力和特殊配合力稳定性都较低,在50％以下。最后讨论了配合力的 测度和不同器官磷含量与磷素利用效率的关系。     

放牧生态系统草畜间供与求的动态特征

随着季节的变化,牧草生产改变着家畜食料及转化摄取食料的能力,在春、夏、秋季绵羊食物的粗蛋白质含量分别高于草地牧草的15.99%、0.43%和2.71%。在冬季两者的含量几乎相等。但粗蛋白质食入量在春季比夏、秋、冬季分别多21.98%、40.40%和352%。干物质食入量在秋季比夏、冬、春季分别多17.64%、38.33%和72.23%,从而导致冬、春两季绵羊因食物不足而体重下降。     

Specific and General Adaptation and Yield Stability of Wheat (Triticum aestivum L.) Genotypes

Mean grain yield performance of 12 wheat and one triticale genotypes were measured at four locations over four consecutive years, using a randomized complete block design with four replications. The genotypes used were commercial cultivars and advanced lines from different wheat breeding projects located in different areas in Iran. Two locations were in semiarid regions and the other two locations in the temperate zones. The combined analysis of variance indicated highly significant genotype-environment (GE) interactions. From combinations of locations and years three sets of environments were generated. Set I and set II, each, consisted of eight environments (two locations and four years) representing semiarid and temperature environments, respectively. Set III consisted of 16 environments including both semiarid and temperate conditions. Set I and set II were used to measure specific adaptation of the genotypes while set III was employed for measuring general adaptation. The methods of Eberhart and Russell (1966) were used for partitioning GE interactions. The mean square associated with the heterogeneity of regression was highly significant under all sets of environments. These observations indicated that a major part of GE interaction could be accounted for by differences in the regression of the individual genotypes. All the genotypes had significant regression mean square under set I, set II, and set III environments, with the exception of two genotypes under set II. However, mean yields, regression coefficients, and the mean squares associated with deviation from regression greatly varied over the sets of environments. Only three genotypes, a commercial cultivar and two new advanced line, were identified as having specific adaptation and yield stability to semiarid environments. Among all the genotypes, only a commercial cultivar was identified as adapted and stable to temperate conditions. Two of the three genotypes which were adapted to semiarid environments also showed general adaptation to set III environments. However, the mean yield of these two genotypes under semiarid conditions (set I) were significantly greater than their respective mean yields under set III environments. Thus, wider adaptability was compensated by lower mean yield. The present study indicates that, while a wide range of environments is necessary and recommended for measuring general adaptation reactions and yield stability of various genotypes, one should not ignore the possibility of finding some genotypes with specific adaptation to specific environments and thus maximizing yield production. Stable genotypes with general of specific adaptation should be utilized in breeding projects in order to develop even more desirable lines.     

Cytoplasmic and nuclear genetic components of membrane stability of winter wheat plants exposed to sub‐zero temperatures

Winter wheat (Triticum aestivum L.) is seeded in the autumn and harvested the following summer, and therefore, must survive multiple episodes of subfreezing temperatures throughout the winter months. Cellular membrane stability following exposure to subfreezing temperatures contributes to the ability to survive these episodes. This study investigated the inheritance of the ability to tolerate subfreezing temperatures with a seven‐parent diallel cross analysis of cellular membrane integrity as measured by electrolyte leakage after exposure to ?10 or ?14 °C. Significant differences in membrane stability were found among the parent lines. The inheritance of the freezing tolerance as measured by electrolyte leakage was complex and characterized by significant additive, dominant and cytoplasmic effects. General combining ability, indicative of additive genetic effects, were significant at both test temperatures, but accounted for 25.5% of the variance at the ?10° C test temperature, and only 4% of the variance at the ?14 °C test temperature. Specific combining ability, indicative of genetic dominance effects, were significant at both test temperatures, but accounted for only 14.6% of the variance at the ?10 °C test temperature, and 38% of the variance at the ?14 °C test temperature. Reciprocal (cytoplasmic) effects were significant and accounted for about 20% of the variance at both test temperatures. Cytoplasmic effects contributing to greater membrane stability were especially apparent in the cultivar Tiber when crossed to Masami, Lewjain, or Hatton. These results suggest that efforts to improve freezing tolerance are complicated by differing gene action at different test temperatures and also may benefit from identifying specific combinations of nuclear and cytoplasm sources that are most conducive to membrane stability following freezing.