Genetics of seedling and adult plant resistance to net blotch (Pyrenophora teres f. teres) and spot blotch (Cochliobolus sativus) in barley

Net blotch (caused by Pyrenophora teres f. teres) and spot blotch (Cochliobolus sativus) are important foliar diseases of barley in the midwestern region of the USA. To determine the number and chromosomal location of Mendelian and quantitative trait loci (QTL) controlling resistance to these diseases, a doubled haploid population (Steptoe/Morex) was evaluated to the pathogens at the seedling stage in the greenhouse and at the adult plant stage in the field. Alleles at two or three unlinked loci were found to confer resistance to the net blotch pathogen at the seedling stage depending on how progeny exhibiting an intermediate infection response were classified. This result was corroborated in the quantitative analysis of the raw infection response data as 2 major QTL were identified on chromosomes 4 and 6M. A third QTL was also identified on chromosome 6P. Seven QTL were identified for net blotch resistance at the adult plant stage and mapped to chromosomes 1P, 2P, 3P, 3M, 4, 6P, and 7P. The 7 QTL collectively accounted for 67.6% of the phenotypic variance under a multiple QTL model. Resistance to the spot blotch pathogen was conferred by a single gene at the seedling stage. This gene was mapped to the distal region of chromosome 1P on the basis of both qualitative and quantitative data analyses. Two QTL were identified for spot blotch resistance at the adult plant stage: the largest QTL effect mapped to chromosome 5P and the other mapped to chromosome 1P near the seedling resistance locus. Together, the 2 QTL explained 70.1% of the phenotypic variance under a multiple QTL model. On the basis of the chromosomal locations of resistance alleles detected in this study, it should be feasible to combine high levels of resistance to both P. teres f. teres and C. sativus in barley cultivars.     

Specific molecular marker of the genes controlling linolenic acid content in rapeseed

In rapeseed, which is an agronomically important oilseed, variation in the linolenic acid content of the oil has been obtained through chemical mutagenesis treatment. Conventional breeding of this quantitative trait, however requires specific molecular markers. By means of biochemical experiments, we have established that the induced variation in linolenic acid content is associated with the fad3 gene encoding the microsomal ¹⁵ desaturase. Using a pair of primers specific to this gene and a doubled haploid progeny derived from a low linolenic x high linolenic acid F₁hybrid, we have identified a polymorphism of the fad3 alleles between the low- and the high-linolenic acid genotypes. The structure exon/intron of the fad3 DNA sequence seems to be very similar to that of the Arabidopsis fad3 gene. The choice of the primer pair allows specific amplification of one of the two rapeseed fad3 genes. The value and contribution of specific markers to conventional plant breeding is discussed.     

Vegetation differences caused by pine vole mound building in subalpine plant communities in the Spanish Pyrenees

The influence of mediterranean pine vole (Microtus (Terricola) duodecimcostatus) mound-building activity in two Western Spanish Pyrenees plant communities (Mesobromion erecti and Festucion eskiae-Nardion strictae) were studied. The plants colonizing the gaps in these areas are different in the two cases considered. The plant composition of surrounding plant communities seems to be the main factor in revegetation. Mound-building activity changes the species' relative frequency and life-form spectrum, decreases the monocytyledonous/dicotyledonous ratio and increases diversity by diminishing the presence of dominant plant species.Abbreviations ME Mesobromion erecti - FN Festucion eskiae-Nardion strictae - (monocots) Monocotyledonous - (dicots) Dicotyledonous     

陆地表层系统动力学机制研究Ⅰ．──陆地表层系统和动力学方程

对陆地表层动力学的研究对象、研究内容及其基本理论方法作了阐述,以多学科综合的观点定义了陆地表层系统,包括时空尺度范围的约定、状态变量的选择、物质循环以及外界因子等的讨论;依据物质和能量守恒原理建立了陆地表层系统的非线性控制方程组,表述了各圈层之间物质循环和能量循环过程、反馈关系及其动力学联系;讨论了控制方程组的整体运作功能以及人类活动对陆地表层系统的影响．     

长白山劲松林场植物群落的分类和排序

将长白山白河林业局劲松林场的５４块样地用聚类分析法划分成６个植被类群,再用ＰＣ－ＶＴＡＢ程序中经过改进的Ｂｒａｕｎ－Ｂｌａｎｑｕｅｔ学派的植被排表分析法进行综合,产生了鉴别概要表,为各个等级的植被类群筛选出诊断种。此外,还用鉴别种地样地记录进行主成分分析,以验证诊断种的有效性,结果表明,ＰＣ－ＶＴＡＢ中的植被排表分析法是筛选鉴别种的有效方法,而鉴别种以显著地提高植被分析和排序的质量。     

苏芸金杆菌发酵生产工艺改进研究：Ⅰ芽孢接种和营养体接种比较

苏芸金杆菌液体深层发酵中用营养体接种二级发酵工艺和用二级发酵初期培养物作种子进行三级发酵工艺是可行的。试验结果表明：二级发酵种子罐营养体最佳移种茵龄为９ｈ左右,此时营养体数量多、整齐、染色均匀,显微镜下菌体有折光点存在,三级接种营养体菌龄约为４ｈ左右,菌体数量多,同步率高,少量染色不均匀。发酵液含菌数和发酵产品毒力均达到芽抱接种相同水平,但生产周期明显缩短４－５ｈ,因此相应提高发酵罐生产能力２０％。     

南京紫金山现代植被表土孢粉的初步研究

 选择南京紫金山现代植被进行植被调查和表土孢粉分析。结合中国东部不同气候带下的几个地点表土孢粉分析,把孢粉百分含量、孢粉组合及孢粉优势种、标志种与植被的各项参数进行对比,找出植被与孢粉之间的关系。为恢复古植被、古生态和古气候提供科学依据。     

川中丘陵人工幼草本层动态研究初报

 川中丘陵为长江中上游防护林体系建设重点区域。本文对荒山荒坡种植柏木、桤木及补播牧草后的植被动态进行了研究。结果表明：在幼林期,随树木郁闭度的增加,林下草本植物的盖度也随之提高,生物量增大,林草之间具良好的共生效益;补播草种可大大加快幼林地植被覆盖。     

鼎湖山植被演替过程中椎栗和荷木种群的动态

 森林群落的演替过程,是以各优势种群的动态为其表现特征的。本项研究系统地研究了鼎湖山森林植被演替过程各优势种群的动态。本文研究演替顶极建群种椎栗和荷木等阳生性种群的动态,结果表明其生态位宽度在演替过程中由入侵针叶林起逐渐开始增大,至阳生性为优势常绿阔叶树阶段时为最大,此后渐渐下降,但不会下降为零。在其演变过程中,这些阳生性的种群格局由集群分布演变为趋于随机分布;其与早期先锋种马尾松树种的生态位宽度重叠值和种间联结值由高向低转变,而与中生性树种却有较高的生态位重叠值和种间联结值,但这两方面的值在后期有减弱的趋向。这些结果一方面说明该种群的先锋特性,另一方面也说明由于成熟群落的循环更新使群落结构出现不均匀与镶嵌,使这些阳生性先锋种群 在演替的后期仍以一定数量存在。     

Comparison of axonemal proteins from two kinds of Tetrahymena. I. Different characteristics of dyneins in heat stability

Tetrahymena thermophila could still swim after incubation of the cell body at 40°C for 30 min, whereas Tetrahymena pyriformis did not show any motility after the treatment. Turbidity measurements revealed that axonemes of T. pyriformis lost ATP-dependent sliding activity by the heat treatment, whereas those of T. thermophilia still had the activity under the same conditions. In connection with this difference in susceptibility to high temperature, the biochemical characteristics of dyneins were compared between the two species of Tetrahymena. Axonemal dyneins from the two species had significant vanadate-sensitive ATPase activity even after the heat treatment. Native gel electrophoresis and the following two-dimensional electrophoresis showed that the outer arm dynein of T. thermophilia is more stable in maintaining native configuration than that of T. pyriformis against the heat treatment, although both treated dyneins keep three (α, β and γ) subunits. Analysis by peptide mapping demonstrated that β- and γ-subunits of the outer arm dynein are considerably different in amino acid sequences between the two species. These results imply that dynein of T. thermophilia changed their amino acid sequences and biochemical characteristics to adapt to high temperature.