Soil water content,carbon, and nitrogen determine the abundances of methanogens,methanotrophs, and methane emission in the Zoige alpine wetland

Journal of Soils and Sediments - Alpine wetland ecosystems can contribute large amounts of methane (CH4) to the atmosphere; however, their emissions vary with environmental conditions. Microbial...     

Human-driven impacts on marine habitats: A regional meta-analysis in the Mediterranean Sea

Habitat destruction is one of the main threats to environmental integrity. Assessing the consequences of human impacts is crucial both to predict and prevent structural and functional changes of habitats. However, to date almost all studies on marine threats, from regional to global scales, have been entirely qualitative and generally based on little more than expert opinion. We have developed a meta-analytical approach to quantify overall effects of various stressors on different Mediterranean habitat types and to compare the relative importance of different impacts across a range of habitats. We first qualitatively reviewed and synthesized 366 experiments (either manipulative or correlative) collected in the literature. After a selection procedure, we finally quantitatively meta-analyzed 158 experiments. We showed that fisheries (destructive or not), species invasion, aquaculture, sedimentation increase, water degradation and urbanization have negative effects on Mediterranean habitats and associated species assemblages. We also explored the overlap between the impacts identified as important in the Mediterranean and those identified by experts as being important globally, highlighting the inadequacies of relying on expert opinion alone. Finally, we drew attention to the critical lack of empirical knowledge about marine systems in many areas of the Mediterranean, which impedes the implementation of effective conservation measures. Our study is the first to synthesize experimental analyses on human-driven impacts on marine habitats across such a broad geographic scale.     

田间试验的空间变异性及其统计控制

利用空间相关模型和传统方差分析模型对小麦和玉米3个田间试验产量数据进行了拟合与分析。结果表明，3个试验都显著存在空间变异，空间变异方差占据剩余变异方差的83.5%~0.4%；相对于传统随机完全区组分析法，空间相关模型法效应比较的标准误平均降低18.4%~14.2%，分析相对效率平均为1.50~1.36，因而比区组控制空间变异更有效；不同空间相关模型分析的结果呈现出一定的差异。建议利用空间相关模型分析田间试验，并利用Akaike信息准则（AIC）进行最佳空间相关模型选择。     

Wheat embryogenesis and haploid production in wheat × maize hybrids

Summary Embryogenesis was analyzed in wheat × maize hybrids using paraffin sectioning. Embryogenesis in wheat × maize hybrids is different from that in self-pollinated wheat plants. Development of the embryo is not accompanied by the formation of an endosperm. The endosperm nuclei remain free in the cytoplasm, fail to advance into the cellular stage, and degenerate at a later time. The antipodal cells quickly degenerate in the fertilized ovaries of wheat × maize hybrids similar to self-pollinated ovaries. The antipodal cells remain normal in unpollinated ovaries. The pre-embryo will abort if it is allowed to develop on the plant, because of a nutritional shortage in the absence of an endosperm. Therefore, embryo rescue is necessary for haploid production from a wheat × maize hybrids. Haploid polyembryos were obtained from spikelet culture of wheat × maize hybrids. The formation of polyembryos is due to the cleavage of the pre-embryo and the effect of 2,4-D. The frequency of haploid embryo production and plant regeneration is affected significantly by maize genotypes, but not by wheat genotypes. The concentration of 2,4-D affects only the size of the embryo.     

Möglichkeiten und Ansätze für einen Gentransfer bei der Zuckerrübe (Beta vulgaris L.)

Zusammenfassung Durch Übertragung von klonierten Fremdgenen läßt sich die genetische Variabilität der Kulturpflanzen wesentlich erweitern. Insbesondere die Übertragung monogen bedingter Resistenzeigenschaften gelingt bei einer zunehmenden Zahl von Kulturpflanzen. Für die ökonomisch wichtige Zuckerrübe ist ein etabliertes Gentransferverfahren bisher nicht verfügbar. Während Einschleusung, Integration und Expression von Fremdgenen in Zuckerrübenzellen und -gewebe mit einer Vielzahl von Gentransfermethoden erreicht werden können, ist die Regeneration transgener Zuckerrübenzellen zu transgenen Pflanzen bisher nur in wenigen Laboratorien gelungen. Die experimentellen Details wurden bisher nicht publiziert. Die vorliegende Arbeit beschreibt Verfahren, die sich für einen Gentransfer bei der Zuckerrübe eignen sollten. Expression und meiotische Stabilität der transferierten Gene werden behandelt sowie Anwendungsmöglichkeiten des Gentransfers bei der Zuckerrübe kurz diskutiert.

---

Chances and approaches for gene transfer in sugar beet (Beta vulgaris L.)

Summary The genetic variability of cultivated plants can be extensively increased by the transfer of cloned genes. Especially the transfer of monogeneously coded resistancies is established for an increasing number of cultivated plants. A routine gene transfer method is not available for the economicly important sugar beet. Though transfer, integration and expression of foreign genes in cells and tissues of sugar beet can be achieved by a number of gene transfer methods, only a few laboratories succeeded in the regeneration of transgenic cells of sugar beet to transgenic plants. The experimental details have not been published until now. This paper deals with methods which could be useful for gene transfer in sugar beet. Expression and meiotic stability of transferred genes are described and the aims of gene transfer in sugar beet are shortly discussed.

---

(Beta vulgaris L.)

. ë . ÿe . . . ë . , . ë , , .

     

Water acidification by air pollutants in the Federal Republic of Germany

In the Federal Republic of Germany (FRG), airborne pollutants are leading to an increased rate of acidification of aquatic systems. In particular, the upper reaches of rivers and obligotrophic lakes in low-carbonate areas are affected. These areas are a minority of the total number of waterways, but are of great importance for environmental protection. Water acidification cannot be viewed as an isolated issue. In forested areas, it is associated with damage to the entire ecosystem. In lakes and streams, one of the most significant effects of water acidification is fish mortality; several bodies of water in which fish were once plentiful are now devoid of fish. With increasing acidification of the ground water, drinking-water supply problems may also be expected, All measures which can be taken to prevent the entry of pollutants into aquatic systems are preferred to those which merely treat the symptoms of acidified aquatic systems (e.g. addition of lime). The Federal Environmental Agency therefore considers the reduction of air pollutants to be the most effective solution to the problem of acidified of aquatic systems.     

Taxonomy and evolution of cultivated plants: Literature review 1980/1981

Summary Important papers on taxonomy and evolution of cultivated plants published in 1980 and 1981 were compiled and briefly discussed.

---

Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1980/1981

Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1980 und 1981 wurden zusammengestellt und kurz kommentiert.

---

: 1980–1981 .

, 1980 1981 . .

---

---

Herrn Prof. Dr. Dr. h. c. mult. H.Stubbe aus Anlaß der 80. Wiederkehr seines Geburtstages gewidmet.     

Taxonomy and evolution of cultivated plants: Literature review 1988/1989

Summary Important papers on taxonomy and evolution of cultivated plants published in 1988 and 1989 were compiled and briefly discussed.

---

Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1988/1989

Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1988 und 1989 wurden zusammengestellt und kurz kommentiert.

---

: 1988–1989

, 1988 1989 . .

     

Organochlorine and Metal Accumulation in Fish (Phoxinus phoxinus) Along a North-South Transect in the Alps

Southern populations of the European minnow fromremote oligotrophic mountain lakes along an Alpinenorth-south transect accumulated more p,p DDE andPCBs than northern populations. As these semi-volatileorganochlorines predominantly evaporate in warmcountries, higher rates of condensation (deposition)are assumed to occur in the southern slopes of theAlps. The higher accumulation of lead and cadmium insouthern population is rather attributed to geogenicand specific environmental impacts than to atmosphericdeposition. Increasing liver ratios of [glutathionedisulfide]/[glutathione], a potential indicator foroxidative stress, from north to south reflect thegenerally higher toxic load at remote sites at thesouthern edge of the Alps. However, histopathologicalchanges in the liver did not correlate withaccumulated toxicants indicating that deposition doesnot lead to severe lesions but induces specificmechanisms for detoxification.     

Ertragsentwicklung im Dauerversuch Ewiger Roggenbau Halle nach den 1990 vorgenommenen Umstellungen in der Düngung

Yield development in the long-term experiment Continuous Rye Cropping Halle after the changes in the fertilization in 1990 The long-term experiment Continuous Rye Cropping being established 1878 on a degraded chernozem (from sandy loess) includes among others a treatment with application of mineral N only over 112 years in which during the last decades the grain yields ranged about 30% below that on the plots with farmyard manure (FYM) or complete mineral fertilization (NPK). The considerable depletion of available P and K in the respective soil was practically overcome in 1990 by a single application of 200 kg P ha^?1 and 400 kg K ha^?1 and thereafter the exclusive fertilization with mineral N was substituted by a combined application of NPK and FYM. Already in the first year the previous yield decline in comparison to ‘NPK’ or ‘FYM’ had been overcome completely. An additional yield increase, however, could only be realized under conditions especially favourable for yield production, so in 1993 and 1995.