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71.
We have studied the seasonal relationship between growth and circulating growth hormone (GH), hepatic GH-binding and plasma insulin-like growth factor-I immunoreactivity in gilthead sea bream,Sparus aurata. The seasonal increase in plasma GH levels preceded by several weeks the summer increase in growth rates. In contrast, a marked increase in hepatic GH-binding with a high degree of endogenous GH occupancy was found during the period of maximum growth which suggests an enhanced sensitivity of liver to GH action. Thus, circulating levels of immunoreactive IGF-I, probably derived from the liver in response to GH action, were positively correlated with growth throughout the experimental period although a consistent relationship between growth and circulating GH was not found. In spite of this, we consider that, in gilthead sea bream, as in several other teleosts, the availability of endogenous GH can limit growth. Thus, under environmental conditions of suboptimal growth, a single intraperitoneal injection of recombinant rainbow trout GH (rtGH) induced over the dose range tested (0.75, 1.5, 3 μg g BW−1) an increase in plasma IGF-I-like immunoreactivity comparable to that seen during the period of maximum growth.  相似文献   
72.
This article documents the impact of site conditions and farming practices on the occurrence of rare and endangered weeds on arable land in the Czech Republic. A survey was conducted between 2006 and 2008 in winter cereals, spring cereals and wide‐row crops. The relationship between the occurrence of plants and explanatory factors was analysed using a multivariate analysis to calculate species frequencies in different types of farming, crops and altitudes. In total, 290 relevés were recorded, with a total number of 172 weed species. Nineteen weeds, classified as rare and endangered species according to the national Czech list, were identified in 106 relevés. The highest effect on the occurrence of rare and endangered weed species was observed for altitude. Almost half of the recorded endangered and rare species belonged to the thermophilous weed vegetation typical for cereals on basic soils. A higher occurrence of endangered species has been confirmed for organic farming, where the sum of frequencies was 4.5 times higher than in conventional farming. Field size was not included in our analyses, but could be a factor affecting weed assemblages. The highest frequency of rare species was recorded in spring cereals, followed by winter cereals and wide‐row crops. Higher numbers were identified within fields with higher weed coverage. Lower farming intensity and diversified farming systems at higher altitudes provided better conditions for the occurrence of rare species than intensively farmed lowlands.  相似文献   
73.
74.
A neutral peroxidase isozyme (pI 7.2) from turnip roots (TNP) was purified to homogeneity and partially characterized. TNP is a monomeric glycoprotein with 9.1% carbohydrate content and a molecular weight of 36 kDa. Optimum pH values for activity using 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and guaiacol as H donors were 4.5 and 5.5, whereas the K(m) values were 0.7 and 3.7 mM, respectively. The ABTS K(m) was approximately 7 times higher than that reported for basic commercial horseradish peroxidase (HRP-C). TNP retained approximately 70% activity after 11 min of heating at 65 degrees C, whereas the activation energy for inactivation (132 kJ/mol) was higher than or comparable to that of other peroxidases. The low ABTS K(m) and high specific activity (1930 units/mg) gave a high catalytic efficiency (500 M(-1) s(-1)). These properties make TNP an enzyme with a high potential as an alternative to HRP in various applications.  相似文献   
75.
水稻许多重要农艺性状都是数量性状,水稻遗传改良的大部分工作就是改良这些数量性状。1980年以后,随着分子标记的出现,水稻高密度遗传连锁图谱的大量绘制,各种作图群体的迅猛构建,功能强大的各种统计学软件的快速开发,全基因组序列测序的完成,特别是多个QTL精细定位和先后克隆,使得我们对数量性状的认识得到了长足的进步,QTL的研究正在走进新时代。  相似文献   
76.
The occurrence of d-amino acids in commercial ripe olives, a well-known sterilized alkali-treated product, was investigated by high-performance liquid chromatography (HPLC) with precolumn automatic derivatization. Absolute amounts of D-amino acids were in total 18.6-38.2 mg/100 g edible portion. The major D-amino acids were D-aspartic acid, D-glutamic acid, D-serine, and D-leucine. Furthermore, to evaluate the effects of sterilization time and olive pH on amino acid racemization, a simulated processing of green ripe olives was carried out. Serine (both free and bound form) was the most-racemized amino acid after heat treatment. Sterilization (15-35 min at 121 degrees C) increased the racemization values of both free and protein-bound amino acids, although in case of protein-bound phenylalanine the increase was not statistically significant. With an increase of pH from 8 to 10 units, the racemization values of all amino acids increased significantly, except for free forms of aspartic and glutamic acids. In general, the effects of the sterilization time and olive pH on total concentration (L + D enantiomers) of each amino acid were also significant.  相似文献   
77.
Zusammenfassung Die Nebenwirkung von Insektiziden auf die Lebensgemeinschaften der Kulturen ist desto tiefer und durchgreifender, um je dauerhaftere Kulturen es sich handelt. Obwohl in den Agrocoenosen Selbstregulation und Gleichgewicht fehlen, bestehen hier doch bedeutende quantitative Zusammenhänge zwischen Schädlingen und ihren Räubern und Parasiten. Diese Zusammenhänge werden an Beispielen von Hauptschädlingen der Hackfrüchte dargestellt.Es wird vorgeschlagen, schon bei der Prüfung von Insektiziden die Wirkungsweise des Insektizides auf die wichtigsten natürlichen Feinde von Schädlingen zu untersuchen.
Summary In the agrocoenoses the intensity of the side effects of insecticides is in proportion to the degree of permanency of the cultures. Although the agrocoenoses do not represent a self-regulated and balanced ecological unit, there are, however, quantitative correlations between the pests and their predators and parasites. These interrelations are demonstrated by examples from the main pests of the root crops.It is suggested that the effects of insecticides on the most important natural enemies of the pests be examined already in the testing stage of the insecticides.

Résumé Les effects secondaires des insecticides sur les agrocénoses sont d'autant plus importants et actifs qu'il s'agit de cultures permanentes. Bien que des régulations spontanées et l'equilibre manquent dans les agrocénoses, il existe done d'importants rapports quantitatifs entre les insectes nuisibles et leurs prédateurs et leurs parasites. Ces rapports seront illustrés par des exemples des principaux insectes nuisibles aux plantes sarclées.On propose d'étudier, dès la mise à l'essai des différents insecticides, le mode d'action de chaque insecticide sur les ennemis naturels les plus importants des insectes nuisibles.


mit 5 Fig.

Vortrag, gehalten am 4. September 1967 auf dem VI. Internationalen Pflanzenschutzkongress in Wien.  相似文献   
78.
The resistance genes Lr9, Lr24, Lr25, Lr29, Lr35 and Lr37, which were not previously utilised in Hungary, have been incorporated into four Martonvásár winter wheat cultivars using marker-assisted selection with PCR-based markers. In the course of a backcross programme, the genes were transferred into Martonvásár wheat varieties and various BC generations were produced. Work aimed at pyramiding resistance genes is currently underway in Martonvásár, and plants containing the gene combinations Lr9 + Lr24, Lr9 + Lr25 and Lr9 + Lr29 are now available. From the BC2F4 generation of the ‘Mv Emma’*3/’R.L.6010’ combination (‘R.L.6010’ is the donor of the Lr9 gene) 287 lines were tested for leaf rust resistance in an artificially inoculated nursery. A co-dominant primer combination was designed to identify both resistant and susceptible offsprings. The results of resistance tests and molecular marker detection agreed in most cases. Designated leaf rust resistance genes were identified with molecular markers in wheat varieties and breeding lines. The Lr26 and Lr34 resistance genes occur frequently in the Martonvásár gene pool, and the presence of the Lr37 gene has also been detected in a number of Hungarian genotypes.  相似文献   
79.
Ohne Zusammenfassung  相似文献   
80.
Results of a comprehensive study are presented on the spatial and depth-related distribution of persistent organic pollutants (POPs) in sediments of the Brno reservoir, Czech Republic. Based on sedimentological observations, three major historic phases were identified related to the evolution of the depositional environment, flow rate, and material input. Data on organic carbon, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides showed specific distribution patterns in a 3-m-deep core. The analysis of the depth trends of the geochemical data combined with sedimentology made it possible to distinguish between remote sources of the pollutants, early weathering alterations of POPs, transport by river associated with organic matter as sorbent on one hand, and local sources weakly related to lithology on the other hand. The integrated sedimentological and environmental geochemical archive provided an improved dynamic view of the pollution in historical terms.  相似文献   
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