重庆市林木种苗生产现状分析

随着我国“六大林业工程”的全面启动以及城市绿化面积的增加，市场对苗木的需求量呈逐年上升趋势。尽快推进林木种苗产业化发展，是适应现代化林业工程造林的需要的，本文通过对重庆市林木种苗生产现状的分析，针对其中存在的问题，提出了促进重庆市种苗产业化的一些建议。     

Einfluß der Entblätterung und des Kartoffelkäferfraßes

Zusammenfassung In Mittelböhmen (340 m Seehöhe) und in Südostböhmen (490 m Seehöhe) wurde der Einfluß der Kartoffelpflanzenentblätterung und des Kartoffelkäferfraßes auf die Kartoffelerträge verglichen. Als Voraussetzung der Auswertung wurden Ermittlungen über das Wachstum der Kartoffelbestände in der Vegetationsperiode und über den Einfluß der Entblätterung auf den Knollenertrag angestellt.1. Es wurden beträchtliche Differenzen im Gewicht der Stauden und in der Beziehung zwischen Blattgewicht und Stengelgewicht an verschiedenen Sorten in Mittel- und Südostböhmen festgestellt. Tabelle 1, 2 und Abbildung 1, 2 und 3.2. Der Einfluß einer totalen Entblätterung der Kartoffelpflanze machte sich zu verschiedenen Zeitpunkten der Vegetationsperiode verschiedentlich bemerkbar. Am Anfang dieses Zeitraums war er schwach; dann stieg er an und erreichte den Höchstwert in der Blütezeit, um daraufhin wiederum abzusinken. Das Ausmaß des Einflußrückgangs hangt einerseits von der Kartoffelsorte, andererseits von den im gegebenen Kartoffelbaugebiet vorherrschenden klimatischen Bedingungen ab. 50 %ige Entblätterung hatte bei der Sorte Sperber eine Ertragserhöhung gegenüber der Kontrollpflanze (um 2,9–26,2 %) zur Folge. Einen ähnlichen Befund veröffentlichten in der UdSSRMolotkowskij (1954) undTschigarew (1963).3. Durch Gegenüberstellung des gesamten Blattflächengewichtes einer Staude zu dem Blattgewicht, das der Kartoffelkäfer im Verlauf seiner larvalen Entwicklung verbraucht, wurden Angaben über die Anzahl der Larven gewonnen die erforderlich ist, um zu verschiedenen Zeitpunkten der Vegetationsperiode Kahlfraß zu verursachen (Tab. 4, Abb. 6). In Milttelböhmen waren zur gänzlichen Abtragung der Blattfläche einer Staude im Juni 11–59 Larven, im Juli 64–82 Larven erforderlich; in Südostböhmen waren im Juni 18 bis 54 Larven und im Juli 195–256 Larven erforderlich. Für die Einschätzung das Ausmaßes des Kartoffelkäferfraßes ist der Zeitraum des Larvenvorkommens von Bedeutung, der durch die Temperaturbedingungen beeinflußt wird. Angesichts der Koinzidenz des Vorkommens von Larven des vierten Stadiums und der frühen Entwicklungsphase der Kartoffelpflanze ist der Fraßschaden des Kartoffelkäfers in wärmeren Lagen wesentlich höher, als in den höher gelegenen und kühleren Gebieten, wo die Larven erst gegen Ende Juli oder Anfang August erscheinen. Zu dieser Zeit ist selbst Kahlfraß nur noch von geringfügigem Einfluß auf den Kartoffelertrag.     

Mice serve as paratenic hosts for the transmission of Caryospora duszynskii (Apicomplexa: Eimeriidae) between snakes of the genus Elaphe

Caryospora duszynskii Upton, Current et Barnard, 1984 was successfully transmitted to snakes of the genus Elaphe by feeding them previously infected mice. Fifty thousand oocysts were orally administered to two mouse strains, BALB/c and Crl:CD-1(ICR)BR, which were subsequently fed to captive-born coccidia-free Elaphe guttata (L.) in two respective independent experiments. Both E. guttata expelled C. duszynskii oocysts in their faeces, beginning on day 18 and 26 post infection (p.i.) and shed oocysts continuously through the end of the experiment, day 230 and 135 p.i., respectively. There were no parasitic stages or lesions in mice, as revealed by histological examination. Experiments proved that rodents serve as paratenic hosts for C. duszynskii. In summary we discuss the life-cycle strategies of Caryospora spp. in reptiles and present three general modes of their development.     

Fine structure of the male reproductive ducts, vagina and seminal receptacle of Cyathocephalus truncatus (Cestoda: Spathebothriidea)

Fine structure of the vas efferens, vas deferens, ejaculatory duct with accessory glands and vagina with seminal receptacle is described in the spathebothriidean tapeworm, Cyathocephalus truncatus (Pallas, 1781) Kessler, 1868. The numerous well-developed prostate glands are characterised by having secretory granules with an electron-dense core surrounded by a matrix of lower electron density. Coalescence of the outer part of the granules with each other takes place in the terminal end of the secretory ducts. The position of prostate glands around the proximal part of the cirrus pouch and terminating in the ejaculatory duct is a characteristic feature of the Spathebothriidea. Up to 20 closely arranged muscle layers make up the muscular cirrus pouch wall with 4 well-developed muscular layers in the ejaculatory duct and cirrus. Both the cirrus and the vagina are covered with the same uniform cone-shaped microtriches. The vagina has an extensive seminal receptacle. All of these structures are well-adapted to insure successful sperm transfer involving ejaculation and storage, probably for both self- and cross-insemination. Cyathocephalus truncatus has a cirrus similar to that of the monozoic, progenetic caryophyllidean, Archigetes sieboldi and well-developed prostate glands like those of the polyzoic pseudophyllidean, Diphyllobothrium latum. The ultrastructural aspects of the male and female reproductive system of C. truncatus are compared with those of other tapeworms.     

Fine structure of the female reproductive ducts of Cyathocephalus truncatus (Cestoda: Spathebothriidea), from salmonid fish

The fine structure of the ovary, ovicapt, oviduct, fertilisation canal, vitelline ducts, vitelline reservoir, ovovitelline duct, ootype and Mehlis' gland, and proximal, middle and distal parts of the uterus of the spathebothriidean cestode, Cyathocephalus truncatus (Pallas, 1781), from salmoniform fish, has been studied for the first time by transmission electron microscopy (TEM). Emphasis was given to characteristics which might shed light on the unclarified phylogenetic position of spathebothriideans, belonging among the most basal tapeworms (Eucestoda). New for cestodes is the finding of a multinucleate cell that plugs the ovicapt lumen. The morphology of the proximal part of the oviduct resembles that of the pseudophyllidean tapeworm Diphyllobothrium latum. After fertilisation in the fertilisation canal, vitellocytes of C. truncatus become associated with fertilized oocytes in the ovovitelline duct. Only one type of Mehlis' gland secretory cell is present. The eggs with electron-dense eggshells containing large pores first appear in the proximal part of the uterus. The middle portion of the uterus has well-developed uterine glands. The distal portion of the uterus has apical microtriches. Ultrastructural data on the female genital system of C. truncatus are compared and discussed with those for other cestodes. However, on the basis of available ultrastructural data it is not possible to conclude whether the Spathebothriidea are phylogenetically closer to the Caryophyllidea or to the Pseudophyllidea.     

Genetic variation within and relationships among five subpopulations of Slovak Thoroughbred

Genetic variation at six microsatellite loci was analysed for five Thoroughbred subpopulations to determine the magnitude of genetic differentiation and the genetic relationships among the subpopulations. Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, with all subpopulations. The genetic diversities and relationships of five Thoroughbred subpopulations were evaluated using six microsatellites recommended by the International Society of Animal Genetics (ISAG). The allele frequencies, the effective numbers of alleles, and the observed and expected heterozygosities were calculated. POPGENE v. 1.31 (Yeh et al., 1997) was used to test for deviations from the Hardy-Weinberg (H-W) equilibrium and to assign F(IS) estimates (Weir, 1990). The utility of microsatellites for evaluating genetic diversity of horses is discussed.     

施肥对红壤稻田硫素演变及供硫能力的影响

研究了进行 15年的不同施肥结构对红壤稻田土壤硫素肥力演变和对土壤供硫能力的影响。结果表明 ,不同施肥结构明显影响土壤全硫、有机硫、无机硫和供硫潜力 (无机硫加部分有机硫 ,40℃KCl浸提 )的演变时间进程以及土壤有机硫的潜在矿化量、矿化常数和矿化半减期 ,稻草还田和有机肥施用有利于土壤硫的积累 ,提高土壤供硫能力 ;连续盆栽幼苗试验结果表明 ,作物吸硫量以稻草还田区 有机肥加化肥区 全化肥区 无肥区 ,与土壤全硫、供硫潜力及土壤硫潜在矿化量顺序一致     

Impact of solar activity on the growth of pine trees: case study

In this work, we focus on the analysis of data for the ring width of two pine tree species: samples of six maritime pines (Pinus pinaster), grown in the north of Portugal, and one sample of Scots pine (Pinus sylvestris), grown in the south of Slovakia. A negative impact of solar activity (SA) was observed on the growth of these pine trees with particularly strong impact in the case of the maritime pines. The width of the annual rings was generally smaller in the years of maximum SA; furthermore, it was found that it is latewood width that is affected whereas earlywood width is not affected; as a corollary, the percentage of latewood also shows a significative negative correlation with SA.     

Field evidence of roof rat (Rattus rattus) faecal contamination of barley grain stored in silos in the Czech Republic

This study represents the first European report of a risk assessment for the contamination of grain by roof rats’ (Rattus rattus L.) faeces in silo structures that have traditionally been considered to be rodent-contaminant proof. In this work, we estimated the rate and magnitude of grain and grain transport silo technology contamination by faeces of R. rattus and identified the routes of entry of rodent faeces into grain stored in silos. We also compared the sizes of rat faeces and stored barley grains to determine whether they could easily be separated using sieves. We found that roof rats were able to heavily contaminate grain surfaces and conveyor belts with faecal deposits during a 3-week observation period. The average contamination rate was 6.90 ± 0.92 faeces/m² (range 0–26 faeces/m²) for grain surfaces and 34.80 ± 8.03 faeces/m² (range 8–87 faeces/m²) for conveyor belts. The size measurements (length, width and surface area) of rat faeces and barley grains showed their high similarity; these results therefore indicate that the physical separation of the two materials using sieves will be problematic.     

加快发展农业循环产业,促进农业面源污染治理

随着我国社会经济的快速发展,农业面源污染已经成为我国环境污染尤其是水环境污染的主要因素,农业面源污染防治和治理工作也越来越得到政府和科技工作者的重视。阐述了当前我国农业面源污染的状况与农业循环产业的内涵。从畜禽养殖业污染控制产业链技术、种植业污染控制产业链技术和农村生活污水污染控制产业链技术体系等方面介绍了农业循环产业链技术的构成,并重点分析了"种养加生"循环一体化生态农业产业园区规划与建设的思路。最后,结合实践提出加快我国农业循环产业体系建设与促进农业面源污染治理的建议,包括政府加强引导、加快科技创新和推广产业园区模式等。