地下部分隔对蚕豆/玉米间作氮素吸收和土壤硝态氮残留影响

利用田间试验,探讨了地下部分隔对蚕豆/玉米间作氮素吸收和土壤硝态氮残留的影响,结果表明:蚕豆/玉米间作,蚕豆不分隔条件下籽粒和秸秆吸氮量比分隔分别增加20 10%,34 43%;玉米不分隔条件下籽粒吸氮量与分隔近似,但秸秆吸氮量比分隔减少13 04%;蚕豆和玉米不分隔条件下土壤硝态氮累积量都高于分隔。蚕豆/空带间作,蚕豆不分隔籽粒吸氮量高于分隔,但土壤硝态氮累积量没有差异。空带/玉米间作,地下部分隔与否,作物吸氮量和土壤硝态氮累积量都没有差异。     

Effects of forest cover type and ratio changes on runoff and its components

Changes in forest cover can affect not only the total runoff from a watershed, but also the runoff components (e.g., surface runoff, interflow, groundwater flow). In this study, based on the WetSpa model simulation method and the recursive digital filtering (RDF) method, the Banchengzi watershed in the mountainous region of Beijing, China, was selected to investigate how changes in forest cover type and cover percentage affect total runoff, surface runoff, interflow, and groundwater flow through scenario settings. Our results show that the difference between the WetSpa model and the RDF method for separating runoff components is small, with only 4.7% and 0.4% difference between the calibration and validation periods. Total runoff in different forest types followed the order shrub forest > coniferous forest > mixed forest > broadleaf forest. Regarding runoff components, the proportions of baseflow (sum of interflow and groundwater flow) to total runoff were 61.1% and 60.8% for broadleaf and mixed forests, which was significantly higher than those of 53.0% and 43.1% for coniferous and shrub forests. However, the proportion of shrub forest baseflow was high in wet years, and that of broadleaf forest baseflow was high in normal and dry years. The proportions of interflow and groundwater flow from various forest cover types to total runoff continued to increase with increasing forest cover rate. Our results have important implications for the implementation of afforestation projects and forest conservation programs, contributing to water resource regulation and ecosystem protection in watersheds.     

Investigation of sprout-growth-inhibitory compounds in the volatile fraction of potato tubers

Summary The fractionation of volatile substances produced by potato tubers using gas liquid chromatography (GC) was followed by assaying fractions for sprout-growth-inhibitory activity using a potato shoot-tip bioassay. A region of the chromatogram having high sprout-growthinhibiting activity was identified and subsequently further resolved by capillary column GC into several peaks, 5 of which gave well-defined mass spectra. Two of these compounds were identified as diphenylamine and dibenzothiophene. Diphenylamine showed high growthinhibitory activity in the bioassay and was shown to be an effective sprout suppressant for whole tubers. The compound was tested in small-scale storage trials using up to 0.5 tonne of potatoes to assess its potential as a sprout suppressant.

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Zusammenfassung Das Vorkommen natürlicher Keimwachstumshemmer in der flüchtigen Fraktion von Kartoffelknollen ist erneut untersucht worden. Die gesamte flüchtige Fraktion, die eine starke Hemmwirkung in einem Kartoffeltriebspitzen-Biotest (Tab. 1) zeigte, wurde mit Hilfe der Gaschromatographie auf einer mit Carbowax 20M gefüllten S?ule abgetrennt. Die chromatographische Abtrennung wurde in 3 Fraktionen aufgeteilt (Abb. 1), die auf ihre wachstumshemmende Wirksamkeit untersucht wurden (Tab. 2). Dabei zeigte eine Fraktion (F3) eine Hemmwirkung des Keimwachstums. Diese Fraktion (Abb. 1) wurde erneut chromatographiert und in drei Unterfraktionen geteilt, die einzeln auf Keimwachstumshemmung untersucht wurden. Die Hemmwirkung wurde den Unterfraktionen F3a und F3b (Tab. 2) zugeordnet. Sie wurden vereinigt und erneut auf einer Kapillars?ule mit Carbowax 20M chromatographiert, wobei mehrere Gipfel auftraten (Abb. 2). Fünf davon ergaben gut definierte Massenspektren. Zwei dieser Verbindungen wurden als Diphenylamin (DPA) und Dibenzothiophen identifiziert (Abb. 3). Die chemische Natur dieser Verbindungen wurde an Hand authentischer Proben dieser Substanzen best?tigt, die identische Retentionszeiten und Massenspektren ergaben. DPA und Dibenzothiophen wurden dem Biotest unterworfen (Abb. 4). Dabei erwiesen sich beide Verbindungen als wirksam, DPA zeigte dabei jedoch die gr?ssere Aktivit?t. Für eine 50%ige Wachstumshemmung im Biotest waren etwa 10×10⁻⁵ mol/l DPA erforderlich, aber 8×10⁻⁵ mol/l Dimethylnaphtalen und 6×10⁻⁵ mol/l 3-Methyldiphenylamin (Abb. 5). Weil DPA ein verh?ltnism?ssig wirkungsvoller Hemmstoff für das Keimwachstum ist und auch bereits in einigen Anwendungen als Lebensmittelzusatz zugelassen ist, wurde es auf seine F?higkeit, die Keimung zu unterdrücken, untersucht. Wenn DPA direkt auf die Knollenoberfl?che gebracht wird, hemmt es die Keimung sehr wirkungsvoll (Tab. 3). Für eine 50%ige Hemmwirkung sind weniger als 5 ppm erforderlich, wenn die Substanz entweder in Aceton gel?st und versprüht wird oder wenn sie auf die Knollenoberfl?che direkt aufgetragen wird. Konzentrationen von 20 ppm schr?nken die Keimung nahezu vollst?ndig ein. Wegen der verh?ltnism?ssig geringen Flüchtigkeit der Verbindung gibt es jedoch Probleme, sie auf den Kartoffelknollen im Lager zu verteilen. Es wurden 2 Applikationsmethoden geprüft (Tab. 4 und 5). Wurde DPA in Acetonl?sung als Nebel ausgebracht, dann war die Verteilung der Substanz unzul?nglich und die Keimunterdrückung ungleichm?ssig. Bei der zweiten Methode wurde die Substanz mit Tonerde gemischt und über die Knollenoberfl?che gest?ubt. Sie war vielversprechend, eine Weiterentwicklung dieser Methode ist jedoch erforderlich. Insgesamt weisen die Ergebnisse darauf hin, dass DPA wirkungsvoll die Keimung unterdrückt, und dass die Notwendigkeit besteht, verbesserte Applikationsmethoden für die Anwendung im Kartoffellager zu entwickeln. Die Beobachtung, dass die Ansammlung flüchtiger Substanzen um die Kartoffelknolle zur Keimhemmung führt, wird im Hinblick auf die vorliegende Arbeit und auf die Ergebnisse früherer Autoren diskutiert. Es wird auch die M?glichkeit erwogen, dass die Wirkung Interaktionen zwischen zwei oder mehreren wachstumshemmenden flüchtigen Substanzen einschliesst.

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Résumé La présence d'inhibiteurs de la germination dans la fraction volatile des tubercules de pomme de terre a été de nouveau recherchée. La fraction volatile totale, ayant une haute activité inhibitrice dans un essai biologique sur extrémité de pousses (tabl. 1), a été isolée par chromatographie gaz-liquide sur colonne de Carbowax 20M. Trois fractions ont été séparées à partir de cette dernière (fig. 1) et leur activité inhibitrice a été étudiée (tabl. 2); une fraction (F3) a montré une action inhibitrice sur la croissance des germes. Cette fraction (fig. 1) a donné trois sous-fractions par chromatographie dont F3a et F3b (tabl. 2) qui possédaient l'activité recherchée. Ces deux fractions ont été mélangées et séparées de nouveau par chromatographie sur colonne capillaire de Carbowax 20M (fig. 2). Il en est résulté un certain nombre de pics dont 5 avaient un spectre bien défini. Deux substances ont été identifiées comme étant la diphénylamine (DPA) (fig. 3) et le dibenzothiophène. L'anologie chimique de ces composés a été confirmée à l'aide des produits purs qui donnaient le même temps de rétention et le même spectre que les substances alors inconnues. DPA et dibenzothiophène ont été utilisés dans un essai biologique (fig. 4) et possédaient quelque activité, celle-ci étant beaucoup plus importante pour le DPA. Environ 10×10⁻⁵ mol/l de DPA sont nécessaires pour inhiber la croissance à 50% dans l'essai biologique alors que 8×10⁻⁵ mol/l et 6×10⁻⁵ mol/l respectivement de diméthylnaphthalène et de 3 méthyldiphénylamine (fig. 5) ont le même effet. Comme le DPA est un inhibiteur efficace, déjà accepté en tant qu'additif alimentaire dans quelques appli ations, il a été testé comme inhibiteur de germination. Appliqué directement à la surface des tubercules, le DPA est un inhibiteur de germination très efficace (tabl. 3). Moins de 5 ppm sont nécessaires pour inhiber 50% de la germination s'il se trouve en solution dans l'acétone et est appliqué par pulvérisation ou au pinceau; à la concentration 20 ppm, il provoque une inhibition presque totale de la germination. Cependant, ce produit étant peu volatile, il pose un problème de dispersion à l'intérieur des tubercules en conservation. Deux méthodes d'application ont été essayées (tabl. 4 et 5); l'application du DPA par brumisation n'a pas donné de bons résultats car sa répartition n'a pas été régulière et le taux d'inhibition n'était pas homogène; mélangé à de l'alumine et appliqué par poudrage à la surface des tubercules, il a donné des résultats encourageants mais qui nécessitent encore des études. En conclusion, le DPA s'avère être un inhibiteur de germination efficace qui demande toutefois encore des recherches sur la méthode adéquate pour obtenir sa dispersion dans les locaux de conservation. Les effects de l'accumulation de substances volatiles autour des tubercules sur l'inhibition de la germination sont discutés en relation avec le présent travail et les découvertes des premiers chercheurs. La possibilité que ces effets mettent en jeu deux inhibiteurs de croissance ou plus est prise en considération.

     

The complete elimination of vicine and convicine from the faba beans by combinations of genetic selection and processing techniques

Out of sixty six faba bean (Vicia faba) cultivars and genotypes grown locally in Egypt and in Syria, the genotype 123 A/45/76 proved to be lowest in its vicine and convicine contents. Furthermore, soaking of this bean variety in 1% acetic acid at 40°C for 48 h resulted in reducing the total vicine and convicine contents of the beans by 90%. Home-made faba beans processing including soaking prior to cooking as in the case of bean cakes resulted in considerable reduction of the vicine and convicine contents by 56 and 34% respectively.     

加强知识产权保护 促进农业快速发展

随着高新技术的迅速发展，知识产权在国民经济发展中的作用日益受到各方面的重视，如何运用知识产权法律制度保护农业技术创新，促进农业快速发展已成为目前科研单位刻不容缓的迫切任务。介绍农业知识产权保护的法律依据和保护范围，并提出加强知识产权保护工作的几点建议。     

The methods to consolidate scattered tenanted lots into large rice paddy lots by the land consolidation projects in Japan

Today in Japan, agricultural productivity of rice cropping farmers is low. In order to get sufficient agricultural productivity, Japanese government is encouraging enlarging core farmers' farm sizes to 10–20 ha by borrowing farm lots from retiring farmers of small farms and carrying out the land consolidation projects to construct large rice paddy lots. In order to realize large rice paddy lots of more than several hectares, it is necessary to consolidate small scattered leased farm lots of core tenant farmers, but it is supposed to be very difficult. In order to clarify how to consolidate those leased lots into large rice paddy lots, I investigated five land consolidation project areas in which large rice paddy lots of more than several hectares were constructed for core tenant farmers. The result shows that (1) large rice paddy lots for core tenant farmers were settled in relatively inferior areas of the project areas, for instance, far from the land owners' residence area. (2) Basically land lenders do not accept their substitute lots settled into large rice paddy lots in such inferior areas, (3) but some land lenders who were eager to lend their farmland to core farmers accepted their substitute lots in such inferior areas. (4) Even in cases that tenant farmers could not consolidate substitute lots of their tenant land into large rice paddy lots, they could consolidate their cultivating lots by adjusting user rights, that is, exchange of user rights of lots between land lenders whose substitute lots were located outside of a large rice paddy lot area and owner farmers whose substitute lots were located in the area. (5) Owner farmers accepted this adjustment on their farmland as they could cultivate superior lots, consolidate their scattered cultivating lots into one place and so on.     

Differentiation of neurons from mouse induced pluripotent stem cells in vitro

AIM: To study the induction method of mouse induced pluripotent stem cells (iPSCs) that differentiate into neurons in vitro. METHODS: Mouse iPSCs were cultured in non-adherent culture dishes for 2 d to form embryoid bodies (EBs). The EBs were cultured for consecutive 2 d in the presence of retinoic acid (RA), and then were plated in the serum-free medium for adherent culture. Seven days later, Pasteur pipette was used to detach the differentiated cells around adherent EBs into “fragment” cell colonies with the help of dissecting microscopes, and these “fragments” were transferred to culture dishes with neural stem cell medium. Another 7 days later, the cells were plated onto the culture dishes using differentiation medium containing fetal bovine serum (FBS) and RA. The morphological changes of the cells were observed under inverted microscope. The iPSCs markers Oct4, Sox2 and SSEA1, the neural stem cell (NSC) marker nestin, the neuronal marker microtubule-associated protein 2 (MAP-2), the astrocyte marker glial fibrillary acidic protein (GFAP) and oligodendrocyte marker myelin basic protein (MBP) were detected by immunofluorescence method. The mRNA expression of GFAP, nestin, β3-tubulin, MAP-2 and MBP was detected by RT-RCR. MAP-2 gene sequence was identified. The proportions of NSCs differentiated from iPSCs and neurons from NSCs were detected by flow cytometry. RESULTS: Mouse iPSCs strongly expressed Oct4, Sox2 and SSEA1, and formed spherical EBs by suspended culture. The EBs were induced by RA and serum-free medium in adherent culture for 2 d, and rosette structure was observed under the microscope. “Fragments” separated by Pasteur pipette from the rosette structure formed neurosphere-like colonies. After the colonies were cultured in adherent condition for 5 d to 7 d in the presence of RA and FBS, the typical neurite was observed under the microscope. The neurospheres expressed nestin and their differentiated derivatives expressed MAP-2, GFAP and MBP, respectively. RT-PCR analysis and gene sequencing showed that the neurons were induced successfully. The results of flow cytometry demonstrated that 63.93%±1.47% of iPSCs differentiated into NSCs and 21.4%±1.70% of NSCs differentiated into neurons. CONCLUSION: Mouse iPSCs proliferate stably and differentiate into neurons in vitro, which provide a reliable source for the treatment of spinal cord injury.     

Valuing Natural Forest Resources: An Application of Contingent Valuation Method on Adaba-Dodola Forest Priority Area,Bale Mountains,Ethiopia

This research employs a contingent valuation method (CVM) to estimate the respondents' willingness to pay (WTP) to gain use and control rights to a natural forest resource at the Adaba-Dodola Forest Priority Area (ADFPA) in the Bale Mountains of Ethiopia. The analysis was based on data collected from 295 households residing in and around the forest resource. Both binary probit and ordered probit models were used to examine socioeconomic factors that determine the respondents' WTP to gain these rights. The estimated mean and median WTP were found to be ETB 24.41 (US$2.54) and ETB 22.14 (US$2.30) annually, respectively. Households with more members, have better exposure to education and training, perceive the need for forest conservation, are member of forest dwellers' association, and who are wealthier in terms of ownership of more cultivated land and livestock are willing to pay more; whereas those households characterized by earning better annual household income, those who got higher starting bid value, and those who live farther away from the prime forest resource are willing to pay less. This can be used to signal that there is a considerable non-market value attached to use and control rights to the natural forest. In particular, membership in official forest user groups has shown a strong and positive relationship with WTP in all the models employed. This implies the approach of participatory management using forest user groups is better both for the sustainability of the forest resource and the livelihoods of the people who depend upon it.     

Community-Based Forest Management: What Scope for Conservation and Livelihood Co-Benefits? Experience from the East Usambara Mountains,Tanzania

The Tanzanian Community-Based Forest Management policy is based on the assumption that formalized forest tenure by village communities results in increased incentives for sustainable forest management. We compared the policy expectations to village forest management practices in northeastern Tanzania. Findings suggest that the practices follow policy in terms of increased security of rights, but exclusionary management of village forests precludes livelihood benefits while costs are unevenly distributed. Management appears effective at the village scale, but concerted efforts are likely to be needed to increase its long-term and landscape-level sustainability, and to create more significant incentives for the communities involved.     

Two Dimensional Nonnegative Sparse Partial Least Squares for Face Recognition

Partial least squares (PLS) algorithm has been widely used in face recognition recent years, but the improved algorithm of PLS did not consider both the constraint of nonnegative and sparsity to improve the recognition accuracy and robustness. To take over these disadvantages, the paper proposes a novel approach to extract the facial features called Two-dimension Nonnegative Sparse Partial Least Squares (2DNSPLS). The main idea of the approach is grabbing the local features via adding the constraint of nonnegative and sparse to 2DPLS, which make the approach gain not only the advantages of 2DPLS, incorporating both inherent structure and category information of images, but also the local features, having nonnegative interpretability and sparsity. For evaluating the approach’s performance, a series of experiments are conducted on two famous face image databases Yale and PIE face databases, which demonstrate that the proposed approach outperforms the state-of-art algorithms and has good robustness to occlusion.