Testing potatoes for field resistance to late blight     

Carl J. Eide  Florian I. Lauer 《American Journal of Potato Research》1967,44(1):9-16

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Tubers from leaf-bud cuttings: A tool for potato seed certification and breeding programs     

Florian I. Lauer 《American Journal of Potato Research》1977,54(10):457-464

The use of leaf-bud cuttings as a tool for rapid clonal increase was studied in 6 cultivars. Small tubers were obtained directly from leaf-bud cuttings maintained for 7 weeks in sand-filled pots or benches. The tubers ranged in size up to 1 1/4 inches (3cm) in diameter. The number of leaf-bud cuttings ranged from 37 to 288, depending on size of mother plant. They averaged 114 cuttings. Almost all of the leaf-bud cuttings produced tubers. The procedure is fast, simple, and provides for rapid increase of selected stocks.  相似文献   

Vertical SOC distribution and aromatic carbon in centuries old charcoal-rich Technosols     

Alexander Bonhage  Thomas Raab  Anna Schneider  Thomas Fischer  Shaghayegh Ramezany  William Ouimet  Alexandra Raab  Florian Hirsch 《European Journal of Soil Science》2022,73(4):e13293

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Pectin does not inhibit intestinal carcinogenesis in APC-deficient Min/+ mice     

Jacobasch G  Dongowski G  Florian S  Müller-Schmehl K  Raab B  Schmiedl D 《Journal of agricultural and food chemistry》2008,56(4):1501-1510

APC-germline mutation creates predisposition for intestinal tumorigenesis. APCMin/+ mice, developing tumors preferentially in the small intestine and only minimally in the colon, were fed pectin-enriched diets (10% galacturonan; degree of methoxylation=37.0 and 70.4%) or standard diet. Pectins used in the present study do not inhibit intestinal tumorigenesis and rather accelerate it in APCMin/+ mice. Both pectins exhibited prebiotic effects associated with high fermentative formation of acetate but producing low butyrate. The differences of the short-chain fatty acid concentrations between cecum and colon and those between colon and feces were larger than expected and increased with cancer progression, indicating an inhibition of butyrate absorption. Pectins transported more bile acids toward the colon than the standard diet and caused a higher generation of secondary bile acids despite lower pH values. Overexpression of COX-2 resulted in lower antioxidative capacity, thus promoting cancer. Apoptosis increased in hyperplasia but decreased in late adenomas. When biological modular design principles are taken into consideration, it can be expected that pectin also reinforces colorectal tumorigenesis of patients suffering from APC gene defects.  相似文献   

Soil-plant hydrology of indigenous and exotic trees in an Ethiopian montane forest     

Fritzsche F  Abate A  Fetene M  Beck E  Weise S  Guggenberger G 《Tree physiology》2006,26(8):1043-1054

Fast-growing exotic trees are widely planted in the tropics to counteract deforestation; however, their patterns of water use could be detrimental to overall ecosystem productivity through their impact on ecosystem water budget. In a comparative field study on seasonal soil-plant water dynamics of two exotic species (Cupressus lusitanica Mill. and Eucalyptus globulus Labill.) and the indigenous Podocarpus falcatus (Thunb.) Mirb. in south Ethiopia, we combined a 2.5-year record for climate and soil water availability, natural-abundance oxygen isotope ratios (delta(18)O) of soil and xylem water, destructive root sampling and transpiration measurements. Soil was generally driest under C. lusitanica with its dense canopy and shallow root system, particularly following a relatively low-rainfall wet season, with the wettest soil under E. globulus. Wet season transpiration of C. lusitanica was twice that of the other species. In the dry season, P. falcatus and C. lusitanica reduced transpiration by a factor of six and two, respectively, whereas E. globulus showed a fivefold increase. In all species, there was a shift in water uptake to deeper soil layers as the dry season progressed, accompanied by relocation of live fine root biomass (LFR) of C. lusitanica and P. falcatus to deeper layers. Under P. falcatus, variability in soil matric potential, narrow delta(18)O depth gradients and high LFR indicated fast water redistribution. Subsoil water uptake was important only for E. globulus, which had low topsoil LFR and tap roots exploiting deep water. Although P. falcatus appeared better adapted to varying soil water availability than the exotic species, both conifers decreased growth substantially during dry weather. Growth of E. globulus was largely independent of topsoil water content, giving it the potential to cause substantial dry-season groundwater depletion.  相似文献   

Chimpanzee reservoirs of pandemic and nonpandemic HIV-1     

Keele BF  Van Heuverswyn F  Li Y  Bailes E  Takehisa J  Santiago ML  Bibollet-Ruche F  Chen Y  Wain LV  Liegeois F  Loul S  Ngole EM  Bienvenue Y  Delaporte E  Brookfield JF  Sharp PM  Shaw GM  Peeters M  Hahn BH 《Science (New York, N.Y.)》2006,313(5786):523-526

Human immunodeficiency virus type 1 (HIV-1), the cause of human acquired immunodeficiency syndrome (AIDS), is a zoonotic infection of staggering proportions and social impact. Yet uncertainty persists regarding its natural reservoir. The virus most closely related to HIV-1 is a simian immunodeficiency virus (SIV) thus far identified only in captive members of the chimpanzee subspecies Pan troglodytes troglodytes. Here we report the detection of SIVcpz antibodies and nucleic acids in fecal samples from wild-living P. t. troglodytes apes in southern Cameroon, where prevalence rates in some communities reached 29 to 35%. By sequence analysis of endemic SIVcpz strains, we could trace the origins of pandemic (group M) and nonpandemic (group N) HIV-1 to distinct, geographically isolated chimpanzee communities. These findings establish P. t. troglodytes as a natural reservoir of HIV-1.  相似文献   

Vitality variation and population structure of a riparian forest in the lower reaches of the Tarim River,NW China     

Maierdang Keyimu  müt Halik  Florian Betz  Choimaa Dulamsuren 《林业研究》2018,29(3):749-760

Since 2000, the Chinese government has implemented emergency water diversion measures to restore the damaged riparian forest ecosystem with dominant tree species Euphrat poplar(Populus euphratica Oliv.)at the lower reaches of the Tarim River. In the present study, comparative analysis of variations in the vitality of P. euphratica trees were made using 2005 and 2010 data to illustrate the revitalization process of riparian forest. Poplar trees within 300 m of the riverbed were positively revitalized, while the vitality of trees farther than 300 m from the river decreased. Population structure was studied to demonstrate the development of poplar community. In the first belt, the class structure for the diameter at breast height(DBH) of P. euphratica fit a logistic model, and the 2nd, 3rd and 4th belt curve fittings were close to a Gaussian model; in other plots they were bimodal. Cluster analysis of the composition of the DBH class of poplar trees demonstrated that those within 16–36 cm DBH were the most abundant(58.49% of total) in study area, under 16 cm of DBH were second(31.36%), and trees 40 cm DBH were the least abundant(10.15%). More than 80% of the trees were young and medium-sized, which means that the poplar forest community in the vicinity of the lower Tarim River is at a stable developmental stage. The abundance of juvenile trees of P. euphratica in the first and second measuring belts was 12.13% in 2005 and increased to 25.52% in 2010, which means that the emergency water transfer had a positive impact on the generation of young P. euphratica trees in the vicinity of the river.  相似文献