18个优质小麦品种(系)Glu-1、Glu-3和Gli-1位点的基因变异特点

为给小麦品质育种提供参考信息,选用我国18份有影响的优质面条和面包小麦品种或种质资源，通过分步法SDS-PAGE和改良A-PAGE分析了其Glu-1、Glu-3、Gli-1位点的基因变异特点。结果表明，由Glu-1住点控制的高分子量谷蛋白亚基共14种图谱，其中，Glu-A1位点上优质亚基1和2^＊分别占61．1％和11．1％，Glu—B1位点上优质亚基14＋15、7＋8、17＋18、13＋16分别占27．8％、27．8％、22．2％、5．6％．Glu_D1位点上优质亚基5＋10占55．6％。Glu—A1、Glu—B1、Glu-D1位点上均为优质亚基的品种（系）有陕451（1，7＋8，5＋10）、95鉴5104（1,14＋15，5＋10）、陕优412（2^＊，7＋8，5＋10）、绵阳89-47（2^＊，13＋16，5＋10）以及中优16、冀5099、绵优1号、绵优2号（1，17＋18,5＋10），占参试品种的44．4％。由Glu-3位点控制的低分子量谷蛋白亚基共12种图谱，小偃6号、PH82-2、陕253、80356、95鉴5104、郑农33等6个品种皆为“a，d，c”；由G1i-1位点控制的醇溶蛋白共12种图谱，小偃6号、PH82-2、陕优225、陕253、80356、中优16、95鉴5104等7个品种皆为“O，new，i”，即发现在Gli-B1位点是一个新等位基因。     

A range-wide model of landscape connectivity and conservation for the jaguar, Panthera onca

Large, wide-ranging carnivores face greater threats and more persistent declines than most other mammal species. An important conservation tool for these carnivores has been range-wide priority-setting exercises that have helped identify critical threats and key populations. However, such exercises often fail to identify functional movement corridors or account for genetic connectivity. We present a new model for jaguar (Panthera onca) conservation that uses a geographic information system (GIS) and expert input to create a dispersal cost surface and identify least-cost corridors connecting the 90 known populations across the jaguar’s range. Results indicate 78% of historic jaguar range, an area of approximately 14.9 million km², still holds potential for jaguar movement and dispersal. We identified 182 potential corridors between populations, ranging from 3 to 1607 km in length; 44 of these corridors are characterized as being of immediate concern due to their limited width, and thus their high potential for being severed. Resultant maps, displaying priority populations and corridors, are used to direct field-based research and conservation efforts. Field assessment and refinement of the corridors is ongoing. This is the first attempt to create and implement such a holistic model of range-wide conservation for a large carnivore species.     

Chromosomal location of genes for resistance to powdery mildew in common wheat (Triticum aestivum L. em Thell.) 7. Gene Pm29 in line Pova

Chromosomal localization and linkage mapping of a powdery mildewresistance gene were conducted in the resistant wheat line Pova, derivedfrom a Triticum aestivum cv. Poros-Aegilops ovata-alien additionline. Monosomic analysis revealed that a major dominant gene was locatedon chromosome 7D. This gene possessed a distinct disease response patternagainst a differential set of Blumeria graminis tritici isolates andsegregated independently from resistance gene Pm19 also located onwheat chromosome 7D. Molecular genetic analysis showed that theresistance gene in Pova was specifically located on the long arm ofchromosome 7D closely linked to one RFLP and three AFLP markers. It isproposed that the new gene be designated Pm29.     

Genetic studies of powdery mildew resistance in common oat (avena sativa L.) I. Cultivars and breeding lines grown in Western Europe and North America

Common oat (Avena sativa L.) cultivars and breeding lines grown in Western Europe and North America were tested against twelve Erysiphe graminis f. sp. avenae mildew isolates collected in Germany and Denmark. These isolates were selected for their ability to produce differential response patterns permitting characterization of five oat mildew resistance (OMR) groups. From a total of 259 cultivars and lines tested 173 accessions showed susceptible responses, 48 accessions were characterized by susceptible or intermediate responses and 38 accessions revealed isolate-specific resistance response patterns. Eight cultivars and lines had resistance patterns of OMR group 1, six cultivars of OMR group 2, and eleven cultivars of OMR group 3. Two cultivars, each possessed resistance patterns corresponding to OMR groups 1 + 3 and 2 + 3 in combination, respectively. Three cultivars exhibited the response pattern of OMR group 3 in association with an additional unknown resistance. Eight cultivars and lines showed a resistance response pattern not yet detected in the documented OMR groups. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic variation in germplasm accessions of Secale vavilovii Grossh

Summary The accurate identification and classification of wild species enhance the utilization of potential plant genetic resources. The wild rye species Secale vavilovii Grossh. may serve to broaden the genetic variation in cultivated rye, S. cereale. The combined analyses of cytological, isozymic and other genetic characteristics in the present study revealed that of the fourteen rye accessions designated as S. vavilovii, only three accessions were correctly classified. Thus it is essential to increase multidisciplinary, international research and collaboration to aid in the classification and utilization of the yet untapped plant germplasm.     

Origin of the nitrogen assimilated by soil fauna living in decomposing beech litter

We investigated the nitrogen source for main taxa of soil fauna in two beech forests of contrasted humus type using ¹⁵N-labelled beech litter and ¹⁵N analysis of soil fauna. ¹⁵N-labelled beech litter was deposited on the topsoil in December 2000 in four stands of different ages at Leinefelde (Germany) with mull humus and in one mature stand at Sorø (Denmark) with moder humus. The fate of the tracer isotope was measured in litter and soil, as well as in the soil fauna, and for each taxa, we calculated the proportion of N in the animal derived from the labelled substrate. Of the original N contained in the litter, 20-41% was lost after 9 months at Leinefelde, and only 10% at Sorø. This loss was counterbalanced by the incorporation of 24-31% external N at Leinefelde, and 31% at Sorø, partly originating from fungal colonisation of the added litter. The proportion of N assimilated from the labelled litter by the different soil animals varied in relation to their mobility and feeding preferences. Large and mobile soil animals, especially predators, derived on average less ¹⁵N because they were also able to feed outside the labelled litter boxes. Detritivores assimilated at most 15% of their nitrogen content at Leinefelde and 11% at Sorø from the decomposing labelled litter. The most labelled taxa at Leinefelde were small fungivorous and coprophagous species, mainly isotomid Collembola such as Isotomiella and Folsomia. At Sorø, best labelled taxa were saprophagous species such as Enchytraeidae, Glomeridae and Phthiracaroidea. These low rates of ¹⁵N assimilation indicate that fresh litter is not directly the main N source for soil animals. The results obtained suggest that soil fauna fed preferentially upon microorganisms colonising the litter at Leinefelde (mull) and from litter itself at Sorø (moder).     

Powdery mildew resistance in Aegilops tauschii coss. and synthetic hexaploid wheats

Summary A collection of 400 Ae. tauschii (syn. Ae. squarrosa) Coss. accessions were screened for powdery mildew resistance based on the response patterns of 13 wheat cultivars/lines possessing major resistance genes to nine differential mildew isolates. 106 accessions showed complete resistance to all isolates, and 174 accessions revealed isolate-specific resistance, among which were 40 accessions exhibiting an identical response pattern as wheat cultivar Ulka/^*8Cc which is known to possess resistance gene Pm2. Expression of both complete and isolate-specific resistance from Ae. tauschii was observed in some synthetic hexaploid wheats derived from four mildew susceptible T. durum Desf. parents, each crossed with five to 38 resistant diploid Ae. tauschii accessions. Synthetic amphiploids involving different combinations of T. durum and Ae. tauschii generally showed a decrease in resistance compared with that expressed by the Ae. tauschii parental lines.     

Coincident scrapie infection and nephritis lead to urinary prion excretion

Prion infectivity is typically restricted to the central nervous and lymphatic systems of infected hosts, but chronic inflammation can expand the distribution of prions. We tested whether chronic inflammatory kidney disorders would trigger excretion of prion infectivity into urine. Urinary proteins from scrapie-infected mice with lymphocytic nephritis induced scrapie upon inoculation into noninfected indicator mice. Prionuria was found in presymptomatic scrapie-infected and in sick mice, whereas neither prionuria nor urinary PrP(Sc) was detectable in prion-infected wild-type or PrP(C)-overexpressing mice, or in nephritic mice inoculated with noninfectious brain. Thus, urine may provide a vector for horizontal prion transmission, and inflammation of excretory organs may influence prion spread.     

Sensitivity of landscape resistance estimates based on point selection functions to scale and behavioral state: pumas as a case study

Estimating landscape resistance to animal movement is the foundation for connectivity modeling, and resource selection functions based on point data are commonly used to empirically estimate resistance. In this study, we used GPS data points acquired at 5-min intervals from radiocollared pumas in southern California to model context-dependent point selection functions. We used mixed-effects conditional logistic regression models that incorporate a paired used/available design to examine the sensitivity of point selection functions to the scale of available habitat and to the behavioral state of individual animals. We compared parameter estimates, model performance, and resistance estimates across 37 scales of available habitat, from 250 to 10,000 m, and two behavioral states, resource use and movement. Point selection functions and resistance estimates were sensitive to the chosen scale of the analysis. Multiple characteristic scales were found across our predictor variables, indicating that pumas in the study area are responding at different scales to different landscape features and that multi-scale models may be more appropriate. Additionally, point selection functions and resistance estimates were sensitive to behavioral state; specifically, pumas engaged in resource use behavior had an opposite selection response to some land cover types than pumas engaged in movement behavior. We recommend examining a continuum of scales and behavioral states when using point selection functions to estimate resistance.     

Integrating occupancy modeling and interview data for corridor identification: A case study for jaguars in Nicaragua

Corridors are critical elements in the long-term conservation of wide-ranging species like the jaguar (Panthera onca). Jaguar corridors across the range of the species were initially identified using a GIS-based least-cost corridor model. However, due to inherent errors in remotely sensed data and model uncertainties, these corridors warrant field verification before conservation efforts can begin. We developed a novel corridor assessment protocol based on interview data and site occupancy modeling. We divided our pilot study area, in southeastern Nicaragua, into 71, 6 × 6 km sampling units and conducted 160 structured interviews with local residents. Interviews were designed to collect data on jaguar and seven prey species so that detection/non-detection matrices could be constructed for each sampling unit. Jaguars were reportedly detected in 57% of the sampling units and had a detection probability of 28%. With the exception of white-lipped peccary, prey species were reportedly detected in 82–100% of the sampling units. Though the use of interview data may violate some assumptions of the occupancy modeling approach for determining ‘proportion of area occupied’, we countered these shortcomings through study design and interpreting the occupancy parameter, psi, as ‘probability of habitat used’. Probability of habitat use was modeled for each target species using single state or multistate models. A combination of the estimated probabilities of habitat use for jaguar and prey was selected to identify the final jaguar corridor. This protocol provides an efficient field methodology for identifying corridors for easily-identifiable species, across large study areas comprised of unprotected, private lands.