Somatic in vitro culture response of Lolium perenne L.: genetic effects and correlations with anther culture   总被引：2，自引：0，他引：2  

Annette Olesen  Morten Storgaard  Sten Madsen  Sven Bode Andersen 《Euphytica》1995,86(3):199-209

Summary Genotypic effects on callus induction and plant regeneration in callus, suspension and protoplast culture, and their correlations with both phenotypic and GCA-values for anther culture response, were studied using 21 genotypes of perennial ryegrass. Differences between genotypes accounted for approximately 40% of the total variation for callus induction and initial callus growth, and 59 and 83% of the variation in callus culture for regeneration percentage and percentage of green plants. Effects of genotypes were less pronounced in suspension culture, where suspensions from the same genotype often behaved differently. Some suspension cultures retained their capacity for green plant regeneration for almost two years, repeatedly producing 80–100% green regenerants during this period. Genotypes with high regeneration percentage and a large proportion of green plants from callus culture were also superior in suspension culture for both regeneration performance and longevity. Regeneration percentage and percentage of green plants were uncorrelated, and probably under different genetic control. While capacity for green plant formation from the different genotypes showed no correlation between anther culture and somatic in vitro culture, a positive correlation was observed between the regeneration percentages in somatic in vitro culture and anther culture (r=0.44^*–0.85^***), suggesting some common genetic control of the two systems.  相似文献   

Suspension culture performance in commercial varieties of perennial ryegrass (Lolium perenne L.)   总被引：1，自引：0，他引：1  

Annette Olesen  Morten Storgaard  Sten Madsen 《Euphytica》1996,88(2):151-157

Summary Suspension culture performance in commercial varieties of perennial ryegrass was studied to assess the effect of variety on suspension culture response and plant regeneration. 179 suspension cultures were established from embryos of mature seeds of 21 varieties and one breeding population. Of these, 123 suspensions were morphogenic (21 varieties) and 66 suspensions (18 varieties) regenerated green plants. A number of suspension lines, originating from two different suspensions, retained the capacity for green plant formation for almost four years. Replicates performed with seed lots of different ages indicated that suspensions initiated from young seeds (1 year) were of better quality than suspensions initiated from older seeds (2–4 years). Varieties differed in their capacity to form morphogenic suspensions and suspensions capable of regenerating green plants, although the effect of variety was relatively small. It was concluded that responsive genotypes can be found within most varieties of Lolium perenne.  相似文献   

Complementary Hotspot Inventory - A method for identification of important areas for biodiversity at the forest stand level     

Ivar Gjerde  Magne Sætersdal  Hans H. Blom 《Biological conservation》2007,137(4):549-557

Forest stands are the basic planning units of managed forest landscapes, and the structural composition of these units is important for conservation of biodiversity. We present a methodological approach for identification and mapping of important structural and environmental features of forest stands. Based on an analysis of habitats of red-listed species and a synthesis of results from research on spatial distribution of forest species, we developed a habitat inventory approach (Complementary Hotspot Inventory, CHI) that is currently used in forestry planning in Norway. The CHI maps fine-scale hotspots for 12 habitat types that are further classified according to positions along main environmental gradients (productivity and humidity). Consisting of different substrates in different environments, these habitats to a large degree support different species assemblages. By incorporating both the hotspot and the complementary approach, the CHI produces data tuned for later conservation measures. The high spatial resolution of data facilitates the use of conservation measures at different spatial scales, from single-tree retention to forest reserves. A validation test of habitats identified by CHI showed that the density of red-listed species was four times that of randomly selected old forests.  相似文献   

Microbial enzyme activities in leaf litter, humus and mineral soil layers of European forests   总被引：2，自引：0，他引：2  

Michael Andersson  Annelise Kjøller  Sten Struwe 《Soil biology & biochemistry》2004,36(10):1527-1537

The rationale of the study was to investigate microbial activity in different soil horizons in European forests. Hence, activities of chitinase and cellulase, microbial biomass carbon (C_mic) and basal respiration were measured in litter, fragmentation, humus and mineral soil layers collected several times from various beech and spruce forests. Sites were selected to form a gradient in N availability. Analyses were also performed on beech litter from a litterbag transplant experiment. Furthermore, microbiological parameters were measured in horizons of beech and spruce chronosequence sites with different stand age in order to investigate the influence of forest rotation, and hence changes in soil organic matter (SOM) dynamics, on microbial activity. Finally in horizons of one beech forest, the seasonal variation of selected microbiological parameters was measured more intensively. β-Glucosaminidase and cellobiohydrolase activities were measured using fluorogenic 4-methylumbelliferyl substrates to estimate chitinase and cellulase activities, respectively. On a spatial scale, chitinase and cellulase activities, C_mic determined by substrate induced respiration, and basal respiration ranged from 144 to 1924 and 6-177 nmol 4-MU g⁻¹ org-C h⁻¹, 8-48 mg C g⁻¹ org-C and 11-149 μg CO₂-C g⁻¹ org-C h⁻¹, respectively; in general values were significantly lower in layers of humus and mineral soil than of litter. Chitinase activity, C_mic and basal respiration from humus and mineral soil layers, together, correlated positively, while none correlated with cellulase activity. Similarly in the litter layer, no correlations were found between the microbiological parameters. On a seasonal scale, a time lag between a burst in basal respiration rate and activities of both enzymes were observed. In general, activities of cellulase and chitinase, C_mic and basal respiration, did not change with stand age, except in the humus layer in the spruce chronosequence, where C_mic decreased with stand age. In the litter layer, cellulase activity was significantly and positively related to the C:N ratio, while only a tendency for chitinase activity was shown, indicating that enzyme activities decreased with increasing N availability. In accordance, the enzyme activities and C_mic decreased significantly with increasing chronic N deposition in the humus layer, while basal respiration only tended to decrease with increasing N deposition. In contrast, enzyme activities in beech litter from litterbags after 2 years of incubation were generally higher at sites with higher N deposition. The results show different layer-specific responses of enzyme activities to changes in N availability, indicating different impacts of N availability on decomposition of SOM and stage of litter decomposition.  相似文献   

Landscape characteristics explain large-scale variation in demographic traits in forest grouse     

Unni S. Lande  Ivar Herfindal  Tomas Willebrand  Pål F. Moa  Torstein Storaas 《Landscape Ecology》2014,29(1):127-139

The effects of landscape composition on species and populations have become increasingly important due to large and rapid habitat changes worldwide. In particular, concern is raised for several forest-dwelling species such as capercaillie and black grouse, because their habitats are continuously changing and deteriorating from human development. Conservation of these species is linked to sustainable forest management that seeks to benefit multiple species, which demands knowledge about demographic rates in relation to forest composition and structure. We related the spatial variation in adult density and chick production of capercaillie and black grouse to landscape characteristics from 13 areas within the boreal forest of Norway. Linear mixed effects models showed that black grouse and capercaillie had similar associations to landscape characteristics. Adult density of both species was positively related to the proportion of old forest (>80 years), but only if the area had large proportions of mid to high productive forests. Chick production was negatively related to the proportion of old forest, but positively to habitat diversity and more so for black grouse compared to capercaillie. However, the result for chick production suggest that other forest types also are important, and that forest grouse needs a variety of habitats during their life history stages. Management that seeks to simultaneously conserve populations of black grouse and capercaillie needs to ensure a matrix of various forest types. A special focus must be on the critical life history of local populations to successfully preserve viable populations, for black grouse and capercaillie this implies protection of old and mid to high productive forest while keeping a heterogeneous landscape.  相似文献   

Neuroscience. Human locomotor circuits conform     

Grillner S 《Science (New York, N.Y.)》2011,334(6058):912-913

  相似文献   

HIV prevention in women: next steps     

Vermund SH  Van Damme L 《Science (New York, N.Y.)》2011,331(6015):284

  相似文献   

Domestication effects on fin nipping, survival and growth in hatchery-reared arctic charr, Salvelinus alpinus (L.), in competition with wild conspecifics     

S I Siikavuopio  B M Baardvik  M Jobling 《Aquaculture Research》1996,27(3):205-211

When reared in captivity, first-generation hatchery-reared Arctic charr, Salvelinus alpinus (L.), from Møkkeland lake, northern Norway, differed from wild-caught conspecifics from the same source. Incidence of caudal fin damage (used as an indirect assessment of aggressive interactions) was high amongst the wild-caught charr, and there was considerable mortality amongst these fish. By contrast, hatchery-reared fish displayed little evidence of fin damage, and mortalities were low. When the charr were held in mixed groups of wild-caught and hatchery-reared fish, the hatchery-reared fish showed the most extensive caudal fin damage. Weight losses and decreases in condition were also greatest amongst the hatchery-reared charr that were exposed to competition with wild fish. The hatchery-reared charr held together with the wild fish also suffered high mortality. Thus, aggression may have been selectively directed towards hatchery-reared fish in mixed groups. Taken together, the results suggest that the energetic costs may be high for the recipients of aggression.  相似文献   

Comparative cardiac pathological changes of Atlantic salmon (Salmo salar L.) affected with heart and skeletal muscle inflammation (HSMI), cardiomyopathy syndrome (CMS) and pancreas disease (PD)     

Muhammad Naveed Yousaf  Erling Olaf Koppang  Karsten Skjødt  Ivar Hordvik  Jun Zou  Chris Secombes  Mark D. Powell 《Veterinary immunology and immunopathology》2013,151(1-2):49-62

The heart is considered the powerhouse of the cardiovascular system. Heart and skeletal muscle inflammation (HSMI), cardiomyopathy syndrome (CMS) and pancreas disease (PD) are cardiac diseases of marine farmed Atlantic salmon (Salmo salar) which commonly affect the heart in addition to the skeletal muscle, liver and pancreas. The main findings of these diseases are necrosis and inflammatory cells infiltrates affecting different regions of the heart. In order to better characterize the cardiac pathology, study of the inflammatory cell characteristics and cell cycle protein expression was undertaken by immunohistochemistry. Immunohistochemistry was performed on paraffin embedded hearts from confirmed diseased cases applying specific antibodies. The inflammatory cells were predominantly CD3⁺ T lymphocytes. The PD diseased hearts exhibited moderate hypoxia inducible factor-1α (HIF1α) immuno-reaction that suggested tissue hypoxia while recombinant tumor necrosis factor-α (rTNFα) antibody identified putative macrophages and eosinophilic granulocytes (EGCs) in addition to endocardial cells around lesions. There were strong to low levels of major histocompatibility complex (MHC) class II immunostaining in the diseased hearts associated with macrophage-like and lymphocyte-like cells. The diseased hearts expressed strong to low levels of apoptotic cells identified by caspase 3 and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) staining. The strong signals for proliferative cell nuclear antigen (PCNA) and TUNEL, and moderate levels of caspase 3 immuno-reactivity suggested a high cell turnover where DNA damage/repair might be occurring in the diseased hearts. Interestingly, the apparently similar cardiac diseases exhibited differences in the immunopathological responses in Atlantic salmon.  相似文献   

Effects of Hyperoxic Conditions on Growth Performance in Juvenile and Adult Green Sea Urchin,Strongylocentrotus droebachiensis     

Sten Ivar Siikavuopio 《Journal of the World Aquaculture Society》2012,43(4):579-584

The effects of hyperoxic conditions on survival, gonad growth, feed intake, and food conversion of adult and somatic growth and survival of juvenile green sea urchin, Strongylocentrotus droebachiensis, were examined. Juvenile and adult sea urchins with initial diameters of 11.5 and 75 mm, respectively, were reared in water with constant oxygen saturations of 100 (control), 115 and 130% for 42 d (juvenile) and 51 d (adult sea urchin) at 8 C and 33‰ salinity. During the experiment the gonad indices of the adults tripled from 7.3% (±1.5) to 21.4% (±4.3), 19.4% (±4.7), and 22.0% (±4.4) for the groups kept at 100, 115, and 130% oxygen saturation, respectively. At the end of the experiment, the differences in gonadal size among the groups were not significant. Neither were there any significant differences in food intake or food conversion ratio among the groups. Only one animal died during the experiment. The juvenile sea urchin kept at 100, 115, and 130% oxygen saturation doubled their test diameter from initially 11.5 mm (±1.5) to 19.9 mm (±1.4), 21.4 mm (±2.1) and 20.6 mm (1.0), respectively, but there were no significant differences in growth among these groups. There was no mortality during the experiments in these groups. Overall, the findings suggest that juvenile and adult S. droebachiensis are unable to utilize hypersaturation of oxygen to increase somatic or gonad growth, but can be reared at hyperoxygenated water for prolonged periods of time without harmful effects.  相似文献