欧洲大黄茎尖组织培养与快速繁殖

就四个欧洲大黄品种的的茎尖组织培养与快速繁殖技术进行了比较研究。结果表明欧洲大黄可用茎尖作为外植体进行离体室内人工快繁。茎尖在MS诱导培养基上培养4周后衍生幼苗。幼苗在MS生根培养基上培养4周可发育出完整的根系。不同品种之间在离体繁殖条件下的衍生能力有较大差异。

Comparison of Responses to Mn Deficiency Between the UK Wheat Genotypes Maris Butler, Paragon and the Australian Wheat Genotype C8MM

Wheat grown in Mn-deficient soil has been widely observed to produce much reduced yields. Breeding for Mn-efficient wheat genotypes adapted to Mn-deficient soils would represent a long-term solution for wheat agronomy. To characterize the physiological basis of Mn efficiency in wheat genotypes would facilitate the breeding programs for producing Mn-efficient wheat. Using a solution culture and a soil culture system in the present study, a Mn-efficient UK wheat genotype Maris Butler and a Mn-inefficient UK wheat genotype Paragon have been compared with a Mn-efficient Australian wheat genotype C8MM in the responses to Mn deficiency in order to characterize the Mn efficiency in these wheat genotypes. Results showed that in solution culture, Marls Butler grown under Mn deficiency had 77% relative dry matter yield of control plants that were grown under Mn sufficiency, whereas CSMM and Paragon had 60% and 58% relative dry matter yield of their respective controls. Results from the soil culture demonstrated that relative dry matter yield remained high for Maris Butler and C8MM （53% and 56%, respectively）, whereas the value for Paragon dropped to 33%. In terms of dry matter yield and photosynthetic efficiency, Maris Butler demonstrated Mn efficiency in both solution culture and soil culture, whereas C8MM showed Mn efficiency only in soil culture. Results also demonstrated that under Mn-depleted supply in soil, plants of C8MM had a significantly higher ability in Mn uptake, whereas plants of Marls Butler showed a higher internal Mn use efficiency in comparison with plants of Paragon. Results from the present study indicate that the ability of C8MM to accumulate higher amounts of Mn is the basis of the improved Mn efficiency of this genotype in comparison with Paragon, and in Marls Butler there is a higher internal use of Mn expressed as an improved photosynthetic efficiency in conferring its Mn efficiency. It is suggested that more than one mechanism has arisen in wheat to confer tolerance to Mn deficiency.

Clearcuts and related secondary dieback undermine the ecological effectiveness of FSC certification in a boreal forest

Background:Over the last 25 years,the prominent forest certification system established by the Forest Stewardship Council(FSC)has used by many companies worldwide for claiming responsible forest management.The objectives of the Russian National FSC standard to decrease the size of clearcuts and the retention of forest elements such as residual seed trees need on-site validation to proof the effectiveness of FSC.To assess the ecological impacts of harvesting practices and benefits of FSC certification,we geospatially compared logging activities with and without FSC certification.Within a sample area covering approximately 3,000 km^(2) in the east of the Russian Arkhangelsk Region,we used available data on tree cover loss and satellite images to assess secondary impacts of clearcuttings on adjacent remnant forests and to quantify the logging intensity.Additionally,the size and structure as well as the density of skidding trails of ten specific clearcuttings located within the sample area were surveyed using satellite images and in the field observation to delineate the boundaries of clearcuts and forested remnants within the clearcuts.Results:We found a significant increase of small-scale tree cover loss in the proximity of the clearcuts.Patchy dieback is possibly linked to the scale and intensity of logging in the surroundings.On the investigated clearcuts,FSC failed to reduce the size,to increase the retention of forest remnants including seed trees on logged areas,and to maintain larger tracts of undisturbed ground and soil compared to clearcuts that were logged before they received FSC-certification.Conclusions:Trees and forest remnants remaining inside an increasingly stressed forest ecosystem matrix may not resist further harvesting-related and climate change-induced stresses and disturbances.Large-scale clearcuttings seem to have negative impacts even in adjacent forests and undermine the ecological effectiveness of FSC certification in the study area.The Russian FSC standard is not clearly setting effective guidelines that induce a change in clearcutting practices in order to reduce ecological risks.

Optimising soft tissue in-growth in vivo in additive layer manufactured osseointegrated transcutaneous implants

Osseointegrated transcutaneous implants could provide an alternative and improved means of attaching artificial limbs for amputees,however epithelial down growth,inflammation,and infections are common failure modalities associated with their use.To overcome these problems,a tight seal associated with the epidermal and dermal adhesion to the implant is crucial.This could be achieved with specific biomaterials(that mimic the surrounding tissue),or a tissue-specific design to enhance the proliferation and attachment of dermal fibroblasts and keratinocytes.The intraosseous transcutaneous amputation prosthesis is a new device with a pylon and a flange,which is specifically designed for optimising soft tissue attachment.Previously the flange has been fabricated using traditional machining techniques,however,the advent of additive layer manufacturing(ALM)has enabled 3-dimensional porous flanges with specific pore sizes to be used to optimise soft tissue integration and reduce failure of osseointegrated transcutaneous implants.The study aimed to investigate the effect of ALM-manufactured porous flanges on soft tissue ingrowth and attachment in an in vivo ovine model that replicates an osseointegrated percutaneous implant.At 12 and 24 weeks,epithelial downgrowth,dermal attachment and revascularisation into ALM-manufactured flanges with three different pore sizes were compared with machined controls where the pores were made using conventional drilling.The pore sizes of the ALM flanges were 700,1000 and 1250μm.We hypothesised that ALM porous flanges would reduce downgrowth,improve soft tissue integration and revascularisation compared with machined controls.The results supported our hypothesis with significantly greater soft tissue integration and revascularisation in ALM porous flanges compared with machined controls.