抗菌肽基因导入桑树获得抗病转基因植株

用携带抗菌肽基因的农杆菌处理桑子叶,在含有羧苄青霉素（Cb）400～500mg／L和卡那霉素（Km）20mg／L的MS培养基上,有32.4％的子叶产生了不定芽;66.5％的不定芽在含有Cb300mg／L和Km30～40mg／L的培养基中,正常生长成2～3cm高的新稍;新梢在含Cb50mg／L和Km10mg／L的生根培养基中有72．6％形成完整根系。3次转化共获得12个株系55株KmR植株。不同株系桑苗叶片DNA点杂交分析显示,7个株系有阳性杂交信号。KmR株系桑苗的抗病性测定显示,5个株系共14株桑苗对青枯病具有较强抗性.     

草莓休眠过程中内源激素含量的变化

研究了草莓休眠过程中,内源ＡＢＡ、ＧＡ３、ＩＡＡ和ＺＴ（玉米素）含量变化。结果表明,同种内源激素在露地和保护地栽培条件下变化趋势相似。深休眠和浅休眠品种同种内源激素含量变化趋势相似,但含量变化在时间上有所差异。     

利用四川竹林资源大力发展园林观赏竹种

四川竹林资源丰富，除大面积的慈竹、硬头黄竹、毛竹、白夹竹等外，还有多种具有很高观赏价值的竹种。随着森林旅游以及人们要求“回归大自然，返朴归真”，物质文化生活水平的不断提高，挖掘和大力发展园林观赏竹具有十分广阔的前景，会取得显著的社会、生态和经济效益。     

Innovative liquid formulation of digestates for producing a biofertilizer based on Bacillus siamensis: Field testing on sweet pepper

A biofertilizer (BF) based on the plant growth promoting rhizobacterium (PGPR) Bacillus siamensis was produced using anaerobic digestate (AD) as the main ingredient of the growth medium, alongside a carbon source from residual origin. The use of residues for the growth of PGPR reduces the production costs of biofertilizers, but makes an assessment of the possible toxicity of residues for the bacteria or plants necessary. Therefore, the growth medium of PGPR was first optimized using the response surface methodology (RSM), followed by phytotoxicity tests and a field trial of the BF in a sweet pepper (Capsicum annuum L.) crop at two different locations. AD at 50% dilution, supplemented with 2.3% sugar beet molasses, was the optimum growth medium for producing the BF, with a bacterial concentration of 10⁹ cfu mL⁻¹. In the field trial, the treatments inoculated with BF and fertilized with decreased mineral N (80%) produced significantly better yields per ha than the controls with decreased N (80%) and full N (100%) without BF. This indicates improved efficiency of N use by the crop, as a consequence of the use of BF.     

Assessment of diffusive phosphate supply in soils by microdialysis

Standard procedures to assess P availability in soils are based on batch experiments with various extractants. However, in most soils P nutrition is less limited by bulk stocks but by strong adsorption and transport limitation. The basic principle of root‐phosphate uptake is to strip phosphate locally from the solid phase by forming a radial depletion zone in the soil solution, optionally enhanced by release of mobilizing substances. Microdialysis (MD), a well‐established method in pharmacokinetics, is capable to mimic important characteristics of P root uptake. The sampling is by diffusional exchange through a semipermeable membrane covering the probes with their sub‐mm tubular structure. Additionally, the direct environment of the probe can be chemically modified by adding, e.g ., carboxylates to the perfusate. This study is the first approach to test the applicability of MD in assessing plant available phosphate in soils and to develop a framework for its appropriate use.We used MD in stirred solutions to quantify the effect of pumping rate, concomitant ions, and pH value on phosphate recovery. Furthermore, we measured phosphate yield of top‐soil material from a beech forest, a non‐fertilized grassland, and from a fertilized corn field. Three perfusates have been used based on a 1 mM KNO₃ solution: pure (1), with 0.1 mM citric acid (2), and with 1 mM citric acid (3). Additionally, a radial diffusion model has been parametrized for the stirred solutions and the beech forest soil.Results from the tests in stirred solutions were in good agreement with reported observations obtained for other ionic species. This shows the principal suitability of the experimental setup for phosphate tests. We observed a significant dependency of phosphate uptake into the MD probes on dialysate pumping rate and on ionic strength of the outside solution. In the soils, we observed uptake rates of the probes between 1.5 × 10⁻¹⁵ and 6.7 × 10⁻¹⁴ mol s⁻¹ cm⁻¹ in case of no citrate addition. Surprisingly, median uptake rates were mostly independent of the bulk soil stocks, but the P‐fertilized soil revealed a strong tailing towards higher values. This indicates the occurrence of hot P spots in soils. Citrate addition increased P yields only in the higher concentration but not in the forest soil. The order of magnitude of MD uptake rates from the soil samples matched root‐length related uptake rates from other studies. The micro‐radial citrate release in MD reflects the processes controlling phosphate mobilization in the rhizosphere better than measurements based on “flooding” of soil samples with citric acid in batch experiments. Important challenges in MD with phosphate are small volumes of dialysate with extremely low concentrations and a high variability of results due to soil heterogeneity and between‐probe variability. We conclude that MD is a promising tool to complement existing P‐analytical procedures, especially when spatial aspects or the release of mobilizing substances are in focus.     

Tissue Culture Response from Seedling Explants of Commercial Barley Cultivars Grown in Bulgaria

Abstract

Only a few studies have been conducted in which regenerability of barley has been examined. In the current study, 17 barley genotypes (nine two-row malting type: Aster, Emon, Ruen, Jubiley, PV101, Körten, Krassi 2, Perun and Igri, and eight six-row feed types: Karnobat, Hemus, Jerun, Veslets, Aheloi 2, Diana, Panagon, and Izrgev) were evaluated for tissue-culture response from seedlings during a three-year period. Regenerable calli were obtained from all tested genotypes. Although there was much variation in regeneration capacity among the cultivars, plants were obtained from all cultivars. The majority of green plants grown to maturity were fertile and normal in appearance. The frequency of embryogénie callus induction and regenerability was influenced by genotype and growth conditions of the donor plants. Genotype was the most important determinant of the in vitro response. The best in vitro performance, based on ability to form regenerable calli and to regenerate plants was observed for Ruen, Aster, and Emon.     

风水文化在植物景观中的应用研究

从风水文化的视角探讨了植物景观中的阴阳属性、五行学说和象征寓意，并以此为指导，研究了风水文化在植物景观的空间营造、物种配置和主题构建三个方面的应用，提出了尊重植物的生长环境和规律、选择有利于人类生活需要和身心健康的植物、赋予植物思想文化内涵，进而构建宜居的植物景观氛围的建议。     

闽南毛竹林合理经营密度的研究

在闽南毛竹分布区的毛竹林分中建立标准地２４７块，利用柯尔莫哥洛夫的正态分布检验法。结合半峰宽理论，分析计算了闽南毛竹林的合理经营密度为１２００株￣１６５０朱／ｈｍ＾２，为闽南毛竹林持续经营提供了理论依据。     

开瓶炼苗对菜用大黄组培苗气孔特性的影响

研究了菜用大黄组培苗开瓶炼苗过程中叶片气孔的特性。结果表明,菜用大黄组培苗经直接开瓶炼苗0~14 d,气孔大小、气孔长径、气孔宽径随开瓶炼苗时间的延长而逐渐减小,并趋向稳定;气孔的关闭率随开瓶时间的延长而迅速增加,达到76.5%;14 d炼苗结束后,叶表皮细胞密度显著增加,气孔密度与气孔指数稍有增加,但不显著。闭瓶炼苗7 d、然后开瓶炼苗7 d可以较快恢复菜用大黄组培苗叶片气孔关闭的适应能力;显微观察发现,不同开瓶时间处理对叶片表皮气孔的细胞结构有明显影响,有光环境与无光环境对炼苗最终没有显著影响。     

Further evidence that in African acacia,white is a warning colour to herbivores: the white pseudo-galls of Vachellia seyal

Pseudo-galls of three East African acacia (Vachellia) species were compared to determine the correlates of gall colour and their potential defensive functions. Although all three species produce white thorns, the pseudo-galls of V. gerrardii and V. drepanolobium are dark coloured. In contrast, pseudo-galls of V. seyal var. fistula are white. Associated with this, they are thin-walled and poorly used by aggressive mutualistic ants. We suggest that this weak functionality is compensated for by the highly visible white colour. This aposematism may also involve mimicry as only the fistula variety of V. seyal has galls and only this variety co-occurs with other Vachellia species that have functional galls. Vachellia seyal seyal does not have pseudo-galls and this variety does not occur with other Vachellia species that have pseudo-galls.