云南红豆杉人工药用原料林春芽数量及其动态

芽是枝、花或花序尚未发育前的雏体,是植物体的重要构件之一,也是植物树冠形成的基础(魏媛等,2010).芽的萌发预示着冬眠结束和生长开始(Yakovlev et al.,2008),并影响着许多过程,以及各种动物行为(Wesolowski et al.,2006).因此,乔木芽萌发、芽的时空变化以及这些变化的机制,对于理解乔木的许多季节现象非常重要,对于制定物种管理方法(Akamine et al.,2007)及探讨森林对气候变化的响应也具有重要价值(Wesolowski et al.,2006;Rohde et al.,2011).植株树冠的形成,很大程度上取决于芽在植物上的着生位置、排列和活动状况.     

黑龙江省西瓜细菌性果实腐斑病防治技术

近年来黑龙江省西瓜细菌性果实腐斑病发病严重。园艺分院西瓜研究室对黑龙江省西瓜果斑病的发病症状等进行了4年的调查,并进行了西瓜果斑病防治方法的试验示范,示范地块的果斑病发病率在两年内控制在了3％、1％以下,总结了防治方法。     

长白赤松和红松土壤微生物活性对高浓度CO_2的响应(英文)

研究了2003 年夏季长白赤松和红松土壤微生物活性对高浓度CO2的响应规律。结果表明,长白赤松和红松土壤细菌数量受高浓度CO2影响显著(p < 0.05)减少;与对照箱(350 μmol ·mol-1 CO2)和裸地(350 μmol ·mol-1 CO2)相比,红松土壤淀粉酶和转化酶活性降低,而长白赤松土壤淀粉酶和转化酶活性却表现为增加;同时发现受700 μmol ·mol-1 CO2处理的红松和长白赤松土壤微生物生物量碳均表现为显著降低。DGGE 结果表明:受高浓度CO2 的影响,长白赤松和红松土壤细菌群落结构发生了明显的变化。研究结果表明土壤微生物对高浓度CO2的响应规律与所研究的的树种有关。图2 表2 参29。     

长白赤松和红松土壤微生物活性对高浓度CO2的响应

Responses of soil microbial activities to elevated CO₂ in experiment sites ofPinus sylvestriformis andPinus koraiensis seedlings were studied in summer in 2003. The results indicated the number of bacteria decreased significantly (p<0.05) under elevated CO₂ forPinus sylvestriformis andPinus koraiensis. Amylase and invertase activities in soil increased forPinus sylvestriformis and decreased forPinus koraiensis with CO₂ enrichment compared with those at ambient (350 μmol·mol⁻¹). The size of microbial biomass C also decreased significantly at 700 μmol·mol⁻¹ CO₂. Bacterial community structure had some evident changes under elevated CO₂ by DGGE (Denaturing Gradient Gel Electrophoresis) analysis of bacterial 16S rDNA gene fragments amplified by PCR from DNA extracted directly from soil. The results suggested that responses of soil microorganisms to elevated CO₂ would be related to plant species exposed to elevated CO₂. Foundation item: The study was supported by Major State Basic Research Development Program of China (2002CB412502) and the Knowledge Innovation Project from Chinese Academy of Sciences (KZCX1-SW-01-03). Biography: JIA Xia (1975), female, Ph. D. candidate of Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan     

桤木采穗圃无性系管理技术研究

研究表明:桤木无性系植株嫩枝总芽数主要取决于树龄和无性系遗传特性,同时与无性系植株定干高度、修枝、施肥等密切相关。在桤木无性系采穗圃中,无性系植株定干高度以90 cm为宜,无性系植株枝条宜进行轻短截,并加强施肥管理,既可提高嫩枝总芽数,又能扩大树冠,增强树势,提高采穗圃穗条的产量和质量。     

多菌灵和青霉素在组培污染中的应用

为了消除植物组织培养过程中出现的真菌和细菌污染 ,而又不杀伤植物组织 ,采用多菌灵和青霉素混合溶液浸泡污染的组培苗茎段的结果发现 ,多菌灵对真菌有杀灭作用 ,对细菌没有明显作用 ;青霉素只对细菌有抑制作用 ,继代后细菌污染照常存在 ;而对污染的组培苗采用 75 %乙醇和 0 .1% Hg Cl2 处理可彻底杀灭真菌和细菌     

潮土长期不同施氮水平对秸秆降解及其细菌群落结构的影响

农田过量施氮所引发的问题已经引起广泛关注,但长期施氮后土壤无机氮水平状况及其对秸秆降解的作用尚不清楚。本研究以中国科学院封丘农业生态实验站长期（2005～2018年）施氮肥（5个施氮水平：0(N0)、150(N1)、190(N2)、,230(N3)和270 (N4)kg ha-1 yr-1）的潮土为研究对象,开展短期（50天）的秸秆降解-土壤培育实验。培育期间监测秸秆碳的矿化、土壤无机氮（硝态氮和铵态氮）、可溶性有机碳、微生物生物量碳的动态变化,利用高通量测序测定细菌群落结构。结果表明,长期施氮后,土壤无机氮含量和秸秆碳的矿化率随施氮水平的升高而增加。不同长期施氮水平的土壤细菌群落结构呈现显著差异。网络分析揭示：秸秆降解过程中细菌群落内部物种间的共现模式随长期施氮水平发生改变,具体体现为长期高施氮水平下细菌群落彼此间的负相关得到了加强;同时,变形菌主导地位减弱、酸杆菌主导地位增强。综上,土壤无机氮含量、细菌群落结构及物种之间的关系随着长期施氮水平的不同发生了改变。本研究探究了长期不同施氮水平下土壤中无机氮的水平状况、秸秆降解状况以及秸秆降解过程中土壤细菌的生物特性,以期为秸秆还田和科学施氮提供一定的数据支撑和思路启示。     

喀斯特生态系统中乔木和灌木林根际土壤微生物生物量及其多样性的比较

我国喀斯特区域面积分布较广,而喀斯特生态系统的退化已成为当前西南地区面临的严重的生态问题。本研究选取贵州中部两种不同植被类型的生态系统—乔木林和灌木林,以乔木林中的白栎、园果化香和灌木林中的火棘、竹叶椒等主要优势树种为对象,研究不同的植物树种对根际土壤微生物生物量及其细菌群落结构的影响。结果显示:乔木林系统中根际土壤微生物生物量碳、氮显著性高于灌木林,植物的根际效应在乔木林中表现更为显著;同时乔木林中的优势树种通过根系分泌物的作用显著提高根际土壤细菌多样性指数,而灌木林中优势树种的根际土壤微生物量及多样性均未表现出明显的根际效应。因此,植被的演替通过改变土壤微生物的特性影响植物-微生物-土壤之间的物质和能量循环,进一步影响喀斯特生态系统的稳定和健康功能。     

Density, structure, and diversity of the cultivable arylsulfatase-producing bacterial community in the rhizosphere of field-grown rape and barley

In this study we investigated the arylsulfatase-producing bacterial community (ARS-BC) in the rhizosphere soils of field-grown rape in comparison with that of barley. For this, the rhizosphere soils from both plant species were sampled four times during plant growth. Soil arylsulfatase (ARS) activity and the density and the structure of the cultivable ARS-BC on M9-Xsulf medium were then determined. ARS activity in rape rhizosphere was greater than in barley rhizosphere and evolved along the phenology in the two rhizosphere soils. In parallel, the average density of ARS-BC in the rape rhizosphere was higher than that in the barley rhizosphere. Moreover, ARS activity is correlated with ARS-BC density both in rape and barley rhizosphere soils. The structure of the ARS-BC in the rape rhizosphere was different from that in the barley rhizosphere. In the rape rhizosphere, the ARS-BC was substantially more structured than in the barley rhizosphere. Among the ARS-BC, Actinobacteria and Pseudomonads were significantly present in the both rhizosphere soils. Actinobacteria predominated in the barley rhizosphere while Pseudomonads were mostly represented under rape. It is possible that the differences in ARS activity observed between rape and barley can be attributed to a different ARS-BC size and/or a different ARS-BC structure under these two plant covers. This impact of rape may be connected to a selective effect of rhizodeposits released by rape roots to the functional bacterial community. Our findings suggest that plant species, via their rhizodeposits, may affect the functional bacterial community and thus influence the dynamic of S in soil.     

Growth measurements of saprotrophic fungi and bacteria reveal differences between canopy and forest floor soils

Canopy-held organic matter develops into a distinct soil system separate from the forest floor in wet temperate coniferous forests, creating a natural microcosm. We distinguished between fungal and bacterial components of the decomposer community in one site with Maple (Acer macrophyllum) and one site with Alder (Alnus rubra) by using direct measurements of growth; acetate incorporation into ergosterol, and leucine incorporation for fungi and bacteria, respectively. The higher organic matter content of the canopy soils correlated with higher fungal growth. The relative importance of fungi, indicated by fungal:bacterial growth ratio, was higher in the canopy soil of the Maple site, while there was no difference in the Alder site. The high C:N ratio of the Maple canopy soil likely contributed to this difference. These results demonstrate a divergence between canopy and forest floor that should be explored to gain insights in decomposer ecology using the natural microcosms that the canopy soils provide.