新型软木原料栓皮槠的采剥,再生试验及理化性能研究

对栓皮槠与栓皮烁树初再生皮在采剥难易、含皮量、再生速度、再生率及其栓皮在外观、质量、化学组成的差异及地理差异等方面进行的对照试验结果表明：栓皮槠栓皮质量好，再生能力强，产皮厚，剥皮工效高，经济效益好，是优良栓皮树种，可用来改造我国的栓皮烁林。     

Contamination and browning in tissue culture of Platanus occidentalis L.

Twigs of 2–3-year-old Platanus occidentalis L. were used as experimental material to find the causes for the contamination and browning in the initial stages of tissue cultures. To compare the degree of browning of explants picked off from different growing seasons, the experimental material was excised from trees on each of the first ten days in January, March, May and July, 2006. The results indicated that the contamination and browning rates of the material cut off in January (14.2% and 30.6%, respectively) and March were somewhat lower than those in July. The pretreatment of soaking the explants in different anti-oxidants and absorbents at the same time could diminish some side effects. The pretreatment of using 10 g·L–1 vitamin C reduced the contamination and brown-ing rate effectively. An orthogonal experiment showed that the optimal factor and level arrangement is 0.5 mg·L–1 BA, 2.0 g·L–1 ac-tive carbon and 1.5 g·L–1 PVP which resulted in a browning rate of only 16.5%. In general, sampling period, physical properties and pretreatment of explants are the main factors responsible for the contamination and browning of material in the initial stages of P. occidentalis tissue cultures.     

Microclimate within beech stands—part II: thermal conditions

Within the framework of an interdisciplinary project on the effects of climate and forest management on beech-dominated deciduous forests (Swabian Jura, south-western Germany), forest meteorological investigations are carried out to analyse the influences of exposure and canopy density on the microclimate within various beech stands (Fagus sylvatica L.). This second paper of the series Microclimate within beech stands focuses on the thermal conditions that exist mainly in the near-surface layer at different test plots. They were analysed by air temperature, T_a, (at 1.5 m a.g.l) and soil temperature, T_s, at six depths measured continuously in the period 1999–2003. The main results can be summarized as follows. (1) The thermal situation within the beech stands described by T_a depended primarily on the turbulent air-mass exchange conditions which were based on the slope-specific energy balance of the forest floor and advective heat fluxes. (2) The thermal situation within the soil described by T_s at 3 and 20 cm depth was governed by the molecular heat transport. Therefore, the heating and cooling rates of T_s were always lower than for T_a. Higher T_a and T_s values for the test plots on the SW slope showed that the thermal conditions within the beech stands depended primarily on the exposure. (3) Based on slope-specific differences of daily extremes of T_a and T_s at 3 cm depth between the silviculturally treated and control plots, the influence of the more pronounced height growth of the understorey vegetation under the near-surface thermal conditions could be clearly verified for the NE slope.Abbreviations PAR Photosynthetically active radiation - PAI Plant area index - LAI Leaf area index     

筋骨草内昆虫蜕皮激素类似物对杨干象的杀虫作用

从不同地点、不同时间采集的多花筋骨草植株不同部位中提取出昆虫蜕皮激素类似物,通过向幼虫人工饲料中添加昆虫蜕皮激素类似物的方法,研究了筋骨草中植物源蜕皮激素对杨干象2龄幼虫的杀虫作用。实验结果表明:(1)在人工饲料中加入1-3 ml的筋骨草提取物,在24天内可以杀死 58%~100%的幼虫;(2)从开花前的筋骨草中提取出的物质的杀虫效果明显优于从花期和开花后的植物中提取出的物质的杀虫作用, 其1 mL、2 mL和3 mL剂量全株提取物的杀虫效果分别达到65.22%、85.07%和98.11%(幼虫校正死亡率);(3)植株的根部提取的昆虫蜕皮激素类似物的杀虫效果要比茎部或叶部提取的好,1 mL、2 mL、3 mL剂量提取物的杀虫效果分别达到100%、98.20%和98.32%;(4)筋骨草提取物的杀虫速度较慢,处理杨干象2龄幼虫16天后杀虫率才超过50%;(5)幼虫取食加有筋骨草提取物的饲料时间长短直接影响幼虫死亡率,16天的取食,幼虫死亡率达到80%以上。筋骨草采集地点和填加植物源蜕皮激素的方式对杀虫效果的影响较小。图3表3参21。     

北沟林场精品流域区华北落叶松林分结构研究

通过对北沟林场精品流域区华北落叶松林分结构进行研究,结果表明:在树种组成复杂程度上,落阔混交林大于华北落叶松纯林,而且落阔混交林的树种组成比纯林更加合理,结构更加稳定,在空间利用上也更加充分;在水平结构上,各树种直径大小分布均匀程度比较:落阔混交林大于华北落叶松纯林;在垂直结构上,落阔混交林有分层现象,但差异不明显,而华北落叶松纯林无明显分层。     

Impact of alpha-cypermethrin on honey bees foraging on spring oilseed rape (Brassica napus) flowers in field conditions

BACKGROUND: Cruciferous oil-bearing crops have gained in importance worldwide. The expansion of the growing area of these crops has caused a proliferation of pests. Exposure to organophosphate, carbamate and pyrethroid insecticides has been associated with bee poisoning in food crops. This study examines the repellent effect of alpha-cypermethrin on the number of foraging honey bees, Apis mellifera L., on fields of spring oilseed rape, Brassica napus L. var. oleifera. RESULTS: The first experiment was conducted on differently sprayed 10 m(2) experimental plots where alpha-cypermethrin was applied at different times. Another experiment was conducted on a 4 ha seed production field divided into two parts: one part was treated with alpha-cypermethrin and the other was not treated with this insecticide. The results show that there was no difference in the number of honey bees between alpha-cypermethrin-treated and untreated patches. The result persisted through three observation years, regardless of varying flower and honey bee densities. CONCLUSION: No repellent effect of the insecticide on honey bees was found even 24 h after spraying. The density of oilseed rape flowers most likely played a major role in choosing the foraging area.     

亚麻萌发期耐盐鉴定体系优化及150份种质耐盐性综合评价

【目的】 优化亚麻萌发期耐盐鉴定体系并综合评价种质资源耐盐性,为亚麻种质资源耐盐性评价及耐盐品种培育奠定基础。【方法】 选用芽长、根长和发芽率作为亚麻萌发期耐盐性鉴定的表型性状。利用13个NaCl浓度梯度胁迫处理30份亚麻种质,分析不同指标变化确定胁迫浓度。用确定的浓度对150份亚麻种质进行胁迫,分别统计相对芽长、相对根长和相对发芽率,利用隶属函数法对供试亚麻萌发期耐盐性进行综合评价,结合聚类分析划分耐盐等级。【结果】 以相对芽长或相对根长为指标时适宜的NaCl胁迫浓度为100 mmol/L,以相对发芽率为指标时适宜的NaCl胁迫浓度为220 mmol/L;150份亚麻种质分划为5个耐盐等级:高耐3份、耐盐36份、中耐67份、敏感33份、高敏11份;油用亚麻亚群中各指标均显著高于纤维亚麻和兼用亚麻。【结论】 不同耐盐指标的最适筛选浓度不同。筛选出的3份高耐亚麻种质可用于亚麻耐盐育种及后续研究。油用亚麻相比兼用和纤用亚麻更耐盐。     

半糯粳稻品种核心标记的筛选及DNA指纹图谱的构建

目的 构建一套基于水稻重要性状基因标记的品种DNA指纹鉴定体系,为加强主栽优良食味半糯粳稻品种的种质管理与品种保护奠定基础。方法 以34个江浙沪主栽优良食味半糯粳稻品种为供试材料,通过已知标记多态性鉴定、公共数据库基因序列比对、基因组重测序等多种方法对水稻重要性状调控基因的关键差异位点进行筛选,开发核心SNP或InDel标记;利用As-PCR技术将SNP标记发展为依据电泳条带鉴别的简单PCR标记,通过电泳条带特征化和类型分析获得基因型信息,构建半糯粳稻品种的DNA指纹图谱库。结果 筛选出来源于40个水稻重要性状调控基因的54个核心标记,包括18个SNP标记和36个InDel标记;54个标记在20个品种中共检测到155个有效特征化条带,转化为155个0/1数据位点,建立各品种的DNA指纹数据库,可区分全部供试品种。遗传多样性分析表明,品种间遗传相似性变异范围为0.47—0.90,其中,南粳7718与苏香粳100的相似性系数最小,而南粳9308与南粳9036的相似性系数最大,二者存在8个数据位点差异。亲缘关系分析可将供试品种划分为6个分支,其中,南粳7718为独立分支,表明其与其他品种间的亲缘关系较远。核心标记鉴定效果的进一步验证表明,该套标记可以对14个半糯粳稻新品种进行有效区分,聚类图显示其分布于Ⅱ、Ⅲ和Ⅳ 3个类群,证实各品种间基因型信息的差异性;并利用该套标记鉴定了一个未知半糯水稻的品种真实性,根据基因型和聚类分析,将其判定为南粳9108。结论 经优化筛选,获得可准确区分当前主推半糯粳稻品种的54个核心标记,并发展为可电泳检测的简单PCR标记,利用该套标记组合构建了34个江浙沪地区主栽优良食味半糯粳稻品种的DNA指纹图谱。     

三个油橄榄品种花芽分化和果实发育过程观测

为研究油橄榄在酸性土壤、夏雨型气候环境下的生长发育特征,因地制宜开展田间栽培管理提供科学依据。以中国南方3个油橄榄适生良种豆果、柯基和尼Ⅰ为材料,比较花芽分化、花期物候、花序特征、单果重和含油率差异。结果显示:3个品种的花芽分化均起始于3月上旬,豆果和尼Ⅰ初花期为5月3日,花期分别为10、6 d;柯基初花期为5月4日,花期11 d。豆果、尼Ⅰ、柯基的平均花序长度分别为2.5、2.5、2.9 cm,单个花序平均小花数量分别为16.3、14.9、17.9个。果实转色的先后次序和成熟期的早晚一致,依次为尼Ⅰ、豆果和柯基;单果重和含油率随着时间的推移均呈上升趋势,但二者增速不同,单果重在果实发育前期增长较快,含油率在果实发育后期增长较快。至10月24日果实成熟度分别达M5(尼Ⅰ和豆果)和M4(柯基),尼Ⅰ的单果重和含油率分别为3.40 g、13.05%,豆果的单果重和含油率分别为1.15 g、14.31%,柯基的单果重和含油率分别为0.77 g、12.31%。综上表明,3个品种花期基本一致,柯基的花量大、花期长,可作为授粉品种加以利用;在果实的生长发育过程中,前期应加强田间肥水管理,以确保树体处于良好的营养水平,为后期油分积累奠定物质基础,同时在梅雨季节要注意及时排水。