7个橡胶树品系树皮结构与农艺性状相关性研究

以我国自主选育的热试662、热试419等7个开割无性系为试材,采用石蜡切片技术,观测树皮乳管列数目、厚度等乳管分化特征参数,分析上述参数与胶乳产量、茎围等主要农艺性状的相关性。结果如下:1)7个品系中,石细胞以内的次生韧皮部厚度与茎围,再生皮的厚度呈正相关。2)胶乳产量与石细胞以内的次生乳管列数目,树皮中的次生乳管列数目与树皮总厚度的比值呈正相关;其中,热试419树皮结构的次生乳管列数目与树皮结构的总厚度的比值明显高于其他品系,次生乳管的总列数最多,乳管分化能力较强,且胶乳产量最高。3)热试9359和RRIM600次生乳管的分化能力较强,产胶潜力大。该实验结果为以树皮乳管分化指标辅助评价主要农艺性状提供了参考,也为参试品系割胶技术的开发提供了依据。     

肉桂和同源根皮不同极性部位的成分分析及其抑菌效果

以肉桂及其同源根皮为原料,采用80%乙醇分别对两者进行回流提取,经系统溶剂法萃取得到两者的石油醚部位、乙酸乙酯部位、正丁醇部位和水部位,并采用滤纸片法研究各极性部位对常见的3种致病菌(金黄色葡萄球菌、大肠杆菌、绿脓杆菌)的抑菌活性。研究结果表明:相同质量的肉桂和根皮提取得到的各极性部位的质量、成分种类及含量均有所差异,其中石油醚部位所含成分大致相同,但主要成分反式肉桂醛、邻甲氧基肉桂醛含量差异较大;两者乙酸乙酯部位、正丁醇部位和水部位分别含有黄酮类,皂苷类和多糖类成分;此外根皮乙酸乙酯部位还含有邻甲氧基肉桂醛、乙酸肉桂酯,根皮水部位含有D-半乳糖。肉桂石油醚部位、根皮石油醚部位、根皮乙酸乙酯部位对3种菌均有一定的抑制作用,当这3个部位的质量浓度均为500 g/L时,对金黄色葡萄球菌、大肠杆菌、绿脓杆菌的抑菌圈直径分别大于(17.62±0.22)、(25.21±2.09)和(12.82±0.30)mm,肉桂乙酸乙酯部位抑菌作用较弱,肉桂和根皮正丁醇部位和水部位对3种供试菌种均无抑制作用。     

The importance of host characteristics and canopy openness for pest management in urban forests

Urban forests are important for the health of cities. These forests face high anthropogenic pressure, including demands on their multi-functional role. Therefore, the impact of pests-induced disturbances may be greater for urban forests than forests outside of cities. Monitoring of pests in their native environment is an important tool for the management of urban forests. To better understand how pest population density is affected by the forest environment, we used the Oak bark beetle, Scolytus intricatus, as a model organism. The study was carried out in 2014–2015 in the urban forests of Pardubice City, Czech Republic. Pest population density was studied at three levels: branch, tree and patch. The increasing branch diameter was identified as an important variable with a threshold of 70 mm for entrance holes and 45 mm for emergence holes. Increasing host tree diameter at breast height with a threshold of 46.8 cm was statistically significant at the tree level in terms of the number of entrance holes. Increasing spring canopy openness was identified as an important variable at the patch level with a threshold of 50.78% and had a decreasing trend for the number of reared adults and their total body size. Big oak trees with thick branches under closed spring canopy are the most susceptible to attack by S. intricatus. Based on our findings, we propose that the maintenance of mature oaks under open canopies is important for urban forest management. Avoiding mixed plantings of oaks and conifers should promote these open canopies and lead to multiple advantages regarding oak silviculture.     

生态因子在马铃薯甲虫地理分布中的作用

本文依据已有的研究,通过探讨马铃薯甲虫Ｌｅｐｔｉｎｏｔａｒｓａ ｄｅｃｅｍｌｉｎｅａｔａ地理分布与各种生态因子之间的相互关系,阐述了马铃薯甲虫地理分布主要是由气候和寄主综合作用决定的,热量因子决定了该虫在纬度上的分布,寄主在其南界形成中起一定作用,而滞育是其适应气候和寄主季节性变化的最主要机制。     

Antioxidant and anti‐inflammatory activities of Pinus radiata bark extract in salmonid cell lines

A fish meal supply shortage is limiting aquaculture development. Currently, plant‐based proteins, such as soya bean meal, are being used as an alternative protein source, despite that such a diet can adversely affect fish, such as by inducing an inflammatory response. A possible solution is to include dietary additives in farm diets to counteract negative effects. One such solution originates from pine bark extracts, which present bioactive properties. In this study, the antioxidant and anti‐inflammatory properties of Pinus radiata bark extracts were evaluated for the first time in a salmonid cell line. This extract chemically demonstrated antioxidant activity through 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH = 58.4 ± 1.1%) and ferric ion reducing antioxidant power (FRAP = 575 ± 17 mgEqFe(II)·g extract^?1) assays. Additionally, the extract showed high flavonoid and phenolic compound contents. Up to 100 mg mL^?1, the P. radiata extract showed no cytotoxicity in the CHSE‐214 salmonid embryo cell line. Moreover, the antioxidant activity of the extract (50 μg mL^?1) was evaluated by a dichlorofluorescein (DCFH) assay in the SHK‐1 salmon cell line challenged with an oxidant stimulus (H₂O₂), showing 58.9% activity. The extract also protected DNA from oxidative damage, as observed through a comet assay. When assessing anti‐inflammatory properties in an in vitro inflammation model, the extract significantly reduced the relative expression of the pro‐inflammatory cytokines interleukin‐1β (IL‐1β), tumour necrosis factor‐α (TNF‐α) and interleukin‐8 (IL‐8) and of the inducible cyclooxygenase‐2 (COX‐2) enzyme. These results suggest a potential application of P. radiata bark extract in functional foods in aquaculture.     

Molecular detection of insecticide resistant alleles

The summary discusses techniques used to investigate mechanisms of resistance in the Colorado potato beetle (Leptinotarsa decemlineata) to several classes of pesticides.     

基于遥感温度植被干旱指数的小蠹虫害预警

针对小蠹虫对森林的危害隐蔽强,症状滞后性明显,在其早期发生时进行遥感识别非常困难。该文基于干旱和虫害存在一定的时滞相关性的假设,提出基于温度植被干旱指数(temperature vegetation dryness index,TVDI)预报小蠹危害的方法。以遭受大面积连续干旱和小蠹危害的云南省中部的石林县为案例区,利用Landsat数据,建立归一化植被指数(normalized difference vegetation index,NDVI)-地表温度(land surface temperature,Ts)特征空间,估算逐像元TVDI。基于地面小班调查的虫害等级数据(健康、轻度、中度和重度4个等级),比较不同虫害等级斑块TVDI差异。同时,以持续干旱2011年轻度受害区为例,结合受害前后云南松林NDVI差值(difference of NDVI before and after the forest attacked by bark beetles,d NDVI)表征实际受害程度的方法,建立TVDI与d NDVI的关系,对2012年进行预测。结果表明,2010-2015年,受害区整体呈下降趋势,TVDI由西向东逐渐变大。健康云南松林TVDI显著高于虫害云南松林(P0.05),且虫害越严重,TVDI越小;2011年,TVDI与d NDVI呈显著负相关(P0.05),可以用线性模型进行拟合,拟合决定系数R2为0.322。采用模型对2012年实际发生情况进行预测,得到预测与实测d NDVI均方根误差RMSE为0.237。在整体干旱的环境下,相对湿润的地方小蠹虫害更严重。因此,可以根据TVDI空间分布特征,找出TVDI相对较小的区域,作为虫害可能发生的重点关注区域,该研究对及时发布虫情监测信息有建设性的意义。     

当归麻口病防治农药组合筛选

在当归主产区甘肃省岷县闾井镇草地村,开展了当归麻口病的发生率调查及其不同药剂组合的筛选试验。结果表明,引起当归麻口病的腐烂茎线虫在0~5cm土层中虫口密度最大,占总虫数的57.12%;不同农药组合对当归麻口病都有一定的防效,其中53.8%的氢氧化铜水分散粒剂+3%阿维菌素乳油复配剂1 000倍液的防治效果最好,防效达到73.56%;当归产量比对照增加了3 076.54kg/hm~2,增产率达29.4%,建议在当归主产区大面积推广应用。     

一种测定巴西橡胶树树皮中过氧化氢含量的方法

研究植物体内 H2O2 的含量变化有助于确认植物提高非生物胁迫耐性的生物技术策略。Ti(Ⅳ)-PAR-H2O2 比色法灵敏度高、特异性强、稳定性好,广泛用于植物 H2O2 测定,但不同研究所用的反应条件不一致。在本研究中,系统优化了 Ti(Ⅳ)-PAR-H2O2 比色法的反应条件,并比较了丙酮提取法和 TCA 提取法对橡胶树萌条韧皮部 H2O2 的提取效果。结果表明,丙酮提取法稳定性差,TCA 提取法稳定性好。本研究报道了一种简单、快速的测定橡胶树树皮 H2O2 的方法,为进一步研究橡胶树中 H2O2 的生理功能打下良好基础。