入侵性食叶害虫椰子织蛾的单倍型多样性分析

【目的】分析危害棕榈科Palmae植物的一种重要入侵食叶害虫椰子织蛾Opisina arenosella单倍型在原产地和入侵地的分布特点,揭示椰子织蛾入侵我国的虫源信息。【方法】利用线粒体COI基因分析16个地理种群共计172个样本,比较椰子织蛾印度种群和入侵地(中国、马来西亚和泰国)种群的遗传关系。【结果】片段长度为625 bp的172条序列共鉴定出12个单倍型,包含15个变异位点,构成2个明显的单倍型分支,其中一个分支由11个单倍型(IN1～IN11)组成,均来自印度种群,单倍型IN1是6个印度种群的共享单倍型,IN2～IN11为独享单倍型;另一个分支为单倍型HAP,由来自中国、马来西亚和泰国的种群共享;HAP与11个来自印度的单倍型IN1～IN11均存在4个变异位点。【结论】入侵地区的椰子织蛾种群来自同一基因型或者具有相同的入侵源;椰子织蛾种群入侵后受环境选择压力,在新栖息地产生新的突变或杂交。     

广西主要蔗区宿根蔗根际土壤微生物群落结构分析

探讨了广西主要蔗区宿根蔗根际土壤微生物的分布情况,结果表明：宿根蔗根际土壤微生物数量总体上表现为：细菌〉真菌〉放线菌。但宜州市和北海市土壤中真菌数量〉放线菌;崇左市土壤中真菌和放线菌相当。     

氨氮胁迫对四鼻须鲤鱼肝脏GST酶活力的影响

实验采用生态毒理学方法,以NH4Cl为实验药物,设置0、50、150和250mg/L实验浓度。通过对野生和养殖群体的四鼻须鲤鱼氨氮对肝脏谷胱甘肽巯基转移酶（GST）活力的影响,比较两个群体抗氨氮能力。结果表明：在相同的氨氮浓度和胁迫时间下,四鼻须鲤鱼养殖群体GST酶活力的变化趋势与野生群体大致相同。除250mg/L浓度组在胁迫5d和10d时,野生群体酶活性略低于养殖群体外,在其余时间点的野生群体酶活性均高于养殖群体,而且,在高浓度氨氮胁迫下,野生群体肝脏的GST酶活性达到峰值的时间比养殖群体更短,显示出较强的抗氨氮能力。     

Remedies for pseudoreplication

Pseudoreplication is the failure of a statistical analysis to properly incorporate the true structure of randomness present in the data. It has been well documented and studied in the ecological literature but has received little attention in the fisheries literature. Avoiding pseudoreplication in analyses of fisheries data can be difficult due to the complexity of the statistical procedures required. However, recent developments in statistical methodology are decreasing the extent to which pseudoreplication has to be tolerated. Seven examples are given here, beginning with simple design-based remedies and progressing to more challenging examples including the model-based remedies of mixed-effects modelling, generalized linear mixed models, state-space models, and geostatistics.     

苯乙酸促进水稻花药愈伤组织的再分化和直接成苗

 研究了苯乙酸（phenylacetic acid，PAA）应用于水稻花药培养的效果。以 2,4-D 为对照，发现PAA不影响愈伤组织诱导率，但显著提高了愈伤组织分化率（p<0. 05），从而显著提高了植株再生率（p<0. 05）。其促进效果与品种、培养基无机盐成分有关，对籼稻品种效果较好。PAA还能有效地促进花药愈伤组织不经转移到分化培养基上而直接在诱导培养基上分化成苗。直接再生的绿苗大多具有旺盛的不定根，可直接移栽到土壤中去。当PAA浓度为10 mg/L 时，特青、02428和亚优2号的直接植株再生率分别达0. 56%, 1. 64%和2. 69%。提高PAA浓度可进一步提高直接植株再生率。利用基于PAA的一步成苗培养法已构建成了3个水稻杂种花培后代加倍单倍体（DH）群体。     

小麦RIL群体遗传连锁图谱的构建及其多态性分析

以普通小麦重组近交系(recombinant inbred lines,RIL)‘Q9086×陇鉴19’为作图群体,利用SSR标记构建小麦遗传连锁图谱.结果表明:通过选用2 187对SSR引物筛选出RIL群体双亲表现多态性的引物共405对,多态性频率为18.52%.不同类型SSR标记多态性频率从小到大依次为Xpsp(4.4%)相似文献   

Comparison of sympatric freshwater turtle populations from an urbanized Sydney catchment

• 1. Australian freshwater turtles are widely distributed throughout the continent, and in each river catchment there are at least two taxa. In south‐eastern Australia Chelodina longicollis and forms of Emydura macquarii co‐habit within a waterway, although they have been shown to partition habitat within the water column in non‐urban bodies of water. Limited comparative data are available for the urban populations.
• 2. Within urban Sydney C. longicollis (eastern long‐necked turtle) and Emydura macquarii dharuk (Sydney short‐necked turtle) share habitat. However, in contrast with non‐urban studies of C. longicollis and other sympatric E. macquarii taxa, it was observed that the population profile of the two species was similar at all sites, and that C. longicollis were present in greater numbers than E. m. dharuk.
• 3. The continued degradation of preferred habitat, low recruitment, and potential competition from introduced turtles place both species in a precarious position.
• 4. The shallow, impounded waterways of the regulated urban bodies of water align more closely with the preferred habitat of C. longicollis than with that of forms of E. macquarii, which prefer deeper flowing waters or large wetlands adjacent to rivers. Emydura m. dharuk may be at greatest risk of extinction in urban areas.
• 5. Across urban Sydney, the low numbers of E. m. dharuk compared with C. longicollis may be due to the lack of mobility of E. m. dharuk such that individuals tend to be stranded in sub‐optimal habitat. In contrast, C. longicollis has a greater propensity for overland movement, and a preference for the ‘new habitat’ resulting from urban impacts on the associated waterways, and thus appears to be able to utilize these modified urban waters more successfully.

Copyright © 2008 John Wiley & Sons, Ltd.     

科尔沁沙地榆树疏林草地物种多样性及乔木种群空间格局

应用多样性指数对科尔沁沙地榆树疏林草地的物种多样性进行了研究,并用空间格局指数测定了乔木种群的分布格局。结果表明,灌木层多样性较低,而草本层物种多样性较高。在生活型功能群中,一、二年生草本处于优势地位,多年生草本具有稳定群落的效应;在生态功能群中,旱生、中生植物占有主体优势,但在群落中又存在植物功能互补效应。乔木种群的分布格局呈现出聚集分布,在其发育过程中具有不同的动态变化特征,即幼苗、幼树阶段为聚集分布,到了成树阶段为随机分布。     

稻-鸭生态系统中二化螟消长动态研究

2003年4～10月,在稻鸭共栖田中,对二化螟发生规律的系统研究结果表明,稻田养鸭能显著减轻二化螟的为害。与对照相比,中稻田养鸭区二化螟为害株率减少13.4%～47.1%;晚稻田减少62.2%。稻鸭共栖能减少化学农药的使用量,具有较好的经济、社会和生态效益。     

山东省棕榈蓟马田间种群对7种杀虫剂的抗药性

采用叶管药膜法测定了山东省4个蔬菜产区棕榈蓟马对7种杀虫剂的抗药性水平。结果表明,供试药剂毒力由大到小依次为多杀霉素甲氨基阿维菌素苯甲酸盐吡虫啉噻虫嗪吡蚜酮高效氯氟氰菊酯辛硫磷;济南、聊城和泰安地区的棕榈蓟马种群对7种药剂基本处于敏感状态,寿光地区的棕榈蓟马对多杀霉素、甲氨基阿维菌素苯甲酸盐、吡虫啉和吡蚜酮产生了6.99~10.83倍的低水平抗性。