南繁区稻瘟病菌遗传多样性和群体遗传结构的AFLP分析

【目的】为了明确南繁区稻瘟病菌(Magnaporthe oryzae)的遗传分化情况,【方法】采用AFLP分子标记技术对南繁核心区(三亚、乐东和保亭)和非核心区(琼中、屯昌和定安)共60个稻瘟病菌菌株的遗传多样性和群体遗传结构进行了比较分析。【结果】聚类分析表明,几乎所有菌株都聚在同一个谱系里,并且该谱系没有明显的亚群;群体遗传结构分析表明,核心区群体的多态性位点百分率、Shannon信息指数和基因流分别为87.89%、0.2738和4.2897,高于非核心区群体的81.37%、0.2703和3.5892;然而,核心区群体的Nei基因多样性指数和基因分化系数分别为0.1657和0.1044,低于非核心区群体的0.1662和0.1223。【结论】这些结果表明核心区和非核心区菌株都存在丰富的遗传多样性,不同群体间均存在较多的基因交流,但遗传变异均主要来自群体内;相比之下,核心区菌株的遗传多样性和遗传分化程度较高。     

terraGIS – a web GIS for delivery of digital soil maps in cotton‐growing areas of Australia

Effective management of soil requires the spatial distribution of its various physical, chemical and hydrological properties. This is because properties, for example clay content, determine the ability of soil to hold cations and retain water. However, data acquisition is labour intensive and time‐consuming. To add value to the limited soil data, remote sensing (e.g. airborne gamma‐ray spectrometry) and proximal sensing, such as electromagnetic (EM) induction, are being used as ancillary data. Here, we provide examples of developing Digital Soil Maps (DSM) of soil physical, chemical and hydrological properties, for seven cotton‐growing areas of southeastern Australia, by coupling soil data with remote and proximal sensed ancillary data. A greater challenge is how to get these DSM to a stakeholder in a way that is useful for practical soil use and management. This study describes how we facilitate access to the DSMs, using a simple‐to‐use web GIS platform, called terraGIS. The platform is underpinned by Google Maps API, which is an open‐source development environment for building spatially enabled Internet applications. In conclusion, we consider that terraGIS and the supporting information, available on the sister web page ( http://www.terragis.bees.unsw.edu.au/ ), allow easy access to explanation of DSM of soil properties, which are relevant to cotton growers, farm managers, consultants, extension staff, researchers, state and federal government agency personnel and policy analysts. Future work should be aimed at developing error budget maps to identify where additional soil and/or ancillary data is required to improve the accuracy of the DSMs.     

熟石灰施用对土壤pH及附子生长发育的影响

[目的]明确熟石灰对附子地酸性土壤的改良作用以及对附子生长发育的影响。[方法]开展盆栽试验研究熟石灰不同施用量对土壤pH、附子生长发育及产量的影响。[结果]不同熟石灰处理(1 350、1 800、2 250 kg/hm~2)均可显著提高土壤pH(P0.05),且不同程度地促进附子出苗、抽茎;中、低用量熟石灰(1 350、1 800 kg/hm~2)能促进附子株高,而高用量(2 250 kg/hm~2)则抑制植株生长;所有处理对附子苗期展叶数均无显著影响;熟石灰用量为1 800 kg/hm~2能提高单株附子产量,而用量为2 250 kg/hm~2能提高附子成活率,促进附子总产量提高。[结论]一定用量的熟石灰能有效调节酸性土壤pH,促进附子生长发育并提高产量。     

Growth and yield responses of upland NERICAs to variable water management under field conditions

This study aimed to investigate the possible causes for inconsistent performances of upland New Rice for Africa (NERICA) varieties in uplands and lowlands, while identifying important determinants in grain yield under deficient soil moisture. We compared the growth and yield of NERICA 1 and NERICA 5 to those of Yumenohatamochi, a Japanese upland variety, and Hinohikari, a Japanese lowland variety, subjected to different water management regimes (continually flooded, supplementary irrigation, and non-irrigation). Under conditions of deficient soil moisture, panicle number per square meter, spikelet number per panicle, and 1000-grain weight of NERICAs decreased, whereas the panicle number of the Japanese varieties experienced little change. In contrast, the grain filling ratio was unaffected by water management, irrespective of variety. The primary source of yield reduction under low soil water conditions was a decrease in spikelet number per panicle, and water stress intensity was the primary factor for the degree of this reduction. Variation in the abortion of secondary rachis-branches caused differences between NERICAs in their spikelet number response to soil moisture deficiency. The inconsistency in NERICA performance across uplands vs. lowlands can be partially attributed to variation in yield response to low soil water conditions. Moreover, water stress intensity and the presence of a water gradient along the vertical soil profile may combine to affect the fluctuation in NERICA performance under upland conditions.     

Exploring connectivity between spawning and nursery areas of Mullus barbatus (L., 1758) in the Mediterranean through a dispersal model

Connectivity between spawning and nursery areas plays a major role in determining the spatial structure of fish populations and the boundaries of stock units. Here, the potential effects of surface current on a red mullet population in the Central Mediterranean were simulated using a physical oceanographic model. Red mullet larvae were represented as Lagrangian drifters released in known spawning areas of the Strait of Sicily (SoS), which represents one of the most productive demersal fishing‐grounds of the Mediterranean. To consider the effect of inter‐annual variability of oceanographic patterns, numerical simulations were performed for the spawning seasons from 1999 to 2012. The main goal was to explore connectivity between population subunits, in terms of spawning and nursery areas, inhabiting the northern (Sicilian‐Maltese) and southern (African) continental shelves of the SoS. The numerical simulations revealed a certain degree of connectivity between the Sicilian–Maltese and the African sides of the SoS. Connectivity is present in both directions, but it is stronger from the Sicilian–Maltese spawning areas to the African nurseries owing to the marine circulation features of the region. However, because the majority of the larvae are transported to areas unsuitable for settlement or outside the SoS, the dispersal process is characterized by a strong loss of potential settlers born in the spawning areas. These results are in agreement with the low genetic heterogeneity reported for this species in the Mediterranean Sea and support the existence of a metapopulation structure of red mullet in the SoS and the adjacent areas.     

五指山耕地土壤养分现状调查与评价

为了明确海南山区耕地土壤养分空间分布特征，为热带山区耕地土壤养分管理提供思路。以海南五指山市耕地为研究对象，采用野外调查、采样和室内分析相结合的方法，阐述土壤养分现状，探讨其土壤养分分布规律。结果表明：五指山耕地土壤总体呈酸性，其pH值为5.1；土壤有机质、有效磷、速效钾和中量元素(钙、镁、硫)含量均为中等或偏下水平，土壤有效铜和有效锌含量较为丰富。五指山耕地土壤酸化和养分含量分布不均主要与气候、母质分布和施肥不平衡有关。     

外源溶磷菌对不同土壤条件下大豆生长特性的影响

为了明确溶磷菌在多种土壤中的应用效果,探讨了两株溶磷菌对黑土及盐碱土种植大豆的促生效应。采用盆栽试验分析了不同处理对大豆光合作用、渗透调节物质含量、生物量、氮磷吸收及产量的影响。结果表明:加菌处理可增加植株Pn,显著降低R6、R8两时期叶片可溶性蛋白、可溶性糖及游离氨基酸含量,增加R2~R8时期大豆株高和根干重,混合土壤中加菌处理也可提高植株地上部分氮、磷及植株全磷、全氮含量。添加wj1和混合菌处理的植株干重优于添加wj3的处理。黑土加混合菌可显著提高大豆R2期叶片WUE,增加V3、R2和R8这3个时期大豆地上、地下部分氮、磷及植株全氮、全磷的含量。黑土加wj1与混合土壤加菌处理的大豆株荚数、总粒数、单株粒重及百粒重均高于未加菌处理。添加外源溶磷菌,对黑土及盐碱土栽培大豆均有不同程度的促生效果,能明显增强大豆在混合盐碱土壤中的适应性,增加植株生物量、氮磷吸收量和产量,且混合菌处理对大豆的促生效应优于wj1及wj3单一菌株处理。     

黔东南州天柱县植烟土壤保育与改良研究

植烟土壤是确保烤烟优质高产的关键因素之一,通过对天柱县植烟土壤烟田基本情况、土壤退化情况、土壤保育与改良情况、土地整理情况等进行调查,结果表明:该烟区地块比较破碎,有便利的排水条件或健全的排水设施,无洪涝灾害的烟田面积为420.00 hm~2,占63.0%;土壤板结发生面积为136.00 hm~2,占基本烟田的20.4%;有机质含量下降发生面积为208 hm~2,占基本烟田的31.2%;水土流失发生面积为169.33 hm~2,占基本烟田的25.4%。为此,应采取土壤改良措施,以促进天柱特色优质烤烟的发展。     

茶树GGPS基因家族的克隆、生物信息学和表达分析

牻牛儿基牻牛儿基焦磷酸合酶(Geranylgeranyl diphosphate synthase,GGPS)是萜类合成途径的结构酶,对植物生长发育具有重要意义。本研究通过RACE和RT-PCR方法克隆得到5条潜在的茶树GGPS序列,分别命名为CsGGPS1-4和CsGGPS9,其中CsGGPS9存在3条等位基因,分别是CsGGPS9-1、CsGGPS9-2和CsGGPS9-3,在系统进化树上与其他基因分成两支。蛋白质序列分析表明,茶树GGPS家族成员都具有polyprenyl_synt结构域,不存在信号肽序列。亚细胞定位预测结果显示,CsGGPS1、CsGGPS2和CsGGPS4定位在叶绿体上,CsGGPS3和CsGGPS9定位在线粒体上。通过Swiss Model进行三维建模,结合"three-floor"模型对茶树GGPS家族成员的功能进行预测,预测结果显示,CsGGPS1、CsGGPS2和CsGGPS4是GGPS;CsGGPS3是异源二聚体形式的牻牛儿基焦磷酸合酶的小亚基;CsGGPS9的催化主产物是碳链数大于30的异戊烯基焦磷酸。q RT-PCR分析表明,CsGGPS1整体表达丰度较低,仅在一芽二叶中表达量稍高;CsGGPS2在茶树各个组织中均有表达,在花中表达量最高,且花发育过程中表达量先上升后下降;CsGGPS3在叶和幼根中的表达量高于花,花发育过程中表达平稳;CsGGPS4在茶树各个组织中表达量数值相近,在花发育过程中表达量变化趋势与CsGGPS2相同;CsGGPS9的表达量在成熟叶中显著低于幼嫩叶片。     

土壤有机碳对沼渣或牛粪施用后温室气体排放潜力的影响—盆栽试验结果

A change in the European Union energy policy has markedly promoted the expansion of biogas production.Consequently,large amounts of nutrient-rich residues are being used as organic fertilizers.In this study,a pot experiment was conducted to simulate the high-risk situation of enhanced greenhouse gas (GHG) emissions following organic fertilizer application in energy maize cultivation.We hypothesized that cattle slurry application enhanced CO2 and N2O fluxes compared to biogas digestate because of the overall higher carbon (C) and nitrogen (N) input,and that higher levels of CO2 and N2O emissions could be expected by increasing soil organic C (SOC) and N contents.Biogas digestate and cattle slurry,at a rate of 150 kg NH4+-N ha-1,were incorporated into 3 soil types with low,medium,and high SOC contents (Cambisol,Mollic Gleysol,and Sapric Histosol,termed Clow,Cmedium,and Chigh,respectively).The GHG exchange (CO2,CH4,and N2O) was measured on 5 replicates over a period of 22 d using the closed chamber technique.The application of cattle slurry resulted in significantly higher CO2 and N2O fluxes compared to the application of biogas digestate.No differences were observed in CH4 exchange,which was close to zero for all treatments.Significantly higher CO2 emissions were observed in Chigh compared to the other two soil types,whereas the highest N2O emissions were observed in Cmedium.Thus,the results demonstrate the importance of soil type-adapted fertilization with respect to changing soil physical and environmental conditions.