全产业链视角下柳州螺蛳粉农业产业化联合体发展探析

为进一步建强、壮大柳州螺蛳粉全产业链,针对原材料生产供应短板的问题,探索由重点龙头企业牵头组建柳州螺蛳粉农业产业化联合体,带动其它涉农企业、村集体经济合作社、农民专业合作社等经营的全产业链组织经营模式.根据柳州螺蛳粉全产业链最终产品流向,研究建立了柳州螺蛳粉商超驱动和实体店驱动的农业产业化联合体两种经典模式.实践表明,...     

Characteristics for Practical Use of Attenuated Isolate UA-Fukushima of <Emphasis Type="Italic">Tomato mosaic virus</Emphasis>

L₁₁A-Fukushima (L₁₁A-F) derived from attenuated isolate LuA of Tomato mosaic virus (ToMV) has the highest ability to cross protect against virulent ToMV among LuA and its derivatives and is stably inherited. Growth, yield, fruit quality and symptom attenuation of inoculated tomato plants did not differ significantly between L₁₁A-F and L₁₁A. The infectivity of progeny viruses in tomato infected with LuA-F was less than 4% of that with virulent ToMV. From these results, L₁₁A-F appears to possess the properties necessary for practical use. To manage L₁₁A-F strictly, a PCR-based assay to detect trace contamination of virulent ToMV in L₁₁A-F preparations was established. Received 10 June 2002/ Accepted in revised form 30 October 2002     

几种杀虫剂对方翅网蝽的田间药效试验

将高效氯氰菊酯以300和450mL/hm2、阿维菌素以600和900mL/hm2和噻虫嗪以150和300g/hm2均匀喷雾,防治越冬方翅网蝽,结果表明:施药后24h后,高效氯氰菊酯平均防治效果达99.51%;噻虫嗪可湿性粉剂的平均防治效果在98.10%;阿维菌素乳油平均防治效果为71.81%。说明这3种杀虫剂对越冬方翅网蝽均有较好防治效果。     

新侵入害虫蔗扁蛾的寄主范围正在扩大

蔗扁蛾Opogona sacchari (Bojer)是一种新传入我国的重要检疫害虫,给花卉生产、园林绿化和华南的经济作物生产造成严重威胁。该虫属鳞翅目Lepidoptera,辉蛾科Hieroxestidae,扁蛾属Opogona,广谱钻蛀性贪食者,已记载的寄主植物达22科49种,其中主要包括一些名贵观赏植物如巴西木[香龙血树Dracena fragrans(L.)]、发财树和经济作物如甘蔗、香蕉等。该虫在南美巴巴多斯为害甘蔗的程度超过蔗螟Diatraea saccharalis,在非洲加那利群岛对香蕉造成毁灭性为害。因此,许多国家将其列为重要的检疫对象。我国1997年正式报道在北京发现此虫,虫源是广州北运的巴西木。笔者在广州及其附近县市的初步调查表明,该虫除主要为害巴西木和发财树外,其寄主范围已扩大至     

实蝇科昆虫转录组研究进展

实蝇科昆虫种类繁多、危害巨大、入侵能力强,倍受植物检疫与入侵生物学领域的关注。转录组代表细胞或组织内全部的RNA转录本,反映特定状态下的基因表达模式。而依赖于高通量测序技术所衍生出的转录组测序给实蝇等非模式生物的研究带来了机遇。本文在检索实蝇科昆虫转录组序列数据和文献报道的基础上,针对实蝇科昆虫转录组的测序现状和初步应用进行了分析和总结,涉及重要经济实蝇的种类鉴定、基础生理、滞育、配子形成和交配生殖、解毒机制及防治和非编码RNA共6个方面。同时,提出了加强重要经济实蝇转录组研究的3个展望:一是加强结构基因组学和功能基因组学方面的多组学结合研究;二是开展microRNA(miRNA)等非编码RNA功能方面的探索研究;三是探索第三代测序技术的应用研究。     

主要发达国家农民职业教育的兴起及发展

经过相当长时期的发展和完善,主要发达国家最终形成了具有各自特色的农民职业教育模式。从宏观上清晰勾勒了主要发达国家农民职业教育的历史发展脉络,划分其为兴起、蓬勃发展和全面繁荣三个发展阶段,并把其在不同历史阶段的发展原因、状况以及内容予以了简要概述。     

辽宁省大豆田杂草发生与危害

采用倒置"W"九点取样法调查辽宁省大豆田杂草,明确了辽宁省大豆田杂草有19科35种,其中阔叶杂草占74.29%,禾本科杂草占14.29%,其他杂草占25.71%;一年生杂草占54.29%,多年生杂草占31.43%。相对多度达10%以上的杂草依次为藜、鸭跖草、稗草、苘麻、反枝苋、红蓼、马唐、铁苋菜、马齿苋和山苦菜。其中藜和鸭跖草相对多度在30%以上,为辽宁省大豆田杂草优势种群。     

Establishment of a comprehensive indicator system for the assessment of biodiversity and ecosystem services

Context

Common indicators are needed to monitor biodiversity loss and the implications for the sustainable provision of ecosystem services (ES). A plethora of different sets of indicators may hinder the identification of major endpoints for large-scale assessments of biodiversity and ecosystem services (BES).

Objectives

We aim to describe the main challenges of indicators for BES assessment and provide suggestions for establishing a comprehensive indicator system.

Methods

An extensive literature review was conducted in this study. We review the main challenges of indicators for BES assessment and propose corresponding improvements from our perspectives of theory and practical applications.

Results

The main theoretical challenges of existing indicators include inconsistent definitions and classifications of ES, misunderstanding of linkages among biodiversity, ecosystem structure, functions and services, and practical problems relate to such issues as indicator representativeness, data availability, and uncertainty. Our suggested improvements include clarifying the main terms, concepts and classification of indicators, establishing a robust conceptual framework with clear interactions among different components and indicators, selecting indicators based on ecosystem properties, streaming existing data into one platform, and strengthening validation of proxies. The steps for constructing a comprehensive indicator system for BES assessment are summarized.

Conclusions

Clear definitions of key terms are indispensable to classify indicators and construct a conceptual framework. Improved understanding of the relations among indicators of biodiversity, ecosystem functions, and ES across multiple scales can guide the development of the indicator system. The integrated indicator system is an important tool for BES assessment to support decision making for sustainable development.

     

不同种质沙棘在干旱条件下营养生长适应性的研究

在干旱条件下,不同种质沙棘的营养生长适应性差异较大,中国沙棘和杂交沙棘的营养生长适应性显著强于俄罗斯良种沙棘,后者各品种间的营养生长适应性有差异;干旱缺水是影响不同种质沙棘的主导因素,年降水量少于400mm时,无灌溉或地下潜水补给的沙棘,营养生长适应性将大受影响,造林建园时应给予充分重视。     

多堆柄锈菌潜育期侵染量实时荧光定量PCR检测体系的建立

为快速及时诊断并定量监测玉米内多堆柄锈菌Puccinia polysora潜育期的侵染量,根据多堆柄锈菌的ITS序列和玉米Actin2基因序列,分别设计多堆柄锈菌特异性引物PpoF/PpoR和Taq Man探针PpoP以及玉米特异性引物ZmF/ZmR和Taq Man探针ZmP,对引物和探针的特异性和灵敏度进行测定,并用这2对引物和探针建立多堆柄锈菌潜育期的实时荧光定量PCR检测体系,定量监测接种后玉米叶片中多堆柄锈菌DNA量随时间的变化。结果表明,多堆柄锈菌和玉米的特异性引物和探针对各自靶标片段均具有良好的特异性,灵敏度分别为10^-3ng/μL和10^-2ng/μL;在接种后24 h,利用所建实时荧光定量PCR检测体系即可在玉米叶片中检测到多堆柄锈菌,且潜育期内多堆柄锈菌的侵染量随时间呈指数增长。表明所建实时荧光定量PCR检测体系可用于多堆柄锈菌潜育期侵染量的定量检测和监测。