稻株拒食活性成分提取方法的改进及提取物对白背飞虱的拒食作用

采用“丁醇法”和“改进丁醇法”提取了抗白背飞虱品种Ｒａｔｈｕ Ｈｅｅｎａｔｉ（ＲＨ１）和感虫对照品种ＴＮ１稻株内的拒食活性成分，在提取液中添加１０％蔗糖和０．５％谷氨酸后测定了对白背飞虱取食行为的影响。白背飞虱在丁醇萃取前的ＲＨＴ提取液上的取食量明显低于萃取后的ＲＨＴ提取液；而在萃取前、后的ＴＮ１提取液中的取食没有显著的差异。由此推测，抗虫品种ＲＨＴ稻株里含有某种对白背飞虱具有拒食作用的活性成分。     

拟水狼蛛对白背飞虱的功能反应和干扰反应

为在白背飞虱Sogatella furcifera(Hovarth)种群动态模拟模型中考虑捕食性天敌的作用,我们于1986年7～8月在实验室条件下研究了拟水狼蛛Pirata subpiraticus雌成蛛对白背飞虱雌成虫和五龄若虫的功能反应(白背飞虱密度为5、10、15、30、60)和对自身密度(1、2、4、8、16)的干扰反应(供给白背飞虱雌成虫20只)。     

我国专家破解水稻抗虫世界难题

60000万 国家杂交水稻重点实验室（武汉大学）朱英国院士团队近日发布新的研究成果：所选育的“红莲型新不育系珞红4A”,对水稻危害最严重的害虫之一褐飞虱具有显著抗性。     

浅谈水稻条纹叶枯病的防治技术

水稻条纹叶枯病是一种病毒性病害,由灰飞虱传播的水稻纤细病毒Tenuivirus侵染引起,近几年在我国北方水稻产区有加重的趋势,应加以重视。通过对其发病症状及发生的原因的研究,提出了相应的防治对策。     

晚稻第五代褐飞虱发生程度的主成分分析

采用主成分分析法对浦江县病虫测报站１９７４～１９９４年褐飞虱发生的有关历史资料进行了分析．结果表明，前６个主成分的累计方差贡献率达８９．５９９％，超过８５％．７月份降雨量、平均最高气温、大雨频数及晚稻前期田间虫量是影响浦江县晚稻第五代褐飞虱发生程度的主要因子     

褐稻虱生物型监测技术的研究

研究及评价了褐稻虱Nilaparvata lugens Stal生物型的不同监测技术,系统地监测了海南、广西和浙江不同田间褐稻虱种群的生物型变化.结果表明,褐稻虱存活率监测法比苗期致害性监测法更直接、敏感;取食频次法能测定群体内各生物型的相对比例,这尤其适合于生物型混合种群的监测;褐稻虱酯酶同工酶差异也是衡量生物型变化的指标之一.自1989年始,以上褐稻虱各种群已由生物型1向生物型2转变,但不同种群内各生物型的比例有一定的差异.本文也重点指出,品种IR26作为鉴别生物型2的品种比品种Mudgo更加合理.     

高效抗虫转基因水稻的研究与开发

植物转基因技术为培育高效抗虫水稻新品种开辟了新的途径。豇豆胰蛋白酶抑制剂 (CpTI)基因是一种广谱抗虫基因 ,该成果采用最新研究策略 ,对该基因进行体外修饰 ,使其转译产物最终定位于细胞的内质网中 ,以增加外源抗虫物质的稳定性。实验证明 ,转修饰cpti基因的植物无论是抗虫蛋白含量还是抗虫能力均比转野生型cpti基因植物有显著的提高。已获大量转基因水稻株系 ,包括著名水稻恢复系明恢 81和明恢 86,并用其配制了杂交组合。转基因抗虫杂交水稻已获国家有关部门批准进行中间试验和环境释放 ,大田试验结果表明 ,转基因杂交水稻具有优良的抗虫特性和广阔的应用前景。     

白背飞虱Sogatella furcifera(Horvath)种群系统的主分量分析

白背飞虱Sogatella furcifera(Horvath)是目前水稻的主要害虫之一,研究此虫发生、猖獗的生态因素对综合治理水稻害虫具有重要意义。本文应用主分量分析(PCA)方法,分析1984年作者等在南京农业大学江浦实验农场的田间调查数据,探索白背飞虱种群系统的状态变量及影响种群数量的主要因子。田间调查于1984年7月至8月在两块单季杂交稻(汕优6号)田进行,3天查1次。方法参照[6];温度、雨量、相对湿度取自当地气象资料,为调查间隙3日平均值。将时间、长翅型雌、雄虫、短翅型雌和雄虫、卵、一至五龄若虫、蜘蛛、隐翅虫、步甲、     

稻田生态系统中飞虱,叶蝉及其天敌的种群动态和相互关系

系统研究了稻田和稻田周围非稻田生境中飞虱、叶蝉和寄生性天敌的种类、分布及其相对丰盛度，并阐明了不同生境间同翅目寄主和天敌的相互关系．稻飞虱和稻叶蝉在非稻田生境中的数量很低，然稻田重要卵寄生蜂Ａｎａｇｒｕｓｓｐｐ．Ｏｌｉｇｏｓｉｔａｓｐｐ．和Ｇｏｎａｔｏｃｅｒｕｓｓｐｐ．在非稻田生境中的平均密度很高．多样性指数低的植被上存在更多的飞虱和叶蝉，同时也保存了许多寄生性天敌．水稻移栽后稻田中节肢动物的数量逐渐上升，至第四周趋于稳定     

水稻黑条矮缩病季节性流行规律及灰稻虱带毒率估测模型研究

根据1998～2000年对临海等地水稻黑条矮缩病季节性发病流行及灰稻虱种群数量相长调查研究结果,阐述了水稻黑条矮缩病季节性流行规律,分析了灰稻虱带毒率与水稻黑条矮缩病发病关系,组建了灰稻虱带毒率估测模型,并应用此模型开展水稻黑条矮缩病中长期灾变趋势预测,测报吻合度达98.63%。     

Ultrabithorax is a key regulator for the dimorphism of wings,a main cause for the outbreak of planthoppers in rice

Rice planthoppers, the most devastating rice pests, occur in two wing forms: the short-wing form for rapid population growth and long-wing form for long-distance migration, which together create the mechanism for outbreak. Here we show that Ultrabithorax (Ubx) is a key regulator for switching between the long- and short-wing forms of rice planthoppers. Ubx is expressed in both forewing and hindwing pads, which is different from the canonical model of Ubx expression. In brown planthoppers, expression of Ubx (NlUbx) is regulated by nutritional status of the rice host. High-quality young plants induce NlUbx expression leading to the short-wing form; low-quality ripe plants reduce NlUbx expression resulting in long-wing form. We also showed that NlUbx is regulated by the insulin receptors NlInR1 and NlInR2. The default expression of NlInR1 inhibits NlUbx resulting in long-wings, while high-quality hosts induce NlInR2 expression, which represses NlInR1 thus promoting NlUbx expression to produce short-wings.     

大麦耐非生物胁迫相关分子标记研究进展

综述分子标记在大麦耐非生物胁迫研究中的应用及其研究进展,包括发育基因效应、野生种或地方种的变异、遗传(QTLs)图谱等。现代引种和育种过程引起物种的遗传变异趋于狭窄、多样性减少,由此可能加重疾病、害虫和非生物胁迫等危害的潜在威胁。发育基因对环境胁迫具有较强的多态性效应;野生大麦和原始地方种为提高耐胁迫性提供了丰富的遗传变异资源。大麦遗传多样性的分离鉴定、遗传图谱构建、及数量性状位点(QTL)分析和分子标记辅助选择,将有助于更好地利用野生种质优良抗性,更有效的选择耐(抗)性基因型。文末从正反两方面简要讨论了分子标记在大麦耐非生物胁迫遗传育种研究中作用。     

Analysis of gene expression profiles in response to Sporisorium reilianum f. sp. zeae in maize (Zea mays L.)

BackgroundHead smut of maize, which is caused by Sporisorium reilianum f. sp. zeae (Kühn), is a serious disease in maize. In order to reveal the molecular mechanism of the resistance to head smut in maize, a microarray containing ∼ 14,850 probes was used to monitor the gene expression profiles between a disease resistant near isogenic line (NIL) and a highly susceptible inbred line after S. reilianum was injected with an artificial inoculation method.ResultsLevels of expression for 3,532 genes accounting for 23.8% of the total probes changed after inoculation. Gene Ontology analysis revealed that the differentially expressed genes participated in physiological and biochemical pathways. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that plant–pathogen interaction, natural killer cell mediated cytotoxicity and benzoxazinoid biosynthesis pathways play important roles in resistance to head smut. Three head smut resistance-related candidate genes, CLAVATA1, bassinosteroid insensitive 1-associated receptor kinase 1 and LOC100217307 with leucine-rich repeat (LRR) conserved domains were identified, each of which is in maize mapping bin 2.09, a region previously shown to include a major QTL for head smut resistance. Furthermore, LOC100217307 was validated by quantitative real-time (qRT)-PCR inferring that this gene may be involved in the resistance to head smut of maize.ConclusionsThis study provided valuable information for cloning, functional analysis and marker assisted breeding of head smut resistance genes.     

One-step,codominant detection of imidazolinone resistance mutations in weedy rice (Oryza sativa L.)

BackgroundWeedy rice (Oryza sativa L.) is a noxious form of cultivated rice (O. sativa L.) associated with intensive rice production and dry seeding. A cost-efficient strategy to control this weed is the Clearfield rice production system, which combines imidazolinone herbicides with mutant imidazolinone-resistant rice varieties. However, imidazolinone resistance mutations can be introgressed in weedy rice populations by natural outcrossing, reducing the life span of the Clearfield technology. Timely and accurate detection of imidazolinone resistance mutations in weedy rice may contribute to avoiding the multiplication and dispersion of resistant weeds and to protect the Clearfield system. Thus, highly sensitive and specific methods with high throughput and low cost are needed. KBioscience’s Allele Specific PCR (KASP) is a codominant, competitive allele-specific PCR-based genotyping method. KASP enables both alleles to be detected in a single reaction in a closed-tube format. The aim of this work is to assess the suitability and validity of the KASP method for detection in weedy rice of the three imidazolinone resistance mutations reported to date in rice.ResultsValidation was carried out by determining the analytical performance of the new method and comparing it with conventional allele-specific PCR, when genotyping sets of cultivated and weedy rice samples. The conventional technique had a specificity of 0.97 and a sensibility of 0.95, whereas for the KASP method, both parameters were 1.00.ConclusionsThe new method has equal accuracy while being more informative and saving time and resources compared with conventional methods, which make it suitable for monitoring imidazolinone-resistant weedy rice in Clearfield rice fields.     

Resisting insects: shifting strategies in chemical control

Throughout the 20th century, scientists developed a variety of chemical compounds to kill insects and other menaces of agriculture and public health. Yet, in many cases, the target insects outmaneuvered the scientists by developing resistance to insecticides--in much the same way as some bacteria can tolerate antibiotics. Insecticide resistance research has involved scientists from a range of disciplines and a variety of institutional contexts that have often guided research strategy. For example, entomologists working at agricultural stations and universities concentrated on insect physiology and evolutionary genetics, while industrial chemists continued the development of novel compounds capable of killing resistant pests. Collaboration between the two groups beginning in the 1940s did not provide a solution to the resistance, but did lead to a strategic shift from pest control to pest management that continues to the present.     

有机物料对高产稻区土壤肥力影响的研究

对高产稻区土壤在氮、磷、钾化肥高水平施用条件下,投入有机物料后对土壤肥力及其产量的影响作了探讨.研究结果表明:增添有机物料后不仅使土壤有机质、速效磷、速效钾含量增加,而且对土壤的团聚水平、团聚度和结构稳定性、通气孔隙、水容量等的土壤物理性状有显著提高;土壤内在的自动调控性能增强,其抗逆性也增加.而单施化肥区土壤有机质略有下降,速效磷增加.速效钾却亏缺.尽管单化区土壤团聚水平、团聚度比试前土壤有所增加,但孔隙水平仍与试前土壤基本类似.所以土壤内在的自动调控性能和土壤的抗逆性均不及稻厩,麦厩区.因此在灾年(多雨)是稻厩、麦厩区产量较单化区分别高10.60％和14.23％,而在正常年景其产量却无明显差异,这可能与高水平化肥施用有关.     

生物有机肥与耕地土壤质量

有机肥的合理施用可以提高土壤肥力质量和农产品品质、增加土壤生物多样性。但有机肥中含有重金属、抗生素、激素与内分泌干扰物、病原生物、抗性菌等污染物及抗性基因的扩散, 有机肥农用可能会对土壤环境质量、健康质量及食品安全造成威胁。此外, 有机肥同化肥一样, 不合理施用也会造成土壤次生盐渍化、土壤N、P积累与淋失、增加温室气体排放等。文章综述了有机肥对土壤肥力质量、环境质量和健康质量的影响, 并对今后的研究趋势进行了展望。     

植物功能基因组研究

植物功能基因组研究是利用基因组序列的信息和高通量的系统分析技术,在基因组水平研究其结构和组织与植物功能在细胞、有机体和进化上的关系。水稻作为最重要的模式作物,应该成为我国植物功能基因组研究的主攻方向。通过建立从结构基因组学到功能基因组学,直至将功能基因组的信息和知识用于开发改良植物的完整研究体系和队伍,使我国在水稻功能基因组研究的整体水平上取得与我国头号水稻种植大国相称的地位。     

蜘蛛种群高密度是稻飞虱轻发生的重要原因

通过在2007～2009年对浙江省三门县何家村生态栽培水稻田连续3年的生态调查发现,在已连续10年不用农药的自然条件下,狼蛛、微蛛等主要天敌与稻飞虱、稻纵卷叶螟等水稻主要害虫在发生动态上存在明显的跟随效应;6～8月蜘蛛对稻飞虱的数量反应呈渐进型的对数回归关系,使得稻飞虱种群处于较低的密度平衡点,控制了稻飞虱种群数量.