稻纵卷叶螟百丛虫苞密度的快速查法

采用Ｉｗａｏ的Ｍ^＊＝α＋βＸ回归式测定稻纵卷叶螟，虫苞种群的α＝０．４３３４＞０，β＝１．３１４９＞１，判定虫苞为聚集分布型；在ｔ＝１，Ｄ＝０．２时其理论抽样数为ｎ＝３５．８/Ｘ＋７．８７；利用有虫苞丛率（Ｐ）与百丛虫苞密度（Ｙ）的关系，建立Ｇｅｒｒａｒｄ模型为Ｙ＝１５７．９７６［－ｌｎ（１－Ｐ）］^{１．０６１６}，其抽样精度可达９０％以上     

番茄田二代棉铃虫发生为害规律及其防治研究

第２代棉铃虫是危害番茄最严重的世代，９５％左右的卵产在番茄植株顶尖至第４复叶层的嫩梢、嫩叶、果萼和茎基上，平均每株落卵３２．８粒。在番茄上的卵量和幼虫量与第１代蛾量密切相关，卵量（Ｙ_１）与第１代蛾量（Ｘ）关系式为：Ｙ_１＝一３１５．９＋１．７７８３Ｘ，ｎ＝６，ｒ＝０．８５６２，幼虫量（Ｙ_２）与第１代蛾量（Ｘ）关系式为：Ｙ_２＝３１．３＋０．１３４Ｘ，ｎ＝６，ｒ＝０．８６５２。在第２代棉铃虫产卵初盛期应用Ｂ.ｔ菌剂含孢子１００亿个／ｍＬ２００倍液喷雾３次，或１．８％爱福丁乳油４５ｍＬ／６６７ｍ^２对水７５ｋｇ喷雾２次，防效显著。     

双带盘瓢虫对桔蚜捕食作用的研究

在实验室条件下,对双带盘瓢虫捕食桔蚜进行了初步研究,用Ｈｏｌｉｎｇ－Ⅱ型和Ｈｏｌｉｎｇ－Ⅲ型功能反应新模型对双带盘瓢虫捕食桔蚜的作用进行拟合。结果表明,功能反应的数学模型为Ｎａ＝１．０８２０Ｎｔ１＋１．０８２０×０．０３３Ｎｔ和Ｎａ＝１３１．３４ｅｘｐ（－５０．９２Ｎｔ－１）。一头双带盘瓢虫对桔蚜的最佳寻找密度为５０．９２头。该瓢虫对桔蚜的捕食作用受自身密度的制约,相互间对捕食率存在干扰。     

水稻孕穗期稻茎毛眼水蝇经济阈值的研究

试验表明，水稻孕穗期每丛水稻茎毛眼水蝇卵数（Ｘ_１）、被害穗数（Ｘ_２）与产量损失（Ｙ）的关系符合下列方程：Ｙ＝－２．０１＋４．５２４Ｘ_１±２．２，ｒ＝０．９９１４；Ｙ＝－０．０７６＋４．９１２Ｘ_２±２．７８，ｒ＝０．９８６３。产量损失的主导因素是水稻受害后，早稻实粒数减少，晚稻总粒数和实粒数减少。根据防治费用，稻谷价格等，导出孕穗期稻茎毛眼水蝇的经济阈值为每丛禾１．９粒卵或１．３４株受害穗。经大田验证，与实际基本相符。     

水稻苗期稻茎毛眼水蝇经济阈值的研究

接虫试验表明，水稻苗期每丛稻茎毛眼水蝇卵数（Ｘ_１）、为害株数（Ｘ_２）与产量损失（Ｙ）的关系符合下列方程：Ｙ＝－７．３１＋３．０１６ｘ１±２．１５，ｒ＝０．９８０４；Ｙ＝－６．７＋３．５３ｘ２±２．１９，ｒ＝０．９８０２。早稻产量损失的主要原因是受害后千粒重和实粒数减少；晚稻为千粒重下降。根据当前的稻谷价格、防治费用等，导出水稻苗期稻茎毛眼蝇的经济阈值为每丛４．６粒卵或３．７４株受害。经大田验证，与实际基本相符     

麦蚜指数调查法的田间应用

采用麦蚜指数调查法进行田间穗蚜计数,所用时间较实际逐个计数明显缩短。本试验平均百穗缩短调查时间１２.９２ｍｉｎ,利用方程Ｙ＝－６２.５＋４.６２Ｘ,推算出的蚜量,误差不超过１头／穗     

日本方头甲捕食桑盾蚧功能反应研究

日本方头甲捕食桑盾蚧量与桑盾蚧成虫和其初孵若虫密度呈负加速曲线关系,属于HollingⅡ型的功能反应。日本方头甲成虫捕食桑盾蚧成虫功能反应式为:Na=1.2329N/(1+0.1015N);捕食桑盾蚧初孵若虫的功能反应式为:Na=1.0709N/(1+0.0042N),其最大捕食理论值分别为1215头和25667头。     

河西灌区棉蚜综合防治技术

通过３年调查明确,棉蚜在河西走廊荒漠绿洲生态环境下的寄主植物有１４科５１种,棉蚜发生高峰期为７月下旬至８月中旬,棉蚜蚜量（Ｘ）与籽棉产量损失率（Ｙ）的回归方程为Ｙ＝１２.０８５４＋０.０１０５Ｘ（ｒ＝０.９６６）;棉蚜的发生与地理环境、气候、灌水、作物布局关系极为密切。室内测定多异瓢虫成虫对棉蚜每日最大理论捕食量为６２５头,其３龄若虫捕食量为５００头。棉区推广以调整作物结构、狠抓棉蚜越冬寄主的冬春防治,实行规范化栽培管理,协调运用各种防治措施,合理用药的综合防治技术规程,累计示范推广２.９万ｈｍ^２,防治效果达９０％以上,增产皮棉２２２.０ｋｇ／ｈｍ^２,增产率为１７.０％。     

临夏地区春蚕豆根腐病发生与为害调查

对甘肃临夏地区的３４０块春蚕豆田根腐病的调查，明确了该区蚕豆根腐病死亡率为１％～９０％，平均为１５．３３％；死亡率小于１０％的地块占调查地块总数５９．７％，大于３０％地块占１７．３５％，随着海拔梯度的增高，蚕豆死亡率逐渐下降。病原真菌主要有腐皮镰刀菌（Ｆｕｓａｒｉｕｍｓｏｌａｎｉ）、燕麦镰刀菌（Ｆ．ａｖｅ－ｎａｃｅｕｍ）、粘帚霉（Ｇｌｉｏｃｌａｄｉｕｍｒｏｓｅｕｍ）和尖孢镰刀菌（Ｆ．ｏｘｙｓｐｏｒｕｍ）     

澳洲瓢虫对吹绵蚧密度功能反应研究

澳洲瓢虫成虫随着吹绵蚁雌成虫、卵及若虫密度的增加，取食量也相反增加，每头瓢虫成虫对吹绵蚧上述各虫态的日均最高取食量分别为９．３３头、４０７．３３粒及１１．６７头；每头瓢虫的日均取食量Ｎａ与吹绵蚧的密度Ｎｔ之间的关系呈负加速曲线，其密度功能反应的数学模型符合Ｈｏｌｌｉｎｇ圆盘方程Ⅱ型，即分别为：Ｎａ＝１．８４Ｎｔ／（１＋０．２０９６Ｎｔ）；Ｎａ＝５．０９２Ｎｔ／（１＋０．０１２７Ｎｔ）；Ｎａ＝１．３４３Ｎｔ／（ｌ＋０．１２５３Ｎｔ）。     

东亚小花蝽对四种害虫的捕食作用

室内饲养的东亚小花蝽Orius sauteri成虫对棉蓟马成虫、烟粉虱4龄若虫、朱砂叶螨雌成螨和甘蓝蚜成虫的捕食作用、种内干扰作用测定结果表明：捕食功能反应均符合HollingⅡ型;东亚小花蝽对棉蓟马的捕食量符合Na=1.0819Nt/（1＋0.08485Nt）,对朱砂叶螨的捕食量符合Na=2.704Nt/（1＋0.1423Nt）,对烟粉虱的捕食量符合Na=1.9641Nt/（1＋0.2455Nt）,对甘蓝蚜的捕食量符合Na=1.5912Nt/（1＋0.1808Nt）。东亚小花蝽的捕食作用有较强的种内干扰反应,捕食率与个体间相互干扰的关系符合Hassell模型。东亚小花蝽的捕食量与害虫密度正相关,寻找效应与害虫密度负相关。在这4种害虫中,小花蝽对朱砂叶螨的瞬间攻击率和最大捕食量均最大、处置时间最短,对棉蓟马的瞬间攻击率最小,对烟粉虱的最大捕食量最小、处置时间最长。     

栗真绥螨和黄瓜新小绥螨对西方花蓟马初孵若虫功能反应的比较

于人工气候箱（23±1℃、RH70%±5%、光照（D∶L=16h∶8h）条件下,在菜豆叶片制作的叶碟上,比较了栗真绥螨与黄瓜新小绥螨对西方花蓟马初孵若虫的功能反应。结果表明：黄瓜新小绥螨和栗真绥螨对西方花蓟马初孵若虫的功能反应均符合HollingⅡ型模型,分别为Na=0.763×Nt/（1＋0.152Nt）和Na=0.257×Nt/（1＋0.032Nt）,对西方花蓟马初孵若虫的攻击率分别为0.763和0.257,处理时间分别为0.199d和0.125d,日最大捕食量分别为5.0头和8.0头。     

异色瓢虫成虫对槐豆木虱的捕食作用

在室内测定异色瓢虫［Harmonia axyridis (Pallas)］成虫对槐豆木虱［Cyamophila willieti（Wu）］若虫的捕食作用。结果表明,异色瓢虫对槐豆木虱若虫的捕食功能反应符合HollingⅡ（1959）型方程,拟合的圆盘方程为Na＝1.128 47Nt/（1+0.010 1Nt）,经χ2适合性测验表明,圆盘方程的预测值与实测值相符;对猎物的捕食选择效应表明,在槐豆木虱和槐蚜(Aphis robiniae Macchiati)之间,异色瓢虫更喜好槐豆木虱;异色瓢虫的捕食率与个体间的相互干扰关系,用Hassell（1969）等的模型拟合为E＝0.577 668P-0.275;对自身密度的功能反应,用Watt(1959)模型拟合为A＝98.73P-0.705 3;在此基础上,根据HollingⅢ型功能反应新模型Na=a•exp (-bN-1t)拟合,求得日均最大捕食量102.3头,最佳寻找密度61.1头。     

Transgenic production of cytokinin suppresses bacterially induced hypersensitive response symptoms and increases antioxidative enzyme levels in Nicotiana spp

Responses of cytokinin overproducing transgenic Nicotiana plants to infections with compatible and incompatible Pseudomonas syringae pathovars were compared. Plants used were transformed with the ipt(isopentenyl transferase) gene that catalyzes the synthesis of cytokinin. In cytokinin overproducing lines that carry the ipt gene fused to the CaMV 35S (Nt+ipt), the wound-inducible proteinase inhibitor II (Ntx+ipt), or the light-inducible Rubisco small subunit protein (Npl+ipt) promoter, development of the hypersensitive response (HR) after infection with incompatible bacteria (P. syringae pv. tomato) was significantly inhibited as compared to the untransformed (Nt) controls. Over a 12 h period following inoculation, P. syrinage pv. tomato populations were slightly reduced in leaves of the cytokinin-overproducing Nt-ipt line compared with the Nt control. When the compatible P. syringae. pv. tabaci was used to infect the ipt transformed lines, slight or no significant differences in necrosis development were observed. Following infection, the titer of P. syringae pv. tabaci increased rapidly in both the transgenic and control lines but was higher in Nt+ipt plants. Leaf superoxide dismutase and catalase enzyme activities were about 60% higher in ipt leaf extracts than in the controls. This augmented antioxidant capacity likely decreased the amount of H(2)O(2) that may be associated with the higher tolerance of plants to pathogen-induced necrosis. In addition, the Nt+ipt lines had a significantly lower molar ratio of free sterols to phospholipids. The more stable membrane lipid composition and the higher antioxidant capacity likely contributed to the suppressed HR symptoms in the cytokinin overproducing Nt+ipt plants. In conclusion, the overproduction of cytokinins in tobacco appears to suppress the HR symptoms induced by incompatible bacteria.     

香梨园山楂叶螨种群动态的研究

采用聚集度指标分析了山楂叶螨聚集强度的时序变化,以指数模型进行拟合数量动态,运用最优分割法分析了山楂叶螨在香梨上的种群动态。山楂叶螨在香梨上的空间格局为聚集分布,分布的基本成分为个体群,聚集强度与叶螨的密度有关。山楂叶螨在香梨上呈指数增长,模型为Nt=15.199 4e0.054 t(R=0.913 2**);将山楂叶螨种群动态划分为3个阶段:发展期、高峰期和衰退期。     

Characterization and pathogenicity of Rhizoctonia isolates associated with cauliflower in Belgium

Sixty-two isolates of Rhizoctonia spp. were collected from Belgian cauliflower fields during 2005 and 2006. The majority of the isolates (60 out of 62) had multinucleate cells and were identified as Rhizoctonia solani . Characterization of anastomosis groups (AGs) was performed using pectic zymograms, PCR-RFLP and sequencing of the rDNA-ITS region. The most prevalent AG was AG 2-1 (55% of isolates), followed by AG 2-1 subset Nt (11%), AG 1-1C (8%), AG 5 (8%), AG 4 HGII (6%), AG 3 (5%) and AG 1-1B (3%). Pathogenic potential towards different vegetable crops and towards maize was determined. Damage to cauliflower and endive was caused by different AGs, with the isolates aggressive towards cauliflower belonging to AG 2-1, AG 2-1 subset Nt, AG 4 HGII, AG 1-1C, AG 1-1B and AG 2-2, and those aggressive towards endive belonging to AG 1-1B, AG 1-1C, AG 2-1 subset Nt, AG 2-2, AG 4 HGII and AG 5. The most aggressive isolates towards bean belonged to AG 2-1 subset Nt and AG 2-2, for lettuce to AG 1-1B and AG 2-1, on carrot to AG 4 HGII and towards maize to AG 2-2. Within the isolates of AG 2-1, variability was observed in PCR-RFLP pattern and in aggressiveness towards several crops, indicating this subgroup to be heterogeneous. This is the first study concerning the occurrence of R. solani AGs causing wirestem in Belgian cauliflower fields and the first report of aggressive isolates of AG 1-1C, AG 2-1 subset Nt and AG 4 HGII associated with cauliflower.     

稗草影响后季稻产量预测式的研究

在肥水等相同的条件下,影响后季稻产量损失的主要因子是夹稗穴率(x_1)和稗草分蘖株数(x_2)。夹稗率高,稗草分蘖株数多,则后季稻产量损失就随之增加。后季稻分蘖末期产量损失率预测式为y=0.7648+0.1591x_1+0.0728x_2,后季稻抽穗期产量损失率预测式为y=1.0025+0.2014x_1+0.0704x_2。经历次资料检验,2个预测式的平均误差率分别为12.2％和13.5％。1984—1985年大田应用结果表明预测式的准确率达83.3％。     

An in vitro screening assay to discover novel inhibitors of 4-coumarate:CoA ligase

4-Coumarate:CoA ligase (4CL, EC 6.2.1.12) exists only in plants and plays an important role in the phenylpropanoid pathway. Identification of inhibitors targeting 4CL provides a novel approach for developing effective plant growth inhibitors (PGIs). The full-length gene of tobacco 4CL (Nt4CL1) was cloned and expressed in Escherichia coli Cast & Chalm. The recombinant 4CL protein was extracted and purified by several purification steps including gel-filtration and anion-exchange chromatography. 4CL activity assay was miniaturized and optimized using a 96-well microplate and a reader. Among 28 existing herbicides, propanil and swep strongly inhibited in vitro 4CL enzyme activity, and they were selected for further studies. The process of this assay can be developed into a high-throughput screening system of PGI targeting 4CL in the phenylpropanoid pathway.     

蚕豆田潜蝇姬小蜂白昼活动规律

本文就蚕豆上潜蝇姬小蜂白昼活动规律进行了研究,在午间13：00-14：00时气温最高时,为潜蝇姬小蜂的活动高峰期,种群(Y)和温度(X)的白昼活动模式为Y=-2．41 1．38x-0．09x^2,r=0．7221;在蚕豆成熟时,潜蝇姬小蜂种群数量最大。