香梨树腐烂病菌表型菌株生物学特性及致病性

<正>0 引言库尔勒香梨是新疆的特色梨种,近年来由于腐烂病的发生,造成巨大的经济损失[1],已成为制约农民增产增收的主要因素。梨树腐烂病菌因产孢体和孢子的形态受环境影响大,故形态鉴定准确性较差,导致国内外病原菌学名使用混乱[2-6]。本试验从库尔勒香梨主产区采集分离得到303株腐烂病菌菌株,选取菌落表型存在明显差异的8株作为研究对象,明确其种类,测定其生物学特性和致病性分化,为揭示香梨树腐烂病菌遗传多样性提供参考,     

江西梨瘿蚊发生与综合防治技术

梨瘿蚊已成为江西省梨树主要害虫,分析梨瘿蚊的发生特点,重点对梨瘿蚊应采取选用的抗虫品种、农业防治、物理防治、生物防治和化学防治相结合的综合防治技术进行较为详尽的概述。     

梨波氏盘菌腐烂病

梨波氏盘菌(Potebniamyces pyri,是一种危害苹果、梨等植物的弱病原菌,除了引起果树树皮的溃疡或坏死外,还可以引起储藏期梨果的腐烂病.该病曾在欧洲的一些国家发现,目前在美国华盛顿州发生严重,给当地梨的生产带来了严重的经济损失.该病在中国尚无分布,因此对P.pyri的研究具有重要意义.     

Pear decline resistance in progenies of <Emphasis Type="Italic">Pyrus</Emphasis> taxa used as rootstocks

Progenies of 39 open-pollinated genotypes belonging to 26 Pyrus taxa were examined for pear decline resistance and pomological traits when used as rootstocks. Following graft inoculation and observation over 18 years, considerable differences in pear decline resistance between and within the progenies were observed. Not affected or little affected and moderately to severely affected trees were observed in all progenies. However, great quantitative differences among them were observed. In the progenies of about one third of the pollinated trees most of the individuals showed a high level of resistance to grafted trees. Significantly different from this group was another third of the progenies that mostly showed high susceptibility in grafted trees. Between these two groups there were progenies that statistically neither differed from the resistant nor from the susceptible group. These progenies were defined as moderately resistant. Significant differences in resistance were also observed between progenies of genotypes of the same species that originated from different locations. These data indicate segregation of the resistance trait and show that seedling progenies are unsuitable as rootstocks in commercial pear growing. Instead, careful selection of suitable genotypes for propagation is required. Great differences between and within the progenies examined were also observed in vigour and yield efficiency.     

四种杀虫剂对梨上瘿螨的田间药效试验

应用4种药剂进行了梨上瘿螨的田间药剂防治，结果表明：施药14d后，0．2％爱诺虫清EC2000倍液、10％哒四螨悬浮液、15％哒螨灵EC和20％灭扫利EC2000、3000倍液可取得良好的防治效果，其防效均达99．1％以上。     

An index for selective toxicity of miticides to phytophagous mites and their predators based on orchard trials

Data from nine trials conducted from 1990 to 1998 in apple orchards in Nova Scotia and Quebec, Canada, were used to estimate the predator-prey selectivity of miticides and their potential compatibility with biological control of mites. The European red mite Panonychus ulmi (Koch) was the dominant and more harmful phytophagous species, followed by the apple rust mite, Aculus schlechtendali (Nalepa). Two predacious mites, the phytoseiid, Typhlodromus pyri Sheuten, and the stigmaeid, Zetzellia mali (Ewing), were often found in the orchards. We used one minus the ratio of mite-days in treated plots to those in the control plots as an index of population suppression and toxicity of the miticides. Miticides were then categorized into classes similar to those employed by the International Organization for Biological Control to rate pesticide toxicity to natural enemies of insect and mite pests. Selectivity of miticides was mostly based on toxicity to P ulmi, the major pest, versus toxicity to T pyri, the major predator, with some consideration of the two lesser species, A schlechtendali and Z mali. In most cases, our findings were in accord with other studies. Abamectin and clofentezine had favourable selectivity (more toxic to the two phytophagous mites than to T pyri). The higher recommended rate of pyridaben (450 g ha(-1)) and two rates of spirodiclofen (180 and 240 g ha(-1)) were neutral (equally toxic to pests and predators). The lower rate of pyridaben (216 g ha(-1)), dicofol, formetanate hydrochloride and propargite were unfavourably selective (more toxic to T pyri). A higher than recommended rate of pyridaben (2160 g ha(-1)) applied before bloom was disruptive--P ulmi-days after treatment were actually greater than with the untreated control. P ulmi resistance to dicofol and propargite were probable complicating factors in some of the orchard trials.     

不同颜色色板对梨瘿蚊的诱集效果及黄板的使用方法

为了探索梨瘿蚊无害化的防治方法,本文连续2年开展了黄色、蓝色、深蓝色、白色、绿色、紫色、灰色、黑色和粉红色9 种不同颜色的色板对梨瘿蚊的诱集效果的比较,同时探索了黄板在田间的使用方法。通过连续2年的调查结果表明,梨瘿蚊对黄色色板趋性最大,与其它8种颜色色板之间存在极显著差异(P<0.05)。当黄色色板的悬挂高度分别为0.5m、1.0m、1.5m 和 2.0m时,以不高于1.5m 的诱杀效果为最佳（P<0.05）;间距分别为 2 m、3 m、4 m 、5 m 和6m时,以4m间距的诱虫量最多,但是不同间距之间的诱虫量在（P<0.05）的水平上差异不显著。诱虫板设在树体的不同方位之间诱虫量的差异不显著（P<0.05）     

不同梨树品种对梨瘿蚊的抗虫性研究初探

摘要：为探明不同梨树品种对梨瘿蚊的抗性,为梨树抗性品种选育和梨瘿蚊（Dasineura pyri Bouche）的防治提供理论参考。以国家果树种质武昌砂梨圃内的30个砂梨品种为材料,通过人工接种梨瘿蚊的方式,对30个砂梨品种接种梨瘿蚊后的植株受害率和叶片受害率进行了调查,并依据一定的标准计算得到综合受害率,从而对其抗虫性进行了评价,筛选出了金黛梨、早生黄金梨和华山梨等3个对梨瘿蚊的抗性较强的砂梨品种。这可为今后开展梨树抗梨瘿蚊品种选育提供重要材料。     

几种生长调节剂及与CaCl2混合处理对"黄花"梨果肉钙含量的影响

为弄清梨幼果钙动态及生长调节物质对其调控作用,以“黄花”梨为试材进行了研究,结果表明：IAA、GA3处理均增加了采收时果肉中总Ca的含量,但推迟了其含量高峰的到来,使用IAA CaCl2、GA3 CaCl2的处理其果肉总Ca含量峰值分别高于单独施用IAA或GA3的峰值,它们峰值到来的时间分别早于IAA或GA3单独处理;NAA处理推迟了果肉中总Ca的含量高峰,没有增加果肉中总Ca的含量,使用NAA CaCl2其果肉总Ca含量峰值与对照和单独施用NAA无显著差异;无论是什么处理,果实膨大期都是果实总Ca含量降低,Ca^2 升高的转变时期;还对促进果实对钙吸收的方法及总Ca和Ca^2 含量变化的生理意义和Ca^2 的功能进行了讨论。     

Comparison of clofentezine and hyxythiazox with cyhexatin for integrated control of European red mite, Panonychus ulmi (Koch)

The ovicides clofentezine and hexythiazox were shown to be compatible with integrated control of European red mite, Panonychus ulmi (Koch), in a replicated field trial conducted over two growing seasons in an apple orchard at Batlow, New South Wales, Australia. Reduced concentrations of clofentezine (5 and 10 g a.i. per 100 litres water—normally 20 g) applied as foliar sprays to run-off, stabilized the predator/prey interaction between P. ulmi and Typhlodromus pyri Scheuten more effectively than low rates of cyhexatin (5 and 10 g a.i. per 100 litres water—normally 20 g). There was no evidence that the effectiveness of clofentezine or hexythiazox would destablize integrated control by eliminating P. ulmi and starving T. pyri. Populations of T. pyri persisted in low numbers on the trees in the absence of P. ulmi or other arthropod food sources on leaves.