山西省小麦新品种抗白粉病鉴定及其利用

１９９１～１９９４年采用人工接种和自然诱发相结合的方法对８７１份小麦新品种（品系）进行苗期和成株期抗白粉性鉴定，筛选出中麦２号、农大０１５、京４１１、京８３７、吉华６号、晋麦３０号、鲁麦１４、晋麦３２、冀麦３０等９份农艺性状突出，抗病性好的品种（系）。这些材料抗病性稳定，有的已供育种部门作杂交亲本利用，有的已大面积推广应用。     

河北省小麦白粉病发生程度的中期预测

根据全省１０个县（市）９ａ的历史资料进行归纳总结，提出小麦白粉病流行结构模型，利用３月下旬至４月中旬的气象因子（降雨量、雨日、平均相对湿度）实况值，用判别分析的方法，对当年小麦白粉病发生程度进行中期预测，经１９９３～１９９４年的应用检验，预测结果与各监测县及全省实况吻合     

Susceptibility of Commercial Tomato Cultivars to Bacterial Wilt in Hydroponic System

Commercially available tomato cultivars were hydroponically cultured for inoculation, with Ralstonia solanacearum (K-101), which causes bacterial wilt, by pouring an inoculum suspension into the nutrient solution. Cultivar susceptibility to the bacteria was evaluated, based on the highest percentage of wilting. Because the length of time for wilt appearance varied among cultivars, some cultivars appeared to be suppressive to the translocation and/or multiplication of the invading pathogen. Thus, this hydroponic inoculation system is effective for examining levels of susceptibility in tomato cultivars to bacterial wilt. Received 13 December 2000/ Accepted in revised form 27 March 2001     

Effect of Film-forming Polymers on Infection of Barley with the Powdery Mildew Fungus, Blumeria graminis f. sp. hordei

The effects of three film-forming compounds, Ethokem, Bond and Vapor Gard, on infection of barley by the powdery mildew fungus Blumeria graminis f. sp. hordei were examined in glasshouse and field experiments. The three compounds provided significant control of powdery mildew infection when applied as pre- or post-inoculation treatments in the glasshouse. Such treatment had no effect on plant growth. Bond and Vapor Gard reduced the germination of conidia of B. graminis by 78% and 85% respectively, and reduced the subsequent formation of appressoria (73% and 85% respectively) and haustoria (75% and 79% respectively). The three compounds were less effective in field experiments, although they provided significant control of mildew infection and had no impact on plant growth and grain yield.     

小麦新资源对条锈病白粉病的抗性鉴定

１９９１～１９９７年在甘谷田间对远缘小麦新资源进行抗条锈病、白粉病鉴定。结果表明，在供试１６０份材料中，对条锈病免疫或高抗、白粉病免疫的有２５份，其抗性比较稳定，是良好的抗源材料，可供抗病育种利用。     

30%氟菌唑可湿性粉剂防治黄瓜白粉病田间药效试验

进行田间试验以明确30%氟菌唑可湿性粉剂防治黄瓜白粉病的效果。结果表明,30%氟菌唑可湿性粉剂能够很好的控制黄瓜白粉病,防治效果明显高于对照,且对作物安全。     

戊菌唑20%水乳剂田间防治草莓白粉病药效试验

为解决当前白粉病在草莓上危害日趋严重的问题,本研究以常用药剂苯醚甲环唑和三唑酮为对照药剂,在田间草莓上测试了戊菌唑20%水乳剂不同使用浓度下对草莓白粉病的防治效果。结果表明,戊菌唑20%水乳剂2个处理浓度的防效显著高于对照药剂苯醚甲环唑10%水分散粒剂处理的防效,且极显著的高于对照药剂三唑酮15%可湿性粉剂处理的防效。     

Evidence for an Osmotic Mechanism in the Control of Powdery Mildew Disease of Wheat by Foliar-applied Potassium Chloride

The mechanism by which foliar application of potassium chloride solution reduces symptoms of powdery mildew disease (Erysiphe graminis f.sp. tritici) of wheat was investigated. The hypothesis that potassium chloride reduces mildew by an osmotic effect on spore germination was tested in three glasshouse experiments. Either potassium chloride solution or the osmoticum polyethylene glycol 200 was sprayed on wheat at the three- or four-leaf stage. The plants were inoculated with spores and spore germination and leaf area affected by mildew were assessed. Leaf water potential was determined as a measure of the osmotic effect of the treatments. Spore germination and leaf area affected by mildew were related to leaf water potential using regression analysis in groups on the data averaged over the three experiments. Both spore germination on the leaf and leaf area affected by mildew were reduced as leaf water potential decreased. There was no difference between potassium chloride or polyethylene glycol in the relationship between spore germination and leaf water potential, but polyethylene glycol was slightly less effective at reducing mildew symptoms at any given leaf water potential. The results are compatible with the hypothesis that potassium chloride reduces symptoms of powdery mildew by an osmotic effect on spore germination.     

Exploration and Exploitation Strategies of Powdery Mildew on Barley Cultivars with Different Levels of Nutrients

The mass fractal dimension (MFD) of colonies of mildew (Erysiphe graminis f.sp. hordei) growing on barley was calculated as a measure of their spatial structure. Despite the elongated shape of the colonies imposed by the leaf cellular structure, the MFD remained constant with scale. The mildew MFD differed on different cultivars of barley, and was greater on leaves produced under higher nutrient level indicating a physiological component. Lower MFD values correspond with the thin spreading growth associated with exploration strategies and higher values correspond to the denser, more branched structure associated with exploitation of the substrate. Cultivars showing exploration strategies induced by resistance expression responded to increased nutrient levels more than those expressing little resistance such as Golden Promise.     

豫北麦区小麦白粉病中期测报技术研究

通过对小麦白粉病１４ａ的发生情况研究分析，初步明确影响豫北麦区小麦白粉病流行的主要因素和主要预测因子是当年早春３月中旬的菌源基数、３～４月份降水量和日照时数，提出了病害中期预测的综合分析预测法和预测指标，建立了病害发生程度预测式，经１９９４～１９９５年预测检验，表明预测结果与发生实际基本一致     

黄瓜白粉病拮抗细菌的筛选与鉴定及其防病机理

通过室内盆栽试验,筛选到对黄瓜白粉病具有显著防治效果(≥90.0%)的细菌12个菌株进行田间小区防病试验,结果表明其中10个菌株具有显著的防治效果,菌株XJT-7、NZT-14-84和BDT-25的防治效果较好,分别为79.02%、67.51%和57.38%。对该3株生防细菌的防病机理初步研究证明他们的胞外代谢产物具有防病作用。通过分类鉴定,确定菌株XJT-7为坚强芽孢杆菌。     

植物白粉病的化学防治进展

对植物白粉病的化学防治历史和发展进行了综述 ,同时介绍了一些重要的药剂及其作用机制 ,并讨论了白粉病化学防治中存在的问题。     

A New Race of Spinach Downy Mildew in Japan

A new race of spinach downy mildew caused by Peronospora effusa occurred in Fukui, Japan. The fungus was capable of affecting spinach cultivars resistant to races 1, 2, 3 and 4, but not some other cultivars. Thus, the fungus had different pathogenicity from race 3 and race 4 of the pathogen and was considered to be a new race of spinach downy mildew in Japan. Received 26 April 2001/ Accepted in revised form 17 August 2001     

Effects of Temperature on the Length of the Incubation Period of Rose Powdery Mildew (Sphaerotheca pannosa var. rosae)

The effect of temperature on the length of the incubation period of rose powdery mildew, caused by Sphaerotheca pannosa var. rosae, was studied. At constant temperature over the range 8–28°C, the length of the incubation period ranged from 3 to 10 days; no visible colonies developed at 30°C after 19 days. The relationship between temperature and the rate of development of mildew colonies within the incubation period under constant temperature was described by two alternative non-linear models (exponential and thermodynamic). The resulting curves were asymmetrically bell-shaped with an optimum temperature of c. 23°C. The two constant-temperature models predicted the development of powdery mildew under fluctuating temperatures with similar accuracy, even though the exponential model fitted the constant temperature data less well than the thermodynamic model. The thermodynamic model failed to fit the fluctuating-temperature data directly, whereas the exponential model fitted those data directly and the fit was similar to the corresponding model from the constant-temperature data. Fitting the models to the combined (constant and fluctuating temperature) data gave results that were nearly identical to those based on the constant-temperature data alone.     

Control of Leveillula taurica in Tomato by Acremonium alternatum is by Induction of Resistance, not Hyperparasitism

Spores of the hyperparasite Acremonium alternatum reduced powdery mildew infection by Leveillula taurica on greenhouse tomato. The effect was slightly increased when spores were applied killed, and therefore not due to direct parasitism. The effect was systemic, protecting untreated leaves above the treated ones. Spores killed by heat had more effect than when killed by UV, so the effect was presumably due to induction of host resistance by substances released when cells were heat killed. The size of the effect depended upon leaf age and level of infection. Effects on primary infection and expansion of successful infections appear to be under independent control.     

宁南霉素和多抗霉素对黄瓜白粉病的控制作用研究

药效试验结果表明,10％宁南霉素可溶粉剂在80、60g/667m^2剂量下第1次施药后10d对黄瓜白粉痛防治效果分别为73．63％、61．55％,第3次施药后14d防治效果达到74．98％、70．83％;10％多抗霉素素可湿性粉剂在80、60g/667m^2剂量下第1次施药后10d对黄瓜白粉病防治效果分别为70．20％、63．95％,第3次施药后14d防治效果分别达到77．64％、71．82％。上述各处理防治效果均高于对照药剂70％甲基硫菌灵可湿性粉剂80、60g,667m^2处理的同期防效,并且对黄瓜安全,是防治黄瓜白粉病优良生物杀菌剂。     

Occurrence of decreased sensitivity of Sphaerotheca fuliginea to ditalimfos

Samenvatting In proefvelden van een instituut voor gewasbescherming te Heraklion op Kreta, waar fungiciden op hun werking tegen komkommermeeldauw worden getoetst, bleek de werking van ditalimfos na toepassing in twee proeven reeds verminderd te zijn. Het optreden van resistentie werd bevestigd in proeven in een klimaatkamer. Voor drie isolaten uit de proefvelden was de ED₅₀ van het middel ongeveer 19 maal zo hoog als die voor zes willekeurige isolaten uit praktijkpercelen.De detalimfos-resistente isolaten waren wel gevoelig voor fenarimol en pyrazophos.In proefvelden, die niet met het fungicide werden behandeld, bleken de resistente isolaten zich temidden van gevoelige isolaten te handhaven gedurende tenminste negen maanden.     

切花月季白粉病发病规律观察

地处秦岭山以南,伏牛山以北的十堰市,群山环抱,地理复杂·东经109°15′~111°45′、北纬31°31′~33°20,′横跨3个纬度线,南北兼有的气候带·盛夏绝对最高气温可达39℃,凌冬最低气温可下降到-12℃,海拔最高3 115 m(神农顶),最低92 m(丹江口市区),年降雨量800~1 500mm,无霜期180 d有余。在这一地带虽有山花烂漫,但切花生产仍属空白·随着改革开放的深入,人民生活水平的提高,切花需求量的增加,单靠南方的鲜花,不单增加了运输成本,鲜花也失去了鲜的韵味(鲜花从剪切到消费者手中最少要3 d时间),1997年十堰试种切花,但引进的几个切花月季品种,…     

小麦霜霉病的发生与防治

小麦霜霉病是一种以土壤传染为主的真菌病害,主要在苗期阶段侵染。在防治上我们通过采取以轮作、选种抗病品种、加强肥水管理和药剂拌种等综合防治措施,使其得到了有效控制。     

根结线虫侵染对番茄叶片保护酶活性的影响

通过对番茄感染南方根结线虫后其叶片中几种保护酶活性的变化进行研究。结果表明:接种南方根结线虫后,番茄叶片中的苯丙氨酸解氨酶(PAL)活性即开始低于对照,随后逐渐恢复至对照水平,15 d之后,酶活性又开始显著低于对照水平,一直持续到第30 d,酶活性恢复到对照水平;多酚氧化酶(PPO)活性变化受线虫侵染的影响较小,在试验期间与对照没有显著性差异;超氧化物歧化酶(SOD)的活性在接种后第1 d即显著低于对照水平,至第7 d的时候恢复至对照水平并持续至第30 d。过氧化物酶(POD)活性在1～20 d均显著高于对照水平。因此,POD活性可以作为早期判断番茄是否感染根结线虫的一项指标。