湖北省郧县小麦白粉病中期预报技术研究

通过对郧县小麦白粉病１３ａ的历史资料的研究分析,初步明确决定病害发生程度的主要因素是当今早春３月上旬末的菌源基数,３月份的平均温度以及３月份降不量与３月份平均温度的乘积,提出了病害发生程度中期预测式：Ｙ＝－２．５３３０７４２２８＋０．０５６１９７７６７２Ｘ１＋０．４９８２１１９８０Ｘ２＋０．００２４３７２４９１８９Ｘ４。历史符合率８４．５％,经１９８５－１９９７年回测检验,结果与发生实际基本一致,     

江汉平原麦区小麦白粉病中期测报技术研究

通过对荆州地区小麦白粉病１９年历史资料的研究分析,初步明确了决定病害发生程度的主要因素是当年早春３月上旬的菌源基数,３月的平均温度,３月的降水量以及３月份降水量与３月平均温度的乘积。提出了病害发生程度中期观测式：Ｙ＝４．６８６６１５＋０．０７０８６３７５９９ｘｌ－０．２９２４６７４７８４ｘ２－０．０２４２４７１０８０５ｘ３＋０．００２５９７２５２６４４ｘ４,历史符合率９０．５％,经１９８１￣１９９     

泽漆对小麦的为害损失及经济阈值研究

为明确泽漆的发生对小麦产量及其构成因素的影响,人工接种结合田间自然出草进行泽漆不同密度对小麦为害损失试验。１９９５－１９９６年研究结果表明,泽漆发生密度和小麦产量及穗数损失率的最佳数学模型均直线函数关系,方程分别为：Ｙ＝－０．３９１８＋１．５１９Ｘ,Ｙ１＝２．２３２＋１．５５３Ｘ。泽漆的发生为害对小麦穗粒数、千粒重的影响不显著。经济阈值计算结果表明,用使它隆进行防除,泽漆发生密度达３．０株／ｍ＾３     

桑瘿蚊发生与气象因素的关系及预测预报初探

）为预报因子，提出桑瘿蚊发生预测指标（见表２）。根据当年的长期气象预测，在５月中旬即可获得６－８月的温度和雨量趋势，从而可提前２到３个月对桑瘿蚊发生趋势作出预测，为基层搞好宣传发动及防治准备工作提供科学依据。２．２．２气象因子的曲线回归式建立将原始资料进行逐步回归筛选，选相关性较好的７月下至８月中旬日照（ｒ＝－０．６８５０）和６－８月温水系数（ｒ＝０．８５０６）为预报因子，组建多元回归预测式：Ｙ＝３．７２８５－０．０１９７６Ｘ１＋０．１８１９Ｘ２±０．５９８０经计算Ｒ＝０．９３７９＞Ｒ０．０１＝０．８８６，说明回归关系可靠，预测式成立。拟合率测验：将历年资料代入预测式回测检验，结果８年资料的历史拟合率为１００％，可作为桑瘿蚊发生程度的中、长期预报。     

茶赤叶斑病的发生规律

于１９８８－１９９４年对茶赤叶斑病的发生规律进行了研究。室内培养表明,２２,２４,２６,２８℃等４个处理均适宜病原菌的生长发育,离体插枝接种显示,品种间有抗性差异,且以晚间接种发病率高。该病流行程度与５－７月３个月的平均ＲＨ（Ｘ１）呈正相关,与８月份雨日数（Ｘ２）呈负相关,其综合影响的二元回归式为Ｙ＝－３７．３８４２＋０．６４７１Ｘ１－０．７０７９Ｘ２,ｒＹ１．２＝０．８２７４,ｒＹ２．１＝－０．     

东北春小麦丛矮病流行规律研究

１９９３年通过重病区的系统调查和流行因素定量测定,明确在灰飞虱是小玫丛矮病最主要的介体,占飞虱种群的９５％以上。灰飞得在中肋地区１年发生３代,在麦茬、草根、土缝内越冬,老熟带毒若虫和成虫是次年主要的初侵染源,其数量和带毒率与小麦全矮病发病率之间具有线性关系。回归求得如下关系：Ｙ＝０．１８２３Ｚ１－５．７４１８Ｘ２－０．０３０９９Ｘ３＋１．１４０４Ｘ４。病情与小麦受侵洒时期密切相关。田间试验表明,三     

粉锈宁和多菌灵混用防治小麦三病效果好

粉锈宁和多菌灵混用防治小麦三病效果好唐韵（四川达县植保站，６３５００２）赤霉病、叶锈病、白粉病是我县小麦的三大病害，据统计，近几年平均发生程度分别为４．２、３．３和２．８级，年均发生面积分别为１，９４、１和０．７７万公顷，年均损失产量４２６．２、１４...     

蚜茧蜂对麦蚜控制作用的初步研究

本文应用二次通用旋转组合设计的方法进行了蚜茧蜂对麦蚜寄生能力的研究,得出了蚜茧蜂的寄生量模型：Ｙ＝９１．４０＋４３．６２Ｘ１＋２０．２７Ｘ２＋７．２５Ｘ１Ｘ２－１６．８３Ｘ１＾２＋３．４３Ｘ２＾２。并对模型进行了分析,表明对总寄生量的影响因素中麦蚜密度的大小大于蚜茧蜂本身密度的大小。在试验密度范围内,蚜虫和蚜茧蜂干扰作用不明显,且有相互促进的作用,但增加速度相同。     

岑溪县早造稻飞虱的发生及主害代发生程度预测

稻飞虱（含白背飞虱与褐飞虱）是岑溪县目前发生危害最大的水稻害虫，一年发生８个世代。经１９年的冬后调查说明有本地虫源，其中以白背飞虱为多。早稻秧田虫量与３月上中旬沟边若虫量有一定关联性（ｒ＝０．６７３０）；外地虫源迁入盛期一般在５月中下旬；第三代系主害代，其若虫高峰期与早稻抽穗盛期至灌浆初期相吻合；经十多年调查资料整理筛选出预测第三代高峰期成若虫密度的相关因子：３月上中旬沟边若虫平均密度（ｘ＿１）、３月中下旬秧田成若虫平均密度（ｘ＿２）、５月份降雨量（ｘ＿５）及５月１５～２５日平均成若虫密度（ｘ＿６）、５月份降雨系数（ｘ＿７）等，分别建立、修订预测式：ｙ＝０．１７６ｘ＿１＋０．２２２ｘ＿２＋０．２０３ｘ＿５＋２．３０２（级）……Ⅰ＇、ｙ＝２．５０７＋０．３４０ｘ＿６＋０．１７１ｘ＿１（级）…Ⅱ＇。Ｒ值和Ｆ值均达极显著水平，历史符合率为９４．７％～１００％。     

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。     

华北地区苗圃毛白杨叶锈病流行预测式的推导

 根据1983-1987年在北京、河北、山东、山西调查的苗圃毛白杨叶锈病病情,结合相应的气象数据,通过逐步回归在18个自变量因子中,筛选出早春百株病芽数(X₁)和发病适温期间降雨量(X₂)的互作因子(X₁X₃),建立预测当年最高病情(Y)的方程式:Y=2.8229+0.0133X₁X₃。
该方程经数学检验合理,两年当中建立模型以外的10例实测病情对方程式进行检验,证明有较高的可靠程度,可在华北地区试用,为防治决策提供依据。     

远中5号中来自天兰偃麦草的一个染色体组对三种锈病的抗性作用

 八倍体小偃麦具有偃麦草的抗锈、大穗、多花等优良性状,是小麦育种中的重要种质资源。本研究通过体细胞染色体组型的观察和比较推断八倍体的小偃麦品种远中5号比其变异系多一组来自天兰(中间)偃麦草(Agropyron glaucum)的特有的染色体组EE或FF。远中5号与其变异系之间对三种锈病的抗性差异表明:远中5号对条锈菌七个生理小种(条中22、23、25、26、27、28、29)和对秆锈菌六个生理小种(21C3、34、34C1、34C2、34C4、119)的抗病基因由来自天兰偃麦草的EE或FF染色体组所携带,而在AABBDD染色体组上存在着对叶锈菌四个生理小种(叶中3、4、20、38)的抗病基因。在EE或FF染色体组上也可能含有抗叶锈病的基因,至少由于EE或FF染色体组的存在大大地提高了远中5号对叶锈病的抗病性。     

1992~1996年我国小麦叶锈菌毒性动态

 利用已知抗叶锈病基因的小麦近等基因系(或单基因系)作鉴别寄主,监测来自我国12个省(市、区)的499份叶锈标样。结果表明:(1)在发现的诸多致病类型(毒性基因组合)中,PHT出现频率较高(26.6%),为优势类型,其余类型的出现频率均在7.4%以下;(2)毒性基因V2a、V9、V15、V19、V20、V24、V28、V29、V37、V38和V13+3Ka的出现频率小于30%,V2b、V18、V25、V27+31和V33+34的出现频率在30%~60%之间,其对应的抗性基因可视为我国小麦叶锈菌的有效抗病基因;(3)不同生态区的叶锈菌株,毒性基因(或基因组合)的组成特点、出现频率及多样性等差异较大。文中建议采用"固定鉴别基因+辅助鉴别基因"的复合鉴定系统,并对小麦抗叶锈病生态育种及抗锈基因分区部署等问题进行了讨论。     

The relationship between wheat yield and stripe rust as affected by length of epidemic and temperature at the grain development stage of crop growth

Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici. was associated with mean losses of up to 84% in the yield of wheat in southern New South Wales, Australia, between 1984 and 1987. Yield loss became smaller in cultivars with increasing levels of resistance in adult plant reaction and did not appear in cultivars with seedling susceptibility and moderate or better adult plant reaction levels in the 3 years when epidemics began after emergence of the flag leaf. However, in 1984 the stripe rust epidemic began during stem elongation, and yield losses of up to 21% occurred in cultivars with seedling susceptibility and a moderate or better adult plant reaction.
Yield was significantly negatively correlated with the proportion of leaf area affected by stripe rust at stages of crop development from the end of heading to late milk. The correlation was greatest at the early milk stage of growth where the relationship was logarithmic. Two factors significantly influenced this relationship. Yield loss increased as the length of the epidemic increased, and decreased as temperature increased during grain development. The relationship that was developed for predicting yield loss accounted for 80-5% of the variance across all experiments, and was:
y = 100(1- e ^10-4×(393+165 L -141 T ))
where y = yield loss (%); X = stripe rust (leaf area affected, range 0-99%) at early milk; L = time from 1% disease to early milk (range 0-70 days); and T = mean daily maximum temperature from 7 days before to 14 days after early milk (range 198-27.5°C).     

Virulence of Puccinia triticina in Turkey and leaf rust resistance in Turkish wheat cultivars

Leaf rust caused by Puccinia triticina is a common disease on wheat in the coastal regions of Turkey. Collections of P. triticina from infected wheat leaves were obtained from the main wheat production zones of Turkey in 2009 and 2010. A total of 104 single uredinial isolates were tested for virulence on 20 lines of Thatcher wheat that differ for single leaf rust resistance genes. Forty-four different virulence phenotypes were identified over both years. Four phenotypes were found in both years. Phenotype FHPTQ found in 2009, with virulence to genes Lr2c, Lr3, Lr16, Lr26, Lr3ka, Lr17a, Lr30, LrB, Lr10, Lr14a, Lr18, Lr3bg, and Lr14b, was the most common phenotype at 15.4 % of the total isolates. Forty-three winter and spring wheat cultivars from Turkey were tested as seedlings with 13 different P. triticina virulence phenotypes from Canada, the US and Turkey. The infection types on the cultivars were compared with infection types on the Thatcher near isogenic lines to postulate the presence of seedling leaf rust resistance genes in the cultivars. Resistance genes Lr1, Lr3a, Lr10, Lr14a, Lr17a, Lr20, Lr23, and Lr26 were postulated to be present in the Turkish wheat cultivars. DNA of the wheat cultivars was tested with PCR markers to determine the presence of the adult plant resistance genes Lr34 and Lr37. Marker data indicated the presence of Lr34 in 20 cultivars and Lr37 in three cultivars. Field plot evaluations of the wheat cultivars indicated that no single Lr gene conditioned highly effective leaf rust resistance. Resistant cultivars varied for combinations of seedling and adult plant resistance genes.     

麦鞘毛眼水蝇为害损失与经济阈值的研究

1989—1990年在甘南藏族自治州合作地区选用青棵农家品种“肚里黄”为试验材料,根据麦鞘毛眼水蝇(IIydrellia chinensis Qi et Li)为害特点,应用田间自然种群与药剂处理相结合的方法,通过线性回归分析、相关分析及通径分析、对青稞不同受害程度与产量损失的关系进行了研究。结果表明:“肚里黄”品种旗叶叶鞘受害程度的大小对青稞千粒重产量的形成有明显的影响,而其它叶鞘的影响不明显;经回归分析,平均严重度(X_2)、为害指数(X_3)与产量损失率(Y)的关系式分别为:Y=4.1599 0.4962X_2和Y=5.4197 0.4718X_3;空壳率的上升是造成产量损失的直接因素;在自然条件下,其经济阈值的数学模型为: X=1/2.58977CN(10.8737CN C_1)(卵量) 据此,合作地区麦鞘毛眼水蝇的防治指标为拔节后期单株卵量4.2粒。     

来自波斯小麦Ps5的一对隐性抗叶锈病基因的染色体定位

为了筛选小麦抗叶锈病资源和发掘新的抗叶锈病基因,对由抗病波斯小麦Ps5与感病粗山羊草Ae38合成的双二倍体Am3进行了单体分析。将中国春单体和二体分别与Am3杂交,测定杂交F1植株的染色体条数以及F1、F2群体对叶锈病的抗/感病性。结果表明:在18℃条件下,Am3对小麦叶锈菌致病类型DHS/GD的抗病性由1对隐性抗病基因控制,该基因来自四倍体亲本波斯小麦Ps5,具有剂量效应,位于5A染色体上。     

不同杀菌剂对小麦叶锈病的防治效果

小麦叶锈病是威胁我国小麦安全生产的重要病害之一,近年来其发生程度有逐年加重的趋势。为了筛选有效的化学防治药剂,对5种杀菌剂进行了田间药效试验。结果表明,5%烯唑醇微乳剂1 000~2 000倍液、430g/L戊唑醇悬浮剂3 000~5 000倍液、10%氟硅唑微乳剂1 500倍液、1 750倍液、20%丙环唑微乳剂400~800倍液、2%武夷菌素水剂300倍液、400倍液试验处理防效均高于50%。从增产效果来看,20%丙环唑微乳剂600倍液的增产率最高,达到42.33%。5%烯唑醇微乳剂2 000倍液,430g/L戊唑醇悬浮剂5 000倍液兼具高防效和高效益(产出/投入),建议推广使用。     

Rust resistance in Salix to Melampsora larici-epitea

A total of 174 Salix (willow) clones belonging to 57 species and 14 interspecific hybrids were inoculated with seven pathotypes of Melampsora larici-epitea using the leaf disc method. Infection types were scored based on the uredinial pustule area data and the inoculum density. A close correlation ( R ² = 0·82) was found between the average pustule area and the average number of spores produced. Most of the willows were also assessed in the field for rust in 1999. Most willow clones belonging to the species native to western Europe were infected by the rust. In inoculation experiments, uredinia developed on 46 S. viminalis clones, out of a total of 47. In the field, all the S. viminalis clones were infected by rust. Within the subgenus Vetrix , eight out of the 17 willow species that originated from North and South America produced rust pustules in inoculation experiments. Of these, S. pellita was most susceptible. Salix irrorata and S. lasiolepsis var. bracelinae produced well developed pustules after inoculation but no rust infections were detected in the field. In both leaf disc tests and field assessments, no rust infections were found on S. candida , S. cordata , S. drummondiana , S. eriocephala , S. hookeriana , S. houghtonii , S. humilis , S. rigida var. mackenziana and S. syrticola . Of 12 species of subgenus Vetrix native to northeast Asia and Japan, only S. kochiana was susceptible both in inoculation tests and in the field. Salix rossica produced no symptoms in leaf disc tests but showed low levels of infection in the field. The maximum infection type scores in leaf disc tests were highly significantly correlated with field disease severity scores (Spearman rank correlation coefficient was 0·76, P  < 1 × 10⁻¹⁰).     

Effects of bean rust (Uromyces appendiculatus) epidemics on host dynamics of common bean (Phaseolus vulgaris)

Epidemics of bean rust ( Uromyces appendiculatus ) and their effects on host dynamics of common bean ( Phaseolus vulgaris ) were studied in three controlled greenhouse experiments, with and without fungicide sprays, on two susceptible bean cultivars, Dufrix and Duplika. Bean plants were artificially inoculated with a suspension of 10⁵ U. appendiculatus urediniospores mL⁻¹ water and temporal disease progress, as well as host growth dynamics (leaf size and defoliation), were monitored on a leaflet basis in comparison with non-inoculated plants, which were sprayed with deionized water. Progress curves of bean rust, expressed as the proportion of leaf area occupied by pustules (uredinia), or as the proportion occupied by total lesion area (= halo areas + pustule area), were well described by logistic functions with maximum disease levels clearly lower than 1. Bean rust epidemics substantially affected host growth by reducing the total leaf area formed by 17·4–35·6% and 35·3–46·2% compared with healthy plants for cvs Dufrix and Duplika, respectively. Fungicide sprays mitigated the negative effect of bean rust, leading to a gain in leaf area of 17–21% compared with unsprayed plants in both cultivars in two experiments, while in another experiment, disease control had no effect in Dufrix, but a clear effect in Duplika. In addition to the growth depression, bean rust also led to pronounced losses of leaf area as a result of reduced leaf size (leaf shrivelling) and accelerated defoliation.