不同葡萄品种对霜霉病的田间苗期抗性评价

对36个葡萄品种(品系)苗期对霜霉病的田间抗病性进行了评价, 结果表明, 不同葡萄品种(品系) 对葡萄霜霉病的抗性存在明显差异, 绝大多数欧美杂交种的抗性要强于欧亚种葡萄, 供试的10个欧美杂种中, ‘瑞峰无核’对葡萄霜霉病表现为高抗; ‘DEMIR’、‘龙宝’、‘红富士’、‘黑奥林’、‘峰后’5个品种表现为中抗。     

葡萄感染霜霉病菌后几种信号物质的变化

以3个抗病性不同的酿酒葡萄品种(‘西拉’‘霞多丽’‘赤霞珠’)叶片为材料,检测霜霉病菌侵染后几种病原相关信号物质,如脱落酸(ABA)、过氧化氢(H2O2)、一氧化氮(NO)、茉莉酸(JA)和乙烯(ETH)等的变化,以探讨葡萄抵御霜霉病菌的信号转导机制。结果表明,H2O2和NO是葡萄感应霜霉病菌的早期信号分子,且抗性较强的品种‘西拉’的变化最为明显;JA和ABA是抗性较差品种‘赤霞珠’应答霜霉病的信号组分。而3个抗性不同葡萄品种的乙烯变化无明显差别。推测H2O2、NO、JA和ABA均参与了葡萄对霜霉病菌的防御反应,但不同品种间信号转导组分可能存在差异。     

不同百合品种对百合灰霉病的抗病性鉴定

为明确不同百合品种对灰霉病的抗病能力,本试验采用离体叶片菌丝块接种和田间孢子液喷雾2种方法测定了百合7个不同品种对百合灰霉病的抗病性。离体测定结果表明,供试的7个品种对百合灰霉病的抗病性存在显著差异,其中‘法兰西’和‘罗蒂娜’为高感品种,‘康斯坦萨’和‘索邦’为高抗品种,‘马可波罗’、‘提拔’和‘西伯利亚’为中抗品种;田间接种发病的测定结果除‘西伯利亚’为高抗品种外其余结果与离体接种结果一致;离体接种和田间接种发病情况的系统调查分析得知,感病品种‘法兰西’和‘罗蒂娜’发病早,病情发展速度快,病情指数高;‘提拔’、‘康斯坦萨’、‘西伯利亚’和‘索邦’等抗病品种发病晚,病情发展缓慢,病情指数低;随着品种抗病性的增强,发病速度和病情指数逐渐降低。     

100个小麦品种资源抗条锈性鉴定及重要抗条锈病基因的SSR检测

了解小麦品种资源对中国条锈菌生理小种的抗病性水平及其所含重要抗条锈病基因,可为合理种植和利用小麦品种提供理论依据。选用中国小麦条锈菌不同生理小种CYR17、CYR32、CYR33和V26及条锈菌混合小种分别对100个小麦品种资源进行苗期和成株期抗条锈性鉴定,并采用SSR分子标记技术检测重要抗条锈病基因Yr5、Yr10、Yr15、Yr18、Yr24和Yr26。结果表明,在苗期对4个生理小种均表现抗病性的有‘Mos311’、‘兰天15号’等30个品种;在成株期表现抗病性的有‘Yeoman’、‘兰天1号’、‘小红麦’等88个品种;苗期和成株期均抗病的有‘Mos311’、‘兰天15号’等30个品种。SSR检测发现,‘贵农22’可能含有Yr5,‘兰天23号’、‘兰天24’号、‘中梁04260’和‘中梁04335’可能含有Yr10,‘Little Joss’和‘中梁5号’可能含有Yr15,‘清农3号’、‘兰天2号’、‘中梁04335’等19个品种可能含有Yr18,检测品种可能均不含Yr24和Yr26。在鉴定中保持稳定抗病性的‘Mos311’、‘兰天15号’等8个品种在抗病品种选育中有重要应用价值。     

欧亚种葡萄自交F1代对白粉病和霜霉病的抗性遗传

采用田间自然鉴定、田间接种鉴定及室内离体叶圆片接种鉴定三种方法,研究了10个欧亚种葡萄品种(系)、一个欧山杂种及其493株自交后代幼苗对葡萄霜霉病及白粉病的抗性及遗传关系,同时对其自交后代抗白粉病和霜霉病的遗传趋势进行了分析.结果表明,供试品种(系)及其自交后代对霜霉病与白粉病的抗性存在极显著相关,自交后代对两病表现伴随遗传现象,初步推断这可能是由葡萄抗病基因的多效性引起.在欧亚种葡萄品种自交后代群体中,虽然90%以上都是感病性中等或高的类型,但仍能够得到一定比例(10%以下)抗病性强的类型,这为利用欧亚种葡萄品种进行自交或品种间杂交选育优质抗病新品种提供了依据.     

黄淮海大豆新品种（系）的抗病性评价

大豆花叶病毒（SMV）、大豆孢囊线虫（SCN）和大豆根腐病（SRR）是危害中国乃至世界大豆生产的3种主要病害。为了评价黄淮海选育的大豆新品种（系）对这3种病害的抗性水平, 采用温网室接种鉴定及田间调查自然发病的方法, 对72份大豆新品种（系）进行了抗病性鉴定。结果表明, ‘中作J8012’、‘蒙01-38’、‘汾豆86’、‘中作X96328’、‘阜08-190’等9个品系对SMV流行株系SC3和SC7表现高抗或抗病, 占参试品种总数的12.5%; ‘周01015-1’、‘远育8号’和‘冀豆17’ 3个品系对SCN 1号生理小种表现中抗; 自然条件下, 抗SRR病情指数在15以下的大豆材料有31份, 占鉴定总数的43.06%; 对SMV和SRR的抗性水平均在中抗及以上的有‘阜08-325’、‘HD0113’、‘太丰6号’等8个品系, 占参试品种数的11. 11%, 而对3种病害的抗性水平均在中抗以上的材料仅有‘冀豆17’1份。本研究的结果可为大豆抗病育种选择亲本和培育多抗性的大豆新品种提供参考。     

芥菜品种资源对芜菁花叶病毒抗病性鉴定研究

1988-1990年向全国收集的658份芥菜品种进行了对芜菁花叶病毒(TuMV)的抗病性鉴定,结果获抗病型2份,中抗型10份,中感型60份,高感型586份,无免疫和高抗类型。鉴定表明品种间抗病性差异显著,变种间抗病性差异小,从中初步筛选出一批抗病和中抗型品种。     

葡萄品种对霜霉病抗性鉴定的生化指标研究

 通过盆栽接种和田间自然发病鉴定,从22个供试葡萄品种中鉴定筛选到1个高抗霜霉病的品种超藤和8个中抗品种饭刚黑、信浓乐、弗雷无核、黑蜜、优选皮奥萘、高妻、京秀、峰后。相关性分析表明,22个供试葡萄品种接种前和接种后2d,PPO、PAL活性和CAT比活性与霜霉病病情指数呈极显著负相关,SOD活性与霜霉病病情指数相关不显著。PPO、PAL活性和CAT比活性与葡萄品种对霜霉病的抗性呈极显著正相关,可利用这3种酶的活性作为葡萄品种霜霉病抗性鉴定的辅助评价指标。     

中国葡萄主要品种对葡萄座腔菌的抗性评价

采用离体有伤接种绿枝条的方法分析了我国25个葡萄主要品种对葡萄座腔菌Botryosphaeria dothidea的抗/感程度并建立了抗性分级标准。根据接种发病后的病斑长度,利用系统聚类方法鉴定不同葡萄品种对葡萄座腔菌的抗性并进行分级,建立了葡萄对葡萄座腔菌的抗性评价方法和抗性分级标准。结果表明,我国25个主要葡萄品种对葡萄座腔菌的抗性存在明显差异,‘巨峰’、‘红宝石无核’、‘藤稔’、‘红地球’、‘香妃’、‘玫瑰香’、‘巨玫瑰’、‘霞多丽’、‘龙眼’、‘西拉’、‘品丽珠’、‘贝达’、‘峰后’、‘梅鹿辄’、‘美人指’、‘赤霞珠’和‘山葡萄洛桑’等17个品种对葡萄座腔菌表现为抗病,‘弗蕾无核’、‘5BB’、‘夏黑’和‘无核白鸡心’表现为感病,而‘维多利亚’、‘牛奶’、‘矢富罗莎’和‘摩尔多瓦’表现为高感。     

鲜食葡萄品种对霜霉病的抗性及抗病机理研究

采用田间自然发病调查，田间接种鉴定和离体葡萄叶圆片室内接种鉴定鲜食葡萄品种对霜霉病的抗性及其抗性机理研究表明，品种间对霜霉病的抗性存在显著差异。可依感病病级分为三类，低感品种有“z工伊豆”、“奥林匹亚”、“山东早红”、“森田尼”、“早玛瑙”。几乎所有的无核品种均高感霜霉病，葡萄对霜霉病的抗性与叶内可滴定酸、还原糖、游离氨基酸含量无显著相关，与叶背气也密度、气孔开度也无相关，而外施高浓度邻苯二酚却显著降低了霜霉病发病程度。     

Dicofol resistance in Tetranychus cinnabarinus: resistance and stability of resistance in populations from Antalya, Turkey

Resistance against dicofol was investigated in the carmine spider mite, Tetranychus cinnabarinus. Higher resistance levels were detected by leaf residual bioassays than by topical bioassays, both done using a Potter spray tower, in almost all populations of T cinnabarinus examined from Antalya, Turkey. For instance, the resistance level at LC₉₅ was 17.5‐fold in topical bioassays but 58.9‐fold in leaf residual bioassays for the population collected from greenhouses in the Topçular district. There were differences of resistance levels at LC₉₅, ranging between 2.6‐ and 23.9‐fold using topical bioassays and between 5.0‐ and 58.9‐fold in residual bioassays, in populations collected from greenhouses from various districts. Populations from cotton showed lower resistance levels against dicofol than populations from greenhouses. Resistance to dicofol at LC₅₀ as indicated by topical and residual bioassays increased 19.7‐ and 100.7‐fold, respectively, in a colony from the laboratory strain of T cinnabarinus selected with dicofol alone for 16 cycles. However, the dicofol resistance at LC₅₀ increased 19.4‐ and 52.0‐fold in another colony selected in rotation with dicofol and tetradifon for six and eight cycles, respectively. The changes in resistance to dicofol 5 months after the selection ceased were as follows: in the colony selected for dicofol alone, using topical and residual bioassays, the resistance levels at LC₅₀ decreased to 11.7‐ and 99.1‐fold, respectively, and in the colony selected in rotation with dicofol and tetradifon to 10.8‐ and 15.8‐fold, respectively. © 2001 Society of Chemical Industry     

Induced resistance: a tool for fungicide resistance management

Induced resistance to the apple scab fungus Venturia inaequalis was demonstrated in greenhouse tests with 12-day-old seedlings of the apple cultivar Golden Delicious treated with methyl 2,6-dichloro-isonicotinate or 3,5-dichlorosalicylic acid prior to inoculation with the causal fungus. Studies of the dose-response of flusilazole on induced resistant plants revealed synergistic effects between both crop protection principles. Therefore, the use of such resistance-inducing compounds in the field might allow a reduction in the number of fungicide applications, and possibly a reduction in dose, thus resulting in improved efficacy of fungicides. There was also evidence that induced resistance could prove to be a valid strategy for the treatment of pathogen populations with reduced sensitivity to a given fungicide. © 1998 SCI     

Biochemistry of insecticide resistance

After briefly summarizing various resistance mechanisms and their effects on certain types of insecticides, attention is focused on gaps in the understanding of resistance. Most resistance mechanisms consist either of a change in sensitivity of the site of action or an increased capacity for detoxication. In both cases such changes could theoretically be due to quantitative changes of an enzyme (more sites of action or more detoxication enzyme) or to qualitative changes (less-sensitive site of action or more efficient detoxication enzyme). Examples have now been found for each of these possible causes of resistance to insecticides, except for an increased amount of sites of action. Whereas examples of the latter mechanism are known for cell lines resistant to anti-cancer chemicals, so far they have not been found in resistance to insecticides. The impact of the different mechanisms on development and stability of resistance is discussed.     

葡萄白粉病抗性鉴定方法优化及品种抗性评价

本研究通过对叶盘保湿方法的改进,不同菌源接种后发病严重度的分析,抗、感病对照品种的确定,建立了一种更为便捷、可靠、稳定的葡萄白粉病室内抗性鉴定方法:取葡萄藤自上而下第2～4片幼嫩叶片,打取直径15 mm的叶盘置于1.5％水琼脂平板进行保湿,采集田间菌源直接制备孢子浓度为2×105个/mL的孢子悬浮液接种,选定抗、感病葡...     

Cytochrome P-based resistance mechanism and pyrethroid resistance in the field Anopheles albimanus resistance management trial

The relative rates of cytochrome P⁴⁵⁰ selection in southern Mexican Anopheles albimanus populations were investigated during a 3 years indoor residual house spraying intervention with a pyrethroid (PYR) or DDT, a mosaic of organophosphate (OP)-PYR, and the annual rotation of OP-PYR-carbamate (CARB). This insecticide resistance mechanism, initially evenly spread in the mosquito population, correlated with PYR resistance during the second treated year, when cytochrome P⁴⁵⁰ contents increased in most villages of the PYR, rotation and mosaic schemes. However, by the third year, mean cytochrome P⁴⁵⁰ contents declined to susceptible levels in mosquitoes of the rotation and one mosaic group but not in the PYR-treated villages. In DDT-treated villages, a continuous decrement of cytochrome P⁴⁵⁰ levels occurred since the first treatment year, and susceptible levels were observed at the end of the intervention. Most correlations of cytochrome P⁴⁵⁰ levels and PYR resistance were lost during the third year, indicating that another mechanism evolved in resistant mosquito populations.     

The effective dominance of resistance genes in relation to the evolution of resistance

Field selection for a rare insecticide resistance (R) gene can be substantially delayed if R is rendered effectively recessive [if all or most heterozygotes ( R + ) are killed by the field dosages] and if a representative sample (+ +, R +, RR) of the population is permitted to escape exposure. The relationship between heterozygote mortality and escape in influencing selection rates has been considered at various frequencies of R. The cases when mating precedes selection, and when selection precedes mating, have been calculated using computer simulations. It is concluded that when R genes are rare it is advantageous (a) to apply the highest possible doses of insecticide in such a form that all exposed insects pick up an amount sufficient to kill all or most heterozygotes, (b) to apply the insecticide to adults after they have mated, rather than to younger adults or to larvae, and (c) to ensure that the proportion of insects given the opportunity to escape contact is as high as practical considerations allow. Once resistance is obvious (when samples are brought into the laboratory for tests), the R gene frequency will have risen to a level which makes the suggested strategy no longer valuable. Alternative strategies are briefly discussed.     

Measures of durability of resistance

ABSTRACT Conventional models for the durability of resistant cultivars focus on the dynamics of the frequency of resistance genes. This leads to a definition of the durability of resistance as the time from introduction of the cultivar to the time when the frequency of the virulence gene reaches a preset threshold. It is questionable whether this is the most appropriate way to measure durability. Here we use a simple epidemiological model to link population dynamics and population genetics to compare three measures of durability: (i) the expected time until invasion of the virulent genotype, by mutation or immigration, and subsequent establishment of a population (T(invasion)); (ii) the virulence frequency related measure of the time for the virulent genotype to take-over the pathogen population ( T(take-over)); and (iii) the additional yield, measured by the additional number of uninfected host growth days (T(additional)). Specifically, we show how the measures of durability are affected by deployment and epidemiological parameters. We use a combination of numerical solution and analytical approximation of a model for the population dynamics of avirulent and virulent genotypes of a pathogen growing in dynamically changing populations of resistant and susceptible cultivars. The three measures of durability are compared. Some consequences of the results for durable resistance in multilines and mixtures and the regional deployment of resistant cultivars are discussed.     

棉叶螨的抗药性现状与治理策略

棉叶螨也称为棉红蜘蛛,属蛛形纲叶螨科,其种类繁多,分布范围广,世代周期短,是为害棉花的一类重要害螨。目前,用于防治棉叶螨的化学药剂主要是神经毒剂及呼吸抑制剂2大类,且棉叶螨对多数药剂产生了不同程度的抗性,以二斑叶螨Tetranychus urticae为首的植食性害螨已成为世界上抗药性最严重的节肢动物之一。美国路易斯安那州棉田二斑叶螨种群对阿维菌素产生了1 415倍抗性,而国内棉花上棉叶螨主要对有机磷类药剂产生了较强抗性,最高为467倍。棉叶螨产生抗药性的机制主要涉及靶标突变及解毒代谢增强,其中靶标突变主要涉及乙酰胆碱酯酶、电压门控钠离子通道和谷氨酸门控氯离子通道等;细胞色素P450单加氧酶、羧酸酯酶和谷胱甘肽S-转移酶等一种或多种解毒酶共同参与害螨对化学药剂的解毒代谢。该文主要从棉叶螨的种类及分布、用于防治棉叶螨的化学药剂、棉叶螨的抗药性现状、抗药性机制解析和抗药性治理策略5个方面进行阐述,提出因地制宜的抗药性治理策略,旨在为棉叶螨的田间防治提供指导。     

小麦高代系的抗旱性状筛选与抗旱性评价

于2020—2021年度和2021—2022年度两个生长季,在杨凌抗旱棚（DS）、杨凌农作一站（YAS）和乾县试验站（QX）3个环境下分别测定了43份和20份小麦高代系的8个农艺性状及8个产量性状,通过计算抗旱指数评价各性状对小麦抗旱指标的贡献率,同时利用隶属函数法、聚类分析等方法进行综合分析,筛选抗旱性强的小麦高代系。结果表明,在干旱胁迫环境（DS）下,小麦的农艺性状和产量性状均受到不同程度的抑制。基于各性状对小麦抗旱指数的贡献度,筛选出生物量、产量、小穗数和千粒重等作为评价小麦抗旱性的重要指标。通过抗旱性综合评价值D和聚类分析将供试小麦品种（系）分为高抗旱、抗旱、中等抗旱、干旱敏感和干旱高敏感5个等级,两年度鉴定出21-1、21-34、21-39、21-18、21-2和22-17共6份高抗旱小麦品系。