辣椒疫病抗性的浸根接种鉴定方法

为建立规模化的辣椒疫病苗期抗性鉴定技术, 将辣椒疫霉人工接种于抗疫病辣椒品种‘ICPN21-03’和感病辣椒品种‘B16144’, 研究了接种菌液浓度?接种时期?病情调查时期和接种方法等对人工接种鉴定效果的影响?结果表明, 接种菌液游动孢子浓度为10个/mL时, 感病品种病情指数为73.37, 可以满足寄主发病的需要; 1 ~ 10真叶期接种均能使植株发病, 但5 ~ 6真叶期接种能反映抗感病品种真实抗性; 接种5 d调查抗感病品种病情指数分别为9.32和73.37, 可明显区别抗感病品种?使用浸根法进行鉴定, 需菌量小, 对接种环境要求小?用37个辣椒品种进行验证, 鉴定结果表明该苗期抗性鉴定技术可很好地对辣椒品种进行抗性水平分级鉴定?     

A Laboratory Assay for Phytophthora infestans Resistance in Various Solanum Species Reflects the Field Situation

Physiological and molecular research on resistance responses of Solanum tuberosum cultivars and partially resistant Solanum species to Phytophthora infestans requires a reliable resistance test that can be used in the laboratory. Laboratory tests performed on detached leaves and intact plants were compared with field tests for similarity of late blight reactions. Detached leaves from field-grown plants were as resistant as detached leaves from climate chamber-grown plants when challenged with P. infestans. However, detached leaves incubated in covered trays at high relative humidity were more susceptible than detached leaves kept in open trays or leaves on intact plants. The incubation conditions of detached leaves in covered trays rather than detachment itself appeared to affect the resistance expression. Detached leaves of some wild Solanum genotypes became partially infected, whereas intact plants were completely resistant when inoculated. Inoculation of leaves on intact plants, however, resulted in lower infection efficiencies. These limitations should be taken into account when choosing the appropriate inoculation method for specific purposes. For resistance screening, laboratory tests proved to be a good alternative for field tests. The ranking of resistance levels for twenty plant genotypes was similar under laboratory and field conditions.     

辣椒疫病生防菌的筛选及其抑菌机制初探

 观测了枯草芽孢杆菌BS、GF1和荧光假单胞菌LX1、BCA1 4株生防菌对7株来源不同的辣椒疫病病菌的拮抗作用和防治效果。结果表明:BS对辣椒疫病病菌菌丝的拮抗作用显著高于其它3株生防菌,抑制率达到33.2%~59.4%;温室防病试验中,BS喷雾处理和BCA1灌根处理对辣椒疫病具有明显的防治效果,防效分别达到56.83%和57.81%。BS抗菌粗提物对病菌菌丝生长具有明显的抑制作用,抑菌作用与抗菌粗提物稀释倍数呈负相关,稀释10倍时抑制率达到100%。BS抗菌粗提物处理使辣椒疫病病菌菌丝分枝增多,分枝间距明显缩短,分枝顶端原生质消解;同时可以显著抑制辣椒疫病病菌游动孢子的萌发速度和萌发率。对绿色荧光蛋白标记的BS菌株(gfp-BS)在辣椒幼苗各部位定殖情况的检测表明:该菌可以通过种子细菌化成功定殖于辣椒植株体内,出苗60 d后仍能检测到荧光标记的菌落,其定殖量维持在10³ cfu/g以上。     

辣椒疫病抗性资源‘CM334’的抗性遗传分析

采用经典遗传分析方法,对来源于美国辣椒疫病抗性资源 ‘CM334’的疫病抗性遗传规律进行了研究。试验将‘CM334’与疫病高感自交系‘949’配制杂交组合,并构建杂交组合的6个世代（P1,P2,F1,F2,B1和B2）,用苗期伤根灌根接种法对其各世代群体植株进行抗性鉴定, 并进行χ2的适合性测验。结果表明: ‘CM334’的抗疫病性状遗传符合一对显性基因控制模式。     

持久抗条锈小麦品种抗病性特点分析

利用我国１５个小麦条锈菌主要流行小种和致病类型，测定了国内外７个持久抗条锈小麦品种的抗病性。结果表明，尽管不同持久抗病品种苗期抗病谱有很大差异，但成株期对许多供试菌系均表现有效抗性。抗病温度敏感性试验显示，随着培养温度由低温、常温向高温提高，持久抗性品种抗性逐渐增强，表现为反应型和严重度降低。抗病基因分析表明，持久抗病品种不仅含有温敏型微效抗病基因，而且含有成株抗病基因，它们共同对品种持久抗条锈性起作用     

华南地区主要番茄品种对南方根结线虫的抗性评价

通过人工接种方式, 对华南地区番茄主要栽培品种对优势根结线虫——南方根结线虫（Meloidogyne incognita）的抗性进行了评价。结果表明,广东栽培品种年丰、红宝石、新星、福安、粤红玉、穗丰、金丰、益丰、丰顺、大丰顺、满丰和法国品种SAINT PIERRE均高度感病; 而法国品种 PIERSOL VFN高度抗病,根结率为0。根据SAS8.0多重比较分析表明,在F0.01的水平上, 品种PIERSOL VFN与其余品种之间对根结线虫的抗性均存在显著性差异,而其他12个品种间对根结线虫的抗性差异不显著。     

贵州省烟草黑胫病菌对甲霜灵的抗药性

为了明确贵州地区烟草黑胫病菌对甲霜灵的抗药性水平, 从贵州省12个市、县采集黑胫病病株, 经分离纯化鉴定, 获得98株黑胫病菌株, 采用生长速率法测定其对甲霜灵的敏感性。结果表明, 采自不同地区的菌株对甲霜灵的敏感性差异较大, 各供试菌株的EC50 值分布范围为0.419 2～20.486 1 μg/mL; 各地区平均EC50 在0.551 9～10.986 0 μg/mL之间; 最低抗药性水平为1.00, 最高抗药性水平为48.87, 相差48.87倍, 各地区平均抗药性水平在1.32～26.21之间。遵义、兴仁、贵定、赫章和兴义有抗甲霜灵菌株出现, 除遵义部分菌株的抗性水平表现为高抗外, 其余菌株对甲霜灵产生的抗性均处于中抗水平。     

43个中国小麦品种(系)抗叶锈性研究

 选用12个墨西哥叶锈菌生理小种对43个中国小麦品种(系)所携带的抗叶锈病基因进行了推导,在25个品种(系)中推导出6个抗叶锈基因Lr1,Lr10,Lr13,Lr14a,Lr16和Lr26,9个品种(系)对本试验所使有的12个叶锈菌生理小种都表现感病反应,另有9个品种(系)携带未知的抗叶锈基因。在墨西哥2个地点进行的田间成株期抗叶锈性试验表明,12个品种(系)表现慢叶锈性,在将来的抗病育种中有一定的应用价值。     

云南白背飞虱不同种群对杀虫剂的抗药性及变化趋势

为了掌握云南不同稻区白背飞虱Sogatella furcifera(Horváth)种群对常用杀虫剂的抗药性及其发展趋势,2012-2015年,连续4年采用稻茎浸渍法在室内测定了滇西沧源、滇西南勐海和滇东师宗3个稻区田间白背飞虱对5种常用杀虫剂的抗药性。云南不同稻区田间白背飞虱对5种药剂的抗性水平总体在0.9~23.4倍,其中对毒死蜱的抗药性最高,除少数年份外,LC502 mg/L,抗性倍数10倍,抗药性达到了中等水平,年度间变化幅度较大;对噻嗪酮的抗药性呈下降趋势,滇西沧源和滇西南勐海种群对噻嗪酮的抗药性由2012年的中抗水平(11.0倍和23.4倍)下降到2015年的4.6倍和7.5倍;3个稻区种群4年对吡虫啉、吡蚜酮和噻虫嗪的抗性倍数最高达7.2、6.5和5.5倍,总体表现为无抗或低水平抗性。由于噻嗪酮和毒死蜱在云南稻区的频繁和广泛使用,田间白背飞虱已对其产生抗药性,建议限制这两种杀虫剂的使用频率或与不同作用方式的药剂轮换使用,其余药剂可以有计划地选用。     

基于EPG技术的棉蚜抗性指标筛选

本文以研究不同抗性水平的棉花材料上棉蚜的取食行为及与其生长发育的关系,筛选可作为棉花抗蚜鉴定指标的刺探电位图谱（Electrical penetration graph,EPG）参数为目的。采用生物测定的方法比较了棉蚜在不同棉花品种上的生长发育参数,利用EPG技术对不同抗性水平棉花上棉蚜的取食行为进行分析,并对生长发育参数与主要的EPG参数进行相关性分析。棉蚜室内生测结果表明,棉蚜在4种高抗品种（辽5632-642、TYJ-98-6、锦454和中G5）上的存活率、产仔数、内禀增长率均较中抗和高感品种低。EPG监测结果显示,在高抗品种上,Np波总次数与总时间均显著高于其他品种,第1次刺探时间靠后且持续时间长,C波和E2波总时间较短,F波和E1波总时间长且次数多;在中抗品种中棉所49(CCRI 49)、中棉所79(CCRI 79)和雷克斯（光叶）上,F波总次数和总时间均较低;在中抗品种非洲E-40和高感品种辽棉6号上,Np波总次数与总时间均低于其他品种,C波总时间与E2波总时间长。结果表明抗性棉花材料对棉蚜生长发育有不利的影响,Np波总次数、E1波总次数、第1次刺探出现时间等5个EPG参数...     

知母提取物诱导马铃薯植株抗晚疫病作用机制初探

为明确知母提取物诱导马铃薯抗晚疫病的作用,本研究测试了经知母提取物处理并接种晚疫病菌后马铃薯植株的超氧化物歧化酶（SOD）、苯丙氨酸解氨酶(PAL)、β 1,3 葡聚糖酶和几丁质酶活性的变化。结果表明,经过知母提取物处理后的马铃薯植株,在受到晚疫病菌侵染后24～96 h,SOD和PAL活性显著升高并持续处于高活性水平;在接种48 h后β 1,3 葡聚糖酶活性开始显著升高,直到接种后96 h一直维持在较高活性水平;而无论是接种晚疫病菌还是经过知母提取物处理,几丁质酶活性都没有发生显著的变化。     

The potential for the Rapid Screening of Potato Cultivars (Solanum tuberosum) for Resistance to Powdery Scab (Spongospora subterranea) using a Laboratory Bioassay

Powdery scab of potato, once established in a field, is difficult to control because of the longevity of the resting spores (cystosori) of the causal organism, Spongospora subterranea f.sp. subterranea. Host resistance is likely to be the most efficient in a long-term control strategy for preventing build-up of field inoculum and spread of the disease. Resistance screening of potato cultivars is mostly done in laborious field trials where disease development is likely to be unpredictable. A bioassay with potato tissue cultured plantlets and cystosori as inoculum is described and was tested for its potential to screen potato cultivars at an early stage for their relative susceptibility to powdery scab by comparing the lab results with field data. With cystosori inoculum of Swiss origin, the laboratory test showed clear differences between the potato cultivars in the severity of zoosporangial root infection which correlated better with ranked tuber infection data, compared to root galling. There are apparent differences in the relative trends in susceptibility between roots and tubers of five selected cultivars when using naturally infested soil instead of prepared cystosori as inoculum in the lab bioassay. Furthermore, differences in the severity of zoosporangial root infection of two selected cultivars were found when cystosori from different countries where used as inoculum. A possible host genotype × pathogen interaction is discussed. The bioassay has the potential to screen and select for resistant material at an early breeding stage thus making field trials not unnecessary but more economical. It will allow the use of a standard set of pathogen collections and facilitate testing for inoculum virulence in infested soils.     

Screening of Urfa pepper landraces for resistance to Meloidogyne incognita

Journal of Plant Diseases and Protection - The root-knot nematodes (Meloidogyne spp.) are significant pathogens that affect the yield and fruit quality in pepper cultivars (Capsicum spp.)....     

疫霉菌对霜脲氰抗性遗传及对霜脲氰和甲霜灵的交互抗性

就疫霉菌对霜脲氰抗性的产生和遗传，以及疫霉菌对霜脲氰和甲霜灵的交互抗性进行了研究。结果表明，苎麻疫霉容易对霜脲氰产生抗药性突变，但抗性在连续３代单游动孢子分离过程中逐渐丧失。大雄疫霉对霜脲氰不易产生抗性突变，恶疫霉、大雄疫霉和苎麻疫霉对甲霜灵和霜脲氰不存在交互抗性     

拮抗细菌对番茄植株抗灰霉病的诱导

通过拮抗细菌多粘类芽孢杆菌W3、Y2和地衣芽孢杆菌W1 0诱导接种和灰霉病菌挑战接种试验 ,明确了 3菌株培养液和去菌液对番茄植株抗灰霉病的诱导作用。 3株拮抗细菌的诱导抗病效果为 2 3 .4%～ 64.5% ,其中W3诱导作用最强。W 3培养液及其去菌液处理后 5d ,诱导效果达最大值 ,且 1 2d后仍有诱抗作用。在 1 0 2 ～ 1 0 1 0 cfu/ml范围内 ,拮抗细菌的诱导活性随浓度增加而增强 ,以≥ 1 0 8cfu/ml的效果最好。拮抗细菌处理叶上部各叶片间诱抗效果无明显差异。     

Usefulness of the Detached Pod Test for Assessment of Cacao Resistance to Phytophthora Pod Rot

The detached pod test by spray method (DPT-SM) was developed to facilitate the screening of cacao genotypes for resistance to Phytophthora pod rot (PPR) caused by Phytophthora palmivora. The test has been adopted in many cacao research institutes, and it is imperative that its validity be assessed. In this study, 40 genotypes from various cacao groups were selected and screened for resistance to PPR by DPT-SM and field observations. Significant variation was observed in the reactions of the selected accessions based on the disease rating scale for DPT-SM and the percentage pod rot from field observations. A correlation coefficient of 0.68 (P<0.001) was observed between the results of year-1 and year-2 field observations. However, relatively lower correlation values were obtained between year-3 and year-1 (r=0.32; P=0.041) and year-3 and year-2 (r=0.35; P=0.025) field observations. A higher level of susceptibility was observed in the third year of field observations (63%) than in the first (15%) and second (25%) years. This suggests that the predisposing factors for PPR were unstable between the years of field observations. Data obtained from the Trinidad and Tobago Meteorological Services showed that the rainfall in November of the third year was higher than the amounts of rainfall in November of the first 2 years of field observations. This month marks the beginning of the main pod harvest season (November–February) and the high rainfall in November of the third year, and the presence of large number of mature pods may account in part for the increase in PPR in the third year of field observations than in the first 2 years. This shows that absolute reliance could not be placed on a single year of field observations in determining clonal resistance to PPR. A correlation coefficient of 0.59 (P<0.001) was obtained between the result of year-2 field observations and DPT-SM. Relatively lower correlation values were observed between DPT-SM and year-1 (r=0.55; P<0.001) and year-3 (r=0.44; P=0.005) field observations. The result of DPT-SM, however, shows a higher correlation (r=0.66; P<0.001) with the average of years 1–3 field observations. This suggests that a stronger association may exist between the result of DPT-SM and the cumulative data on field observations for a period longer than 3 years. The correlation (r=0.66; P<0.001) observed in this study confirms the usefulness of DPT-SM as an effective method of assessing clonal resistance to PPR and predicting field reaction in the long term. Since field observations are labour intensive and expensive to conduct on a yearly basis, the DPT-SM offers a cheaper and effective means of assessing clonal resistance to PPR. Being a non-destructive inoculation method, the DPT-SM provides a suitable option for cacao collections in genebanks to be assessed. It is also a cost-effective method for use in cacao breeding programmes. Based on its reliability, the DPT-SM has been adopted in the CFC/ICCO/IPGRI cocoa project ‘Cocoa Germplasm Utilization and Conservation: A Global Approach’ for the assessment of cacao resistance to PPR in several cocoa producing countries.     

Susceptibility of Broccoli Cultivars to Bacterial Head Rot: In Vitro Screening and the Role of Head Morphology in Resistance

Head rot is a major disease of broccoli caused by the soft rot pathogens Pseudomonas fluorescens and Erwinia carotovora. Two in vitro pathogenicity tests were evaluated as a methods to identify broccoli cultivars susceptible or resistant to bacterial head rot. One test used mature heads excised from the plant and inoculated with squares of cotton lint which had been soaked in a bacterial suspension. The other test involved stab-inoculating axenically grown seedlings. With the excised head test, susceptible cultivars showed a black soft rot, whilst less susceptible or moderately resistant cultivars showed only watersoaking, or browning and slight softening of the tissue. No cultivar was completely resistant. Ten cultivars were tested, and their susceptibility ratings corresponded with previously recorded field data, with one exception. This laboratory test could be used to screen for susceptibility to head rot in broccoli breeding programmes. The seedling test distinguished differences in aggressiveness among bacterial isolates but not cultivar susceptibility. Increasing head size correlated negatively with disease resistance. Head shape, i.e. cultivars which showed a domed shape rather than a flat shape, was positively correlated with disease resistance. Thus small domed heads are more resistant to head rot than large flat heads. Other morphological characteristics, viz. floret prominence and number, and sepal stomatal number were not correlated with host resistance.     

辣椒嫁接抗病砧木筛选及嫁接栽培技术

共选取8个砧木品种,通过生长势观察、抗病性调查、亲和力观测等试验, 筛选出综合性状突出的砧木ZM608,进行了抗性测定,接菌后7、15、30 d的死株率为0、0、2.5%,而本地主栽品种陇椒2号分别为2.5%、21.25%、37.5%。经较大面积嫁接示范推广,辣椒疫病死株率控制在6%以内。