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1.
The green cypress (Cupressus sempervirens) is of great interest for ornamental, reforestation and windbreak use in the whole Mediterranean basin. In Italy, seed material selected for resistance to the fungus Seiridium cardinale is produced in seed orchards by controlled crosses of parent trees. The insect pest showing the highest impact on seed cone production is Pseudococcyx tessulatana (Lep.; Tortricidae), which attacks cones during the initial growth period as well as full-grown cones. The impact on the seed cone crop of the tortricid was estimated on a clone patented for its resistance to cypress canker (Agrimed 1). The attack was inversely related to the cone crop, as it concerned 36.7% of cones in 1999 (high crop year) and the 66% in 2000 (low crop year). In both years, about 90% of the surveyed branches revealed cones attacked by P. tessulatana by the 1st life-cycle larvae, whereas only 40% of branches were also attacked by the larvae of the 2nd life cycle. The highest attack rate per branch was always observed on branches bearing a low number of cones. The potential of two control methods against P. tessulatana to protect cones which result from crossing a mother tree Agrimed 1 with selected father trees was also evaluated in 2000. The protection given by a sleeve surrounding the branch was almost complete (0.4% cone mortality), whereas a cone mortality of 24.3% was observed on branches treated by the insecticide diflubenzuron. Sleeves appear to be useful to protect branches on which special crosses were done, but are expensive and time-consuming and may favour the attack of the mealybug Planococcus vovae inside the sleeve. The insecticide application may represent a valid alternative, especially when protection should be directed toward a high number of branches.  相似文献   

2.
双唑草酮为中国创制的新型对羟基苯基丙酮酸双氧化酶(HPPD)抑制剂类除草剂,已于2018年取得中国农药登记。为了测定其对麦田抗性杂草荠菜的除草效果,共采集了36个荠菜种群,其中1个敏感种群采自未施用过除草剂的路边,其他35个疑似抗性种群均采自于中国苯磺隆使用历史超过20年的冬小麦田。在温室中采用整株盆栽法测定了荠菜种群对双唑草酮、苯磺隆、双氟磺草胺、甲基二磺隆、唑草酮和2甲4氯的抗性水平。结果表明,有28个种群对苯磺隆产生了抗性,其中种群K16009、K17005、15053和17003表现出高水平抗性。这4个种群对其他除草剂的交互抗性检测试验表明:种群K16009、K17005和15053对双氟磺草胺和甲基二磺隆表现出高水平交互抗性,其抗性指数范围为25-321,其GR50值远高于供试药剂登记的田间推荐剂量;而上述4个抗性种群对双唑草酮、唑草酮和2甲4氯均较为敏感,其GR50值均低于供试药剂登记的田间推荐剂量。唑草酮和2甲4氯也可用于小麦田抗性荠菜种群的防治,但该类药剂对施药时间要求较为严格。本研究结果表明,双唑草酮可有效防除对乙酰羟基酸合成酶(AHAS)类除草剂已经产生抗性的荠菜。  相似文献   

3.
The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997–2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8%) and D. populneus (29.4%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8%, and the highest mortality observed in individual study was 20.2%.  相似文献   

4.
The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997–2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8%) and D. populneus (29.4%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8%, and the highest mortality observed in individual study was 20.2%.  相似文献   

5.
The efficacy of an atmosphere with a high content of carbon dioxide under a pressure of 5 and 10 bar against young eggs of Ephestia kuehniella Zeller (Lep.: Pyralidae) and adults of Stegobium paniceum (L.) (Col.: Anobiidae) and Oryzaephilus surinamensis (L.) (Col.: Cucujidae) was investigated. At a pressure level of 10 bar, a 100% mortality in eggs of E. kuehniella was obtained after 4 hours. Complete control was not obtained with the adult beetles, except for a 2 hour-treatment at 10 bar with individuals of S. paniceum, which not were offered protection. It is demonstrated that when working with an atmosphere of carbon dioxide under pressure of 10 bar for 2 hours, even a slight protection from food material will influence the mortality. The reason for these findings are discussed.  相似文献   

6.
千金子为稻田恶性杂草,随着稻田免耕、直播技术的发展,千金子在稻田迅速蔓延,已成为稻田危害最严重的杂草之一,影响水稻产量和现代水稻轻型栽培技术的推广。随着稻田化学除草剂的常年使用,千金子对氰氟草酯等多种除草剂已产生抗药性。有研究表明,千金子对氰氟草酯产生的较高抗性与其靶标基因2027号和1999号位点突变有关。此外,千金子对除草剂代谢分解速率的快慢与其产生抗药性的程度也有着密切的关联。另有报道证实,谷胱甘肽S-转移酶活性的增强提高了千金子对除草剂的代谢。本文综述了国内外稻田千金子的抗药性现状和抗性的产生机制,简述了稻田千金子抗药性研究的重要性,并提出了抗性千金子治理策略,以期为抗性千金子的防治提供参考。  相似文献   

7.
The effects of Glomus intraradices, Pseudomonas alcaligenes and Bacillus pumilus on the root-rot disease complex caused by the root-knot nematode Meloidogyne incognita and the root-rot fungus Macrophomina phaseolina in chickpea was assessed by quantifying differences in the shoot dry mass, pod number, nodulation, and shoot content of chlorophyll, nitrogen, phosphorus and potassium. Inoculation of plants with G. intraradices, P. alcaligenes and B. pumilus alone and in combination significantly increased shoot dry mass, pod number, and content of chlorophyll, nitrogen, phosphorus and potassium in plants inoculated with pathogens over that in the uninoculated control plants. P. alcaligenes caused a greater increase in shoot dry mass, pod number, chlorophyll, nitrogen, phosphorus and potassium in plants with pathogens than did G. intraradices or B. pumilus. Combined application of G. intraradices, P. alcaligenes and B. pumilus to plants inoculated with pathogens caused a greater increase in shoot dry mass, pod number, nitrogen, phosphorus, and potassium than did an application of P. alcaligenes plus B. pumilus or of G. intraradices plus B. pumilus. Root colonization by G. intrardices was high when used alone, while inoculation with the pathogens reduced root colonization by G. intraradices. In the presence of P. alcaligenes and B. pumilus, root colonization by G. intraradices increased. In plants inoculated with just one antagonist, P. alcaligenes reduced galling and nematode multiplication the most, followed by G. intraradices, then B. pumilus. The greatest reduction in galling, nematode multiplication and root-rot was observed when both bacterial species and G. intraradices were applied together.  相似文献   

8.
SAUR(Small auxin-up RNA)是生长素早期响应逆境胁迫的基因,本文研究白菜型油菜全基因组中SAUR家族的信息,分析了该家族成员的基本特征。以强抗寒性白菜型冬油菜品种陇油7号(L7)和弱抗寒性冬油菜品种陇Lenox(X)为试验材料,采用低温和干旱处理,应用荧光定量技术分析不同基因在不同品种中的表达特性,筛选差异表达基因,为研究生长素早期应答基因调控白菜型冬油菜生长点发育机理提供支撑。结果表明:白菜型油菜的BraSAUR基因共有142个,在10条染色体中不对称分布,主要分布在2、3号染色体上,基因长度较短,且大多数基因没有内含子。qRT-PCR结果表明,低温处理后,与CK相比,在两个品种的叶片中,Bra029452的表达量变化趋势不同,24 h时在L7中的表达量是X的24倍,在生长点中,Bra010501在L7中24 h时表达量达到CK的4倍,而在X中是先增加后降低的趋势。模拟干旱胁迫后,Bra029452在L7的叶片中的表达量均显著高于CK,在X中则是逐渐降低,在L7的生长点中1 h和24 h表达量均高于CK,但在X中则表现为先降低后升高。低温胁迫和干旱胁迫条件下,Bra029452基因表达量在强抗寒性油菜品种L7的叶片及生长点中均逐渐升高,可推断该基因同时参与白菜型冬油菜耐受低温、干旱的调控过程。  相似文献   

9.
抗坏血酸过氧化物酶(Ascorbate peroxidase, APX)是植物活性氧代谢中重要的抗氧化酶之一,在植物抵抗氧化胁迫方面发挥重要作用。利用生物信息学方法对芹菜基因组中的APX基因家族成员进行鉴定和分析,并通过实时荧光定量PCR(quantitative real\|time PCR, qRT-PCR)验证分析AgAPXs在高温胁迫下的表达情况,为开展芹菜APX基因参与高温胁迫调控机制提供依据。结果表明:芹菜基因组中共有9个APX基因,随机分布在5个染色体上,并出现了基因片段复制现象;大多数基因被定位在细胞质中。系统发育分析表明,AgAPX基因家族可分为3个亚族,同一亚族中的成员具有相似的基因结构和基序。启动子顺式元件分析表明,大多数AgAPX基因含有多种与生长发育、植物激素和逆境胁迫相关的顺式元件。高温胁迫下,芹菜APX活性提高。qRT-PCR分析表明,AgAPXs在不同时间的高温处理下表达具有显著差异,并与转录组表达丰度相一致,AgAPX2AgAPX3AgAPX4AgAPX5AgAPX7的表达量和APX活性具有显著相关性,推测AgAPXs可能参与了芹菜抵御高温的调控过程。本研究初步鉴定并提供了芹菜APX基因家族成员信息,为今后进一步探索芹菜APX基因功能提供了重要的研究基础。  相似文献   

10.
从北京通州地区芹菜软腐病样中分离获得的菌株QC01在实验室条件下能浸软芹菜叶柄组织,并能引起温室种植的芹菜软腐症状的产生。经病原菌表型特征分析,确定该菌株为有鞭毛的革兰氏阴性果胶杆菌Pectobacterium。QC01与参试的P.carotovorum subsp.odoriferum(Pco)菌株T5和CC1均具备在37℃以及在含有7%Na Cl培养基中生长的能力;能分解柠檬酸盐和液化明胶;除常见碳源外,QC01还能降解α-甲基葡糖苷、麦芽糖、山梨醇、阿拉伯糖和阿拉伯半乳聚糖。基于16S rRNA基因完整序列系统发育关系表明,QC01与其他Pco菌株聚集成明显的Pco类群。QC01和CC1 type II与已报道的Pco菌株JKI 582 type II和NB 1892的16S rRNA基因完整序列相似性为100%。这是首次在中国发现Pectobacterium carotovorum subsp.odoriferum引发芹菜软腐病。  相似文献   

11.
The relationship between Xenorhabdus nematophilus and Photorhabdus luminescens, the bacterial symbionts of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora, against the diamondback moth, P. xylostella (L.), pupae showed the pathogenic capability of P. luminescens to be over that of X. nematophilus. They gave 60 and 40% mortality with LC50 values of 5×104 and 5.5×105 cells/ml, respectively.The number of bacterial cells influences the rate of killing the pupae of P. xylostella and a direct correlation between mortality of the pupae, percentage of deformed adults and the spraying dose with significant differences were observed. An inverse correlation found between the no. of eggs laid/female, percentage of hatching, adult survival and the spraying dose. These bacterial effects have been attributed to different toxic bacterial enzymes which damage the haemocytes and inhibit activation of the humoral immune system of the insect.  相似文献   

12.
The relationship between Xenorhabdus nematophilus and Photorhabdus luminescens, the bacterial symbionts of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora, against the diamondback moth, P. xylostella (L.), pupae showed the pathogenic capability of P. luminescens to be over that of X. nematophilus. They gave 60 and 40% mortality with LC50 values of 5×104 and 5.5×105 cells/ml, respectively.The number of bacterial cells influences the rate of killing the pupae of P. xylostella and a direct correlation between mortality of the pupae, percentage of deformed adults and the spraying dose with significant differences were observed. An inverse correlation found between the no. of eggs laid/female, percentage of hatching, adult survival and the spraying dose. These bacterial effects have been attributed to different toxic bacterial enzymes which damage the haemocytes and inhibit activation of the humoral immune system of the insect.  相似文献   

13.
田间小菜蛾抗药性监测及毒理机制研究   总被引:9,自引:0,他引:9  
田间监测结果表明,福州地区小菜蛾Plutella xylostella(L.)已对生产上常用的各类杀虫剂产生不同程度的抗性,从9月至次年5年期间,田间小菜蛾表现出较高水平的抗性,而在8月份则表现出明显低的抗性水平,短期高温和长期低温的环境条件可明显抑制小菜蛾幼虫的AChE和CarE活性,但短期低温的环境条件对小菜蛾幼虫的AChE和CarE活性影响不大,饲养温度的变化不会影响小菜蛾幼虫AChE和Ki值,但在较高的酶与杀虫剂的反应温度下,有机磷对小菜蛾、菜青虫和黄曲条跳甲AChE的抑制作用显著增高,此外,探讨了田间影响小菜蛾抗性水平的环境因素及毒理学机制。  相似文献   

14.
Trifluralin in cotton and benfluralin in groudnut. incorporated pre-planting. gave satisfactory control of grass weeds and increased crop yields substantially. Oxadiazon as a pre-planting treatment did not give satisfactory additional control of dicotyledons resistant to the first two herbicides. A post-sowing mechanical ridging operation controlled some herbicide resistant weeds, but its effects depended on timing, weed species and growing conditions. Supportive hand weeding of resistant weeds (mainly dicotyledons) was most effective 4 weeks after crop emergence. Crop yields similar to clean weeded controls were achieved by combining trifluralin or benfluralin with moderate supportive hand weeding and re-ridging. Herbicide applications could be made several months before crop planting during the dry season, giving more effective use of spray equipment and operatives. Delays of up to 24 hours between spraying and incorporation by normal cultivation could be tolerated without loss of herbicidal activity.  相似文献   

15.
Maize rough dwarf disease caused by Rice black-streaked dwarf virus (RBSDV) is transmitted by planthopper in China. Identification and development of resistant hybrids are complicated because of the inconsistencies in viral disease pressure every year. Marker-assisted selection can provide means for main-taining virus resistance alleles even in the absence of disease. In this paper a F2 segregation population was constructed to identity the molecular markers linked to the resistance gene using a cross between a resistant and a susceptible parents (Qi319×Ye107). Fifteen-day-old seedlings of F2 population were exposed to small brown planthoppers carrying RBSDV for 3 days in specific inoculation chamber. The inoculated plants were transplanted to screenhouse after removing the insects completely. In plant maturity stage the disease resistance of all the individuals were visually assessed. The results showed that 17, 8, 11, 51 and 122 plants were scaled from 0-4 respectively, in which 0 means no symptoms and 4 represents highly susceptible. Chi-square test demonstrated that the segregation ratio of phenotype was 1∶15 (resistant: susceptible) or 1∶6∶9 (resistant∶moderate∶susceptible) in the F2 population, indicating RBSDV resistance of maize was controlled by two recessive genes. The F2 individuals DNA were extracted and 261 SSR (simple sequence repeat) primers derived from maize genome ten chromosomes were selected from maize GDB database to construct genetic linkage map. The linkage map consisted of 71 polymorphic SSR markers, spanning a genetic distance of 996.6 cM with an average interval of 14.0 cM between adjacent markers. The resistant and susceptible gene pools were set up for BSA (bulked segregant analysis) and 6 polymorphism markers were obtained with BSA-SSR method between the two pools. The F2individuals were further analyzed with 6 polymorphism markers. Chi-square test showed that phi 051, umc1407 and umc1432, mapped on chromosome 7 and 10, exhibited segregation distortion significantly and very significantly in susceptible individuals. These three SSR markers were identified as potential markers linked to the resistant loci.  相似文献   

16.
Pathogenic and genetic diversity in Ascochyta rabiei populations in Pakistan were evaluated. Biological pathotyping of 130 A. rabiei isolates (obtained from hierarchically collected samples) was conducted on a set of three chickpea differentials, i.e. ILC 1929 (susceptible), ILC 482 (tolerant) and ILC 3279 (resistant), under controlled conditions. Disease severity data were recorded 12 days after inoculation. Statistical analysis grouped the isolates into three pathotype classes. Four isolates belonged to pathotype I (least aggressive), 79 isolates to pathotype II (medium aggressive) and 47 isolates to pathotype-III (highly aggressive).Genetic analysis was performed using RAPDs and oligonucleotide fingerprinting, where Hinf I-digested DNA was hybridized to the32P-endlabeled oligonucleotide probes (CAA)5, (GAA)5, (GA)8, (CA)8and (GATA)4. Dendrograms produced by cluster analysis discriminated 46 genotypes in the A. rabiei population of Pakistan. Genetic distances and relatedness between isolates were calculated. At a genetic distance of 0.3, genotypes were divided into six distinct genotype groups A, B, C, D, E and F containing 16, 11, 2, 5, 5 and 7 isolates, respectively. Most of the genotypes were area specific or predominated in certain areas but did not belong to a distinct pathotype, while most of the aggressive isolates (pathotype III) occurred in Northern Punjab and in the North Western Frontier Province.  相似文献   

17.
通过田间试验研究了溴氰虫酰胺对小菜蛾的田间防效,分析了露地栽培条件下溴氰虫酰胺在花椰菜上的消解动态和最终残留情况。结果表明:田间药效试验中10%溴氰虫酰胺可分散油悬浮剂按推荐高剂量(有效成分21 g/hm2)施药后24 h~7 d对小菜蛾的防效为92.8%~98.3%;按2倍推荐高剂量(有效成分42 g/hm2)施药,溴氰虫酰胺在花椰菜上的消解半衰期为3.86 d,其残留超标风险与田间用药量、用药次数正相关。建议生产中采用10%溴氰虫酰胺可分散油悬浮剂以有效成分21 g/hm2的剂量用药,每季最多施药2次,露地栽培条件下花椰菜上安全间隔期为3 d。  相似文献   

18.
绿豆抗旱指标鉴选与评价   总被引:3,自引:0,他引:3  
采用人工盆栽控水试验,对21份绿豆种质资源进行抗旱期综合评价,鉴选绿豆品种抗旱性指标体系。结果表明,与绿豆抗旱性相关的10个指标经主成分分析被分为3个主成分,其中茎高、茎粗、结荚数、叶面积、叶绿素含量、丙二醛含量、脯氨酸含量与绿豆抗旱性密切相关。采用聚类分析,并结合绿豆隶属函数法综合分析,将21份绿豆品种分成:强抗旱品种为‘良丰1号’、‘HX04037’和‘榆绿1号’,中抗旱性品种为‘嫩绿1号’、‘兴绿1号’、‘天山大明绿’、‘西绿1号’、‘绿宝绿豆’、‘赤绿3号’、‘白绿1号’、‘中绿1号’、‘晋绿1号’、‘八宝绿豆’、‘中绿6号’、‘鑫绿1号’和‘HX04050’,弱抗旱性品种为‘冀北12-1号’、‘绿珍珠2号’、‘ZKY-2’、‘白绿522’和‘邯绿8号’。  相似文献   

19.
种子丸粒化是种子包衣的重要类型,与常规的种子包衣相比,种子丸粒化不仅可以改变种子形状,使种子外形标准化,而且有效成分携带量更大、有效成分间相容性更好。本研究以不规则的大葱种子为对象,考察了不同填料及黏结剂用于种子丸粒化的性能,在获得优化配方的基础上,对所制备丸粒的微观结构进行了表征。结果表明:将硬脂酸镁和滑石粉按质量比1:2混合后作为填料,以质量分数为1%的羧甲基纤维素钠水溶液作为黏结剂时,较适合用于大葱种子的丸粒化,所制得的丸粒各项指标合格,符合种子丸粒化的要求。微观结构电镜观察表明,采用不同填料制备的丸粒在微观结构上存在明显差异,填料间的结合越紧密,丸粒的强度越大。添加农药对丸粒化种子的影响评估结果表明,合理添加适宜的农药对种子发芽影响较小。本研究通过宏观性质与微观结构相结合,进一步丰富了种子丸粒化研究基础理论,对提高精量化播种和规范化种植水平具有一定参考价值。  相似文献   

20.
关中西部不同绿豆品系的产量和光温水特性   总被引:3,自引:0,他引:3  
分析不同绿豆品系的产量和光、温反应,确定不同绿豆品系对光、温反应的敏感性。以2012—2014年国家绿豆区域试验14个参试品系为试验材料,于全生育期记录各品系平均温度、平均降水和光照时间,并干成熟期分期采摘,全区计产,分析不同绿豆品系对产量和气象因子的敏感性。试验结果表明,不同品系的产量高稳系数存在差异,品系10(维绿8号)高稳系数最高,较对照品系增加54.3%;不同绿豆品系的光、温、水反应特性差异显著,其中有9个品系(品系1,2,3,6,7,8,10,11,12)的光稳系数高于对照(P0.05),7个品系(品系1,2,3,6,7,8,11)的温稳系数高于对照(P0.05),8个品系(品系1,2,3,6,7,8,10,11)的水稳系数高于对照(P0.05);以光稳系数、温稳系数和水稳系数为基础对14个绿豆品系进行划分,其中对环境反应稳定的品系4个、敏感的品系有4个和中间类型的有6个。夏播绿豆不同品系对环境反应的敏感程度分为稳定型、中间类型、敏感型,其中属于中间类型的绿豆品系10能够获得更高更稳定的产量。  相似文献   

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