番茄早疫病菌抗啶酰菌胺菌株的适合度及生物学特性

为了评价番茄早疫病菌Alternaria solani对啶酰菌胺的抗性风险,采用菌丝直径法和孢子萌发法探讨番茄早疫病菌抗啶酰菌胺菌株的适合度变化和生物学性状差异。结果表明:番茄早疫病菌对啶酰菌胺的抗性可稳定遗传;与敏感菌株相比,抗性菌株的菌丝生长减慢,产孢量明显增多,病斑直径达8.5 mm以上,致病力显著增强,产毒量也有增加的趋势,但孢子萌发率无显著差异;啶酰菌胺对抗性菌株的防效显著下降为64.17%~33.49%;抗性菌株的最适p H范围变宽为5~9;中抗菌株的最适温度(25℃)、最佳碳源(淀粉和乳糖)和氮源(蛋白胨)没发生变化,但高抗和极高抗菌株的最适温度范围变宽为25~30℃,最适碳、氮源发生了变化。其中,高抗菌株的最适碳、氮源分别为乳糖和大豆粉;极高抗菌株的最适碳源为淀粉,最适氮源为玉米粉和蛋白胨。表明番茄早疫病菌对啶酰菌胺产生抗性后,较易存活而形成优势群体,因此需采取一定措施延缓抗性的发展、延长啶酰菌胺的使用期限。     

上海地区草莓灰霉病菌对啶酰菌胺的敏感性检测及抗性机制分析

为明确上海地区草莓灰霉病菌Botrytis cinerea Pers. 对主要防治药剂啶酰菌胺的敏感性水平及抗性机制,采用平皿法检测了采自上海市6个区县的195株草莓灰霉病菌株对啶酰菌胺的敏感性,并分析了其中20株不同敏感型菌株的琥珀酸脱氢酶基因序列。结果显示:啶酰菌胺对上海地区草莓灰霉病菌菌丝生长的EC₅₀最小值为0.15 μg/mL,最大值大于110 μg/mL;对孢子萌发的EC₅₀最小值为0.19 μg/mL,最大值大于50 μg/mL。上海地区草莓灰霉病菌对啶酰菌胺的抗性频率为29.74% (抗性水平大于10),高抗频率为20.51% (抗性水平大于100)。该抗性的产生与琥珀酸脱氢酶SdhB亚基发生H272R或P225F突变有关,其中H272R突变发生较为普遍。研究表明,上海地区草莓灰霉病菌对啶酰菌胺的抗性水平及抗性频率较高,主要抗性机制为病原菌琥珀酸脱氢酶SdhB亚基上的H272R突变。     

番茄灰霉病菌对咯菌腈的抗性诱变及抗药突变体的生物学特性

为评估番茄灰霉病菌Botrytis cinerea对咯菌腈的抗性风险,就室内经紫外照射获得抗药突变体的方法及抗性突变体的生物学性状进行了研究。结果表明:番茄灰霉病菌分生孢子的紫外照射亚致死时间为90~120 s;经亚致死时间紫外照射后,4个亲本菌株中有2个菌株共产生了6个抗咯菌腈的突变体,其EC50值是亲本菌株的310倍以上,抗性突变频率为3.13×10-7;经紫外照射诱变获得的所有抗性突变体在菌丝生长速率、产孢量、产菌核能力及其在番茄果实上的致病性方面均比其亲本菌株明显降低。相关分析显示,所得抗咯菌腈突变体对氟啶胺、啶菌唑、啶酰菌胺和嘧霉胺无交互抗性。表明番茄灰霉病菌对咯菌腈的抗药性风险较低。     

我国葡萄灰霉病菌对四霉素和啶酰菌胺的敏感性测定

灰霉病是葡萄生产上的重要病害之一,严重影响葡萄果实的品质和产量。为明确葡萄灰霉病菌对四霉素和啶酰菌胺的敏感性,本研究分别采用菌丝生长速率法和孢子萌发法测定了四霉素和啶酰菌胺对采自云南省宾川县、湖北省武汉市和辽宁省北镇市60株葡萄灰霉病菌的有效抑制中浓度EC₅₀,建立了敏感性基线,并分析了二者之间的交互抗性。结果显示,葡萄灰霉病菌对四霉素和啶酰菌胺的敏感基线分别为0.245和1.115 μg/mL;上述葡萄灰霉病菌均对四霉素敏感,而11.7%的菌株表现为啶酰菌胺抗性。并且四霉素与啶酰菌胺之间不存在交互抗性(r=-0.040,P>0.05)。因此,四霉素可作为防治葡萄灰霉病的候选药剂,研究结果对两种杀菌剂的科学使用以及葡萄灰霉病的可持续防控具有重要的理论和实践意义。     

灰葡萄孢对氟唑菌酰羟胺不同敏感型菌株的生物学特性

为明确灰葡萄孢对氟唑菌酰羟胺不同敏感型菌株的生物学特性差异,将9个不同敏感型菌株在无药PDA平板上继代培养10代后,测定其对氟唑菌酰羟胺的敏感性。采用菌丝生长速率法分别在PDA平板和离体叶片上测定了其菌丝生长速率、产孢量、孢子萌发率和致病性,以及其对温度、pH值和葡萄糖的敏感性,并对其编码琥珀酸脱氢酶的SdhA、SdhB、SdhC和SdhD 4个亚基基因进行了克隆与测序。结果显示:从田间获得的2个低抗菌株、2个中抗菌株和2个高抗菌株对氟唑菌酰羟胺的敏感性变异指数在0.60~1.15之间,而通过室内药剂驯化获得的高抗菌株BLH5F对氟唑菌酰羟胺的敏感性变异指数为0.23;除低抗菌株WP8的菌丝生长速率显著低于2个敏感菌株,以及中抗菌株WP6和高抗菌株WPE9的产孢量显著低于2个敏感菌株外,其余各抗性菌株在菌丝生长速率、产孢量、孢子萌发率和致病性方面均无显著差异。整体而言,7个抗性菌株在对温度、pH值和葡萄糖的敏感性方面与敏感菌株无显著差异。基因克隆及测序结果表明,室内药剂驯化获得的高抗菌株BLH5F SdhB基因的272位由组氨酸变为了精氨酸 (H272R),田间获得的低抗、中抗和高抗各2个菌株均为SdhB基因的225位由脯氨酸变为了亮氨酸 (P225L)。综合分析表明,灰葡萄孢对氟唑菌酰羟胺不同敏感型菌株具有相似的适合度。因此,推测在药剂的选择压下,抗氟唑菌酰羟胺的灰葡萄孢菌株在田间容易形成优势种群。     

西瓜蔓枯病菌啶酰菌胺抗性突变体的生物学特性研究及其Sdh B基因位点检测

为评价西瓜蔓枯病菌对啶酰菌胺的抗性风险,了解其抗性机理,室内通过药剂驯化方法获得2株啶酰菌胺的抗性突变体XF21-3和YC60-1,测定了抗性突变体的生物学特性,并通过对Sdh B基因片段的测序比对,分析了西瓜蔓枯病菌对啶酰菌胺的抗性机理。生物测定结果表明:啶酰菌胺对2株抗性突变体的EC50值分别为108和124 μg/mL,抗性倍数（RR）分别为1 007和1 347,均为高抗菌株;抗性突变体的菌丝生长速率和产孢量均大于亲本菌株,但其致病性与亲本菌株无显著差异,对外界环境渗透压的敏感性低于亲本菌株;此外,啶酰菌胺与萎锈灵、戊唑醇、乙霉威及醚菌酯之间均不存在交互抗性,但与噻呋酰胺之间存在交互抗性。Sdh B基因片段测序及比对结果表明,高抗性突变体中Sdh B亚基277位上的氨基酸所对应的碱基由CAC突变为TAC,即由组氨酸（His）突变为酪氨酸（Tyr）。研究表明,西瓜蔓枯病菌在药剂选择压力下容易形成啶酰菌胺的抗性群体,且抗性突变体的离体适合度高于亲本菌株,此外,啶酰菌胺与同类型杀菌剂噻呋酰胺之间存在交互抗性,因此认为西瓜蔓枯病菌对啶酰菌胺具有中等抗性风险;同时进一步验证了Sdh B亚基277位上的氨基酸突变（His→Tyr,CAC→TAC）是西瓜蔓枯病菌对啶酰菌胺产生抗性的原因。     

山西省番茄早疫病菌对苯醚甲环唑的敏感性及抗性突变体的适合度

为了解山西省番茄早疫病菌Alternaria solani对苯醚甲环唑的抗性,采用菌丝生长速率法检测了该病菌对苯醚甲环唑的敏感性,分析了抗性水平和抗性指数;同时通过室内诱导获得了苯醚甲环唑抗性突变体,检测了突变体的抗性遗传稳定性、交互抗性和适合度。结果表明:分离自大同、忻州、长治、晋中和运城5市的101株菌株的EC50范围为0.005～3.315 mg/L,均值为0.428 mg/L,其中敏感菌株占97.03%,低抗菌株占2.97%;抗性指数范围为0.295～0.447,均值为0.343。10株中抗突变体抗性均不能稳定遗传、生长速率减慢、产孢量降低、孢子萌发能力减弱、致病力下降;但在药剂压力下,突变体的致病力强于敏感菌株。苯醚甲环唑与代森锰锌、多抗霉素、啶酰菌胺无交互抗性,而与啶菌噁唑存在交互抗性。因此,今后需加强番茄早疫病菌对苯醚甲环唑的田间抗性监测,在生产过程中轮用或混用不同作用机制的药剂以延缓该病菌对苯醚甲环唑抗性的发展。     

上海地区草莓灰霉病菌对啶酰菌胺的抗性现状研究

为研究上海地区草莓灰霉病菌对啶酰菌胺的抗性现状,本文在上海采集了草莓灰霉病样,共分离纯化得到115株草莓灰霉病菌(Botrytis cinerea)。采用菌丝生长速率法测定了草莓灰霉病菌对啶酰菌胺的敏感性数据。结果表明,所测定的115株灰霉菌株中抗性菌株的比例占13. 9%,以中抗水平为主,共检测到16株抗性菌株,其中12株为中抗菌株,低抗和高抗菌株各检测到2株。田间试验数据显示,啶酰菌胺对草莓灰霉病3次药后防效在80%左右。综合两方面的数据,目前上海地区草莓灰霉病菌对啶酰菌胺已经产生了一定的抗性,需要引起重视,但啶酰菌胺在实际生产中用以防治草莓灰霉病仍是可行的。     

河北省设施番茄灰霉病菌对啶酰菌胺和咯菌腈的敏感性

 为明确河北省设施番茄灰霉病菌对啶酰菌胺和咯菌腈的敏感性,2013-2016年,采用菌丝生长速率法测定了采自河北省八个地区的2 425株灰霉病菌对啶酰菌胺和咯菌腈的敏感性。2013-2016年监测数据显示,河北省设施番茄灰霉病菌对啶酰菌胺和咯菌腈的敏感性呈下降趋势。2016年从河北省不同地区采集的番茄灰霉病菌对啶酰菌胺具有相似的敏感性,且对啶酰菌胺产生了低水平的抗性,仅在唐山地区检测到了啶酰菌胺的高抗菌株;而不同地区采集的灰霉病菌对咯菌腈的敏感性具有差异,但均为咯菌腈的敏感菌株。因此,啶酰菌胺和咯菌腈仍可用于番茄灰霉病的防治,但应严格控制其使用频率,监测灰霉病菌对其敏感性变化动态。     

啶酰菌胺不同抗性类型多主棒孢的生物学特性

由多主棒孢Corynespora cassiicola引起的黄瓜棒孢叶斑病是黄瓜上的重要病害。本研究测定了对啶酰菌胺不同抗性类型多主棒孢的生物学特性差异和环境适合度，旨在为探明多主棒孢对啶酰菌胺的抗性变化机制提供生物学研究基础。随机选取不同地区24株对啶酰菌胺具有不同抗性类型的多主棒孢，分析了7种类型抗性突变体对几种不同琥珀酸脱氢酶抑制剂类 (SDHIs) 杀菌剂的交互抗性、不同抗性类型多主棒孢在无药剂选择压力下的抗性遗传稳定性，以及抗性突变体在不同碳源、氮源、温度等环境条件下的生物学特性及适合度。结果表明:除突变类型SdhB-H278Y及SdhB-H278R对啶酰菌胺与氟吡菌酰胺之间存在负交互抗性外，其他突变类型对啶酰菌胺与吡噻菌胺、氟吡菌酰胺及萎锈灵之间均表现为正交互抗性；所有突变类型菌株的抗药性均能稳定遗传；不同突变类型菌株之间致病性存在差异，其中SdhD-D95E突变体的致病力最强；利于所有突变类型菌株生长的碳源是麦芽糖，氮源种类则对突变体的生长影响不显著；各突变类型菌株的最适生长温度范围为25~30 ℃，其中突变体SdhD-D95E在高于30 ℃条件下菌丝生长速率大于其他突变体；耐热性研究中，抗性突变体经65 ℃高温处理45 min后无法存活，同时发现，60 ℃条件下突变体能正常生长，而敏感菌株不能生长；各质量浓度NaCl处理下，SdhD-D95E突变菌株菌丝生长速率快于其他突变菌株，而SdhB-H278Y突变菌株慢于其他突变菌株；葡萄糖对SdhB-H278R突变菌株的生长较为重要。研究表明，对啶酰菌胺不同抗性类型多主棒孢突变菌株的生物学特性及适合度存在差异，SdhD-D95E突变菌株适合度有所提高，表明该突变类型多主棒孢在田间具有较强的竞争力，容易形成优势种群。     

Effects of a lectin-like protein isolated from Acacia farnesiana seeds on phytopathogenic bacterial strains and root-knot nematode

Acacia farnesiana lectin-like protein (AFAL) showed bacterioestatic effects against Xanthomonas axonopodis pv. passiflorae (Gram-negative) and Clavibacter michiganensis michiganensis (Gram-positive), with the latter being more sensitive. This effect is probably due to the ability of AFAL to interact with the bacterial cell wall where we observed that AFAL induced macroscopic change. The maximum bacterial growth inhibition was approximately 78% when incubated with Gram-negative strains, and as high as 92% percent for the Gram-positive one. The antibacterial effect of flavonoids (rutin, quercetin and morin) was also observed using low concentrations against both bacterial strains. Prior incubation of both with AFAL at high concentrations increases the inhibitory effect of flavonoids on bacterial growth. The potential use of AFAL as a control agent against the root-knot nematode Meloidogyne incognita was investigated as well, showing anti-nematode properties involving both egg hatching and motility. In the juvenile second-stage, AFAL showed reduction in larval mobility when measured against a control group. The results suggest that AFAL is effective against M. incognita and could be used as a component of integrated pest management programs. These data also suggest that lectins probably play a role in plant defense not only against invertebrate phytopathogens, herbivores and fungi but also against bacteria.     

枯草芽胞杆菌对离体荔枝果实霜疫霉病、炭疽病的防治效果

为了进一步明确从土壤中筛选得到的拮抗细菌OR-1、OR-2、OR-3、ON-6的分类地位和生防效果,采用形态学观察、理化特性结合分子生物学方法,鉴定这4株细菌皆为枯草芽胞杆菌Bacillussubitilis.拮抗菌对荔枝霜疫霉菌、炭疽菌菌丝生长均具有明显抑制作用,ON-6菌株的发酵液对菌丝生长的抑制率最高,分别为92.34％和70.36％,其次是OR-1菌株.拮抗菌处理组褐变指数均小于对照组以及杀菌剂处理组,且差异达显著水平(P＜0.05),OR-1菌株防褐变效果最好.常温下,拮抗菌发酵液对离体鲜果病害防治效果优于对照组和杀菌剂处理组,其中ON-6菌株的防治效果最佳;4℃低温储藏处理40天后,拮抗菌发酵液处理组的防治效果高于对照和杀菌剂处理组,且差异显著(P＜0.05),以ON-6和ON-3菌株的防治效果最佳.表明拮抗菌发酵液对荔枝鲜果上的霜疫霉菌和炭疽病菌有一定的抑制作用.     

Agrobacterium-mediated transformation efficiency is altered in a novel rice bacterial blight resistance cultivar and is influenced by environmental temperature

Y73 is a progeny of asymmetric somatic hybridization from an elite japonica rice cultivar (Dalixiang) and a wild rice (Oryza meyeriana), which shows high resistance to bacterial blight. It has a similar genetic background to its recurrent parent, Dalixiang, but Y73 has a high resistance to both bacterial blight and Agrobacterium. The transformation efficiency of Y73 was 35.7%, while Dalixiang had higher transformation efficiency (71.2%) under the same co-cultivation temperature (25 °C). These results indicate that the resistance to Agrobacterium tumefaciens in Y73 was linked with its characteristic of bacterial blight resistance, and was obtained from its donor parent, O. meyeriana. Further studies also showed that the resistance to A. tumefaciens was weakened at a lower temperature (20 °C). To study its molecular mechanism, the expression levels of genes associated with Agrobacterium-mediated transformation (OsMPKs, OsVIP1s and OsPR1s) in rice were investigated by Quantitative real-time PCR (qRT-PCR) analysis. The expression levels of OsMPK genes remained unchanged at different temperatures, while all OsVIP1s and almost all OsPR1s were up-regulated and transformation efficiency of Y73 was increased notably when infected by Agrobacterium at 20 °C compared with 25 °C. This study suggests that the bacterial blight resistance genes in Y73 also have an effect on Agrobacterium-mediated transformation and that the response to temperature is associated with the regulation of MAPK/VIP1 defense signaling pathway.     

The effects of Artemisia annua L. and Achillea millefolium L. crude leaf extracts on the toxicity, development, feeding efficiency and chemical activities of small cabbage Pieris rapae L. (Lepidoptera: Pieridae)

The biological effects of two important medicinal plants, Artemisia annua L. and Achillea millefolium (L.) (viz, mortality, growth, and feeding indices as well as enzyme and non-enzymatic activities) were studied on small white Pieris rapae L a deleterious pest of cruciferous plants under controlled conditions (16:8 h L:D at 25 ± 1 °C and 65 ± 5% RH). The LC₅₀ and LC₂₅ values were 9.387% and 3.645% for A. annua L. and 4.19% and 1.69% for A. millefolium (L.), respectively. At the lowest concentration (0.625%), the deterrency was 29.826% and 44.185% for A. annua L. and A. millefolium (L.), respectively. Feeding indices were variously affected with changes in a number of parameters and an increase in larval and pupal duration. The activity level of alkaline phosphatase increased sharply while alanin and aspartate aminotransferases showed a sharp decrease. For non-enzymatic compounds, the amount of glucose and uric acid increased, but total protein and cholesterol decreased. These results indicate that these two medicinal plants might possess potential secondary metabolites that may be useful for controlling potential insect pests.     

枣镰翅小卷蛾成虫的寄主趋向和产卵选择

采用固相微萃取(SPME)和GC-MS分析研究木枣和酸枣挥发物成分,并测试枣镰翅小卷蛾触角电位(EAG)反应、寄主趋向和产卵选择,以探明枣镰翅小卷蛾的寄主选择机制。结果显示,在萌芽期,木枣和酸枣嫩叶的挥发成分均为罗勒烯、2-甲基-2-菠烯、α-法呢烯和邻苯二甲酸二丁酯4种,但相对含量稍有不同。枣镰翅小卷蛾成虫对木枣和酸枣2种寄主都有强烈的EAG反应,且同一寄主上雌蛾的EAG反应值极显著地高于雄蛾,其EAG值是雄蛾的3.3倍。枣镰翅小卷蛾对木枣表现强烈的趋向反应,而对酸枣的趋向不明显,且雌虫的趋向反应显著高于雄虫。木枣上的产卵量显著高于酸枣,且木枣枣吊上的单雌产卵量为307.9粒,极显著地高于酸枣枣吊上的产卵量(182.9粒)。研究表明,枣镰翅小卷蛾雌蛾在寄主选择中起主导作用,木枣是其嗜好寄主。     

Analysis of two acetylcholinesterase genes in Bombyx mori

Two acetylcholinesterases (AChE, EC 3.1.1.7) cDNAs were identified and cloned from silkworm, Bombyx mori. One of those, BmAChE-o cDNA, is comprised of 3197 nucleotides which encode 638 amino acids, having an amino acid sequence homology of 72% with Drosophila melanogaster Ace-orthologous AChE (AO-AChE). In some species, another AChE group based on the sequence, Drosophila Ace-paralogous AChE (AP-AChE) has been recognized in relation to organophosphate- or carbamate-resistance, but there have been few reports of AP-AChE among lepidopteran species. However, we isolated the AP-AChE from lepidopteran silkworm, and cloned full ORF as BmAChE-p, which cDNA consisted of 2465 nucleotides that encode 683 amino acids. The homologies with other AP-AChEs were over 60% when compared. Although silkworm is not a target of pesticides, the genomic information obtained in this study will contribute to insecticide-resistance study on lepidopteran pest species.     

菜豆普通细菌性疫病菌在土壤和植株残体中的越冬能力

为评估菜豆普通细菌性疫病菌地毯草黄单胞杆菌菜豆致病变种或褐色黄单胞菌褐色亚种在土壤及植物残体中的越冬能力,对采自黑龙江、内蒙古、山西、河北及新疆的18块菜豆生产田的20份土壤及14份植物残体样品进行病原菌分离和鉴定。在MT选择性培养基上有12个土壤样品和13个植株残体样品提取液产生典型的类似黄单胞菌菌落。选取29个分离物进行致病性测定,有27个分离物对菜豆品种"英国红"致病。利用地毯草黄单胞杆菌菜豆致病变种和褐色黄单胞菌褐色亚种的特异性引物X4c/X4e及褐色黄单胞菌褐色亚种特异性引物Xf1/Xf2对29个分离物进行多重PCR检测,其中17个分离物为地毯草黄单胞杆菌菜豆致病变种,10个分离物为褐色黄单胞菌褐色亚种。结果表明,菜豆普通细菌性疫病菌可以在黑龙江、内蒙古、山西、河北的一些菜豆种植区的土壤及植株残体中越冬存活。     

苏云金杆菌亚致死浓度对美国白蛾及其寄生蜂生长发育的影响

为阐明苏云金杆菌Bacillus thuringiensis(Bt)与白蛾周氏啮小蜂Chouioia cunea Yang的协同作用,分别用103~108孢子/m L的6个Bt浓度处理美国白蛾Hyphantria cunea 2龄幼虫后,通过室内试验测定了Bt对其致死、亚致死效应,及亚致死浓度Bt对寄生蜂子代出蜂的影响。结果表明,浓度106孢子/m L处理组美国白蛾均未能化蛹;而106孢子/m L处理组均能化蛹并羽化,且幼虫发育历期随Bt浓度的增加而延长,平均蛹重在74.92~92.18 mg之间,均高于对照的68.66 mg,但蛹重不呈线性规律变化。当Bt对美国白蛾平均校正死亡率低于17.17%时,幼虫发育历期延迟不明显,但平均蛹重为101.11~124.34 mg,均高于对照;接蜂后能够正常出蜂,出蜂率为33.13%~51.25%,每蛹出蜂量为117.43~143.42头,均显著高于对照。表明用平均校正死亡率低于20%的Bt处理对白蛾周氏啮小蜂的寄生有利,2种生防措施协同作用存在增效潜力。     

Biological and biochemical responses of Biomphalaria alexandrina to some extracts of the plants Solanum siniacum and Artemisia judaica L.

The molluscicidal activity of cold water, boiled water, methanol, ethanol, acetone and chloroform extracts of Solanum siniacum and Artemisia judaica L. plants against Biomphalaria alexandrina snails was carried out. The tests revealed plant’s ethanol extract was more toxic to the snails than the other tested extracts. Therefore, it was tested against snails’ fecundity (M_x), reproduction rate (R₀) and their infection with Schistosoma mansoni miracidia. In addition, biochemical parameters and the activities of some enzymes in tissues of snails treated with the two tested plants were determined. As well, glucose concentration in snails’ hemolymph was evaluated. Exposure of B. alexandrina snails to plant’s ethanol extract led to a significant reduction in their survival and snails’ fecundity, reproduction rate. In addition, it caused a considerable reduction in the infectivity of S. mansoni miracidia to the snails. Also, it caused a reduction in number of cercariae per snail during the patent period and in the period of cercarial shedding. The results revealed that the glucose concentration in hemolymph and Lactate level in soft tissues of treated snails were increased (P < 0.001) while glycogen, total protein, the lipid content and the pyruvate level in snail’s tissues decreased (P < 0.001). The activities of lactic dehydrogenase (LDH), pyruvatekinase (PK) and cytochrome oxidase (CY) enzymes in homogenate of snail’s tissues were reduced (P < 0.001) in response to treatment with the two tested plants while protease (PR) activity increased (P < 0.001). It is concluded that the application of LC₂₅ of ethanol extract of S. siniacum and A. judaica L. may be helpful in snail control as it interferes with the snails’ biology and physiology.     

加州新小绥螨对柑橘全爪螨的控制潜力

为了确定加州新小绥螨Neoseiulus californicus (McGregor)的国内品系在生物防治中的潜力,采用捕食者功能反应方法,研究了加州新小绥螨、江原钝绥螨Amblyseius eharai Amitai et Swirski、尼氏真绥螨Euseius nicholsi (Ehara et Lee)和拟长毛钝绥螨A.pseudolongispinosus Xin,Liang et Ke对柑橘全爪螨Panonychus citri AaGregor的捕食作用,加州新小绥螨对柑橘全爪螨的功能反应可以很好地拟合HollingⅡ圆盘方程,对柑橘全爪螨卵的捕食能力显著高于其它3种捕食螨,4种捕食螨对柑橘全爪螨卵的功能反应参数a/Th分别为20.8342、6.9458、0和6.1634;加州新小绥螨对柑橘全爪螨卵、幼螨、前若螨、后若螨和成螨功能反应分别为20.8342、42.0721、29.1849、22.1204和5.6284.加州新小绥螨密度越大,柑橘全爪螨种群数量下降越快,在益、害比为5∶30下,柑橘全爪螨种群数量在第4天就能得到控制.结果表明,加州新小绥螨国内品系对柑橘全爪螨表现出很大的控制潜力.