南砧1号作砧木嫁接西瓜防治枯萎病效果好

防治枯萎病效果好以金钟冠龙、京欣1号、庆红宝西瓜品种为接穗，南砧1号为砧木，以接穗品种未嫁接苗作对照，采用顶心插接法嫁接。嫁接苗长到团棵期进行大田移栽。定点定株(100株)于拉蔓期、结瓜期、膨大期调查发病株，计算病株率及防效。成熟期测定产量和品比质量。结果：接穗与砧木亲和力高，嫁接苗易成活，拉蔓期嫁接苗病株率为0，结瓜期金钟冠龙、京欣1号、庆红宝嫁接苗病株率分别为0.33％、0.33％和0.67％，防效分别为93.4％、93.4％和86.6％；西瓜膨大期为枯萎病发病盛期，嫁接苗病株率分别为0.67％、0.33％和0.67％，防效分别为88.8…     

西瓜嫁接防枯萎病的嫁接技术

枯萎病是西瓜上发生危害最严重的病害。瓜地发生此病轻则减产,重则成片死亡,甚至全园毁灭。对于枯萎病的防治,目前还没有特效药,也没有理想的抗病品种,通过轮作换茬防病,轮作年限太长,土地有限,影响了西瓜生产的发展,挫伤了瓜农的积极性,针对这个问题,我们分别在红壤山地与旱田进行了嫁接防病试验,采用葫芦、南瓜、冬瓜等抗病强的品种做砧木均能达到防病的目的,其中以葫芦做砧木表现最好,抗病率达100%,增产15%～40%,既可耐寒抗病又能节省肥料(砧木强大的根系,吸肥能力强,从而提高了肥料利用率),同时解决了西瓜产区因轮作防枯萎病造成的土地…     

利用茎尖嫁接脱毒培养无裂皮病的脐血橙

脐血橙是六十年代从摩洛哥引入的优良品种。在试种中表现果实品质好和晚热等性状,有推广前途。但是这个品种的植株普遍受裂皮病感染。在用枳或(木黎)檬(如广西的土柠檬)作砧木时,砧木树皮严重开裂,植株显著矮化、衰退,产量很低,甚至整株死亡。在用耐病的红桔或酸桔作砧木时,植株     

春季猕猴桃嫁接技术

正近年来,猕猴桃产业在农村蓬勃发展。农业科技人员、种植户都在不断摸索经验,总结实用方法。春季嫁接猕猴桃,主要把握"三个关键"。1接穗及砧木选择接穗要从品种纯正、长势健壮、腋芽饱满、无病虫害的一年生丰产优良株上采集。砧木应是根颈部粗度在0.6 cm以上,无病害。如果是大树改接良种,要对多年生枝重回缩,1年生枝留2~3芽短截,疏除过密、过弱的多年生枝。2嫁接方法猕猴桃嫁接方法有劈接法、舌接法、芽接法。     

西瓜应用嫁接栽培的优点

西瓜应用嫁接栽培技术,可以利用砧木品种对土传病害的抗性,解决主产区多年栽培后轮作困难,克服重茬障害。西瓜应用砧木嫁接栽培技术的主要优点有。     

猕猴桃夏季嫁接技术

猕猴桃嫁接较困难,如单一采用春接,一次未活,只有来年春季再接,延长了投产年限。为此通过试验,现介绍猕猴桃生长季节,采用不同的方法嫁接,次年株产达１０ｋｇ以上。这样,春、夏、秋季均可嫁接。一、砧木和接穗选择砧木应是接近地面的新梢,嫁接部位粗度和木质化程...     

烟草嫁接苗对黑胫病的抗性鉴定

嫁接技术是植物病害绿色防控的有效措施之一,为探寻抗烟草黑胫病的高抗嫁接组合,本研究以4个高抗烟草品种为砧木,生产上4个主栽品种为接穗,开展了不同嫁接组合烟苗对黑胫病的抗性鉴定。人工接种黑胫病菌后,以‘Florida 301’作砧木时烟苗发病率和病情指数分别为0~4.76%和0~2.86;以‘革新3号’作砧木时分别为0~20.71%和0~15.72;以‘Beinhart 1000-1’作砧木时分别为1.11%~13.18%和1.11~11.47;以‘L8’作砧木时分别为20.02%~65.33%和13.58~60.89,而以接穗品种‘K326’、‘云烟87’、‘NC55’和‘红花大金元’自根苗的发病率和病情指数分别为:‘K326’,39.98%和35.46,‘云烟87’,45.81%和39.18,‘NC55’39.33%和35.93,‘红花大金元’,74.67%和65.48。统计分析结果表明,以‘Florida 301’、‘革新3号’和‘Beinhart 1000-1’品种为砧木的嫁接苗发病率与病情指数均极显著低于接穗品种自根苗(P0.01);‘L8’品种为砧木时,只有‘云烟87’作接穗的发病率与病情指数极显著低于‘云烟87’自根苗(P0.01)。采用平板涂布计数法,对抗、感黑胫病烟草品种根际微生物数量进行了测定,研究了抗、感病品种根际微生物群落结构,结果表明,抗、感病品种均是根际细菌根际放线菌根际真菌,且根际细菌、放线菌数量远多于真菌数量,抗病品种的根际微生物数量整体上多于感病品种。     

嫁接换根防治保护地黄瓜枯萎病

黄瓜是保护地生产中的重要品种,经济价值高,群众喜受,黄瓜枯萎病是保护地生产中的重要病害,轻的发病率10—20%,重的50%以上,甚至毁种,病害为害程度随着连作年限的增加则加重。防治黄瓜枯萎病尚无理想的药刘。利用南瓜根系强大对黄瓜枯萎病菌有高度抗性的特点,用南瓜做砧木,黄瓜做接穗,嫁接换根,能有效的防治枯萎病,防效达到95%—100%,并能减轻疫病的为害程     

砧木与西瓜品种对黄瓜绿斑驳花叶病毒病的耐病性比较

在上茬棚栽嫁接西瓜上黄瓜绿斑驳花叶病毒病严重发生的田块,应用DAS-ELISA检测法检测播种的10个砧木和西瓜品种对该病毒病的耐病性,发现品种间耐病性差异较大,且西瓜品种耐病性强于砧木品种。5个西瓜品种的病株率为5.0%(小兰)~50.0%(宁波美都),5个砧木品种的病株率为63.6%(强力南瓜)~100%(抗枯先锋1号)。     

胡杨嫁接繁殖研究初报

以小美旱、新疆杨、二白杨、柳树为砧木,采用“炮捻”劈接以及“T”字型、方块型、“舌”型芽接方式就嫁接繁殖胡杨技术进行了试验研究,选择确定小美旱是胡杨嫁接繁殖的优良砧木,而“舌”型芽接是最佳的嫁接方式,其平均成活率可达86.3%。进一步在不同时期进行“舌”型芽接,证明8月中、下旬为胡杨芽接的适宜时期,适时嫁接成活率高达94%,一般可保证成活率在80%以上。有关研究结果表明,通过嫁接技术可以解决胡杨无性繁殖难题,从而使生长与形质俱佳的胡杨优良无性系应用于林业生产,这对于保护胡杨优良基因资源、改善西部生态环境以及开发与利用盐碱地资源等具有重要意义。     

氯虫苯甲酰胺对稻纵卷叶螟的防效及对稻田有益节肢动物的安全性评价

研究了20%氯虫苯甲酰胺悬浮剂对稻纵卷叶螟的防效及对稻田常见有益节肢动物的安全性。室内毒力测定结果显示：将20%氯虫苯甲酰胺悬浮剂稀释3 000、6 000倍浸渍水稻叶片,接稻纵卷叶螟幼虫24 h死亡率在40%左右, 96 h死亡率达100%。稻田小区和大面积示范试验结果显示：药后14 d,氯虫苯甲酰胺对稻纵卷叶螟的防效分别为90.59%、97.07%,高于药后4、7 d的防效。其防效好于氟虫腈、虫酰肼+辛硫磷。田间与施药前相比,药后14 d球腹蛛显著增加,微蛛、狼蛛的数量及蜘蛛总量无显著差别。室内测定,氯虫苯甲酰胺处理后,黑肩绿盲蝽及稻虱缨小蜂的死亡率在0~6.67%。上述结果表明：氯虫苯甲酰胺对稻纵卷叶螟有很好的防效,且对稻田有益节肢动物安全。     

Effects of low temperatures on pupal survival of the stone leek leafminer Liriomyza chinensis (Diptera: Agromyzidae)

Abstract

The cold-hardiness of Liriomyza chinensis pupae was measured in the laboratory by observing pupal mortality at low temperatures. Pupal mortality increased with decreasing temperature and with extended cold exposure time. No recently pupated pupae (6 h) were able to survive after 16 days of chilling at 0, 2.5 and 5°C, but 42.9% survival was observed at 10°C. Pupae at different developmental stages showed significant difference in mortality, with very low levels of mortality observed for older pupae (4 and 7 days) after exposure to 0°C for 16 days. The lethal time for 50% survival (LT₅₀) increased with increasing age of pupae. LT₅₀ for 4-day-old pupae exposed to 0°C was 52.1 days. Analysis of mean temperatures at several localities indicated that L. chinensis is able to overwinter outdoors in southern regions, but is unable to overwinter in open fields in northern regions of Japan, suggesting that overwintering in these regions would only occur in greenhouses.     

Evidence of synergy between prochloraz and deltamethrin in apis mellifera L.: a convenient biological approach

We have studied the synergistic action of deltamethrin and prochloraz in bees in laboratory experiments that allowed us to express dosages in terms of field rates (g ha^?1). It was established that, used alone, deltamethrin at 0·125 g ha^?1 and prochloraz at 25 g ha^?1 did not produce mortalities different from that of the control during 96 h of observation. Sprayed as a mixture of these doses, deltamethrin and prochloraz produced 67·5% corrected mortality within 24 h and 74·1% corrected mortality within 50 h. Sequential treatments of deltamethrin and prochloraz spaced by a 0·8-day interval reduced the synergistic action of both molecules. At 50 h, the lethal effects were 27·5% corrected mortality for the treatment of deltamethrin followed by prochloraz and 23·8% corrected mortality for the treatment of prochloraz followed by deltamethrin. Results are discussed in terms of mode of action and sub-lethal effects.     

氟虫腈粉剂对黑胸散白蚁的药效研究

氟虫腈粉剂对黑胸散白蚁具有明显的毒杀效果,至施药后第8d时,7个浓度(5%、2.5%、1%、0.5%、0.25%、0.1%和0.05%)处理的白蚁全部死亡。随着氟虫腈粉剂浓度的降低,其致黑胸散白蚁全部死亡的时间逐渐延长。其中5%和2.5%氟虫腈粉剂致白蚁全部死亡所需时间为2d,0.1%~1%所需时间为5~6d,而0.05%所需时间为8d。氟虫腈粉剂在黑胸散白蚁群体中具有显著的一级传毒能力,但其它级别的传毒能力并不明显。因此,施工人员在使用氟虫腈粉剂时,需在白蚁危害范围内采取"多点少施"的方法,以确保对白蚁的灭治效果。结合氟虫腈粉剂在室内和室外的药效表现,我们认为,1%~2.5%氟虫腈粉剂可在实际灭治中取得较好效果。     

氯虫苯甲酰胺亚致死剂量对棉铃虫生长发育和解毒酶活性的影响

在室内采用培养基混药法测定氯虫苯甲酰胺亚致死剂量(LC10、LC25和LC50)对棉铃虫生长发育和体内3种解毒酶系的影响。结果表明:各剂量处理3龄幼虫48h后饲养,各处理组当代(F0)3～6龄幼虫历期均比对照组延长0.2～3.8d,但成虫平均历期比对照组缩短0.8～2.5d,子代(F1)1～6龄幼虫历期均比对照组延长0.2～2.6d,成虫平均历期比对照组缩短0.1～0.5d;各剂量处理后,各处理组F0代3～6龄幼虫和蛹的体重、F1代4～6龄幼虫和蛹的体重均比对照组减轻,且剂量越大,体重减轻越显著;各处理组F0代种群趋势指数分别比对照组下降了16.27%、58.51%和71.17%,F1代分别下降了13.66%、52.61%和66.63%;各处理组F0代3～6龄幼虫体内的羧酸酯酶(CarE)和细胞色素P450O-脱乙基酶(P450-ECOD)比活力均高于对照组,其中6龄幼虫这两种酶比活力分别比对照组提高了5%～16%和23%～66%,但各处理组谷胱甘肽硫转移酶(GSTs)比活力均低于对照组,其中6龄幼虫GSTs比活力分别比对照组降低了16.23%、58.51%和71.17%。表明在LC10～LC50剂量范围内,氯虫苯甲酰胺处理棉铃虫3龄幼虫的亚致死剂量越高,其生长发育受抑制越显著,P450-ECOD和CarE比活力上升越高,GSTs比活力下降也越大。     

蜡蚧轮枝菌可分散油悬浮剂对枸杞棉蚜取食行为的影响

为探究枸杞棉蚜经2种蜡蚧轮枝菌可分散油悬浮剂处理后的取食行为差异，本试验利用浸渍法对棉蚜进行室内毒力测定，并利用刺吸电位图谱技术对棉蚜在枸杞植株上的取食行为进行测定。结果表明，棉蚜的死亡率随着制剂浓度和处理时间的增加而增加，处理后棉蚜的死亡率逐渐增加，第2天2种制剂最高浓度的校正死亡率达到40%以上。5 d后2种制剂的致死作用达到最强，其最高浓度处理下的校正死亡率分别达到96.97%和95.97%。2种蜡蚧轮枝菌可分散油悬浮剂3个浓度处理的棉蚜在总记录时间为8 h内均产生7种波形，分别是非刺探波np波、路径波C波、电位下降波pd波、韧皮部分泌唾液波E1波、韧皮部被动取食波E2波、机械阻碍波F波、木质部主动取食波G波。1#制剂np波和C波随浓度的增加而增加，其余波随浓度的增加而降低，2#制剂np波和C波随浓度的增加先增加后降低，其余波随浓度的增加先降低后增加。棉蚜成虫拒食时间由长至短依次为2#制剂1×10⁶ cfu/mL浓度、1#制剂4×10⁶ cfu/mL、2#制剂4×10⁶ cfu/mL、1#制剂1×10^6<...     

Combined treatments of spinosad and chlorpyrifos-methyl for management of resistant psocid pests (Psocoptera: Liposcelididae) of stored grain

The combined efficacy of spinosad and chlorpyrifos-methyl was determined against four storage psocid pests belonging to genus Liposcelis. This research was undertaken because of the increasing importance of these psocids in stored grain and the problem of finding grain protectants to control resistant strains. Firstly, mortality and reproduction were determined for adults exposed to wheat freshly treated with either spinosad (0.5 and 1 mg kg(-1)) or chlorpyrifos-methyl (2.5, 5 and 10 mg kg(-1)) or combinations of spinosad and chlorpyrifos-methyl at 30 degrees C and 70% RH. There were significant effects of application rate of spinosad and chlorpyrifos-methyl, both individually and in combination, on adult mortality and progeny reduction of all four psocids. Liposcelis bostrychophila Badonnel and L. decolor (Pearman) responded similarly, with incomplete control of adults and progeny at both doses of spinosad but complete control in all chlorpyrifos-methyl and combined treatments. In L. entomophila (Enderlein) and L. paeta Pearman, however, complete control of adults and progeny was only achieved in the combined treatments, with the exception of spinosad 0.5 mg kg(-1) plus chlorpyrifos-methyl 2.5 mg kg(-1) against L. entomophila. Next, combinations of spinosad (0.5 and 1 mg kg(-1)) and chlorpyrifos-methyl (2.5, 5 and 10 mg kg(-1)) in bioassays after 0, 1.5 and 3 months storage of treated wheat were evaluated. The best treatment was 1 mg kg(-1) of spinosad plus 10 mg kg(-1) of chlorpyrifos-methyl, providing up to 3 months of protection against infestations of all four Liposcelis spp. on wheat.     

核型多角体病毒与中红侧沟茧蜂对寄主棉铃虫的联合效应

为明确寄生蜂中红侧沟茧蜂Microplitis mediator与核型多角体病毒（nucleopolyhedrovirus,NPV）对寄主棉铃虫Helicoverpa armigera的联合效应,测量中红侧沟茧蜂和NPV单处理及复合处理后棉铃虫幼虫的形态学指标,并统计棉铃虫幼虫死亡率及寄生蜂中红侧沟茧蜂子代存活率。结果显示,处理3 d和5 d后,中红侧沟茧蜂和NPV单处理及复合处理的棉铃虫幼虫体长、体宽、头壳宽度、体重均显著低于对照,但各处理之间差异不显著。接入浓度为2.5×10⁴ OBs/mL和2.5×10⁶ OBs/mL NPV时,中红侧沟茧蜂和NPV这2种生防因子对棉铃虫均表现为拮抗效应或累加效应。接入浓度为2.5×10⁴ OBs/mL NPV时,先寄生后接毒和先接毒后寄生处理的棉铃虫实际死亡率分别为4.35%和14.26%;接入浓度为2.5×10⁶ OBs/mL NPV时,棉铃虫实际死亡率则分别为31.55%和94.19%,先接毒后寄生处理的棉铃虫实际死亡率均显著高于先寄生后接毒处理的实际死亡率。接入浓度为2.5×10⁶ OBs/mL NPV时,先寄生后接毒和先接毒后寄生处理的寄生蜂子代存活率分别为54.51%和3.71%,前者显著高于后者。表明中红侧沟茧蜂寄生和NPV侵染均能显著抑制棉铃虫的生长发育,但两者联合应用时拮抗效应明显且对寄生蜂子代有影响,同时用于生物防治棉铃虫时应谨慎。     

Avermectin exposure induces apoptosis in King pigeon brain neurons

The effect of avermectin was studied on King pigeon brain nerve cells by cytotoxicity [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, MTT] and apoptosis [acridine orange/ethidium bromide (AO/EB) assay, transmission electron microscope (TEM) evaluation, measurement of mitochondrial membrane potential (Δψm), phosphatidylserine (PS) exposure, caspases activities, DNA fragmentation, reactive oxygen species (ROS) and caspase-3 mRNA expression] within the 2.5–10 μg L⁻¹ concentration-range. The results revealed that within the concentrations of 2.5–10 μg L⁻¹, avermectin showed obvious cytotoxicity and induced apoptosis in a dose-dependent manner to neurons of King pigeon in vitro. Cell viability were 99.93 ± 8.52%, 82.02 ± 4.99% and 78.23 ± 5.67% after 24 h of treatment with avermectin at the concentrations of 0, 2.5 and 5 μg L⁻¹, which decreased to 56.36 ± 2.17% of 10 μg L⁻¹. Treated cells showed typical apoptosis morphological changes including cytoplasmic vacuolation, chromatin condensation, unclear nuclear membrane and decreased/swollen mitochondria. Typical biochemical hallmarks of apoptosis including Δψm loss, PS exposure, activations of caspase-3, caspase-8 and caspase-9, DNA fragmentation were observed too. Moreover, the levels of ROS in the avermectin treatment groups increased significantly compared to control group. Furthermore, the caspase-3 mRNA levels increased significantly following AVM treatment. In conclusion, our experimental results show that avermectin has cytotoxicity to brain neurons of King pigeon in vitro and the mechanism of neurotoxicity induced by avermectin is closely related to apoptosis.     

小菜蛾越冬生物学特性研究

研究了小菜蛾不同虫态的过冷却点,蛹的低温生存能力和越冬能力。小菜蛾的过冷却现象比较明显,蛹期过冷却点最低(-20.12℃),成虫次之(-16.56℃),幼虫期高(平均为-13.72℃),其中4龄幼虫过冷却点最高(-8.5℃)。表明在不同虫态中,蛹的抗低温能力最强。在-10、-5、0℃和5℃条件下,小菜蛾蛹的LT50、LT90、LT99.9随着温度的降低而缩短;蛹死亡99.9%需要的时间分别为10.29、21.68、27.77、41.39d,表明在冬季温度连续低于0℃时间超过28d的地区,小菜蛾不能越冬。连续两年冬天的埋蛹试验结果,蛹在北京4个地点的越冬死亡率均为100%。结合我国的气候区划分析,初步确定小菜蛾在北京地区野外不能越冬。