"以螨治螨"生物防治技术在棉田中的应用

害虫生物防治是害虫综合治理(IPM)的一项重要措施,对有效、长久地控制有害生物,提高农产品质量,减少环境的污染,延缓害虫产生抗药性等有着重要的意义。释放天敌昆虫胡瓜钝绥螨来控制棉叶     

临潼石榴花期西花蓟马防治试验初探

临潼是我国六大石榴产区之一,随着该地区石榴品种不断丰富,近几年,西花蓟马对该地为害日趋加重,严重影响石榴品质和产量.文章采用物理防治和药剂防治两种方法,通过对比4种粘虫板诱集效果和3种药剂防效,对临潼石榴花期西花蓟马防治进行了初步探讨.花期试验结果表明:信息素蓝板对西花蓟马成虫的诱集效果最好,普通蓝板次之,花型黄板和普...     

利用胡瓜新小绥螨携带玫烟色拟青霉菌兼防茄子蚜虫和叶螨

利用胡瓜新小绥螨携带玫烟色拟青霉菌兼防蚜虫和叶螨是一种新的生物防治思路,为了证实其可行性,笔者对所得玫烟色拟青霉菌的孢子萌发条件及毒性等进行研究。通过小容器空气湿度调节法测定分生孢子最适萌发温、湿度;并在适宜条件下,测定1×10⁴~1×10⁸孢子/mL浓度的分生孢子悬浮液对蚜虫和胡瓜新小绥螨的毒力;试验设置：（1）空白对照;（2）释放50头胡瓜新小绥螨;（3）喷洒20mL10⁷孢子/mL孢子悬浮液;（4）喷洒20mL10⁷孢子/mL孢子悬浮液后释放50头胡瓜新小绥螨;（5）释放20头沾满分生孢子粉的胡瓜新小绥螨;（6）释放50头沾满分生孢子粉的胡瓜新小绥螨,共6种处理,进行盆栽试验。结果表明玫烟色拟青霉菌该菌株分生孢子最适萌发温、湿度为25~30℃、95%~100%RH,在此条件下,第10天时,1×10⁸孢子/mL浓度下,蚜虫和胡瓜新小绥螨的累积校正死亡率分别为86.52%和41.78%,该菌株相同浓度的孢子悬浮液对蚜虫的毒力远大于对胡瓜新小绥螨的毒力,符合作为利用胡瓜新小绥螨携带,用以防治蚜虫的虫生菌的条件。通过盆栽试验,3、4、6处理的效果最好,第8天蚜虫数量几乎降为0,而且相对而言,捕食螨带菌最省工、省料,还可以兼防叶螨。所以,适宜温、湿度条件下,利用捕食螨带菌同时防治蚜虫和红蜘蛛是可行的方法。     

蔬菜小虫防治措施

<正>现在蔬菜种植规模越来越大,栽培样式的多样化,导致蚜虫、粉虱、害螨、蓟马等小虫也比较多,还有烟粉虱、美洲斑潜蝇、南美斑潜蝇和西花蓟马等外来入侵种,为害极大而且无法根治,这些小虫物特点是分布面广、数量极大,主要吸食植物汁液、掠夺养分,对蔬菜正常生长,叶片黄化、干枯,果实畸形等情况,影响很大,还分泌蜜露引起煤污病,传播病毒病,影响蔬菜的产量、品质,效益上也大打折扣。     

西花蓟马在低温下的生长发育和繁殖研究

为探明低温对西花蓟马[Frankliniellaoccidentalis(Pergande)]生长发育和繁殖的影响,全面了解西花蓟马的生活习性,为其综合防治提供依据。将西花蓟马分别置于5℃、10℃低温培养箱中,每天观察记录2种环境温度下西花蓟马的生长发育和繁殖情况。研究表明,5℃下西花蓟马不能完成生活史,卵不能正常孵化;1龄若虫可以发育到2龄,但2龄若虫不能继续发育至蛹;蛹能够发育至成虫但成虫不能产卵;10℃下西花蓟马能够完成生活史,但是发育历期显著延长。上述结果表明,低温导致西花蓟马的发育速度减慢,后代数量骤减,但西花蓟马转移至室温环境后,能够恢复正常生长,说明其具有很强的低温耐受性,防治中应充分注意西花蓟马的这一低温耐受特性,在早春温度回升和其种群数量开始上升时及时进行防治。     

捕食螨对烟草育苗期蓟马防治效果研究

为明确捕食螨对烟草蓟马的防治效果,本文调查了云南泸西中枢育苗期蓟马发生情况及种类,并对比研究了不同捕食螨释放数量、释放方式及携带微生物菌剂的防治差异。结果表明：蓟马种类主要为西花蓟马,其次为八节黄蓟马,发生高峰期在4月中旬左右;捕食螨投放100头/盘防治效果最好;均匀撒施捕食螨对蓟马防治效果显著优于开袋放置及空白对照(P<0.05);捕食螨搭载球孢白僵菌对蓟马控制效果最好,搭载金龟子绿僵菌与不带菌相差不大,但均显著高于空白对照(P<0.05)。     

蓟马在韭菜上的发生规律和防治

蓟马在韭菜上发生十分严重,影响了韭菜的产量和品质。本文鉴定了韭菜上蓟马的种类,研究了蓟马在韭菜田间的危害症状、发生规律以及防治方法。试验结果表明韭菜上的蓟马形态特征为西花蓟马,ITS分子鉴定结果显示扩增片段520bp,与西花蓟马的碱基序列相似度达到99.81%。西花蓟马在韭菜田间离地80cm高度的空间分布较集中;晴天时,在下午15:00～17:00时间段上西花蓟马出现频率较高;雨水对西花蓟马的致死作用明显,致死率为29.30%;田间防治试验筛选出20%呋虫胺可溶性粒剂和40%啶虫脒粒剂对田间韭菜西花蓟马的防治效果较好,其中20%呋虫胺可溶性粒剂1500倍液的喷雾防治效果最佳,达92.56%。     

非致死浓度农药对虚伪钝绥螨繁殖和定居的影响

通过测定捕食螨类中的虚伪钝绥螨在13种农药不同浓度下的死亡率,确定了农药对虚伪钝绥螨的非致死浓度(LC_0～10).明确了各种非致死浓度农药对其繁殖和定居的影响.菊酯类农药如灭百克、灭扫利、氯氰菊酯、功夫、天王星.特异性昆虫生长调节剂爱力螨克和杀菌剂粉锈宁不仅减少其产卵量.而且降低它在植株上的定居率;氧化乐果影响其定居;克螨特影响其繁殖;尼索朗、双甲脒、卡死克和阿波罗对其繁殖和定居都没有显著影响.是比较安全的.植株上残留的某些微量农药不仅影响虚伪钝绥螨的繁殖能力.而且严重影响其定居.这在协调生防和化防的关系中应予以重视.     

食螨蓟马的发生生态和捕食量

茶园中所指的螨类是指神泽叶螨,由于神泽叶螨嗜好危害茶树新芽,直接影响茶叶产量和品质。神泽叶螨的天敌类,已知的主要有长刺钝绥螨、食螨蓟马、瘿蚊、隐翅虫等。一般认为这些种类中最早研究应用的为长刺钝缨螨,特别是在静冈县较大范围内发生,且已成为抑制神泽叶螨发生的主要天敌。比长刺钝缨螨发生稍少的为食螨蓟马。食螨蓟马属缨翅目、蓟马科,雌成虫约0.8毫米,雄成虫比雌成虫稍小。前翅的茎部、中部和近先端处有3对褐色斑纹,全体上有6个斑点,由此称为六点蓟马,体色呈黄白色,幼虫刚孵化时呈半透明的白色,随着生长发育而逐渐成为黄白色。蛹包括前蛹、后蛹在内地呈乳白色,其步行活动较缓慢。     

棚室西花蓟马的为害及高效防治新技术

<正>西花蓟马又名苜蓿蓟马,是一种检疫性害虫,近几年从国外传入我国。该虫为杂食性害虫,目前已知寄主植物达500多种,几乎是遇到什么吃什么,为害性相当大。不仅受害的叶片、果实伤痕累累,而且常诱发多种病菌趁虚而入,造成更大的损失。由于人们对它不了解,加上其个头微小,不容易被发现,待为害症状明显可见后才     

Resistance to western flower thrips in greenhouse cucumber: effect of leaf position and plant age on thrips reproduction

Three greenhouse cucumber (Cucumis sativus L.) accessions, previously selected for low levels of damage after infestation with Frankliniella occidentalis (Pergande), were tested for resistance against F. occidentalis in a no-choice greenhouse experiment at the mature plant stage. The three accessions showed a strong reduction in thrips damage compared to the susceptible control. The effects of leaf position and plant age of the four cucumber accessions on the reproduction of F. occidentalis were determined in a leaf disc assay. Leaf position had a significant effect on thrips reproduction, whereas plant age, within the test range, had not. In general, reproduction was higher on young leaves. Reproduction as measured on leaf discs from certain leaf positions was strongly correlated with resistance of mature plants in the greenhouse, and can therefore be used as a quick test to screen cucumber accessions for resistance against thrips. This revised version was published online in July 2006 with corrections to the Cover Date.     

Variation in performance of western flower thrips populations on a susceptible and a partially resistant chrysanthemum cultivar

Variation in host plant performance among populations of a phytophagous insect pest is a potential threat to the durability of host plant resistance. Aggressive biotypes may overcome the protective properties of formerly resistant cultivars. Therefore, it is of interest to study such variation in breeding programs for host plant resistance to insects. In the present study, the performance of ten populations of Frankliniella occidentalis, the western flower thrips, was determined on a susceptible and a partially resistant cultivar of chrysanthemum, Dendranthema grandiflora. Damage, reproduction, and adult survival were determined using an excised leaf assay. Significant differences between the two cultivars and among the ten populations were found for all three characteristics. In general, damage, reproduction and adult survival were reduced on the resistant cultivar when compared to the susceptible cultivar. Some populations showed, in comparison to the reference population from the Netherlands, much higher damage and reproduction on one or both chrysanthemum cultivars. But also in these populations performance on the resistant cultivar was poor compared to the susceptible cultivar. This revised version was published online in August 2006 with corrections to the Cover Date.     

Seasonal variation in resistance of chrysanthemum cultivars to Frankliniella occidentalis (Thysanoptera: Thripidae)

Seasonal variation in the level of host plant resistance can have important consequences for the repeatability of tests to measure host plant resistance to insect pests. In the present study, the levels of resistance to Frankliniella occidentalis of a susceptible and a partially resistant cultivar of chrysanthemum, Dendranthema grandiflora, were determined throughout the year. Thrips damage, reproduction and adult female survival were determined on excised leaves in Petri dishes under uniform conditions. Strong seasonal fluctuations were observed in these three characteristics. On leaves from plants grown in winter, damage, reproduction, and survival were higher than on leaves from plants grown in summer. Clear differences in resistance were observed between the susceptible and the partially resistant cultivar on leaves from plants grown in winter, while differences disappeared in summer. Damage on both cultivars and survival on the susceptible cultivar were negatively correlated with mean daily solar radiation during plant growth, suggesting that the level of resistance depends on light intensity during plant growth. This was confirmed in an experiment carried out in summertime with shaded and unshaded plants. Leaves from control plants, grown under high light intensity had a higher level of resistance than leaves from shaded plants grown under reduced light intensity. There were clear differences in resistance between the cultivars under shaded conditions (low light intensity), but not under unshaded control conditions (high light intensity). This revised version was published online in July 2006 with corrections to the Cover Date.     

Factors affecting haploid production in wheat using the Hordeum bulbosum system. 1. Genotypic and environmental effects on pollen grain germination,pollen tube growth and the frequency of fertilization

Summary A quantitative examination of pollen grain germination and pollen tube growth within the overy wall was made in selected wheat × tetraploid H. bulbosum hybridizations, to investigate the effect of the wheat and the H. bulbosum genotype on these characters. As expected, variation at the known crossability loci had no effect on pollen grain germination. The frequency of pollen tube penetration of the ovary wall was, however, severely reduced when the dominant alleles were present. Pollen tube penetration was nevertheless observed in 3 of the 110 ovaries examined of the non-crossable cultivar Highbury. The H. bulbosum genotype had a much smaller effect on these characters, but significant differences between the clones were observed in the numbers of pollen tubes initially penetrating the ovary wall. Although two H. bulbosum genotypes showed no significant differences in the number of ovaries with pollen tubes at the base of the ovule, significant differences in the frequency of fertilization were observed. The possible cause of this discrepancy is discussed.The frequency of fertilization in crossable wheat × H. bulbosum hybridizations was improved by the application of gibberellic acid within 10 minutes of pollination, and reduced by an increase in the ambient temperature from 20°C to 26°C. Fertilization following the pollination of non-crossable wheat genotypes was not affected by either of these factors.     

水分胁迫对玉米花粉活力和花受精能力的影响

抽穗期的玉米植株经不同强度水分胁迫处理后,花粉和花丝中ＳＯＤ活性下降,膜脂过氧化作用增强,对生物膜系统产生直接伤害,电解质外渗率增加,电镜下观察到线粒体和细胞质膜破坏,胞间连丝膨大变形,甚至断裂,粗糙内质网卷曲成空心筒状,甚至部分解体,导致代谢紊乱,物质运输受阻,影响花粉和花丝发育,降低雌穗花丝受精能力,减少穗粒数,从而造成减产。耐旱性不同的玉米,其花粉和花丝活力及花丝受精能力受水分胁迫的影响不同     

Pollen characteristics and stigma receptivity for <Emphasis Type="Italic">Anemone coronaria</Emphasis> L.

To obtain crossing products, an efficient pollination and subsequent fertilization is essential. This efficient pollination is achieved by pollen germination and tube growth. Here, these pollen characteristics of 2 genetically differentiating cultivars of Anemone coronaria L. were investigated in vitro. For the essential components boron, calcium and an osmoticant, only calcium showed to be crucial for pollen germination. Boron concentrations influenced the pollen tube length with a concentration of 100 mg l^?1 H₃BO₃ resulting in the longest pollen tubes. For the osmoticant sucrose, a concentration of 100 g l^?1 caused a significant positive effect on both pollen germination and pollen tube length for the 2 cultivars. The cultivars reacted similarly with respect to the investigated compounds. Next to this, the pollen development was correlated with 8 different flower stages in A. coronaria. As a final point, the germination of an optimized pollen germination medium was compared with in vivo pollen germination in cross-pollinations within the same cultivar (identified by aniline blue staining). For ‘Mistral Wine’, pollen germination percentage was lower in vitro than in vivo, while ‘Wicabri Blue’ pollen showed no significant difference in germination rates in vivo and in vitro. To achieve fertilization a following requisite is that the stigma is receptive. To study this, the most receptive female flower stage of the 8 different flower stages for A. coronaria was characterized by aniline blue staining. A. coronaria clearly showed protogyny.     

Pollen and pollination experiments. V. An empirical basis for a mentor pollen effect observed on the growth of incompatible pollen tubes in pear

Summary The self-incompatible pear cultivar Doyenne du Comice was selfed with the aid of the mentor pollen technique (self pollen mixed 1:1 with compatible pollen) and the pioneer pollen method (compatible pollen applied 14 h in advance of the self pollen). Observations on tube growth in the style showed that inviable methylated pollen was ineffective either as mentor or pioncer pollen, having no effect on the performance of the self pollen which stopped growing at about one quarter of the style from the stigma. Calculations made on the basis of the obtained data indicated that the viable untreated or irradiated pioneer and mentor pollen, the former somewhat better than the latter, aided the self pollen tubes to reach the base of the style.     

EMS诱变隐性单基因大麦雄性核不育性的遗传分析

应用甲基磺酸乙醋(EMS)1%溶液处理四棱大麦蒙克尔,获得了隐性单基因核不育材料.遗传分析可育与不育按3∶1分离.不育性稳定,不出现中问类型,遗传行为简单,不育株率较高,易于转育.大麦是典型的自花授粉作物,所获的雄性不育株,在大田条件下由于花粉量不足,结实率变动在0.51～2.25%之间,引入开放授粉特性,对雄性不育系的利用十分重要.雄性核不育基因对雌性器官无不良作用,人工授粉不育株的结实率可达74.10～87.47%,分离出的可育株结实正常,纯合可育株育性可靠,因而作为育种工具,在轮回选择中应用有较大价值.