安阳棉蚜寄主专化型及其形成机制初步分析

为了解安阳地区棉蚜寄主专化型情况,进行了棉蚜不同寄主转接的适合度测定。结果显示,棉花上与黄瓜上的棉蚜相互转接后其存活率及繁殖力均明显下降,不能建立种群;棉花上的棉蚜转接到西葫芦上时,其存活率及繁殖力与其原寄主无显著差异;黄瓜上的棉蚜转接到西葫芦上时,其净增殖率及内禀增长率均显著地高于其原寄主;黄瓜上棉蚜对西葫芦的适应性比棉花上棉蚜强。表明安阳地区棉蚜存在黄瓜和棉花两种寄主专化型,且都可以利用西葫芦。进一步对3种植物苗期叶片游离氨基酸进行测定,结果显示,游离氨基酸种类及总量均在西葫芦中最多,棉花中次之,黄瓜中最少。寄主植物游离氨基酸种类及含量的多少会影响棉蚜的生长与繁殖,可能是棉蚜寄主专化型形成的影响因素之一。     

尖孢镰刀菌古巴专化型FocGDSL1基因功能分析

在尖孢镰刀菌古巴专化型4号小种基因组中鉴定到一个编码GDSL家族脂肪酶的基因FocGDSL1。序列分析发现该蛋白在镰刀菌属中及其保守。为了研究FocGDSL1的功能和其对尖孢镰刀菌致病力的影响,首先利用同源重组原理构建了该基因的敲除突变体菌株,并进一步对其表型进行了分析。结果发现,FocGDSL1的缺失不影响尖孢镰刀菌的营养生长及其对抑菌药物的抗性;但是FocGDSL1突变株中色素的合成明显减少。与此同时,FocGDSL1突变株对香蕉植株的致病力显著下降。这些结果表明FocGDSL1虽然不是控制尖孢镰刀菌菌丝生长的关键基因,但是FocGDSL1是尖孢镰刀菌重要的致病力因子,可能是尖孢镰刀菌在侵染的前期,分泌FocGDSL1来降解宿主细胞壁和细胞膜,进而使病原菌在宿主体内定殖。     

非生物胁迫对棉花次生代谢及棉蚜种群消长的影响

盐碱、干旱等非生物胁迫影响棉花的次生代谢,而次生代谢可能影响棉株上的害虫发生。为明确非生物胁迫与次生代谢及棉蚜种群消长三者间的关系,以不同浓度氯化钠(NaCl)和聚乙醇(PEG)溶液分别处理棉苗,测定了棉叶组织内棉酚和可溶性糖含量的变化,并观察了棉蚜在被处理棉苗上的生长发育及繁殖情况。结果发现,100和200 mmol·L~(-1) NaCl处理棉苗的棉酚含量分别比不含NaCl的对照提高20%和53.5%,可溶性糖含量分别提高15.7%和46%。盐胁迫显著延长棉蚜的发育历期并降低繁殖率,100和200 mmol·L~(-1) NaCl处理的棉蚜若蚜期分别比对照延长6.4%和9.9%,单雌产蚜量分别减少22.6%和52.3%。干旱胁迫也影响棉花叶片棉酚和可溶性糖含量,质量分数2.5%和5%的PEG处理棉株的棉酚含量分别比对照提高39.7%和61.5%,可溶性糖含量分别提高14.2%和47.1%,生长在PEG处理棉株上的棉蚜的若蚜期分别延长7.4%和16.5%,单雌产蚜量分别减少26.8%和55.8%。叶片内棉酚和可溶性糖含量均与棉蚜若蚜期呈显著正相关,与棉蚜的产蚜量呈显著负相关。由此推断,盐碱、干旱等非生物胁迫增强了棉苗的次生代谢,导致棉酚和可溶性糖等次生代谢产物大量积累,抑制了棉蚜种群的消长。     

不同棉花品种对棉蚜羧酸酯酶活性影响的研究

对取食不同棉花品种后棉蚜羧酸酯酶比活力测定结果表明：不同棉花品种对棉蚜羧酸酯酶活性影响较大，并且能影响棉蚜羧酸酯酶对底物的活性。棉蚜取食高抗品种后，总的羧酸酯酶活力提高，并且酶活力与单宁的含量呈不显著的正相关（ｒ＝０．７８７）。这种相关性表明棉花中的单宁的含量可能是影响棉蚜外源解毒酶活性提高的一个因素，同时棉蚜羧酯酯酶的活性也是衡量棉花抗性的一个指标。     

不同受害程度的棉株对棉蚜种群的影响

通过室内对不同密度棉蚜两次为害棉株的生态学参数测定，结果表明：棉株在受到棉蚜二次为害后，无论是棉株生长点或是不同生长期棉株受害，均可影响棉蚜种群数量下降，增长率降低，发育历期增大，扩散率提高，体色趋变黄色。可以证明受害棉株明显存有诱导抗性，且６片真叶以后的诱导抗性大于６片真叶以前。     

棉蚜乙酰胆碱酯酶对杀虫剂不敏感的分子机制

棉蚜是第一个用RT-PCR方法发现具有2个不同乙酰胆碱酯酶(AChE)基因的昆虫,2个基因编码的氨基酸序列的相似性仅48%.进化分析表明,两者相距甚远,分化于昆虫纲出现以前.从棉蚜2个AChE中发现多个抗药性相关突变位点,但功能表达证实AChE-1可能是两类杀虫剂的主要作用靶标,AChE-1的S431F和A302S突变导致对多种有机磷和氨基甲酸酯类杀虫剂的敏感性降低,但对某些杀虫剂品种的敏感性反而升高.并讨论了需进一步研究的问题.     

尖孢镰刀菌亚麻专化型Folcdc15基因参与调控分生孢子发生和菌丝生长

通过对尖孢镰刀菌亚麻专化型Folcdc15基因敲除及敲除突变体互补试验,探究该基因在尖孢镰刀菌亚麻专化型中的功能。对Folcdc15基因进行DNA测序后,使用Split-Marker技术,构建含有潮霉素抗性基因(hph)缺失盒。通过PEG介导法转入野生型原生质体,在含有潮霉素的选择培养基上进行转化子筛选,通过PCR正负筛选确定敲除突变体。利用pZWH1载体构建含有Folcdc15的互补载体pZLY1,将其转入敲除突变体中进行互补测验。与野生型hm相比,敲除突变体ko1菌落生长速率下降了73%,菌丝形态发生了显著改变,菌丝变短且分叉变多,分生孢子隔膜数量增多长度增加,分生孢子数量显著减少。亚麻侵染试验表明,ko1的致病力显著降低。通过互补测验发现,回复突变株ca1恢复了Folcdc15基因缺失带来的分生孢子产量及形态、菌落生长和形态及致病力的缺陷。Folcdc15参与调控尖孢镰刀菌亚麻专化型的分生孢子发生及菌丝生长。     

转基因棉对棉蚜生长发育及其主要代谢物质含量的影响

近年来,转基因棉田非靶标害虫种群数量呈明显的上升趋势,棉蚜是转Bt(Bacillus thuringiensis)基因棉田发生危害较严重的非靶标刺吸性害虫之一.在实验室内,棉蚜分别用转Bt基因棉和亲本常规棉饲养40代以上,采用酶联免疫法( ELISA)检测转Bt基因棉SGK321上棉蚜体内的Bt蛋白含量,研究转Bt基因...     

非棉田生境对棉蚜及其天敌的影响

农田生态系统中不同植物生境条件下天敌种类及种群动态,对农田害虫的生态治理和持续控制具有十分重要的意义。选择不同类型的棉田,系统调查棉田中棉蚜及其周围生境中天敌的种群动态。结果表明,新疆南部棉区非棉田生境中的天敌种类多、数量大、发生期早。在同一地区、同一年份不同类型的棉田棉蚜发生的总趋势大致相同,但其进入棉田的时期、发生量有较大差异。主要天敌瓢虫、草蛉、食蚜蝇进入棉田的时间最早的是类型I,最晚的是类型Ⅳ。食虫蝽类最早进入类型Ⅱ,类型Ⅳ最晚。调查期内各类天敌的总数,瓢虫数量最多的是类型I,最少的是类型Ⅳ;草蛉、食蚜蝇、食虫蝽和蜘蛛总量最多的是类型Ⅱ,最少的是类型Ⅳ。由此可见,非棉田生境是影响棉田天敌的主要因素之一,为新疆棉蚜的生态调控理论提供了依据。     

Y型玉米雄性不育化杂交种形态特征及推广可行性初探

该文以如皋市大面积推广的掖单１３号不育化杂交种为例,研究Ｙ型不育化杂交种与同核型杂交种（用保持系配制的杂交种）个体植株发育及产量结构方面的差异。研究结果表明,不育化杂交种的生长速度快,整齐度高,增产因素显著。同时,制种省工节本,纯度好,产量高,推广是可行的。     

新疆棉蚜生物型的研究

在新疆主要棉蚜寄主植物之间进行了接种试验，确立了不同的棉蚜食物专化型—瓜蚜型和棉蚜型。二者各自在瓜类和棉花上独立存在，互相不能直接迁移定植；初步推断出棉蚜在新疆存在３种生活周期型：（１）异寄主全周期型，以石榴和黄金树等为越冬寄主，棉花为侨居寄主；（２）同寄主全周期型，初步观察棉蚜在黄金树上能完成生活周期；（３）不全周期型有两种情况，一是瓜蚜型夏季在田间瓜类作物上营孤雌生殖生活，秋季进入温室和大棚的黄瓜等寄主上继续营孤雌生殖生活；二是夏季在棉花上营孤雌生殖生活，秋季进入温室和大棚的扶桑等寄主上继续营孤雌生殖生活；并采用ＲＡＰＤ－ＰＣＲ技术对不同寄主植物上的棉蚜种群进行了检测。     

几种药剂对棉苗蚜、伏蚜的毒力测定和药效试验

测定了13种杀虫剂防治棉蚜的效果.经室内系列生物测定结果表明:啶虫脒、吡虫啉、阿维菌素、丁硫克百威、辛硫磷和毒死蜱6种药剂防治棉苗蚜、伏蚜的效果都很好;并选择这6种药剂进行了田间小区试验,试验结果基本与室内生测的结果相符,经总体评价认为:啶虫脒、吡虫啉、阿维菌素和丁硫克百威可以作为理想的防治棉蚜的杀虫剂.     

Preliminary Study on Metabolic Resistance Mechanism of Aphis craccivora in Intercropping Field of Cotton and Peanut to Imidacloprid

[Objective] This study aims to explore the difference of imidacloprid resistance between Aphid gossypii and Aphid craccivora in intercropping field of cotton and peanut, and the mechanism of imidacloprid resistance to A. craccivora, so as to scientifically control these pests and to effectively avoid the rapid development of the resistance to imidacloprid. [Method] Two A. gossypii field populations and two A. craccivora field populations were collected from intercropping field of cotton and peanut in Juye and Linqing county of Shandong province, China. The bioassay experiment with two A. gossypii field populations, the bioassay and synergism experiment in two A. craccivora field populations were performed by the leaf dipping method. In addition, the activities of carboxylesterase (CarE), glutathione S-transferase (GST) and cytochrome P450 monooxygenase (P450) were assayed in the susceptible strain and two field populations of A. craccivora. [Result] Two A. gossypii field populations from Linqing and Juye exhibited moderate levels of resistance to imidacloprid, with the resistance ratios of 43.2- and 54.6-fold, while two A. craccivora field populations from Linqing and Juye showed susceptible and low level of resistance to imidacloprid, with the resistance ratio of 3.7- and 8.3-fold, respectively. According to the synergistic experiments, PBO and DEM significantly synergized imidacloprid in A. gossypii field population of Juye with the synergistic ratio of 3.63- and 1.95-fold, respectively, and TPP had no effect on imidacloprid toxicity. In A. craccivora field population of Linqing, PBO significantly synergized imidacloprid with the synergistic ratio of 3.05-fold, and DEM and TPP had no effect on imidacloprid. Further enzyme activity tests revealed that the activities of P450 and GST in Juye A. craccivora population were significantly higher than susceptible strain, and the activity of CarE had no significant difference between Juye A. craccivora population and susceptible strain. However, the activity of P450 in Linqing A. craccivora population was higher than susceptible strain, and the activities of CarE and GST had no significant differences. [Conclusion] Sensitivity of the two aphids in intercropping field of cotton and peanut to imidacloprid were greatly different, and P450 and GST may play an important role in resistance of A. craccivora to imidacloprid. The results are valuable for reasonable use of pesticides to delay the development of pesticide resistance of two aphids.     

新疆棉花主栽品种的抗蚜性及其机制研究

 对新疆棉区主栽的9个棉花品种进行了叶片形态特性、生化物质含量测定,结果表明,品种间抗蚜程度存在显著差异,新海21号抗蚜性最强,中棉所35和81-3感蚜。品种叶片的蜡质含量越高,对棉蚜的抗性越强,茸毛密度大,影响棉蚜的取食;游离棉酚和可溶性糖含量与抗蚜程度呈显著正相关;单宁含量与蚜害指数呈显著正相关;氨基酸中的谷氨酸含量越高,抗蚜性越强。逐步回归和相关分析发现,氮含量和氨基酸总量与抗蚜程度无明显相关性。品种的抗蚜性是多种特性综合作用的结果。     

Advantages of Different Tillage Systems and Their Effects on the Economically Important Pests, Thrips tabaci Lind. and Aphis gossypii Glov. in Cotton Fields

An experiment to assess advantages of different tillage and their effects on Aphis gossypii Glov. and Thrips tabaci Lind was conducted during the 2000 and 2001 cotton growing seasons in cotton fields at Adnan Menderes University, Agricultural Faculty Research Center, located in Ayd?n Province, Turkey. The tillage systems examined were conventional, strip, precision and ridge tillage. Two insect population densities were not affected by the type of tillage systems during either year. However, significant differences in populations were observed in thrips populations on 31 May 2000 and 18 May 2001 and aphid populations on 24 May 2000 and 11 May 2001. The results show that the highest yield was observed in all conservation tillage systems in 2000 and ridge tillage system in 2001. Early maturity was higher in both precision and ridge tillage systems. In addition, tillage systems did not affect fibre properties. As a result, the application of conservation tillage is more advantageous in cotton in respect of early maturity and total yield.     

转基因抗虫棉对棉蚜生长发育和繁殖的影响

以常规棉泗棉3号上饲养10代的棉蚜作为虫源,以其亲本为对照,在室内分别研究了转单、双价基因抗虫棉对棉蚜的短期影响,及单价抗虫棉对棉蚜的长期效应。结果发现,单价抗虫棉GK12和双价抗虫棉SGK321在短期内对棉蚜生长发育、繁殖和生命表参数无显著影响。在抗虫棉上取食1代的棉蚜,各龄发育历期、成虫寿命、产仔数和产仔历期、内禀增长率、净增长率、平均发育历期等和取食亲本的棉蚜之间均无显著差异。在GK12上取食37代的棉蚜与取食亲本常规棉泗棉3号和在GK12上取食1代的棉蚜之间以上各指标也无显著差异。可见,单价抗虫棉GK12和双价抗虫棉SGK321在短期内对棉蚜的生长发育和繁殖均无显著影响,GK12在长期内对棉蚜也未产生显著影响。     

棉花和瓜类上棉蚜相互转换后取食行为的EPG研究

实验采用 EPG技术测定了棉花和 3种瓜类上棉蚜转换后的取食行为 ,结果表明 ,西瓜、黄瓜和南瓜上的棉蚜转接到棉花叶片上取食 ,均可出现 A、B、C、E、F和 G6种取食波 ,其中寻食刺探的次数和时间均较少 ,且每次达到韧皮部吸取营养的时间长于 1 0 min。而棉花上的棉蚜转到黄瓜叶片后 ,寻食和刺探的时间占整个处理时间的95 %以上 ,口针到达韧皮部的次数少、持续时间很短。黄瓜叶片不利用于棉花上棉蚜的取食     

Regulation of Free Amino Acid in Cotton at the Seedling Stage by Aphis gossypii Feeding

[Objective] Free amino acids are important nitrogen nutrients, and their changes reflect the interaction between insects and host plants. The purpose of this experiment was to study the effect of aphid feeding on the free amino acid content of host cotton in seedling stage. [Method] The seedling cotton infected by aphid with different damage grades was selected from the field and analyzed the content of free amino acid in euphylla, cotyledon, hypocotyl and root. [Result] The content of free amino acids in cotton tissues increased after feeding by Aphis gossypii, and the content of free amino acids in cotyledon, hypocotyl and root is more than 2 times of the level 0. The content of non-essential amino acids increased more significantly than that of essential amino acids. The changes of single free amino acid content in different tissues were not completely consistent, and the Asn and Glu increased significantly in all tissues. [Conclusion] The feeding behavior of cotton aphid affects the nutritional level of cotton tissue and the content of free amino acid increased significantly.