棉花型和黄瓜型棉蚜(Aphis gossypii Glover)的寄主适应性及转移通道

采用寄主转接建立生命表的方法研究了棉花型和黄瓜型棉蚜对不同寄主植物的适应性,以及两寄主型棉蚜是否可通过中间桥梁寄主实现寄主互换的问题。结果表明,两寄主型棉蚜直接互换寄主后,其存活和繁殖力显著下降,表现为棉花型和黄瓜型棉蚜的净增殖率比在原寄主上分别下降980倍和12倍,平均世代寿命缩短5～12d。两寄主型棉蚜均能利用木槿植物,并且适应性没有显著差异。但是两寄主型棉蚜均不能在车前草和大叶黄杨上存活和繁殖后代。西葫芦作物对棉蚜在木槿、棉花和黄瓜寄主上的相互转移起到了重要的桥梁寄主作用。冬寄主木槿上棉蚜可通过甜瓜或西葫芦转移到黄瓜寄主上,棉花和黄瓜上棉蚜也可通西葫芦作物分别转移到黄瓜和棉花作物上,从而形成棉蚜在不同寄主植物间的相互转移通道,造成为害和病毒病的扩张。     

棉蚜种群寄主转换的适应和变异规律研究

系统研究棉蚜在不同寄主植物间地其种群特征的影响。通过Ｗeibull函数模拟,生命表分析和高氏距离分析比较得出,棉蚜从冬寄主向夏寄主转换移时,木槿与石榴、石榴与花椒间表现有明显分离。４种夏寄主间相互转换时也有一定组合间有显著差异,但当经若干代生长、繁殖后４ 的种夏寄主上种群作比较时,其差异性均没有达到明显分离的程度。     

棉蚜对寄主的选择及寄主专化型研究

采用叶片选择法,生命表及EPG技术研究了棉蚜对寄主植物的选择和专化性,结果表明,棉花上生长的棉蚜对棉花,西葫芦和西瓜叶片均具有强选择性,而对黄瓜和南瓜选择性弱,西瓜,南瓜和黄瓜上生长的棉蚜对其原寄主选择性强,而对棉花选择性弱,棉花上的棉蚜转接到黄瓜和南瓜上,其存活率和繁殖力极低,棉蚜的取食行为在黄瓜和马铃薯,黄瓜和棉花之间存在明显的寄主专化型,黄瓜与棉花上的棉蚜相互转接均难成功,而黄瓜和马铃薯上的棉蚜转移具有不对称性。     

棉花型和黄瓜型棉蚜对寄主植物的适合度

采用寄主转换建立生命表及触角电位 (EAG)方法比较了棉蚜两寄主专化型 (棉花型和黄瓜型 )对不同夏季作物的适合度。结果表明 ,棉花型蚜转到黄瓜上及黄瓜型蚜转接到棉花上均不能正常产仔繁殖和建立种群。两种蚜型均不能在茄子和苋菜上建立种群。黄瓜型蚜能在豇豆上建立种群 ,但棉花型蚜不能 ,表现出两种寄主型棉蚜对夏寄主利用上存在显著差异。受棉蚜为害 12～ 36 h后的黄瓜或棉花植株仍不适合于棉花型或黄瓜型蚜 ,表现出黄瓜型蚜不能在被棉花型蚜为害过的棉株上正常存活和繁殖 ,棉花型蚜也不能在被黄瓜型蚜为害过的黄瓜苗上存活和繁殖。两种寄主型蚜对不同寄主叶片丙酮提取物的触角电位表明 ,黄瓜型蚜对棉花、哈密瓜和马铃薯叶片提取物的反应显著强于棉花型蚜 ,而对黄瓜和甜瓜叶片提取物的反应上两种蚜型差异不显著。文中同时对棉花型和黄瓜型棉蚜产生的生态机制进行了讨论。     

5个棉蚜组织蛋白酶B基因克隆及在不同寄主专化型中的表达分析

昆虫组织蛋白酶B在昆虫代谢中发挥着重要作用。本研究从棉蚜Aphis gossypii Glover的转录组数据库中挑选Cath B并克隆得到全长cDNA序列,使用qRT-PCR分析这些基因在不同寄主专化型棉蚜不同龄期中的相对表达量。通过分析棉蚜体内5个高表达组织蛋白酶B基因不同发育阶段的表达谱,比较了不同专化型棉蚜在寄主转换之后的表达差异。研究发现,这5个基因在不同龄期不同寄主上均表达。棉花型棉蚜在棉花寄主上不同基因间的表达各不相同。黄瓜型棉蚜在黄瓜Cucumis sativus L.上AgCb-1、AgCb-2、AgCb-3基因均在成蚜时期表达量相对较高,AgCb-4、AgCb-5基因表达量则与之相反。分别将棉花型棉蚜和黄瓜型棉蚜转接到西葫芦Cucurbita pepo L.上后,棉花型棉蚜AgCb-1、AgCb-4基因和黄瓜型棉蚜AgCb-1、AgCb-2、AgCb-3基因均在成蚜不同时期的表达量显著大于转接前。结果表明：AgCb-1、AgCb-2、AgCb-3、AgCb-4、AgCb-5基因表达量伴随着棉蚜的生长发育以及寄主的转换,表现出不同的差异。说明组织蛋白酶在棉蚜对寄主植物的适应性过程中可能发挥作用。     

危害枸杞的棉蚜Aphis gossypii Glover

<正>棉蚜Aphis gossypii Glover是一种常见害虫,主要危害次生寄主棉花、玉米、大豆、西瓜、黄瓜、南瓜、茄子、西葫芦、月季、核桃、丁香、金橘等,也危害原生寄主石榴、花椒、木槿和鼠李等。危害枸杞的蚜虫种类多为棉蚜,无翅孤雌蚜体型宽椭圆形,活体淡墨绿色,腹管黑色,玻片标本腹     

不同寄主植物与棉蚜酯酶活性的关系

通过测定不同越冬寄主植物棉蚜Aphis gossypii种群α-乙酸萘酯（α-NA）酯酶的活力,结果表明：山东高密棉田棉蚜种群酯酶活力是北京花椒棉蚜酯酶活力的2.4倍,石榴、木槿上棉蚜酯酶活力是花椒棉蚜酯酶活力的1.3-1.5倍,不同寄主植物棉蚜α-NA酯酶和β-NA酯酶的频率分布表明：鼠李、花椒棉蚜的α-NA酯酶频率分布范围较集中,酯酶活力（每0.033头蚜虫的OD值）小于0.10时的频率分别为70%和62%,其个体累积率达50%时的酯酶活性（EF50）分别为0.08和0.085(每0.033头蚜虫的OD值）;石榴、木槿和棉苗上α-NA酯酶频率分别为25%、31%和45%,其EF50分别的0.154、0.1368和0.1138,酯酶活力明显比鼠李和花椒棉蚜高;高密棉蚜为4%,EF50为0.2113,频率分布范围较宽。β-NA酯酶的频率分布,鼠李、花椒、木槿和棉苗上棉蚜酯酶活力（每0.033头蚜虫的OD值）小于0.10时为52%-62%的个体,EF50分别为0.098、0.084、0.102和0.091,寄主之间差异不大,而石榴和高密棉蚜分别为23%和3%,EF50分别为0.135和0.2136,与其它4个寄主有明显差异。     

棉蚜(Aphis gossypii)种群寄主分化和季节分化的微卫星引物PCR研究

通过对棉蚜群体进行室外观察、室内培养和分子遗传标记的DNA多态性分析（用3个微卫星序列为引物进行PCR）等研究,结果表明：1、冬寄主（木槿、石榴和花椒）上棉蚜种群分化较小（种群相似笥指数在0.833-0.917之间）,而冬寄主种群和夏寄主（棉花和南瓜）种群之间有较大的分化（种群相似性指数在0.589-0.756之间）。2、棉蚜自然种群是由体色不变的生物型（干母为黄色,其后代始终为黄色）和体色可变型生物型（干母为绿色,其后代有绿色和黄色两种体色）组成的混合种群。3、黄色小型蚜（伏蚜）来源于混合类群,但主要来自绿色干母多代选择分化的黄色后代,也有小部分可能来处在干母黄色的体色不变型。     

棉花型和瓜型棉蚜产生有性世代能力的分化

为了明确寄主专化性是否会影响棉蚜的繁殖策略或生活史对策,采用低温和短光照组合（18℃,L∶D=8∶16）分别对棉花型和瓜型棉蚜进行有性世代的诱导,比较两寄主专化型棉蚜产生有翅蚜、雄性母、雌性母及无翅孤雌蚜的能力。结果表明：两寄主专化型棉蚜在产生有性世代能力上存在显著差异,表现为棉花型棉蚜在诱导后代中产生有翅蚜、雄性母和雌性母的比率显著高于瓜型棉蚜,并且雌、雄性母产生的时间明显早于瓜型棉蚜。瓜型棉蚜在诱导条件下产生无翅孤雌蚜的比率显著高于棉花型棉蚜,并且发现有不产生有性世代的营专性孤雌生殖个体,而在棉花型棉蚜中没有发现。产生性母蚜的棉花型和瓜型棉蚜均可同时产生孤雌胎生后代。寄主型与诱导时间长短对棉蚜有性世代的产生存在交互作用。采集于田间棉花和黄瓜上的棉蚜,也表现为棉花上的易产生有性世代,在诱导的第2代中产生性母蚜的比率显著高于黄瓜上的棉蚜,并且性母蚜比率在诱导的第2代与第3代间无显著差异; 但黄瓜上的棉蚜性母蚜产生比率第3代显著高于第2代。由此推测,棉蚜寄主专化性的形成与生活史特性的分化有关。     

不同生物型棉蚜对夏寄主葫芦科作物的选择

于2008、2009年连续两年采用模拟田间自然扩散法,系统地研究了棉花型棉蚜和甜瓜型棉蚜有翅蚜对11种夏寄主的选择性.结果表明,棉花型棉蚜对杂交葫芦、小西葫芦表现出强选择性及适应性,而对香瓜、黄瓜、西瓜及甜瓜均不选择,或即使选择其若蚜在其上也不能存活;甜瓜型棉蚜对甜瓜、香瓜、南瓜、黄西葫芦、大西葫芦、杂交葫芦等均表现较强选择性,而对棉花及小西葫芦表现不选择.但是,甜瓜型棉蚜在小西葫芦上也能产若蚜并存活.从而证明小西葫芦是两种寄主型棉蚜的共同寄主,有可能成为两者相互转换的桥梁寄主.     

Effect of reproductive mode on host plant utilization of melon aphid (Hemiptera: Aphididae)

Variation in the reproductive mode of melon aphid Aphis gossypii Glover occurred on the large geographic scale, but the performance of different reproductive modes to use host plant is poorly understood. Life tables of melon aphid population that undergo the anholocyclic, androcyclic, and intermediate reproductive mode were conducted on different host plants. The results showed that the anholocyclic and androcyclic strains could become adults and produce offspring on cotton Gossypium hirsutum L., whereas the intermediate strain could not. The survival rate, net reproductive rate (R(0)), and intrinsic rate of natural increase (r(m)) of the androcyclic strain on cotton were significantly greater than that of the anholocyclic strain. The three strains could aptly use cucurbits host plants including cucumber Cucumis sativa L., pumpkin Cucurbita moschata (Duchesne ex Lam.), and zucchini Cucurbita pepo L.; survival rate and R(0) were not significantly different on these two host plants. Moreover, the r(m) of the anholocyclic strain on cucumber and the androcyclic strain on pumpkin and zucchini were significantly greater than that of the other two strains. The abilities of the three strains to use a host plant were flexible, because their r(m) on pumpkin or zucchini became equal after rearing for four successive generations; furthermore, the intermediate strain attained the ability to use cotton, and the performance of anholocyclic and intermediate strains to use cotton also significantly increased after feeding on pumpkin or zucchini for one or three generations. It was concluded that the reproductive mode and feeding experience affected the performance of melon aphid to use a host plant.     

Presence of two host races of Aphis gossypii Glover (Hemiptera: Aphididae) collected in Turkey

The aphid, Aphis gossypii, is a primary pest of citrus, cotton, cucurbits and greenhouse‐grown vegetables in Turkey and throughout Europe. There is some previous empirical data suggesting that host‐adapted genotypes of this aphid exist which may in fact be host‐races. To determine if host races of A. gossypii are indeed present in the eastern Mediterranean region of Turkey, reciprocal host transfer experiments and life table analyses were performed with multiple asexual lineages (= clones) of the aphid collected from different hosts. The collection hosts included citrus, cucumber, eggplant, okra, sweet pepper and cotton. Aphid developmental times on the host from which the aphid was originally collected (= collection or natal host) were shorter (5.2–6.0 days) and had a higher intrinsic rate of population growth (r_m = 0.25–0.44) than the 6.6–7.3 days required when the aphid was reared on a non‐original collection host (= non‐collection host or non‐natal host) and had r_m = 0.03–0.30. Total immature mortality of the cotton clone, especially in the first nymphal stage, was high (51–100%) with low r_m (0–0.03) on cucumber, citrus and sweet pepper. Aphid populations transferred from citrus, eggplant and okra to cotton (r_m = 0.29–0.30) did not differ significantly in their performance from that of the cotton population on cotton (r_m = 0.34), whereas that from sweet pepper and cucumber populations (r_m = 0.22–0.24) were significantly lower. These data have allowed us to separate A. gossypii into two distinct biological groups: (a) a ‘generalist’ population obtained from cucumber, sweet pepper, citrus, eggplant and okra which exhibited statistically better development on cotton; versus (b) a population from cotton which, by comparison on reciprocal hosts, developed poorly on non‐natal hosts except on eggplant. Development of the cotton clone on cucumber and okra was not improved after four successive generations on the non‐natal host. The good development of A. gossypii from eggplant and cotton on these reciprocal hosts suggests that these particular clones were similar, if not identical, host races.     

杀虫剂及不同地区寄主植物对棉蚜酯酶的影响

通过滤纸酯酶反应法比较 4种有机磷杀虫剂对北京和山东高密地区取食不同寄主植物的棉蚜β-乙酸萘酯 (β -NA)酯酶的抑制作用。结果表明高密地区不同寄主植物上的棉蚜 β -NA酯酶活力高的个体多于北京地区 ,同时辛硫磷对高密地区不同寄主植物上的棉蚜 β -NA酯酶的抑制作用亦高于北京地区 ,而久效磷和DDVP对两地区不同寄主植物上的棉蚜种群中 β-NA酯酶的抑制作用相似。     

Identification of Aphis gossypii Glover (Hemiptera: Aphididae) Biotypes from Different Host Plants in North China

Background

The cotton-melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a polyphagous species with a worldwide distribution and a variety of biotypes. North China is a traditional agricultural area with abundant winter and summer hosts of A. gossypii. While the life cycles of A. gossypii on different plants have been well studied, those of the biotypes of North China are still unclear.

Results

Host transfer experiments showed that A. gossypii from North China has two host-specialized biotypes: cotton and cucumber. Based on complete mitochondrial sequences, we identified a molecular marker with five single-nucleotide polymorphisms to distinguish the biotypes. Using this marker, a large-scale study of biotypes on primary winter and summer hosts was conducted. All A. gossypii collected from three primary hosts—hibiscus, pomegranate, and Chinese prickly ash—were cotton biotypes, with more cotton-melon aphids found on hibiscus than the other two species. In May, alate cotton and cucumber biotypes coexisted on cotton and cucumber seedlings, but each preferred its natal host. Both biotypes existed on zucchini, although the cucumber biotype was more numerous. Aphids on muskmelon were all cucumber biotypes, whereas most aphids on kidney bean were cotton biotypes. Aphids on seedlings of potato and cowpea belong to other species. In August, aphids on cotton and cucumber were the respective biotypes, with zucchini still hosting both biotypes as before. Thus, the biotypes had different fitnesses on different host plants.

Conclusions

Two host-specialized biotypes (cotton and cucumber) are present in North China. Hibiscus, pomegranate, and Chinese prickly ash can serve as winter hosts for the cotton biotype but not the cucumber biotype in North China. The fitnesses of the two host-specialized biotypes differ on various summer hosts. When alate aphids migrate to summer hosts, they cannot accurately land on the corresponding plant.     

Resistance of aphis gossypii (Homoptera: Aphididae) to fenvalerate and imidacloprid and activities of detoxification enzymes on cotton and cucumber

Resistance of two strains of cotton aphid, Aphis gossypii Glover, to fenvalerate and imidacloprid were determined on cotton (Gossypium hirsutum L.) and cucumber (Cucumis sativa L.) after resistance selection of one strain to fenvalerate for 16 consecutive generations, and of a second strain to imidacloprid for 12 consecutive generations on cotton in greenhouses. Dose-response and activities of detoxication enzymes of the fenvalerate-resistant strain (R-fenvalerate), the imidacloprid-resistant strain (R-imidacloprid), and a susceptible strain (S) were determined. After 16 consecutive generations of selection, resistance of A. gossypii to fenvalerate increased >29,000-fold and to imidacloprid 8.1-fold. On cucumber. resistance of the R-fenvalerate strain to fenvalerate increased 700-fold and to imidacloprid 3.6-fold. However, the most significant finding in this study was that the R-imidacloprid strain exhibited cross-resistance to fenvalerate, with a resistance ratio of 108.9-fold on cotton and 3:3.5-fold on cucumber, whereas the R-fenvalerate strain did not show significant cross-resistance to imidacloprid on either plant species. Both resistant strains of A. gossypii were more resistant to fenvalerate on cotton than on cucumber, whereas their susceptibility to imidacloprid on otton and cucumber were not significantly different. The response of the S strain to fenvalerate and imidacloprid were similar on cotton and Cucumber. Activities of acetylcholinesterase (AChE) and alpha-naphthylacetate (alpha-NA) esterases of A. gossypii were significantly different among the three strains, with the R-fenvalerate strains having the highest, followed by the R-imidacloprid strain, and the S strain the lowest. The activities of the AChE and alpha-NA esterases for all three strains were also significantly higher on cotton than on cucumber. The resistance mechanism and resistance management strategies for the R-fenvalerate and R-imidacloprid strains of A. gossypii to fenvalerate and imidacloprid on cotton and cucumber are discussed.     

取食不同寄主植物对棉蚜后代抗药性的影响

测定了5种药剂对棉蚜Aphis gossypii抗氰戊菊酯、吡虫啉品系和敏感品系取食棉花、黄瓜和石榴的后代的毒力,并对它们的后代体内乙酰胆碱酯酶和羧酸酯酶的比活力做了初步探索。结果表明,氰戊菊酯抗性品系取食棉花比取食黄瓜的后代对氰戊菊酯的抗性大76.4倍,对灭多威、氧乐果、硫丹和吡虫啉的抗性也大0.5～4.6倍;取食石榴的后代对5种药剂的抗性介于取食棉花和黄瓜的之间。吡虫啉抗性品系的测定结果与氰戊菊酯抗性品系基本一致。敏感品系取食黄瓜比取食棉花的后代对5种药剂的敏感性更高。3个品系取食不同植物的后代相比,其体内乙酰胆碱酯酶的比活力,取食棉花的为取食黄瓜的2.4～2.8倍;羧酸酯酶的比活力,取食棉花的为取食黄瓜的1.8～2.4倍。证明棉蚜的抗性和敏感品系取食的寄主植物不同,可引起对药剂敏感性的变化。乙酰胆碱酯酶和羧酸酯酶活力的变化均是引起这种变化的重要因素。     

棉花型和瓜型棉蚜形态和生态适应力的分化

棉蚜由于长期在同种或同类植物上生活,形成了多种寄主专化型。本研究以室内长期用单一寄主培养的棉花型和瓜型棉蚜为材料,采用形态测定、生命表技术、对寄主的选择性试验,以及接触刺激等方法,研究了两寄主型棉蚜的形态分化和生态适应力的差异。结果表明,瓜型棉蚜的一些形态特征值（如体长）极显著地大于棉花型个体,但是头宽、口针和各腿节的长度与体长的比值却极显著的小于棉花型个体。采用7个形态指标与体长的比值,可将瓜型和棉花型棉蚜区分开来。在24℃和26℃下瓜型蚜的净增殖率（R₀）极显著地高于棉花型蚜。27℃和32℃显著缩短了瓜型蚜的平均世代长度,而对棉花型蚜无影响。棉花型蚜对接触刺激的反应比瓜型蚜敏感。两寄主型蚜对寄主的选择能力表现为瓜型蚜显著强于棉花型蚜。因此,两寄主型棉蚜存在明显的形态和生态适应力的分化。