再探棉蚜体色变化的生态遗传学机理

作者对各种不同生境中蚜虫体色进行了观察,并通过胚胎解剖、染色体镜检研究了棉蚜体色规律性变化的原因。试验结果表明,棉蚜体色在世代内稳定不变;在世代间则随温度升高体色由绿渐变至黄。温度降低,体色又由黄渐渐转绿。统计检验证实:棉蚜体色变化与营养、寄主种类、光照光质、栽培条件等无关;仅与温度密切相联;性蚜体色与初产卵卵色均为绿色。木槿、花椒上的深黄色棉蚜,其体色不随温度改变,表明其已构成棉蚜体色变化的遗传多态现象。体色随温度变化的蚜虫在生态遗传学上属于基因型对环境条件的反应规范。     

影响麦长管蚜体色变化的主导因素

研究麦长管蚜Macrosiphum avenae(Fabricius)体色变化生态主导因素,田间红色麦长管蚜种群对不同抗蚜性寄主的反应和自然条件下,不同体色麦长管蚜的生殖力以及后代种群体色变化情况。结果显示:在实验温度范围内,麦长管蚜种群中红体色蚜虫所占比例随温度升高而增加,在28,29,30,31℃时,红体色蚜虫所占比例分别为6.66%,38.30%,70.60%和65.24%。麦长管蚜体色变化过程中,温度起到重要的作用,而与光周期和寄主营养的关系甚微。红体色麦长管蚜在不同抗蚜性的品种上其种群消长情况存在差异。田间红绿体色麦长管蚜经2代观测,平均蚜量比值分别为9.96和15.85,生殖力差异不显著。在小麦抽穗期到乳熟期红体色麦长管蚜个体比例随着田间条件的改变逐代升高(分别由第1代的17.55%和14.70%增至第2代的29.80%和42.2%)。     

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。     

短时间高温处理对棉蚜存活的影响

为探索棉蚜Aphis gossypii Glover种群动态与高温的关系,研究了不同温度(30、34、38、42、46℃)、不同处理时间(1、2、5、8h)对棉蚜存活的影响。结果表明:在同一处理时间条件下,棉蚜的存活率随着温度的升高而降低;在同一处理温度下,棉蚜的存活率随处理时间的延长而降低。30～38℃温度范围内,棉蚜存活率降低缓慢,从42℃开始棉蚜的存活率迅速降低。棉蚜半数致死温度随着处理时间的延长而降低;相同处理时间条件下,若蚜半数致死温度高于成蚜,若蚜较成蚜更耐高温。     

不同温度条件对棉蚜、棉长管蚜种间竞争关系的影响

【目的】棉蚜Aphis gossypii和棉长管蚜Acyrthosiphon gossypii是棉花上的共存种,本文拟明确不同恒温条件下两种蚜虫单种和共存时的种群动态、有翅蚜发生及在棉株上的分布情况,探讨温度对两者种间竞争的作用。【方法】棉蚜、棉长管蚜单种、混合初始等蚜量设置,分别置于室内21、24和27℃恒温条件下,系统调查记录各处理种群数量、有翅蚜数量及在棉株上的分布,应用内禀增长率rm、空间分布情况、有翅蚜比例为竞争判别指标。【结果】棉蚜单种种群过程的rm均大于棉长管蚜,共存条件下一种对另一种蚜虫的rm均没有显著影响;棉蚜种群97%以上在叶片活动,棉长管蚜在叶片的比例为55%~75%;同一温度条件,两种共存不影响对方在棉花叶片和茎秆上的分布;棉蚜和棉长管蚜主要分布于棉花中上部。随温度升高,共存种群中棉蚜向棉株下部移动的比例增加,单种和共存种群棉长管蚜趋向于棉株上部移动。同一温度条件下,共存对棉蚜上下分布没有明显影响。21℃和27℃棉蚜的存在对棉长管蚜没有显著影响,但24℃时共存可使棉长管蚜在下部的比例明显增加;随温度的升高,棉蚜有翅蚜比例下降显著,而棉长管蚜无显著变化。【结论】适温范围内,两种蚜虫种间竞争的存在不影响彼此的内在繁殖能力,棉蚜比棉长管蚜具有更强的内在竞争能力;温度对棉蚜在竞争活动空间上的影响不明显,而对棉长管蚜的上下位置的选择有一定作用;种间竞争和种内竞争加速棉蚜有翅蚜的发生。     

棉蚜DNA多态性RAPD PCR分析(英文)

应用RAPD PCR技术研究了不同寄主和不同季节棉蚜的DNA多态性。从 2 0种随机引物中筛选出 3种引物 ,用它们的扩增结果进行Nei的遗传距离计算 ,并根据遗传距离对所研究的棉蚜种群做聚类分析。结果表明南京地区花椒上的棉蚜与其它 4种寄主上的棉蚜在DNA水平有明显的分化。聚类分析表明 ,棉蚜季节性种群可分为 3大类群 ,即春、秋季黄色型 ,春、秋季绿色型和黄色小型蚜 (伏蚜 )。而小型蚜的遗传关系与春、秋季绿色型最为接近。     

枸杞棉蚜形态和生物学特性研究

【目的】棉蚜Aphis gossypii Glover是一种分布广泛的重要农业害虫,其寄主范围较广。近年发现棉蚜严重为害一种新的寄主植物枸杞Lycium barbarum L.。枸杞是名贵中药材和食物,枸杞上生活的棉蚜的生活史特征尚不清楚。为了更好地预测预报和有效防控枸杞棉蚜,减轻枸杞的受害损失,本研究对栽培枸杞上棉蚜的生物学特性进行了系统研究。【方法】在田间条件下,对青海栽培枸杞树上的棉蚜各蚜型和虫态进行了详细调查,记述了各虫态的形态特征、发育历期、生活史、寄主植物、习性、发生规律及天敌种类。【结果】枸杞树上的棉蚜为害嫩枝梢、叶片、花蕾和果实,引起枸杞果产量和品质严重下降。枸杞棉蚜有6种蚜型,即孤雌蚜(有翅型和无翅型)、性母蚜、性蚜(性雄蚜和性雌蚜)和干母蚜,蚜型间的形态有明显差异,可用于区别不同的生活史阶段。枸杞棉蚜原寄主是枸杞,在青海一年发生10~16代,以滞育卵在枸杞树干和树枝上越冬,翌年4月上中旬开始孵化产生干母,5月产生无翅孤雌蚜进行孤雌生殖,6月开始产生有翅孤雌蚜,在田间迁飞扩散,7月和8月田间出现两次蚜虫数量高峰,孤雌蚜一直延续至9月,田间开始产生性母蚜、性雄蚜和性雌蚜,在枸杞树上进行有性生殖,10月中旬是交配、产卵高峰期,随后卵进入滞育越冬。若虫共4龄。无翅型若蚜期平均10.22±3.32 d,有翅型若蚜期平均9.55±2.53 d;无翅型成蚜寿命平均10.10±1.07 d,有翅型成蚜寿命平均8.97±1.34 d;1代无翅型蚜虫总寿命平均20.32±6.31 d,有翅型蚜虫总寿命平均18.52±4.51 d;孤雌蚜繁殖后代中无翅型若蚜数量平均为17.86±5.66头/雌,有翅型若蚜数量平均为15.33±3.76头/雌。枸杞田捕食和寄生棉蚜的优势天敌有多异瓢虫Hippodamia variegata(Goeze)、七星瓢虫Coccinella septempunctata L.、丽草蛉Chrysopa formosa Brauer和蚜茧蜂。【结论】枸杞树上棉蚜生活周期为全周期型。与其他寄主上的棉蚜比较,枸杞棉蚜体型更大、发育期更长、繁殖后代个数明显较少。在枸杞树上种群数量一年发生有2个高峰期,分别在7月和8月,有别于前人报道的其他寄主上棉蚜种群数量的1个高峰期出现在5-6月。这些差异可能与棉蚜对枸杞寄主和青藏高原环境产生生态适应性有关,其适应机制需进一步探索。     

不同类型棉田生态系统中棉蚜种群能量动态及其生态学效率分析

本文以能量为统一单位,以生理学时间为尺度,建立了计算世代重叠的棉蚜种群能流参数模型,分析和比较了不同播种时间、间套作、免耕和化学防治处理的棉田生态系统中棉蚜种群的生产力、摄入量及生态学效率。结果表明：（１）棉蚜种群能量生产的９８％来自于伏蚜时期,而苗蚜与秋蚜不足２％;（２）播种期推后,苗蚜种群生产力、摄入量减少,而伏蚜、秋蚜的生产力、摄入量增加;套间作,使苗蚜、秋蚜种群生产力、摄入量减少,伏蚜种群的生产力、摄入量增加;（３）化学防治对棉蚜种群生产力、摄入量有一定的作用,其作用强度依农药品种及施药次数而异;（４）各类型棉田棉蚜种群的同化效率与净生态学效率变化幅度较小,而摄入利用效率变化幅度较大。由此进一步探讨了不同类型棉田棉蚜的管理对策。     

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。     

棉蚜种群季节性变异的生态条件

研究棉蚜在不同温度下取食不同生育期棉叶后种群的变动情况。通过Weibull函数模拟、生命表分析和高氏距离分析比较表明,无论在苗期和蕾期,随着渐度的升高棉蚜种群的死亡高峰日均提前,世代寿命明显缩短;然而,在20-25℃范围内,相同温度时棉蚜生活在棉花蕾期叶上的繁殖力明显高于苗期叶上的繁殖力。在30℃时繁殖力普遍明显下降,温度20-25℃最适于棉蚜的生长与繁殖。且棉花殖生长期比营养生长期更适于棉蚜的生存和繁殖,温度与棉花生育期都是导致苗蚜与伏蚜生长与繁殖差异的外界因素。     

The effect of color polymorphism on mortality in the aphidMacrosiphoniella yomogicola

We examined body color polymorphism in the aphidMacrosiphoniella yomogicola from July to September 1993. We classified body color into eight types: green 1, green 2, red 1, red 2, white, orange, yellow and mist. The frequencies of body color varied with time and among patches of the host plant, yomogi (Artemisia spp.). Color diversity within a shoot was calculated using the Shannon diversity index. Of five usable data sets, three showed negative relationships between color diversity and mortality. The regression coefficients for two of these relationships were significant. No significant relationship between mortality and the number of aphids was found. The color diversity was not significantly related to a particular body color found on a yomogi shoot. Color polymorphism may be maintained because selection may favor a high color diversity on the host plant shoot.     

Do aphids paint the tree red (or yellow)—can herbivore resistance or photoprotection explain colourful leaves in autumn?

We explored two mutually nonexclusive hypotheses on autumnal leaf colouration. The co-evolutionary hypothesis states that autumnal leaf colouration functions as a handicap signal to herbivorous insects, whereas the photoprotection hypothesis posits that plant pigments primarily protect the plant against cold-induced photoinhibition and enhance nutrient transfer. To contrast both hypotheses, we compared yellow and red leaf colouration in three groups of mountain ash (Sorbus aucuparia L.). Two montane groups of different age were characterised by low aphid numbers and low temperature, and a lowland group by high aphid numbers and high temperature. There were no consistent altitudinal differences in leaf colouration. Compared to young trees, adult trees developed fewer red but more yellow leaves at high altitude. In the lowland population, the development of red leaf colour was related to decreasing daytime temperature, whereas the appearance of yellow leaf colouration corresponded to the decreasing photoperiod. This is consistent with the photoprotection hypothesis. Individual differences in red and yellow leaf colouration were inversely correlated to the number of fruits, which might be interpreted as a trade-off between reproductive and protective commitment. Temperature effects explained variation in aphid numbers over time and leaf colouration explained aphid distribution on a given day. As predicted by the co-evolutionary hypothesis, strongly coloured individuals harboured fewer aphids than green or dull-coloured ones. Since decreasing temperature reduced the number of migrating aphids but induced red leaf colouration, these processes are not mutually fine-tuned, which likely restricts the potential for co-evolution between mountain ash and aphids.     

棉蚜种下变型的数值分类研究

分别对在四种夏寄主及棉花两个生育期和三个温度下的棉蚜的14个形态特征进行了种下数值分类研究。通过聚类分析和高氏距离分析,结果表明：夏寄主四季豆、西葫芦、棉花苗期的绿色蚜和黄色蚜间及蕾期的触角6节蚜型和5节蚜型间都无明显差异。但马铃薯蚜与棉花苗蚜、棉花苗蚜与伏蚜间的形态特征存在相当明显的分离,室内温度达30℃时棉蚜的形态特征与伏蚜相似。并分析出可用7个主要形态特征区分这些种下变型。     

RAPD‐PCR DETECTION OF DNA POLYMORPHISM OF COTTON APHID*

Abstract The RAPDPCR technique was used to determine the DNA polymorphism of the aphid Aphis gossypii(Glover) collected from different host plants and in different seasons. Three primers were selected from 20 primers and used for cluster analysis based on the data of Nei's genetic distance (D). The results showed that the aphids on Chinese prickly ash differentiated obviously from the aphids on the other four host plants at DNA level. The seasonal population of cotton aphid might be clustered into three groups, i.e. the spring and autumn yellow colored aphids, the spring and autumn green colored aphids and the yellow dwarf form aphid in summer. However, the genetic relationship of dwarf form was more closely to the spring and autumn green colored aphid.     

The major carotenoid pigments of the grain aphid, Sitobion avenae (F.) (Hemiptera: Aphididae)

The economically important grain aphid, Sitobion avenae (F.) shows colour polymorphism, with brown and green forms predominating. Colour is determined both genetically and in response to environmental factors, including nutrition. The biological significance of the colour polymorphism is unknown, although seasonal changes occur in the frequency of colour morphs in the field, whilst the brown morph may have adaptive significance in terms of hymenopterous endoparasitism. The ground colour of aphids is produced by haemolymph pigments, aphins (glucosides) and carotenoids. The latter may be under the synthetic control of intracellular endosymbiotic bacteria. In this study, the major carotenoid pigments of a brown and a green clone of S. avenae were examined using thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC), and their absorbance spectra recorded. Using TLC, the brown clone produced five bands of different R_f, ranging from yellow, to orange-pink to pink in colour. In contrast, the green clone gave only a single yellow band of higher R_f than any of the bands of brown aphids. Following separation of carotenoids by HPLC, brown aphids gave seven peaks and green aphids five. Comparison of absorbance maxima with known published values for carotenoids provides strong evidence for the identification of four of the carotenoid pigments from brown aphids (RB-4, 3,4-didehydrolycopene; RB-5, torulene; RB-6; lycopene; RB-7, γ-carotene) and one from green aphids (RG-2, α-carotene). The other carotenoids remain unidentified. The biosynthesis and possible biological relevance of the various pigments of S. avenae are briefly discussed.     

3种寄主上桃蚜的选择性及形态分化

桃蚜是一种重要的农业害虫,寄主广泛,种下分化复杂。以采自黄土高原旱作区桃树、烟草、甘蓝上的桃蚜为研究对象,通过叶片选择法、传统比较形态测定法研究了3种寄主上桃蚜的选择性及形态分化。结果表明:在3种寄主同时存在的情况下,烟草上的桃蚜嗜食烟草,表现为63.5%的桃蚜选择烟草叶,13.8%选择甘蓝叶,8.2%选择桃叶,而甘蓝和桃树上的桃蚜对原寄主没有表现出明显的嗜好性;从形态指标来看,3种寄主上的桃蚜在体长、触角末节长度、后足腿节长度、触角与体长的比例方面存在显著差异(P0.05),说明这几个特征可以作为区分这3种寄主上桃蚜的依据。综合分析可以初步认为黄土高原旱作区烟草上的桃蚜可能形成了寄主专化型-烟草型。     

棉蚜种下变型的数值分类研究

 分别对在四种夏寄主及棉花两个生育期和三个温度下的棉蚜的14个形态特征进行了种下数值 分类研究。通过聚类分析和高氏距离分析,结果表明：夏寄主四季豆、西葫芦、棉花苗期 的绿色蚜和黄色蚜间及蕾期的触角6节蚜型和5节蚜型间都无明显差异。但马铃薯蚜与棉花苗 蚜、棉花苗蚜与伏蚜间的形态特征存在相当明显的分离,室内温度达30℃时棉蚜的形态特征 与伏蚜相似。并分析出可用7个主要形态特征区分这些种下变型。     

Effect of light intensity on colour morph formation and performance of the grain aphid Sitobion avenae F. (Homoptera: Aphididae)

The grain aphid Sitobion avenae F., one of the major pest aphids of cereals in Central Europe, exhibits colour polymorphism, even within the same clones. Although there is evidence that green and brown morphs of S. avenae contain different carotenoids, the mechanisms determining the induction of colour morphs are unknown. The common understanding is that the formation of colour morphs is controlled by light and affected by genetic and environmental factors and by host plant species. So far, there is no unequivocal evidence that light intensity, photoperiod, or a mixture of several variables are involved in the induction of S. avenae colour formation, resulting in the induction of S. avenae colour formation and carotenoid synthesis.Here we determined the effect of light intensity on the colour formation and performance of ten clones of S. avenae with experiments that controlled for the effects of host plant and genetic factors. We found that some clones remained green under all test conditions. In other clones, colour morph formation was controlled by light. The synthesis of carotenoids correlated with changes in colour formation. Host plant did not affect colour formation in the ten clones studied. Although colour of the aphid clones did not affect their performance, high light intensity increased the fecundity and fresh weight of S. avenae clones, while low light intensity stimulated the production of alatae.