【作者】 胡祖庆；

【导师】 赵惠燕；

【作者基本信息】 西北农林科技大学 ， 农业昆虫与害虫防治， 2007， 硕士

【摘要】 麦长管蚜Sitobion avenae (Fabricius),属同翅目Homoptera,蚜科Aphididae,世界各地均有分布。在我国,麦长管蚜是禾谷类作物上的重要害虫,并能传播大麦黄矮病毒病(BYDV)。麦长管蚜同其它蚜虫一样,具有一个典型的生物学特性,即多型多态现象。麦长管蚜有绿、红色两种体色生物型,引起这种体色生物型的原因目前还不清楚。巴克纳氏菌(Buchnera aphidicolia)是蚜虫体内的主要共生细菌。巴克纳氏菌与蚜虫(Buchnera-Aphid)之间的共生关系是细菌与真核生物共生演化得最完美、最和谐的例子。由于共生细菌为蚜虫生物合成提供所需的代谢酶,以适应新的寄主植物的过程。但共生细菌在蚜虫体色生物型变异过程中扮演着什么角色?其作用机理如何?目前还未见报道。为了探明共生菌对不同生物型麦长管蚜的影响,本文以绿色和红色两种体色生物型麦长管蚜作为实验材料,用广谱抗生素利福平处理后得到脱共生麦长管蚜。从以下四个方面对不同体色型麦长管蚜进行了比较研究,结果表明:1.共生菌对绿色型麦长管蚜生长发育和繁殖的影响共生菌对绿色型麦长管蚜生态学影响显著:脱共生蚜虫体重减轻,发育历期延长,有效积温增大,发育起点温度降低,平均世代时间延长,净增殖率、内禀增长率均远远降低。共生与脱共生麦长管蚜都表现出随着温度的升高全若虫期的发育历期缩短,并均在21℃时达到最大生殖力。2.不同体色生物型麦长管蚜分子诊断用利福平处理5d和10d后的两种体色型麦长管蚜,光学显微镜和PCR检测均表明此时麦长管蚜体内都仍然有共生菌存在;在利福平处理15d后,光学显微镜和PCR检测均表明此时两种色型麦长管蚜体内均无共生菌存在。PCR检测技术与光学显微镜技术相结合表明,麦长管蚜在抗生素处理15d后,其体内共生菌完全被除去。这对以后的进一步研究具有一定的参考价值。3.共生菌对两种体色型麦长管蚜体内总蛋白质的影响与共生蚜虫相比,绿色型脱共生麦长管蚜的总蛋白含量按每毫克鲜重计算和按照每头蚜虫计算分别降低了47%和83%,而红色型脱共生麦长管蚜分别降低了71%和91%。说明绿色型和红色型麦长管蚜的营养状况均明显恶化;且红色型麦长管蚜的营养状况恶化程度要比绿色型麦长管蚜高。4.共生菌对两种体色型麦长管蚜酶活力的影响与共生蚜虫相比,绿色型麦长管蚜脱共生后ALT和AST酶活力分别下降了50%和58%。而红色型麦长管蚜分别下降了82%和72%。说明经抗生素脱共生处理后麦长管蚜虫体内氨基酸之间的转换遭到干扰,且红色型麦长管蚜受到干扰大。与共生蚜虫相比,绿色型麦长管蚜脱共生后GS酶活力升高了118%,而红色型麦长管蚜升高了164%。说明经抗生素脱共生处理后麦长管蚜体内氨的转运受到干扰,且红色型麦长管蚜受到干扰大。本研究为进一步探索共生菌与体色变化与进化关系提供了一定的理论依据,用生命表等生态学方法研究共生菌对蚜虫影响国内外还未见报道。更多还原

【Abstract】 Sitobion avenae (Homoptera:Aphididae), is one of the most important pests to cereal crop, distributing all over the world. Moreover, it is an efficient vector of several plant virus, especilly Barley Yellow Dwarf Virus (BYDV). Just like other aphids, based on the tipical characteristic-polymorphism, Sitobion avenae has the green and red body color biotypes. So far, the mechanism of biotype is unknown.Buchnera aphidicolia is the primary symbiotic bacteria of the aphid. The Aphid- Buchnera symbiosis is probably the most perfect and harmonious model for the encaryot and bacteria. In addition, it seems likely to be related with biotype that Buchnera provides metabolic enzymes for the aphid’s biosynthesis in order that it can adapt to new host. At present, the role of symbiotic bacteria in the biotypes mutation and its mechanisms haven’t been reported yet.In order to reveal the effects of symbiotic bacteria on the different biotype aphid, the two biotype Sitobion avenae were treated with the broad spectrum antibiotic, rifampicin. At the same time, it comparably analysed the color biotypes in the four directions. The results are as follows:1.The influence of symbiotic bacteria on the green aphids growth, development and reproduction.Compared with symbiotic aphids, the results showed that Bacteria-free aposymbiotic aphids displayed reduced adult fresh weight; prolonged duration of the nymphs; increased nymph duration effective accumulated temperature (EAT); reduced threshold temperature; prolonged length a generation; decreased net reproduction rate and intrinsic increases rate. Besides, both symbiotic aphids and Bacteria-free aposymbiotic aphids nymphs duration decreased with increased temperature. the top of productivity for both of them were all in the 21℃.2. Molecular diagnosis of Buchera bacteria from two body-color biotypes aposymbiotic aphidsThrough light microscope and PCR technique, there still exist Buchnera in the two biotype aphids after rifampicin treated for 5 days and 10 days. After rifampicin treated for 15 days, buchnera don’t exist. It is significance that Buchnera was disrupted completely after rifampicin treated for 15 days Through light microscope and PCR technique. 3. The impact of Buchnera on the total protein content of the two body-color biotypes aphids.Comparing to symbiotic aphids, As for per milligram aphid and per aphid, the content of the total protein of the Green aposymbiotic aphids reduced by 47% and 83%, while the the Red ones reduced by 71% and 91%. This meaned both green aposymbiotic and red aposymbiotic aphids, the nutrition condition obviously became worse, and red aphids worse than green ones.4. The impact of Buchnera on the enzymes of ALT, AST, GS of the two body-color biotypes aphids.Comparing to symbiotic aphids, the activity of ALT, AST in the rifampicin-treated Green aphids reduced by 50%,58%, however, the red ones reduced by 82%, 72%. This means that the effect of the Buchnera on the transferase of amino acid in the Red aphids is much more than the Green aphids.On the one hand, comparing to symbiotic aphids, the activity of GS in the green aphids increased by 118% while the one in the red aposymbiotic aphids increased by 164%. This means that the effect of the Buchnera on the transferase of ammonia in the Red aphids is much more than the Green aphids.This study offer theoretical explain for the evolution relation both Buchnera and aphid body color to change, and it hasn’t been reported yet that studying of Buchnera and Aphids with the way of the life table.更多还原