Effects Of A Facultative Endosymbiont Arsenophonus Nasoniae On Biological Traits Of Aphis Gossypii

There are many kinds of secondary symbiotic bacteria in insects.Primary symbiotic bacteria provide essential amino acids,vitamins and other nutrients for the inscts;secondary endosymbionts can help insects increased fecundity,protect their hosts against natural enemies,tolerate heat stress,enhanced defense ability of pathogenic microorganisms,increase the capacities of host aphids to use host plant.What was the effect of secondary endosymbiotic bacteria Arsenophonus in the Aphis gossypii on biology characteristics and the ability to adapt dfifferent host plant,there are no research reports.This study was Aphis gossypii aphid collected from different host plants,detected and compared Arsenophonus infection.We studied the effect of Arsenophonus on biological characteristics of the cotton aphid at the same time.This study obtained the following main results:Using PCR method,detected symbiotic bacteria species and ratio in Aphis gossypii collected from three host plants in Nanjing,China:cotton,cucumber and zucchini.It was found that the Rickettsia,Spiroplasma and Arsenophonus infection of cotton aphids.In the cotton population,the infection frequency of Arsenophonus was significantly higher than aphid populations of cucumber and zucchini,the frequency of hibiscus population was in the middle.The micro satellite eight pairs of primers were identified out of Aphis gossypii A,B,C,D four genotypes and found A genotype Arsenophonus infection rates was high,B and C genotype was low.Established a lineae without Arsenophonus naturally,a lineage naturally infected Arsenophonus.Useing antibiotic eliminated Arsenophonus,obtained a lineage artificially cured the Arsenophonus.Under rearing at cotton,zucchini and cucumber leaves,the net reproductive rate,the average generation lifetime and intrinsic rate of natural increase of the nine lineages were studied.The results show that lineages in A genotype:average life expectancy was no significant difference between infection and without Arsenophonus lineage,but fecundity and intrinsic growth rate were higher or significantly higher than those without Arsenophonus infection.Analyse cotton genotypes and Arsenophonus infection by two factor analysis showed that,the aphid life in the zucchini and cotton host leaf,cotton aphid genotypes has no significantly affected to average life expectancy,net reproductive rate,intrinsic rate of increase,and Arsenophonus infection influence reached significant level.But in cucumber plant life,cotton aphid genotypes and Arsenophonus infection of cotton aphid population has a significant effect to average life expectancy,net reproductive rate,intrinsic rate of increase.In addition to the average life expectancy with the aphid live in cotton leaves,Aphis gossypii in the cotton,zucchini and cucumber leaves net growth rate,average life expectancy and the intrinsic rate of increase of index interaction effects by cotton aphid genotypes and Arsenophonus bacteria.Compare with different density 20 head/dish,40/dish,60/dish,80/glass cotton aphid in three genotypes and infection and infection of Arsenophonus bacteria strains alate offspring.The results show that in genotype A and C,Arsenophonus infection advance the cotton aphid produce winged offspring,and in genotype B infection Arsenophonus the alate production is reduced.Three factor analysis results show that Arsenophonus bacteria of aphids had no significant effect,but population density and cotton aphid genotypes significantly affected alate offspring ratio.In a word,Arsenophonus on the population biology characteristics of cotton aphid according to different aphid genotypes.