Effects of insulin on the growth and development of the entomopathetic nematode Steinernema kraussei 0657L and its symbiotic bacterium Xenorhabdus bovenii 0657L
Effects of insulin on the growth and development of the entomopathetic nematode Steinernema kraussei 0657L and its symbiotic bacterium Xenorhabdus bovenii 0657L
[Aim]To investigate the effects of insulin on the growth and development of the entomopathogenic nematode Steinernema kraussei 0657L and its symbiotic bacterium.[Methods]The 3rd instar larvae of Galleria mellonella were infected with 1.5 mL of 3 000/mL S.kraussei 0657 L suspension,the symbiotic bacterium Xenorhabdus bovenii 0657L was isolated from S.kraussei 0657 L after 24 h culture at 25 ℃.S.kraussei 0657L was fed with X.bovenii 0657L treated with 1∶500 and 1∶5 000 insulin,respectively,the colonial diameter and growth rate of X.bovenii 0657L were measured by stereomicroscope at 1-6 d after insulin treatment,the lifespan,survival rate,number of head swing per 30 s and number of swallows per 30 s of S.kraussei 0657 L were calculated to evaluate its average lifespan,locomotion and swallowing ability.[Results]The colonial diameters of X.bovenii 0657L in 1:5 000 insulin and 1∶500 insulin treatment groups were increased by 77.2％and 54.0％,respectively,during the logarithmic growth period(at 2 d after treatment)as compared with that of the blank control group.The growth rates of X.bovenii 0657 L in 1:5 000 insulin and 1:500 insulin treatment groups were increased from 68.0 μm/d of the blank control group to 120.4 and 104.7 μm/d,respectively.The lifespans of S.kraussei 0657 L in 1:5 000 insulin and 1:500 insulin treatment groups were increased by 27.3％and 45.5％,respectively,as compared with that of the blank control group.The numbers of head swing per 30 s of the 3rd instar larvae of S.kraussei 0657L in 1∶5 000 insulin and 1:500 insulin treatment groups were increased by 56.3％and 74.7％,respectively,as compared with that of the blank control group.The numbers of swallows per 30 s of the 3rd and 4th instar larvae and adults of S.kraussei 0657L in 1∶5 000 insulin and 1∶500 insulin treatment groups were increased by 50.9％and 65.5％,26.8％and 35.2％,23.7％and 21.1％,respectively,as compared with that of the blank control group.[Conclusion]Insulin can significantly promote the growth and increase the growth rate of single colony of the symbiotic bacterium X.bovenii 0657L of S.kraussei 0657L,which can prolong the lifespan of S.kraussei 0657 L and improve the locomotion and swallowing ability of entomopathogenic nematode indirectly.The results of this study can provide a scientific basis for extending the shelf life of entomopathogenic nematodes and provide a theoretical basis for efficient biological control of entomopathogenic nematodes.
关键词
卡森斯氏线虫/伯氏致病杆菌/胰岛素/昆虫病原线虫/共生细菌/生长发育/寿命/运动/吞咽
Key words
Steinernema kraussei/Xenorhabdus bovenii/insulin/entomopathogenic nematodes/symbiotic bacteria/growth and development/lifespan/locomotion/swallow
维普
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