The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mel- lonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found ...The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mel- lonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found lethal to the Galleria larvae. Toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. When filter and sand substrates were compared, the later one was observed as appropriate. Similarly, bacterial cells and secretion in broth were more effective at 14% moisture and 25 °C temperature treatments. Maximum insect mortality (100%) was observed when bacterial concentration of 4×106 cells/ml was used. Similarly, maximum bacterial cells in broth (95%) were penetrated into the insect body within 2 h of their application. However, when stored bacterial toxic secretion was applied to the insects its efficacy declined. On the other hand, when the same toxic secretion was dried and then dissolved either in broth or water was proved to be effective. The present study showed that the bacterium, X. nematophila or its toxic secretion can be used as an important component of integrated pest management against Galleria.展开更多
In this study, the efficacy of the native isolates of Trichoderma species to promote the growth and yield parameters of cucumber and to manage Fusarium wilt disease under greenhouse conditions were investigated. Ninet...In this study, the efficacy of the native isolates of Trichoderma species to promote the growth and yield parameters of cucumber and to manage Fusarium wilt disease under greenhouse conditions were investigated. Ninety native Trichoderma antagonists were isolated from Grassland and forest soil in different geographical regions of Inner Mongolia, China. Applications of T. cf. harzianum T1, T2, T3, T4, T5, T6, T7, TS, T10, T11 and T. atroviride （T9） exhibited the least disease incidence （by 0%） also the same strains shows 100% of relative control effect. Cucumber seedling treated with T. cf. harzianum （T2 and T1） isolates showed a significant stimulatory effect on plant height （by 13 and 14 cm respectively） and the highest shoot and root fresh weight were recorded by T. asperelloides （T27） and T. gamsii （T17） by 1.62 gm and 0.97 gm respectively, in comparison to untreated control and treated control （10 cm and 4 cm, 1.27 gm and 0.22 gm and 0.82 gm and 0.10 gm）. Therefore, the antagonist （T1, T2, T3, T4, T5, T6, T7, T8, T8, T10, and T1 1） is chosen to be the most promising bio-control agent for Fusarium oxysporum f. sp. Cucumerinum and further study have to be exploited for sustainable disease management program.展开更多
Naturally occurring mutations in surface proteins of Hepatitis B virus(HBV) usually result in altered hepatitis B surface antigen(HBsAg) secretion efficiency.In the present study,we reported two conserved residues,M75...Naturally occurring mutations in surface proteins of Hepatitis B virus(HBV) usually result in altered hepatitis B surface antigen(HBsAg) secretion efficiency.In the present study,we reported two conserved residues,M75 and M103 with respect to HBsAg,mutations of which not only attenuated HBsAg secretion(M75 only),but also suppressed HBV genome replication without compromising the overlapping p-gene product.We also found M75 and M103 can initiate truncated surface protein(TSPs) synthesis upon over-expression of full-length surface proteins,which may possibly contribute to HBV genome replication.However,attempts to rescue replicationdefective HBV mutant by co-expression of TSPs initiated from M75 or M103 were unsuccessful,which indicated surface proteins rather than the putative TSPs were involved in regulation of HBV genome replication.展开更多
In present study, a neogregarine from Crioceris asparagi is reported for the first time in Turkey. C. asparagi （common asparagus beetle） is an important pest of Asparagus officinalis L. crops in Turkey and the world...In present study, a neogregarine from Crioceris asparagi is reported for the first time in Turkey. C. asparagi （common asparagus beetle） is an important pest of Asparagus officinalis L. crops in Turkey and the world. Therefore, determining of the protist pathogens of C. asparagi is aimed. During the study, a total of 1,099 C. asparagi adults were examined thoroughly using a light microscope. Insects were collected from the provinces of Manisa, Eskisehir and Bahkesir in Turkey, with 117 of them collected from Manisa, 204 of them from Bahkesir and 778 of them from Eskisehir. A neogregarine pathogen was found in Bahkesir and Manisa. Total infection rate was 18% for Bahkesir between the years 2014-2015 and 15.3% for Manisa in 2011. Oocysts of the neogregarine pathogen were observed only in malpighian tubes of C. asparagi adults. Fresh mature oocysts of the neogregarine was measured as 9.34 ± 0.74 lam （n = 50） in length and 5.27 ± 0.36 μm （n = 50） in width. Identification of entomopathogens is prerequisite for their use in biological control.展开更多
文摘The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mel- lonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found lethal to the Galleria larvae. Toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. When filter and sand substrates were compared, the later one was observed as appropriate. Similarly, bacterial cells and secretion in broth were more effective at 14% moisture and 25 °C temperature treatments. Maximum insect mortality (100%) was observed when bacterial concentration of 4×106 cells/ml was used. Similarly, maximum bacterial cells in broth (95%) were penetrated into the insect body within 2 h of their application. However, when stored bacterial toxic secretion was applied to the insects its efficacy declined. On the other hand, when the same toxic secretion was dried and then dissolved either in broth or water was proved to be effective. The present study showed that the bacterium, X. nematophila or its toxic secretion can be used as an important component of integrated pest management against Galleria.
文摘In this study, the efficacy of the native isolates of Trichoderma species to promote the growth and yield parameters of cucumber and to manage Fusarium wilt disease under greenhouse conditions were investigated. Ninety native Trichoderma antagonists were isolated from Grassland and forest soil in different geographical regions of Inner Mongolia, China. Applications of T. cf. harzianum T1, T2, T3, T4, T5, T6, T7, TS, T10, T11 and T. atroviride （T9） exhibited the least disease incidence （by 0%） also the same strains shows 100% of relative control effect. Cucumber seedling treated with T. cf. harzianum （T2 and T1） isolates showed a significant stimulatory effect on plant height （by 13 and 14 cm respectively） and the highest shoot and root fresh weight were recorded by T. asperelloides （T27） and T. gamsii （T17） by 1.62 gm and 0.97 gm respectively, in comparison to untreated control and treated control （10 cm and 4 cm, 1.27 gm and 0.22 gm and 0.82 gm and 0.10 gm）. Therefore, the antagonist （T1, T2, T3, T4, T5, T6, T7, T8, T8, T10, and T1 1） is chosen to be the most promising bio-control agent for Fusarium oxysporum f. sp. Cucumerinum and further study have to be exploited for sustainable disease management program.
基金supported by the National Basic Research Program of China(2007CB512900)
文摘Naturally occurring mutations in surface proteins of Hepatitis B virus(HBV) usually result in altered hepatitis B surface antigen(HBsAg) secretion efficiency.In the present study,we reported two conserved residues,M75 and M103 with respect to HBsAg,mutations of which not only attenuated HBsAg secretion(M75 only),but also suppressed HBV genome replication without compromising the overlapping p-gene product.We also found M75 and M103 can initiate truncated surface protein(TSPs) synthesis upon over-expression of full-length surface proteins,which may possibly contribute to HBV genome replication.However,attempts to rescue replicationdefective HBV mutant by co-expression of TSPs initiated from M75 or M103 were unsuccessful,which indicated surface proteins rather than the putative TSPs were involved in regulation of HBV genome replication.
文摘In present study, a neogregarine from Crioceris asparagi is reported for the first time in Turkey. C. asparagi （common asparagus beetle） is an important pest of Asparagus officinalis L. crops in Turkey and the world. Therefore, determining of the protist pathogens of C. asparagi is aimed. During the study, a total of 1,099 C. asparagi adults were examined thoroughly using a light microscope. Insects were collected from the provinces of Manisa, Eskisehir and Bahkesir in Turkey, with 117 of them collected from Manisa, 204 of them from Bahkesir and 778 of them from Eskisehir. A neogregarine pathogen was found in Bahkesir and Manisa. Total infection rate was 18% for Bahkesir between the years 2014-2015 and 15.3% for Manisa in 2011. Oocysts of the neogregarine pathogen were observed only in malpighian tubes of C. asparagi adults. Fresh mature oocysts of the neogregarine was measured as 9.34 ± 0.74 lam （n = 50） in length and 5.27 ± 0.36 μm （n = 50） in width. Identification of entomopathogens is prerequisite for their use in biological control.
