Developing appropriate control measures for the Mahogany shoot borer, Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swi...Developing appropriate control measures for the Mahogany shoot borer, Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq （Sapindales： Meliaceae）. Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides. To identify a potential fungal biocontrol agent, we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch. against this pest. The average survival time and conidial yield of IWST-Ma7 was higher （6.2 to 7.3 days and 4.9 to 4.7 x 105 conidia/ml） than the standards. Sig- nificant difference in sporulation on the cadavers between isolates, doses and incubation periods were substantiated for the selection of potential strain. The mycotoxic effects of crude soluble protein extract when in- corporated in the artificial diet, the ARSEF 2596 and ARSEF 3603 showed LDs0 value of 3.7% and 5.6%. However, IWST-Ma7 was highly lethal with significant lowest LDs0 value of 2.6%. The enzyme activity of IWST-Ma7 was highest for chitinase, CDA, protease and lipase viz., 1.90 U/mg, 1.80 U/mg, 0.98 U/mg and 0.80 U/mg respectively. However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity. The ITS regions （5.8S rDNA and 28S rDNA） of seven isolates of M. anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp. Based on ITS regions, phy- logenetic tree have been constructed and the isolates have been grouped in to 5 clades. The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.展开更多
Metarhizium anisopliae as an essential entomopathogenic fungus has been known to produce destruxins （a kind of cyclo-peptidic mycotoxins） and blastospores in submerged culture. Blastospores and destruxins are candid...Metarhizium anisopliae as an essential entomopathogenic fungus has been known to produce destruxins （a kind of cyclo-peptidic mycotoxins） and blastospores in submerged culture. Blastospores and destruxins are candidates for in- secticides, but the relations of both productions and the impact factors are unclear yet. In this study, we investigated the effects of inoculums, rotation, dissolved oxygen （DO） on the productions of blastospores and destruxins A and B （DA and DB） in submerged culture of M. anisopliae strain MaQ01. The results indicated that DO levels were regulated by inoculum amounts and rotation speeds, meanwhile, the productions of DA, DB and blastospores were also closely influenced by those factors. Totally, when DO value was more than 40%, the higher productions of destruxins and blastospores were achieved, by contrast, lower than 40% of DO values resulted in lower productions. The regression analysis suggested that the productions of DA, DB and blastospores were positively correlated with the DO levels. Meanwhile, the positive correlations between the productions of DA or DB and blastospores were also found. Briefly, when the rotation is 150 r min-1 and the inoculum is 1.0xl06 spore mL-1, the DA, DB and blastospores achieved the best production of 61.81 mg mL-1, 24.74 mg mL-1 and 5.73x 108 spore mL-1, respectively. In addition, the pathogenicities of blastospores and conidia against Plutella xylostella were bioassayed. The higher mortalities of P. xylostella were totally recorded in blastospore treatments than in conidia treatments, especially in lower dosages and earlier periods. Our research will give some new insights to production of destruxins and blastospores by using M. anisopliae.展开更多
Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates ...Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates tightly clustered into one or the other of two groups that diverged at 12%. Results suggested that certain genotypes of the fungus, that grouped together, were able to infect moth larvae while others did not. A fragment of 760 bp, which presents high homology with a host-adaptation related protein coding gene, distinguished between aggressive and non-aggressive isolates. Neither mycelial growth nor sporulation rate or presence of known virulence genes was correlated with mortality values. Some isolates, including the most aggressive isolate ARSEF2518, were compatible with deltamethrin. Deltamethrin treatment killed all the larvae after seven days whereas fungal and mixed treatments respectively reached the same mortality after 28 and 21 days.展开更多
Entomopathogenic fungi, such as Metarhizium anisopliae, are able to control various insect pests. These fungi attack the integument of the host using an enzymatic complex. Among the enzymes found in this complex, chit...Entomopathogenic fungi, such as Metarhizium anisopliae, are able to control various insect pests. These fungi attack the integument of the host using an enzymatic complex. Among the enzymes found in this complex, chitinase is an important component. However, the relation between the chitinase production and the virulence from different M. anisopliae strains has not been analyzed. In this manuscript it is presented the chitinase production by four M. anisopliae strains with different potential of virulence in Solid-State Fermentation using silkworm chrysalis as substrate. The higher chitinase level was obtained with the strain IBCB 360 (7.14 U/g of substrate) with potential virulence of 68% on Diatrea saccharalis. The enzyme production was optimized for all strains using a factorial planning (CCRD) considering the cultivation time and medium humidity as independent variables. The maximal production of chitinase was obtained at a range from 8 to 12-days old cultures and from 45% to 62% of moisture according to the surface response plot, with high R2 value. The enzyme production by the strain IBCB 167 was increased two-folds under optimized conditions, while for the strains IBCB 360 and 425 the chitinase production was increased four-folds and nine-folds for the strain IBCB 384.展开更多
为明确金龟子绿僵菌CQMA421对防治花生蛴螬的减药防控效果,本试验采用撒施、油悬浮剂拌种和粗喷雾方法,以及与不同化学农药混用的试验设计探究金龟子绿僵菌CQMA421对花生地下害虫蛴螬的防控效果及其对花生产量的影响.结果表明:单独应用...为明确金龟子绿僵菌CQMA421对防治花生蛴螬的减药防控效果,本试验采用撒施、油悬浮剂拌种和粗喷雾方法,以及与不同化学农药混用的试验设计探究金龟子绿僵菌CQMA421对花生地下害虫蛴螬的防控效果及其对花生产量的影响.结果表明:单独应用绿僵菌CQMA421生物农药的4种处理对蛴螬的防治效果显著低于2种与化学药剂混用处理;采用50%氯虫苯甲酰胺FS 60 mL拌种加绿僵菌CQMA421 OF 60 mL下针期粗喷雾处理杀虫效果、保果率和产量最好,分别为82.3%,83.99%和279.23 kg/667 m 2,而且操作方便、省工省时,可以进行大面积推广应用;667 m 2用5%辛硫磷颗粒剂6 kg效果与绿僵菌CQMA 42160 mL拌种处理相当,从化学农药减量及绿色防控需求来看,应逐步被替代.展开更多
文摘Developing appropriate control measures for the Mahogany shoot borer, Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq （Sapindales： Meliaceae）. Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides. To identify a potential fungal biocontrol agent, we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch. against this pest. The average survival time and conidial yield of IWST-Ma7 was higher （6.2 to 7.3 days and 4.9 to 4.7 x 105 conidia/ml） than the standards. Sig- nificant difference in sporulation on the cadavers between isolates, doses and incubation periods were substantiated for the selection of potential strain. The mycotoxic effects of crude soluble protein extract when in- corporated in the artificial diet, the ARSEF 2596 and ARSEF 3603 showed LDs0 value of 3.7% and 5.6%. However, IWST-Ma7 was highly lethal with significant lowest LDs0 value of 2.6%. The enzyme activity of IWST-Ma7 was highest for chitinase, CDA, protease and lipase viz., 1.90 U/mg, 1.80 U/mg, 0.98 U/mg and 0.80 U/mg respectively. However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity. The ITS regions （5.8S rDNA and 28S rDNA） of seven isolates of M. anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp. Based on ITS regions, phy- logenetic tree have been constructed and the isolates have been grouped in to 5 clades. The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.
基金supported by the Special Fund for Forest Scientific Research in the Public Welfare (201304408)the Open Fund of Key Laboratory of Forest Diseases and Insect Pests in Guangdong Province, China
文摘Metarhizium anisopliae as an essential entomopathogenic fungus has been known to produce destruxins （a kind of cyclo-peptidic mycotoxins） and blastospores in submerged culture. Blastospores and destruxins are candidates for in- secticides, but the relations of both productions and the impact factors are unclear yet. In this study, we investigated the effects of inoculums, rotation, dissolved oxygen （DO） on the productions of blastospores and destruxins A and B （DA and DB） in submerged culture of M. anisopliae strain MaQ01. The results indicated that DO levels were regulated by inoculum amounts and rotation speeds, meanwhile, the productions of DA, DB and blastospores were also closely influenced by those factors. Totally, when DO value was more than 40%, the higher productions of destruxins and blastospores were achieved, by contrast, lower than 40% of DO values resulted in lower productions. The regression analysis suggested that the productions of DA, DB and blastospores were positively correlated with the DO levels. Meanwhile, the positive correlations between the productions of DA or DB and blastospores were also found. Briefly, when the rotation is 150 r min-1 and the inoculum is 1.0xl06 spore mL-1, the DA, DB and blastospores achieved the best production of 61.81 mg mL-1, 24.74 mg mL-1 and 5.73x 108 spore mL-1, respectively. In addition, the pathogenicities of blastospores and conidia against Plutella xylostella were bioassayed. The higher mortalities of P. xylostella were totally recorded in blastospore treatments than in conidia treatments, especially in lower dosages and earlier periods. Our research will give some new insights to production of destruxins and blastospores by using M. anisopliae.
文摘Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates tightly clustered into one or the other of two groups that diverged at 12%. Results suggested that certain genotypes of the fungus, that grouped together, were able to infect moth larvae while others did not. A fragment of 760 bp, which presents high homology with a host-adaptation related protein coding gene, distinguished between aggressive and non-aggressive isolates. Neither mycelial growth nor sporulation rate or presence of known virulence genes was correlated with mortality values. Some isolates, including the most aggressive isolate ARSEF2518, were compatible with deltamethrin. Deltamethrin treatment killed all the larvae after seven days whereas fungal and mixed treatments respectively reached the same mortality after 28 and 21 days.
基金supported by Fundacao de Apoio a Pesquisa do Estado de Sao Paulo(FAPESP)and Coor-denadoria de Apoio ao Ensino Superior(CAPES).
文摘Entomopathogenic fungi, such as Metarhizium anisopliae, are able to control various insect pests. These fungi attack the integument of the host using an enzymatic complex. Among the enzymes found in this complex, chitinase is an important component. However, the relation between the chitinase production and the virulence from different M. anisopliae strains has not been analyzed. In this manuscript it is presented the chitinase production by four M. anisopliae strains with different potential of virulence in Solid-State Fermentation using silkworm chrysalis as substrate. The higher chitinase level was obtained with the strain IBCB 360 (7.14 U/g of substrate) with potential virulence of 68% on Diatrea saccharalis. The enzyme production was optimized for all strains using a factorial planning (CCRD) considering the cultivation time and medium humidity as independent variables. The maximal production of chitinase was obtained at a range from 8 to 12-days old cultures and from 45% to 62% of moisture according to the surface response plot, with high R2 value. The enzyme production by the strain IBCB 167 was increased two-folds under optimized conditions, while for the strains IBCB 360 and 425 the chitinase production was increased four-folds and nine-folds for the strain IBCB 384.
文摘为明确金龟子绿僵菌CQMA421对防治花生蛴螬的减药防控效果,本试验采用撒施、油悬浮剂拌种和粗喷雾方法,以及与不同化学农药混用的试验设计探究金龟子绿僵菌CQMA421对花生地下害虫蛴螬的防控效果及其对花生产量的影响.结果表明:单独应用绿僵菌CQMA421生物农药的4种处理对蛴螬的防治效果显著低于2种与化学药剂混用处理;采用50%氯虫苯甲酰胺FS 60 mL拌种加绿僵菌CQMA421 OF 60 mL下针期粗喷雾处理杀虫效果、保果率和产量最好,分别为82.3%,83.99%和279.23 kg/667 m 2,而且操作方便、省工省时,可以进行大面积推广应用;667 m 2用5%辛硫磷颗粒剂6 kg效果与绿僵菌CQMA 42160 mL拌种处理相当,从化学农药减量及绿色防控需求来看,应逐步被替代.
