A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i>
<i>Monochamus alternatus</i> is a serious trunk-boring pest. The isolation and utilization of entomopathogenic fungi to manage <i>M. alternatus</i> is important. Here, a new strain GQH6 of <i>Metarhizium robertsii,</i> isolated from the Loess Plateau, was identifi...
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MDPI AG
2024-03-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/12/3/514 |
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| author | Ji-Yang Zheng He-Liang Shi Dun Wang |
| author_facet | Ji-Yang Zheng He-Liang Shi Dun Wang |
| author_sort | Ji-Yang Zheng |
| collection | DOAJ |
| description | <i>Monochamus alternatus</i> is a serious trunk-boring pest. The isolation and utilization of entomopathogenic fungi to manage <i>M. alternatus</i> is important. Here, a new strain GQH6 of <i>Metarhizium robertsii,</i> isolated from the Loess Plateau, was identified morphologically and molecularly. The virulence of the strain GQH6 against the third-instar larvae of <i>M. alternatus</i> was studied. Then, the pathological process, including symptom observation and histopathological observation, was also researched. The corrected mortality was 100% at 10<sup>9</sup> and 10<sup>8</sup> conidia/mL, and 88.89 ± 5.88% at 10<sup>7</sup> conidia/mL. The LC50 was 1.93 × 10<sup>6</sup> conidia/mL and the LC90 was 1.35 × 10<sup>7</sup> conidia/mL. And the LT50 of the strain GQH6 was 3.96 days at 10<sup>9</sup> conidia/mL, and 4.99 days at 10<sup>8</sup> conidia/mL. These virulence indices showed high virulence against <i>M. alternatus</i> larvae. In addition, the symptoms of the infected <i>M. alternatus</i> larvae were obvious. After one day, dark spots appeared and increased in number. By four days, white mycelia appeared. Finally, the larvae body became green. Similarly, the histopathological changes after infection were obvious, mainly manifested in muscle tissue rupture, adipose tissue fracture and midgut disintegration. These results demonstrated that the <i>M. robertsii</i> strain GQH6 isolated from the Loess Plateau was highly virulent against <i>M. alternatus</i> larvae of the third instar. |
| first_indexed | 2024-04-24T18:00:13Z |
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| last_indexed | 2024-04-24T18:00:13Z |
| publishDate | 2024-03-01 |
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| series | Microorganisms |
| spelling | doaj.art-3854207186dc42aba3a44de244da59162024-03-27T13:55:41ZengMDPI AGMicroorganisms2076-26072024-03-0112351410.3390/microorganisms12030514A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i>Ji-Yang Zheng0He-Liang Shi1Dun Wang2Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, ChinaKey Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, Northwest A&F University, Yangling 712100, ChinaKey Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China<i>Monochamus alternatus</i> is a serious trunk-boring pest. The isolation and utilization of entomopathogenic fungi to manage <i>M. alternatus</i> is important. Here, a new strain GQH6 of <i>Metarhizium robertsii,</i> isolated from the Loess Plateau, was identified morphologically and molecularly. The virulence of the strain GQH6 against the third-instar larvae of <i>M. alternatus</i> was studied. Then, the pathological process, including symptom observation and histopathological observation, was also researched. The corrected mortality was 100% at 10<sup>9</sup> and 10<sup>8</sup> conidia/mL, and 88.89 ± 5.88% at 10<sup>7</sup> conidia/mL. The LC50 was 1.93 × 10<sup>6</sup> conidia/mL and the LC90 was 1.35 × 10<sup>7</sup> conidia/mL. And the LT50 of the strain GQH6 was 3.96 days at 10<sup>9</sup> conidia/mL, and 4.99 days at 10<sup>8</sup> conidia/mL. These virulence indices showed high virulence against <i>M. alternatus</i> larvae. In addition, the symptoms of the infected <i>M. alternatus</i> larvae were obvious. After one day, dark spots appeared and increased in number. By four days, white mycelia appeared. Finally, the larvae body became green. Similarly, the histopathological changes after infection were obvious, mainly manifested in muscle tissue rupture, adipose tissue fracture and midgut disintegration. These results demonstrated that the <i>M. robertsii</i> strain GQH6 isolated from the Loess Plateau was highly virulent against <i>M. alternatus</i> larvae of the third instar.https://www.mdpi.com/2076-2607/12/3/514<i>Metarhizium robertsii</i><i>Monochamus alternatus</i>virulencesymptom observationhistopathological observation |
| spellingShingle | Ji-Yang Zheng He-Liang Shi Dun Wang A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i> Microorganisms <i>Metarhizium robertsii</i> <i>Monochamus alternatus</i> virulence symptom observation histopathological observation |
| title | A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i> |
| title_full | A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i> |
| title_fullStr | A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i> |
| title_full_unstemmed | A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i> |
| title_short | A New Strain of <i>Metarhizium robertsii</i> Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against <i>Monochamus alternatus</i> |
| title_sort | new strain of i metarhizium robertsii i isolated from loess plateau and its virulence and pathological characteristics against i monochamus alternatus i |
| topic | <i>Metarhizium robertsii</i> <i>Monochamus alternatus</i> virulence symptom observation histopathological observation |
| url | https://www.mdpi.com/2076-2607/12/3/514 |
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