Scholarlink

<p>The Gram-positive bacterium <i>Bacillus thuringiensis</i> (<i>Bt</i>) has emerged as a cornerstone of biological pest control, due to its potent insecticidal properties. This study delves into the diversity and insecticidal potential of fifty native <i>Bt</i> isolates against the 28-spotted potato ladybird or hadda beetle, (<i>Henosepilachna vigintioctopunctata</i> Fabricius, 1775), a notorious phytophagous coleopteran pest wreaking havoc on vegetable crops. Microscopic analysis revealed a fascinating array of crystal morphologies including, bipyramidal (62%), cuboidal (34%), spherical (64%), and spore-encrusted crystal (18%) forms. Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) profiling identified Cry proteins with molecular weights spanning 15 to 135&#xa0;kDa, while Polymerase Chain Reaction (PCR) screening detected the <i>cry3</i> gene exclusively in isolate, T121. Notably, none of the studied <i>Bt</i> isolates tested positive for the <i>cry7</i>,<i> cry8</i>,<i> cry26</i>,<i> cry28</i>, or <i>cry10Aa</i> genes. The flagellin (<i>hag</i>) gene was isolated from the T121 isolate and inserted into the pJET1.2/blunt vector. Sequencing of the cloned gene revealed 100% similarity with the flagellin gene of <i>Bacillus thuringiensis</i> subsp. <i>tenebrionis</i>. Bioassays against first instar grubs of <i>H. vigintioctopunctata</i> recorded mortality rates ranging from 0% to 100% with T121 achieving complete mortality at 25&#xa0;µg/mL. These findings underscore the potential of native <i>Bt</i> isolates, particularly T121, as effective biocontrol agents, paving the way for sustainable and eco- friendly pest management solutions.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Molecular profiling and screening of indigenous Bacillus thuringiensis (Bt) isolates against Henosepilachna vigintioctopunctata (Coleoptera: coccinellidae)

  • 期刊论文

  • 发表日期：

    2026年7月20日

查看全文
  • Eniya Arumugam,
  • Balasubramani Venkatasamy,
  • Murugan Marimuthu,
  • Raveendran Muthurajan,
  • Raghu Rajasekaran,
  • Rajadurai Gothandaraman,
  • Kokiladevi Eswaran

摘要

The Gram-positive bacterium Bacillus thuringiensis (Bt) has emerged as a cornerstone of biological pest control, due to its potent insecticidal properties. This study delves into the diversity and insecticidal potential of fifty native Bt isolates against the 28-spotted potato ladybird or hadda beetle, (Henosepilachna vigintioctopunctata Fabricius, 1775), a notorious phytophagous coleopteran pest wreaking havoc on vegetable crops. Microscopic analysis revealed a fascinating array of crystal morphologies including, bipyramidal (62%), cuboidal (34%), spherical (64%), and spore-encrusted crystal (18%) forms. Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) profiling identified Cry proteins with molecular weights spanning 15 to 135 kDa, while Polymerase Chain Reaction (PCR) screening detected the cry3 gene exclusively in isolate, T121. Notably, none of the studied Bt isolates tested positive for the cry7, cry8, cry26, cry28, or cry10Aa genes. The flagellin (hag) gene was isolated from the T121 isolate and inserted into the pJET1.2/blunt vector. Sequencing of the cloned gene revealed 100% similarity with the flagellin gene of Bacillus thuringiensis subsp. tenebrionis. Bioassays against first instar grubs of H. vigintioctopunctata recorded mortality rates ranging from 0% to 100% with T121 achieving complete mortality at 25 µg/mL. These findings underscore the potential of native Bt isolates, particularly T121, as effective biocontrol agents, paving the way for sustainable and eco- friendly pest management solutions.