کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4557804 1628235 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Histopathological and molecular insights into the ovicidal activities of two entomopathogenic fungi against two-spotted spider mite
ترجمه فارسی عنوان
دیدگاه های هیستوپاتولوژیک و مولکولی در فعالیت های تخم گذار دو قارچ انووموپاتوژنیک علیه دو عنکبوت
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
چکیده انگلیسی


• Conidia attached to mite egg shell germinate at 24 h post-spray.
• Extended germ tubes penetrate into egg shell at 48 h post-spray.
• Successful infection disrupts mite embryo at 98 h post-spray.

Entomopathogenic fungi can infect and kill spider mite eggs but their ovicidal activities are poorly understood. Here we gain histopathogenical and molecular insights into the ovicidal activities of Beauveria bassiana and Isaria fumosorosea against the two-spotted spider mite, Tetranychus urticae. Scanning electronic microscopy indicated successful adhesion and germination of fungal conidia on egg shell at 24 h post-spray (HPS). Germ tubes of both fungi could penetrate into egg shell with penetration pegs at 48 HPS. Interestingly, the germ tubes of B. bassiana may elongate on egg surface to locate appropriate sites for penetration, acting as ‘searching’ hyphae. Aside from the normal penetration, the germ tubes of I. fumosorosea can be completely or partially embedded into egg shell for a distance of extension, forming shell humps. Light microscopy of ultrathin sections of infected eggs showed shrunken (affected) or disrupted embryos at 48–96 HPS despite little effect on egg cleavage at 24 HPS. However, distinguishable hyphal cells were hardly found inside the embryos lacking oxygen although fungal outgrowths were abundant on unhatched (killed) eggs. In PCR with specific probes, the 18S rDNA signals of B. bassiana (412 bp) and I. fumosorosea (454 bp) in the DNA extracts from surface-cleaned mite eggs increased at 0–96 HPS, confirming fungal colonization in the infected eggs. We consider that the colonization on shell surface and underside could rely upon extending hyphae for uptake of egg nutrition, resulting in embryo disruption. Our observations add knowledge to microbial control of spider mites.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Invertebrate Pathology - Volume 117, March 2014, Pages 73–78
نویسندگان
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