M.Sc. Tezi Görüntüleme

Student:	Şerife İŞCİ
Supervisor:	Doç. Dr. Kazım SEZEN
Department:	Biyoloji
Institution:	Graduate School of Natural and Applied Sciences
University:	Karadeniz Technical University, Turkey

Title of the Thesis:	Investigation of Bacterial Flora and Microbial Control Agents of Gryllotalpa gryllotalpa
Level:	M.Sc.
Acceptance Date:	11/8/2009
Number of Pages:	73
Registration Number:	i2085

Summary:

Gryllotalpa gryllotalpa (Orthoptera: Gryllotalpidae) is an economical important pest which damage on roots of a lot of plants. Up to now, there is no effective biological control against this pest around the world.

The aim of this study is to determine bacterial flora of the Gryllotalpa gryllotalpa and find out an opportunistic pathogen to use are possible microbiological control agent against this pest. For this purpose, G. gryllotalpa nymphs were collected from Trabzon and Tokat different fields. The bacterial flora of this pest and the microbial potential of bacterial isolates were determined.

As a result, 15 different bacteria were isolated from G. gryllotalpa nymphs. 12 of these bacteria determined and characterized at species level and three of them characterized at genus level. In this study, we determined morphological, physiological and biochemical properties, metabolic enzyme profiles by API 20E and API 50CH panel test systems. 16S rRNA gene sequence analyses were also performed to determine isolates at molecular level. The isolates were identified asBacillus thuringiensis kurstaki, Serratia sp., Bacillus gibsoni, Bacillus sp., Providencia vermicola, Bacillus licheniformis, Bacillus clausii, Enterobacter aerogenes, Paenibacillus xylanilyticus, Enterobacter sp., Providencia rettgeri, Serratia nematodophila, Providencia alfalifacien, Enterobacter hormehechi and Bacillus arsenicus. The insecticidal activities were determined against the nymphs of G. gryllotalpa (Ort.: Gryllotalpidae) and the larvae of Malacosoma neustria L. (Lep.: Lasiocampidae) at 3.6x109, 1.8x109 cfu/ml dose, respectively within ten days. The highest insecticidal activities are 100% for B. thuringiensis subsp. kurstaki and Bacillus arsenicus on G. gryllotalpa and 75, 70% on M. neustria, respectively. Our results indicate that especially B. thuringiensis subsp. kurstaki (Gg1) may be valuable as a microbial control agent for G. gryllotalpa.

Keywords: Bacterial flora, Biological control, Gryllotalpa gryllotalpa, Insect pathology,16S rRNA