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Biological Characteristics of a High Virulent Isolate of Metarhizium Anisopliae and Histopathology of Infected Anoplophora Glabripennis Larvae

Author: WangBaoHui
Tutor: HuangDaZhuang
School: Agricultural University of Hebei
Course: Forest Protection
Keywords: Metarhizium Anoplophora glabripennis Filter Biological characteristics Histopathology
CLC: S763.38
Type: Master's thesis
Year: 2009
Downloads: 90
Quote: 1
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Abstract

Metarhizium anisopliae Metarhizium anisopliae in biological classification of imperfect fungi belonging to Amon, Cong Terrier Agonomycetales, Tubercularia spore Branch, Metarhizium, is a broad-spectrum insecticide fungi, parasites 8 can mesh, 30 Division of the more than 200 species of insects, but also parasitic mites and nematodes. Currently, in many countries as an important means of biological control for pests. This article from the soil trapping method using mealworm isolated Metarhizium 8 through biometrics, and with the virulence of a commercially available strain for comparison screened out a Anoplophora glabripennis (Anoplophora glabripennis) larvae have higher toxicity The Metarhizium MS01 strain and the strain of the biological characteristics of Anoplophora glabripennis eggs, adults and larvae of pathogenicity, Anoplophora glabripennis larvae infestation manner and Anoplophora glabripennis larvae infected after histopathological changes were studied. The main results are as follows: 1, strains were isolated and cultured, highly pathogenic strain screening. With yellow mealworm (Tenebrio molitor) trapping method PPDA medium this strain were isolated and cultured from 16 soil samples were isolated from Metarhizium 8, the separation rate of 50%, of which 46 Yang Lin seized the highest rate of infection Metarhizium 52.4%. Meanwhile Anoplophora glabripennis larvae were bioassay, and commercially available kill cockroach Metarhizium spores for virulence comparison. The results show that the virulence of different strains differ, in which the strongest virulence strains MS01 corrected mortality and infection rates were 100% and 83.33%, fatal when LT ₅₀ is 2.69d, LC50 LC ₅₀ was 1.68 × 10 ^{6 mL ^{-1 . Compared with the commercial strains, MS01 strain to 8d 100% mortality, infection rate was 90.4%, and its death rate was faster, LT ₅₀ is 5.25 d. It will strain MS01 strain as a target for biological characteristics, as a field control Anoplophora glabripennis larvae alternative strains. 2, M. anisopliae strain MS01 biological characteristics. Nutrition and appropriate temperature and humidity, light and ultraviolet radiation that affect growth and virulence strains the level of the main factors. The strain vegetative growth and sporulation of the optimum medium are PPDA, optimum humidity of 100% relative humidity, at 26 ℃ under the strain best vegetative growth, sporulation is greater, 28 ℃ under the highest sporulation spore germination earliest, alternating light conducive to sporulation, 7 d 7 d light alternately dark lighting conditions, the highest sporulation, vegetative growth is also better, different UV irradiation time Metarhizium anisopliae strain MS01 no significant effect on vegetative growth, With UV irradiation time increased, decreased its sporulation. 2% glucose, 1.5% peptone mixture of nutrient solution most conducive to spore germination. 3, MS01 strain Anoplophora glabripennis eggs, adults and at different temperature and humidity effects on larval pathogenicity. Metarhizium anisopliae strain MS01 not directly infect Anoplophora glabripennis eggs, but the adult feeding, spawning, hatching and larval survival have an impact glabripennis adults infected with Metarhizium MS01, you can reduce their food consumption and fecundity and the greater the concentration of inoculum, the more reduced and transmitted to offspring through horizontal transmission reduces offspring survival. MS01 strain Anoplophora glabripennis larvae produce optimum temperature for pathogenic role of 26 ℃, the optimum humidity is 100%. 4, Anoplophora glabripennis larvae infected with Metarhizium symptoms and histopathological changes. Anoplophora glabripennis larvae infected with Metarhizium MS01, the parasite color and external morphology changes accordingly. By paraffin tests showed that Metarhizium MS01 treated 24 h, spores can be attached to Anoplophora glabripennis larvae surface, 48h after glabripennis larval epidermis is broken down, the mycelium into the blood chamber and proliferate to invade point near fat, muscle, trachea, Malpighian tubules, digestive tract and other tissues invasion. Infected larvae died after 3 d, tissues and organs are subject to infection. With continued Metarhizium dead insects in vivo proliferation, tissues and organs in varying degrees of damage. Mycelium after 5 d break the surface, the formation of hyphae in the outer layer of the parasite and has conidia production.}}

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CLC: > Agricultural Sciences > Forestry > Forest Protection > Forest Pest and Disease Control > Pest and its control > Coleoptera
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