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Toxicity screening of various plant extracts against nematodes Meloidogyne incognita Chitwood and Radopholus similis Cobb and characterization of their nematicidal components / Ruth Sarra-Guzman

By:

Guzman, Ruth Sarra [author]

Contributor(s):

Davide, Romulo G [adviser]

Material type: Text

TextLanguage: English Publication details: Los Ba�os, Laguna, 1984. Cavite State University- Main Campus,Description: 197 pages : illustrations ; 28 cmContent type:

text

Media type:

unmediated

Carrier type:

volume

Subject(s):

DDC classification:

581.2 G99 1984

Online resources:

Click here to view thesis abstract and table of contents

Abstract: GUZMAN, RUTH SARRA. University of the Philippines at Los Banos, July 1984. Toxicity Screening of Various Plant Extracts Against Meloidogyne incognita Chitwood And Radopholus similis Cobb and Characterization of their Nematicidal Components. Major Professor: Dr. Romulo G. Davide Solvent extracts of eight plant species were screened for toxicity against two economically important nematode genera, namely: Meloidogyne incognita Chitwood and Radopholus similis Cobb. The plant species were: Anthocephalus chinensis (Lamb.) Rich ex Walp, Desmodium gangeticum (Linn.) DC, Artemisia vulgaris Linn., Eichornia crassipes (Mart.) Solms, Leucaena leucocephala (Lam.) de Wit, Allium cepa Linn., Allium sativum Linn. and Moringa oleifera Lam. The extracts showed definite indications of toxicity in immersion bioassay and pathogenicity tests. However, degrees of toxicity varied among the different species although results could favorably compare with toxicity values obtained with the standard pesticides used namely, Nemacur 10 G (fenamiphos), Temik 10 G (aldicarb) and Rotenone, a pesticidal compound taken from Derris elliptica. Mortality data after 48 hours and percent reduction in hatchability and infection parameters were the bases for comparison, i.e., number of egg mass, nematode population in root and number of galls for M. incognita; lesion number and nematode population in root and soil for R. similis. The crude extracts of A. chinensis, E. crassipes and As cepa showed outstanding results in the toxicity tests. Subsequently, these extracts were fractionated by preparative thin-layer chromatography and purified in order to isolate the active principle. Separated fractions were again bioassays on the test organisms to test their nematicidal activity in this purified state. The Ae cepa crystals, Fraction 2 of A. chinensis and Fraction 1 of E. crassipes showed high toxicity. Characterization of the active components by ultraviolet and infrared spectrophotometry suggested the presence of a ketone in the A. cepa crystal, a phenolic aldehyde in A. chinensis Fraction 2 and a carboxylic acid in E. crassipes Fraction 1 as responsible for nematicidal activity.

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Holdings ( 1 )
Title notes ( 4 )

Holdings
Item type	Current library	Collection	Call number	Materials specified	URL	Status	Notes	Date due	Barcode
Theses / Manuscripts	Ladislao N. Diwa Memorial Library Theses Section	Non-fiction	581.2 G99 1984 (Browse shelf(Opens below))		Link to resource	Room use only	T-1392		00002286

Thesis (Ph.D. - - Plant Pathology) University of the Philippines, College, Laguna.

Includes bibliographical references.

GUZMAN, RUTH SARRA. University of the Philippines at Los Banos, July 1984. Toxicity Screening of Various Plant Extracts Against Meloidogyne incognita Chitwood And Radopholus similis Cobb and Characterization of their Nematicidal Components. Major Professor: Dr. Romulo G. Davide

Solvent extracts of eight plant species were screened for toxicity against two economically important nematode genera, namely: Meloidogyne incognita Chitwood and Radopholus similis Cobb. The plant species were: Anthocephalus chinensis (Lamb.) Rich ex Walp, Desmodium gangeticum (Linn.) DC, Artemisia vulgaris Linn., Eichornia crassipes (Mart.) Solms, Leucaena leucocephala (Lam.) de Wit, Allium cepa Linn., Allium sativum Linn. and Moringa oleifera Lam. The extracts showed definite indications of toxicity in immersion bioassay and pathogenicity tests. However, degrees of toxicity varied among the different species although results could favorably compare with toxicity values obtained with the standard pesticides used namely, Nemacur 10 G (fenamiphos), Temik 10 G (aldicarb) and Rotenone, a pesticidal compound taken from Derris elliptica. Mortality data after 48 hours and percent reduction in hatchability and infection parameters were the bases for comparison, i.e., number of egg mass, nematode population in root and number of galls for M. incognita; lesion number and nematode population in root and soil for R. similis.

The crude extracts of A. chinensis, E. crassipes and As cepa showed outstanding results in the toxicity tests. Subsequently, these extracts were fractionated by preparative thin-layer chromatography and purified in order to isolate the active principle. Separated fractions were again bioassays on the test organisms to test their nematicidal activity in this purified state. The Ae cepa crystals, Fraction 2 of A. chinensis and Fraction 1 of E. crassipes showed high toxicity.

Characterization of the active components by ultraviolet and infrared spectrophotometry suggested the presence of a ketone in the A. cepa crystal, a phenolic aldehyde in A. chinensis Fraction 2 and a carboxylic acid in E. crassipes
Fraction 1 as responsible for nematicidal activity.

Submitted to the University Library 01/07/1994 T-1392