1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Faculty of Science and Technology / Fakulti Sains dan Teknologi

Title:	Effect of volatile organic compounds of cruciferous plants on the responding behaviour of diamondback moth Plutella xylostella L. and its natural enemies
Authors:	Ismail Emhamed Abdurahman Abuzid (P51225)
Supervisor:	Idris Abd. Ghani, Prof. Dr.
Keywords:	Cruciferous plants Diamondback moth Plutella xylostella L. Volatile organic compounds
Issue Date:	1-Dec-2017
Description:	The chemical identity of volatile organic compounds (VOCs) produced by plants differs depending on the plant species and the injury' cause. The objectives of this study were: 1) to evaluate the effect of VOCs of differently damaged cruciferous Brassica oleracea (BO), Brassica nigra (BN) and Brassica juncea (BJ) plants at Diamondback Moth Plutella xylostella (DBM) 2) and at its natural enemies in olfactory experiment 3) to determine the effects of VOCs released from differently damaged BO plants on DBM and its natural enemies in a screen-cage 4) to extract and analyze VOCs released from differently damaged crucifers plants. In olfactory experiment, results showed that the DBM females were found significantly more on the injured BJ compared to the undamaged plant. In contrast, the olfactory response was found to be significantly higher towards the undamaged plant in the case of BO. Similar results were observed for the BN. The results of this experiment showed a differential in VOCs produced for different treatments; as such it is confirmed that these VOCs were involved in causing differential responses of DBM females and they could be the main attractant for DBM females. The DBM parasitoid, Cotesia vestalis (CV) females were attracted significantly more by BO plants damaged by DBM than by the undamaged plants. No significant difference was observed between the mean number of CV females responded to BO plants aphid-damaged or mechanically-damaged and that of CV females responded to undamaged plants. Results also showed that there was no significant different between the mean numbers of Diadegma semiclausum (DS) females responded to plants damaged by DBM larvae than those responded to undamaged plants. The egg parasitoid, Trichogramma australicum (TA) females did not elicit significant responses to volatiles released from BO plants and were not interested at all by the BO volatiles. Results of this study demonstrated that the response of parasitoids females to damaged plants depends on the information sent by herbivores infesting the plants. The damage could cause a variation or difference in the VOCs emitted by the same plant which contributed to the differences in the parasitoid responses. In the screen-cage test, there was no significant difference in the number of DBM females found on the plants. The difference in the chemical signals emitted by plants was possibly involved in the acceptance or rejection of potential hosts. CV females showed high significant attraction to plants damaged by DBM that to undamaged plants. No significant difference was observed between the mean number of CV females responded to plants damaged by aphid, mechanically-damaged and that responded to undamaged plants. Significantly more DS females were found on DBM-damaged plants. The differences in the emission of the herbivore-induced volatiles from DBM-damaged plants could offer parasitoids females enough information to discriminate between plants infested by their hosts. Gas Chromatography MS was used to extract volatiles from plants, differently damaged and non-damaged plants. The results demonstrated that there were significant differences (P < 0.05) in quantities and qualities of volatile chemicals released by non-damaged and damaged plants. Hope the information obtained from these studies to help and to find secure DBM integrated management methods.,Certification of Master's/Doctoral Thesis" is not available
Pages:	171
Call Number:	TD196.O73A238 2017 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.