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Title:	Kajian DNA barkod dan genetik populasi serangga perosak terpilih tanaman dagangan Malaysia
Authors:	Siti Zafirah Ghazali (P68112)
Supervisor:	Salmah Yaakop, Dr.
Keywords:	DNA barkod Serangga perosak Tanaman dagangan Dissertations, Academic -- Malaysia Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	17-Aug-2015
Description:	Pengawalan serangga perosak utama merupakan antara aspek terpenting bagi memastikan peningkatan hasil tanaman dagangan negara. Oleh itu, maklumat yang tepat mengenai spesies serangga perosak dan struktur populasinya adalah penting dalam memastikan kejayaan strategi Pengurusan Serangga Perosak Bersepadu (IPM). Objektif kajian ini adalah untuk menjalankan pengecaman ke atas beberapa spesies serangga perosak utama di Malaysia dengan menggunakan kaedah molekul iaitu gen sitokrom oksidase subunit I (COI) dan mengkaji struktur populasi genetik spesies terpilih iaitu ulat bungkus, Metisa plana Walker menggunakan gen COI dan Sitokrom b (Cyt b). Sebanyak 14 spesies serangga perosak utama tanaman di Malaysia iaitu M. plana Walker, Pteroma pendula Joannis, Rhynchophorus ferrugineus (Olivier), R. vulneratus (Panzer), Sesamia inferens (Walker), Chilo polychrysa Meyrick, Bactrocera carambole Drew & Hancock, B. papayae Drew & Hancock, Plutella xylostella (Linnaeus), Conopomorpha cramerella (Snellen), Herpetogramma platycapna (Meyrick), Oryzaephilus surinamensis (Fauvel), Tribolium castaneum (Herbst) dan Cadra cautella (Walker) yang menginfestasi 10 spesies tanaman dan produk simpanan iaitu kelapa sawit (Elaeis guineensis Jacquin), kelapa (Cocos nucifera L.), padi (Oryza sativa L.), belimbing (Averrhoa carambola L.), jambu batu (Psidium guajava L.), petola (Luffa acutangula L.), cili (Capsicum annum), kubis (Brassica oleracea L.), koko (Theobroma cacao), paku pakis (Angiopteris evecta (G. Forst.) Hoffm) dan produk simpanan beras (O. sativa) telah berjaya dikumpulkan dari beberapa ladang dan gudang di Semenanjung Malaysia. Bagi tujuan pengecaman menggunakan pendekatan molekul, DNA sampel telah diekstrak, dijujuk dan dibandingkan di pangkalan data Barcode of Life Database (BOLD) dan Basic Local Alignment Search Tool (BLAST). Seterusnya, analisis pengelompokan Neighbor-Joining (NJ) dan jarak genetik serangga perosak telah dijalankan bagi mengesahkan status spesies serangga perosak. Hasil pengecaman menggunakan pendekatan molekul telah berjaya menghasilkan pengecaman yang tepat, cepat dan berjaya menyumbang jujukan baru kepada sistem BOLD, seterusnya mampu menyelesaikan masalah dalam pengecaman berdasarkan ciri-ciri morfologi dan variasi yang wujud antara spesies. Hasil kajian populasi genetik terhadap spesies ulat bungkus M. plana mendapati bahawa populasi M. plana di Semenanjung Malaysia (Perak: Tapah; Selangor: Shah Alam; Johor: Kluang dan Muar) dicirikan oleh kepelbagaian genetik yang rendah dan perbezaan di antara populasi yang terhad. Hasil ujian statistik Fu's Fs yang positif dan corak multimodal pada graf taburan mismatch menunjukkan populasi M. plana di Semenanjung Malaysia berada dalam keadaan yang seimbang. Namun, kajian terhadap populasi M. plana di Tapah menunjukkan berlakunya perubahan genetik yang berkemungkinan disebabkan oleh penggunaan racun perosak berlebihan dan menjadikan ulat bungkus di kawasan ini rintang terhadap racun perosak. Sementara itu, aliran gen (Nm) iaitu 7.50 (COI) dan 2.10 (Cyt b) antara populasi Tapah dan Shah Alam adalah paling tinggi berbanding populasi lain. Di akhir kajian ini mendapati bahawa pengecaman yang tepat dan penentuan struktur populasi spesies serangga perosak mempunyai implikasi yang besar bagi menjayakan program IPM.,Prevention and management of major insect pests of commercial crops in Malaysia is one of the most important aspects to ensure the increase of crop yields. Hence, accurate information on the pest species and their population structures is essential for ensuring the success of Integrated Pest Management (IPM) strategies. The objectives of this study were to conduct molecular identification using the cytochrome c oxidase I (COI) gene of dominant insect pests of commercial crops in Peninsular Malaysia and to investigate the population genetic structure of a selected pest species namely Metisa plana Walker using the COI and cytochrome b (Cyt b) genes. Samples of a total of 14 species of dominant insect pests of commercial crops i.e. M. plana Walker, Pteroma pendula Joannis, Rhynchophorus ferrugineus (Olivier), R. vulneratus (Panzer), Sesamia inferens (Walker), Chilo polychrysa Meyrick, Bactrocera carambole Drew & Hancock, B. papaya Drew & Hancock, Plutella xylostella (Linnaeus), Conopomorpha cramerella (Snellen), Herpetogramma platycapna (Meyrick), Oryzaephilus surinamensis (Fauvel), Tribolium castaneum (Herbst) and Cadra cautella (Walker) that infest 10 selected commercial plants and stored products namely oil pam (Elaeis guineensis Jacquin), coconut (Cocos nucifera L.), rice (Oryza sativa L.), star fruit (Averrhoa carambola L.), guava (Psidium guajava L.), ridge gourd (Luffa acutangula L.), pepper (Capsicum annum), cabbage (Brassica oleracea L.), cocoa (Theobroma cacao), fern (Angiopteris evecta (G. Forst.) Hoffm) and rice storage product were successfully collected from several farms and warehouses in Malaysia. DNA of the samples were extracted, sequenced and compared to the Barcode of Life Database (BOLD) and the Basic Local Alignment Search Tool (BLAST) database. Then, clustering based on Neighbor-Joining (NJ) and genetic distance analyses were carried out to verify the identification of the pest species. Molecular identification was successful resulting in precise and time consuming species identification, as well as also contributing several new sequences to the BOLD database. Molecular identification was be able to solve problems raised in the identification process based on morphological characteristics and variations that exist between species. The results of the population genetic study of M. plana showed that population of M. plana in Peninsular Malaysia (Perak: Tapah; Selangor: Shah Alam; Johor: Kluang and Muar) was characterized by low genetic diversity and limited population differentiation. The results of statistical Fu's Fs test and multimodal pattern on the mismatch distribution graph showed that the M. plana populations in Peninsular Malaysia were in equilibrium. However, population of M. plana in Tapah showed the occurrence of genetic changes that might be caused by excessive use of pesticides which made the bagworm in this area resistant to pesticides. Meanwhile, gene flow (Nm), 7.50 (COI) and 2.10 (Cyt b) between the populations of Tapah and Shah Alam was the highest compared to the other populations. In conclusion, precise identification and determination of the population structure of M. plana have been proven to have great implications in the successful implementation of IPM program.,Sarjana Sains
Pages:	219
Call Number:	QH442.S567 2015 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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