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Title:	Kajian morfologi dan molekul ke atas mutan orkid Dendrobium Sonia yang terhasil daripada penyinaran gama
Authors:	Sakinah Ariffin (P45262)
Supervisor:	Wickneswari Ratnam, Prof. Dr.
Keywords:	orkid Orchids
Issue Date:	28-Sep-2012
Description:	Mutan Dendrobium Sonia yang berlainan warna bunga hasil daripada penyinaran gama dipilih untuk kajian ini untuk menentukan pengekspresan gen utama dalam tapak jalan flavonoid dan mengesan variasi jujukan DNA pada calon gen bagi pengesahan dan pembangunan penanda. Sebanyak 2000 plantlet dihasilkan daripada kultur tisu orkid yang telah didedahkan kepada sinaran gama pada dos 35 Gy diaklimatasi dan ditanam. Penyaringan mutan dilakukan sehingga pokok mengeluarkan bunga. Sebanyak 100 pokok yang mengeluarkan bunga berbeza telah dipilih untuk kajian morfologi. Pencirian dilakukan ke atas mutan yang menunjukkan perubahan stabil dari segi warna dan bentuk bunga berbanding kawalan. Penggredan warna bunga dilakukan dengan menggunakan carta warna Royal Horticultural Society of London (carta warna RHS). Didapati, mutasi aruhan oleh sinaran gama telah menyebabkan perubahan pada warna dan saiz bunga. Sebanyak 11 kumpulan mutan iaitu Dendrobium Sonia KeenaHiengDing', Dendrobium Sonia KeenaOval', Dendrobium Sonia KeenaRadiant', Dendrobium Sonia KeenaAhmadSobri', DS 35- White A, DS 35-Lace, DS 35-1/M, DS 35-1/B, DS 35-1/J, DS 35-1/S dan DS 35-N telah dapat dicirikan daripada populasi mutan ini. Pelbagai variasi warna bunga pada petal, sepal dan labelum diperhatikan di mana warna merah keunguan (induk kawalan) berubah kepada ungu, merah jambu keunguan, ungu lembayung dan putih. Chalcone synthase (CHS) dan flavonoid 3'5'hydroxylase (F3'5'H) yang terlibat dalam tapak jalan flavonoid telah dipilih untuk analisa pengekspresan gen warna secara kuantitatif relatif menggunakan tindak balas real-time PCR kuantitatif (qPCR). Pemencilan RNA total dilakukan daripada tisu petal dan sepal tiga bunga yang berwarna merah keunguan (D. Sonia), bunga warna merah jambu keunguan (mutan DS 35-1/M) dan bunga warna putih (mutan DS 35-White A). Gen CHS diekspreskan paling tinggi dalam sepal bunga putih dan paling rendah dalam sepal dan petal bunga merah jambu keunguan. Namun begitu, pengekspresan gen F3'5'H pula tidak menunjukkan perbezaan ketara di dalam setiap tisu yang dikaji. Kehadiran polimorfisme pada jujukan DNA gen CHS dalam mutan orkid Dendrobium Sonia menjelaskan perbezaan dalam pengekspresan gen ini di antara bunga putih dan merah jambu keunguan.,Gamma irradiated Dendrobium Sonia mutants with different flower colours were selected for this study to determine the expression of key genes in the flavonoid pathway and identify DNA sequence variations in the candidate genes for validation and marker development. A total of 2000 plantlets produced from tissue culture of orchids that have been exposed to gamma irradiation at dose of 35 Gy were acclimatized and planted. Screening of mutants was done until the plants flowered. A total of 100 different plants which produced flowers were selected for morphological study. Characterization was performed on mutants that showed a stable change in terms of flower colour and shape compared to the control. Flower colour grading was done by using the Royal Horticultural Society of London Colour Chart (RHS Colour Chart). Induced mutations by gamma irradiation resulted in changes for flower colour and flower size. A total of 11 groups of mutants, Dendrobium 'Sonia KeenaHiengDing', Dendrobium 'Sonia KeenaRadiant', Dendrobium 'Sonia KeenaOval', Dendrobium 'Sonia KeenaAhmadSobri', DS 35-White A, DS 35-Lace, DS 35-1/M, DS 35-1/B, DS 35-1/J, DS 35-1/S and DS 35-N were characterized from the mutant population. Colour variation in the petal, sepal and labellum ranged from the purplish red colour (control) to purple, purplish pink, purple violet and white. Chalcone synthase (CHS) and flavonoids 3'5'hydroxylase (F3'5'H) involved in the flavonoid pathway were selected for gene expression study using real-time quantitative PCR (qPCR). Total RNA was isolated from the petal and sepal of three flower colour variants - purplish red flowers (control D. Sonia), purplish pink flowers (mutant DS 35-1/M) and white flowers (mutant DS 35-White A). Expression of CHS gene was the highest in sepals of white flowers and the lowest in both sepals and petals of purplish pink flowers. Expression of F3'5'H gene was similar in all the tissues examined. Detection of DNA sequence polymorphism in the CHS genes among the Dendrobium Sonia mutants may explain the difference in gene expression detected between the white and purplish pink flowers,Master/Sarjana
Pages:	108
Call Number:	QK495.O64S235 2012 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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