Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
Bunga Hibiscus rosa-sinensis L. variasi crested peach dan double orange berbeda dari variasi single pink karena memiliki petal tambahan petaloid . Struktur petaloid tersebut diduga berasal dari modifikasi organ reproduktif bunga homeosis . Peristiwa homeosis yang terjadi dihipotesiskan karena gen kelas C AGAMOUS yang berperan dalam pembentukan androecium dan gynoecium tidak terekspresi. Oleh karena itu dilakukan penelitian yang bertujuan untuk mengetahui ekspresi gen AGAMOUS secara kualitatif pada bunga single pink, crested peach, dan double orange. Analisis ekspresi gen AGAMOUS dilakukan dengan cara mengisolasi RNA dari androecium dan gynoecium ketiga variasi bunga menggunakan metode CTAB yang dimodifikasi. Sampel RNA diubah menjadi cDNA menggunakan reverse transcriptase, yang selanjutnya diamplifikasi dengan teknik PCR menggunakan primer AG1 dan AG2. Produk PCR AG1 menghasilkan variasi pita dengan ukuran 100, 200, dan 300 bp, sedangkan hasil PCR AG2 menghasilkan pita yang berukuran 200 bp. Hasil analisis sekuensing terhadap produk PCR primer AG1 dan AG2 menunjukkan gen AGAMOUS terekspresi pada semua sampel. Hasil tersebut mengindikasikan bahwa perubahan struktur organ reproduktif bunga tidak disebabkan oleh hilangnya ekspresi gen AGAMOUS, sehingga perlu dilakukan analisis ekspresi gen AGAMOUS beserta interaksinya dengan gen lain. ......Hibiscus rosa sinensis L. crested peach and double orange types are different from single pink type in terms of their additional petals petaloid . The petaloid structure is thought to have originated from reproductive organs modification homeosis . AGAMOUS is class C gene that plays role in androecium and gynoecium formation. Loss of AGAMOUS gene expression is assumed to cause modifications occur in reproductive organs. Therefore, this study aims to determine the qualitative expression of AGAMOUS gene on single pink, crested peach, and double orange flowers. Analysis of AGAMOUS gene expression was done by isolating RNA from their androecium and gynoecium using the modified CTAB method. The RNA sample was converted to cDNA using reverse transcriptase, before further amplified by PCR technique using AG1 and AG2 primers. The AG1 PCR product produces bands of 100, 200, and 300 bp, while the PCR AG2 produces single band of 200 bp. The analysis of sequencing results showed that AGAMOUS gene expressed in all samples. Therefore, petaloids presents in crested peach and double orange flowers are not caused by loss of AGAMOUS gene expression. The homeosis occurred should be analyzed not only based on AGAMOUS gene expression, but also should include other gene and their interactions.

Abstrak :
Penelitian dilakukan untuk mengetahui variasi bunga Hibiscus rosa-sinensis L. bentuk crested di alam, serta hubungannya dengan ekspresi gen MADS-box. Sebanyak 200 sampel bunga crested diamati secara morfologi melalui pengukuran panjang staminal column, perhitungan perhiasan bunga, dan pengamatan visual permukaan luar ovarium. Sebanyak 137 sampel bunga crested diamati secara anatomi melalui pengamatan visual struktur internal ovarium. Hasil pengamatan morfologi dan anatomi menunjukkan tingginya variasi bunga H. rosa-sinensis bentuk crested. Salah satu karakter yang menentukan tingginya variasi bunga crested di alam adalah keberadaan petal tambahan yang diduga tumbuh di lokasi keberadaan stamen dan petal akibat gejala homeosis. Homeosis pada bunga crested diduga karena tidak terekspresikannya gen C yang merupakan salah satu kelas dari gen MADS-box. Untuk membuktikan dugaan tersebut, dilakukan pengamatan molekular melalui analisis gen MADS-box yang berperan dalam proses pembungaan. Dari kelima kelas gen MADS-box yang diamati, hanya gen C yang berhasil diamplifikasi. Hasil menunjukkan bahwa gen C terekspresi di semua bagian bunga crested. Berdasarkan hasil tersebut, homeosis pada bunga crested bukan disebabkan karena tidak terekpresikannya gen C. Dibutuhkan penelitian lebih lanjut untuk mengetahui tingkat ekspresi tiap kelas gen MADS-box terhadap variasi bunga crested di alam. ......The aim of this study is to know the variation of Hibiscus rosa-sinensis L. crested flower in nature, and to know its correlation against MADS-box gene expression. The study was conducted through morphological, anatomical, and molecular observation. Morphological sections were carried out on 200 samples of flowers by measuring the length of staminal column, counting the number of perianthium, and observing the external structure of ovaries. Anatomical sections were carried out on 137 samples of flowers by observing the internal structure of ovaries. The results showed that H. rosa-sinensis crested flower has a high variety in the shape of flower. Two main parts of crested flower that effecting its variety in nature are staminodium petaloid and stamen-petal intermediate that lied in the position of stamen and petal. This phenomenon is assumed as homeotic due to the absence of C gene expression that belong to MADS-box gene family. Based on molecular observation, AGAMOUS gene (MADS-box class C) expressed in all of crested flower parts, including staminodium petaloid and stamen-petal intermediate. This results is on contradiction with the assumption that homeosis in H. rosa-sinensis caused by the absence of gene C. Further research is needed to know the expression of others MADS-box class genes expression, including their level of expression in each parts of crested flower.