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Abstrak :
Hibiscus rosa-sinensis memiliki variasi pada bentuk bunga single, crested, dan double. Variasi tersebut disebabkan adanya perubahan struktur stamen menjadi bentuk lembaran (petaloid) pada bunga crested dan double. Pembentukan struktur petaloid tersebut merupakan gejala homeosis yang disebabkan oleh mutasi pada gen homeotik pengatur identitas organ bunga. Gen homeotik bunga termasuk ke dalam kelompok gen MADS-box yang dibedakan berdasarkan fungsinya menjadi gen kelas A, B, C, D, dan E. Gen yang berfungsi dalam mengatur pembentukan identitas stamen adalah gen kelas B, C, dan E. Penelitian ini bertujuan untuk menganalisis gen APETALA3 dan PISTILLATA (kelas B), AGAMOUS (kelas C), serta SEPALLATA1 (kelas E) pada petal dan struktur stamen bunga H. rosa-sinensis variasi single, crested, dan double, serta mengetahui homologi gen-gen tersebut dengan gen-gen ortolog pada spesies tumbuhan yang berbeda. Isolasi DNA genomik dilakukan menggunakan kit ekstraksi DNA genomik. Selanjutnya, amplifikasi gen dilakukan menggunakan primer AP3, PI, AG-1, AG-2, AG Kombinasi 1 dan 2, SEP1-1, dan SEP1-2. Sekuensing dilakukan pada amplikon gen yang berhasil diamplifikasi, yaitu pada amplikon gen PI, AG-1, AG Kombinasi 1, SEP1-1, SEP1-2. Hasil sekuensing berkualitas tinggi diperoleh dari amplikon gen PI, AG Kombinasi 1, dan SEP1-2. Penyejajaran sekuens gen yang diperoleh dengan gen target menunjukkan persentase kemiripan yang rendah. Hal tersebut dapat terjadi karena adanya perubahan sekuens gen MADS-box akibat proses evolusi tumbuhan. Oleh karena itu, desain primer untuk mendapatkan sekuens target perlu dilakukan kembali dengan mempertimbangkan kemungkinan diversifikasi gen MADS-box pada spesies tumbuhan yang berbeda. ......Hibiscus rosa-sinensis has variations in the form of single, crested, and double flowers. This variation is caused by a change in stamen structure to form petaloids in crested and double flowers. The formation of these petaloid structures is a symptom of homeosis caused by mutations in homeotic genes that regulate flower organ identity. Flower homeotic genes belong to the MADS-box gene group which are distinguished based on their function into A-, B-, C-, D-, and E-class genes. The genes that function in regulating the formation of stamen identity are B-, C-, and E-class genes. This research is done to analyze the APETALA3 and PISTILLATA (B-class), AGAMOUS (C-class), and SEPALATA1 (E-class) genes in the petal and stamen structure of single, crested, and double H. rosa-sinensis flower variations, as well as to know the homology of these genes with other ortholog genes from different plant species. Genomic DNA isolation was carried out using an extraction kit. Next, gene amplification was performed using primers AP3, PI, AG-1, AG-2, AG Combinations 1 and 2, SEP1-1, and SEP1-2. Sequencing was carried out on the amplicons of the genes that were successfully amplified, namely the amplicons of the PI, AG-1, AG Combination 1, SEP1-1, SEP1-2 genes. High quality sequencing results were obtained from the amplicons of the PI, AG Combination 1, and SEP1-2 genes. Sequence alignment between obtained and target genes showed a low percent similarity. This can occur due to changes in the MADS-box gene sequence caused by the process of plant evolution. Therefore, primer redesign to obtain target sequences needs to be done by considering the possibility of MADS-box gene diversification in different plant species.

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.