<![CDATA[AbstrakHibiscus rosa-sinensis L. atau kembang sepatu merupakan tanaman hias yang memiliki banyak manfaat dan merepresentasikan sifat poliploidi. Tujuan penelitian ini yaitu untuk mengetahui Indeks Mitosis (IM) dan jumlah kromosom pucuk daun H. rosa-sinensis pada beberapa variasi waktu. Indeks Mitosis dan waktu pengambilan pucuk sangat diperlukan untuk studi kromosom karena pada tahap tersebut karakter-karakter kromosom dapat diamati dengan jelas dan mudah dihitung. Waktu pengambilan pucuk yang dilakukan yaitu pada 08:00, 10:00, 12:00, 14:00, 16:00 WIB. Pembuatan sediaan kromosom dilakukan menggunakan metode squash menggunakan pewarna Aceto-orcein. Tahapan perlakuan meliputi perendaman pucuk daun di dalam air dingin selama 3 jam, fiksasi dalam larutan Carnoy selama ±24 jam, dan hidrolisis dalam larutan HCl 5N selama 30 menit. Hasil penelitian menunjukkan nilai IM tertinggi meristem pucuk daun H. rosa-sinensis variasi single pink besar muncul pada pukul 10:00 sebesar 94%. Berdasarkan hasil tersebut dapat disimpulkan bahwa waktu sampling yang optimal untuk analisis kromosom H. rosa-sinensis L. variasi single pink besar adalah pukul 10:00 dengan jumlah kromosom 2n= ca. 69-111. Hasil penelitian ini dapat dijadikan dasar untuk studi kromosom selanjutnya serta acuan untuk sampling variasi lainnya.Abstract Hibiscus rosa-sinensis L. is an ornamental plant that has many benefits and represents the character of polyploidy. The purpose of this study is to find out the Mitotic Index of leaf shoots Hibiscus rosa-sinensis on several shoots sampling times. The Mitotic Index and the timing of shoots sampling time are very necessary for chromosome studies because at this stage chromosomes characters can be clearly observed and easily calculated. Period time of collection the leaf shoots is from 08:00 AM to 16:00 PM, with two hours interval each at 08:00, 10:00, 12:00, 14:00, 16:00 . The chromosome preparation was carried out by using the squash method and aceto-orcein staining. The treatment steps included soaking the leaf shoots in cold water for 3 hours, fixation in Carnoy solution for ± 24 hours, and hydrolysis in 5N HCl solution for 30 minutes. The results showed that chromosomes were clearly visualized during the phase with the highest Mitotic Index.  In addition, the percentage of Mitotic Index was found to be in line with the percentage of cells in late prophase. Among several sampling time variations, the highest Mitotic Index of Hibiscus rosa-sinensis leaf shoots appeared at 10:00 at 94% with the chromosome numbers of 2n= ca. 69-111. According to the data obtained, it is concluded that 10 AM is the most optimum sampling time that can be used as the basic information for further chromosome studies.]]>
