<![CDATA[ABSTRACT Roselle flower petals are plant organs that are popularly used as herbal drinks and natural dyes. As a raw material for herbal medicine, dried roselle flower petals contain vitamin C and antioxidants. The primary pigment of hibiscine was identified as daphniphylline, which is used to treat hypertension, pyrexia, and liver damage. To obtain high quality herbal raw materials, it is necessary to use characterized seeds sources. In addition, information on the tolerance of roselle plants to abiotic environmental stresses is also needed to develop roselle cultivation on marginal land. Seed physiology studies by stress induction at seed level, and the growth of roselle plants from commercial germplasm were carried out. The aim of this study was to determine the best method for breaking seed dormancy, tolerance level to stimulated abiotic stress on seeds, and to determine plant growth character in the field. Based on the rapid test, the viability of the seeds used was 98%, whilst significant different in breaking the dormancy in terms of vigor index character with the highest index value obtained by immersion in water at 50oC for 10 minutes and 250 ppm GA3 (85.33%). The dormancy of roselle seed breaking could be carried out chemically (250 ppm GA3 and 0.3% KNO3) or physically (wound, hot and cold water). There were significant differences in the characters of hypocotyl length, root length, and wet weight of sprouts depending on the dormancy seed breaking treatments. The results of the abiotic stress test on roselle seeds sprouts showed significant differences on the germination rate, hypocotyl length, and root length. Tested roselle seeds were tolerant to Al3+ and NaCl stresses that are potential to be developed in acid soil due to aluminum and in saline soil. Based on the results of field observations, in general, each individual plant had different growth character and yield. The results of the principal component analysis showed that the six observed characters i.e plant height, branch number, stem diameter, leaves number, early fruit bolls number and fresh fruit weight contributed to the total variability. Based on the total fresh fruit weight, ten plants were then selected for further study. Keywords: Roselle, seeds, physiology, stresses, growth ABSTRAK Kelopak bunga rosela populer digunakan sebagai minuman herbal dan pewarna alami. Kelopak bunga rosela memiliki kandungan vitamin C dan antioksidan yang bermanfaat sebagai bahan baku obat herbal. Pigmen utama hibiscine diidentifikasi sebagai daphniphylline yang digunakan untuk obat hipertensi, pireksia dan kerusakan hati. Untuk mendapatkan bahan baku obat herbal berkualitas perlu digunakan sumber benih bermutu. Untuk mengetahui potensi budidaya pada lahan sub optimal, tingkat toleransi tanaman rosela terhadap cekaman lingkungan abiotik perlu diketahui. Studi fisiologi benih, perlakuan cekaman pada tingkat benih dan pertumbuhan tanaman rosela dari plasma nutfah komersial telah dilakukan. Tujuan penelitian ini untuk mengetahui teknik pematahan dormasi benih, toleransi terhadap cekaman abiotik yang distimulasi pada benih serta mengetahui karakter pertumbuhan tanaman di lahan. Hasil uji viabilitas cepat, benih yang digunakan memiliki viabilitas lebih dari 98%, sedangkan metoda pematahan dormasi menghasilkan perbedaan nyata pada karakter indeks vigor dengan nilai indeks tertinggi diperoleh pada perlakuan perendaman air 50oC selama 10 menit dan 250 ppm GA3 (85,33%). Pemecahan dormansi rosela dapat dilakukan secara kimia (250 ppm GA3 dan 0,3% KNO3) maupun fisik (pelukaan, air panas dan dingin). Terdapat perbedaan nyata pada karakter panjang hipokotil, panjang akar, dan bobot basah kecambah berdasarkan perbedaan perlakukan pemecahan dormansi. Hasil uji cekaman abiotik pada kecambah rosela menunjukkan perbedaan nyata untuk daya berkecambah, panjang hipokotil, dan panjang akar. Benih rosela yang diuji memiliki toleransi terhadap cekaman Al3+ dan NaCl sehingga potensial dikembangkan pada lahan masam akibat aluminium dan salin. Berdasarkan hasil pengamatan di lapangan, setiap individu yang diamati umumnya memiliki karakter pertumbuhan dan daya hasil berbeda. Hasil analisis komponen utama diketahui bahwa enam karakter yang diamati berkontribusi terhadap keragaman yaitu tinggi tanaman, jumlah cabang, diameter batang, jumlah daun, jumlah bakal buah dan bobot basah buah. Berdasarkan bobot basah buah total, berhasil diseleksi 10 tanaman yang dapat diuji lebih lanjut. Kata kunci: Rosela, benih, fisiologi, ,cekaman, pertumbuhan]]>
