Pengaruh arang aktif terhadap pencokelatan pada kultur daun Dendrobium lasianthera J.J.Sm telah diteliti di Laboratorium Fisiologi Tumbuhan Departemen Biologi. Penelitian bertujuan untuk mengetahui respons eksplan terhadap penambahan arang aktif pada medium ½ MS (Murashige dan Skoog) modifikasi dan untuk mengetahui konsentrasi arang aktif yang tepat dalam mengurangi pencokelatan pada kultur daun Dendrobium lasianthera. Pemberian arang aktif pada medium ½ MS modifikasi dibagi menjadi empat kelompok: Kontrol (K =0%), Perlakuan 1 (P1 = 0,1%), Perlakuan 2 (P2 = 0,2%), dan Perlakuan 3 (P3 =0,3%). Hasil penelitian menunjukkan bahwa penambahan arang aktif 1%, 2%, dan 3% dapat mengurangi pencokelatan, yaitu 10% eksplan mengalami pencokelatan, 78% eksplan tetap hijau, dan 12% eksplan mengalami bleaching. Konsentrasi arang aktif 3 g/l cenderung lebih baik dalam mengurangi pencokelatan.

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The effect of activated charcoal to browning in leaf culture of Dendrobium lasianthera J.J.Sm were studied in the Laboratory of Plant Physiology at Department of Biology. This study was aimed to know the respons of explants and to determine the best concentration of activated charcoal to minimize the browning. Treatment of activated charcoal in ½ MS medium divided into four group: Control (K = 0%), Treatment 1 (P1 = 0,1%), Treatment 2 (P2 = 0,2%), and Treatment 3 (P3 = 0,3%). Explant responded by browning (10%), staying green (78%), and bleaching (12%). The result showed that activated charcoal 1%, 2%, and 3% can minimize the effect of browning. The best result were obtained with ½ MS medium supplemented with 3 g/l activated charcoal.