KARAKTERISTIK FISIOLOGIS ISOLAT Sclerotium sp. ASAL TANAMAN SAMBILOTO - HARTATI, SRI YUNI; TAUFIK, E.; SUPRIADI, SUPRIADI; KARYANI, N. (Jurnal Penelitian Tanaman Industri, 2008)
ABSTRAKSclerotium sp. merupakan jamur patogen baru pada tanamansambiloto (Andrographis paniculata Ness.) yang dapat mengakibatkankematian. Penyebaran jamur ini masih terbatas di KP Cimanggu, Bogordan KP Cicurug, Sukabumi, Jawa Barat. Tujuan penelitian adalah untukmengetahui  pengaruh  beberapa  faktor  lingkungan  seperti  suhu,kelembaban udara (RH), pH, dan cahaya terhadap pertumbuhan isolatSclerotium sp. asal sambiloto pada media PDA serta kisaran inangnya.Penelitian dilakukan di laboratorium dan rumah kaca Balai PenelitianTanaman Obat dan Aromatik (Balittro), Tahun 2005. Faktor lingkunganyang diuji yaitu suhu ruangan (20, 28, 35 dan 40) o C, kelembaban udara(RH 55, 75, 85, dan 100)%, pH (4, 5, 6, 7, dan 8) dan kondisi cahaya(terang, gelap, dan terang dan gelap selang 12 jam secara bergantian). Ujikisaran inang dilakukan terhadap 3 varietas jagung (ketan, pematung, dansokong) dan 3 varietas kacang tanah (jerapah, kelinci, dan simpai) sertatanaman sambiloto sebagai pembanding. Inokulasi dilakukan dengan caramenempelkan sclerotia jamur di bagian pangkal batang tanaman uji dekatpermukaan tanah. Pengamatan pertumbuhan jamur pada media agar yangdiperlakukan dan pengamatan intensitas serangan penyakit dilakukansetiap hari. Hasil penelitian menunjukkan bahwa isolat Sclerotium sp. asaltanaman sambiloto tumbuh baik pada suhu (20-35) 0 C, RH (55-100)%, danpada kisaran pH 4-8 serta pada kondisi terang atau gelap secara terusmenerus maupun bergantian selang 12 jam. Hasil uji kisaran inangmenunjukkan bahwa Sclerotium sp. dapat menyebabkan kematian tidakhanya pada tanaman sambiloto, tetapi juga pada dua varietas kacang tanah(simpai dan jerapah), sedangkan pada jagung tidak menyebabkan kematian(tahan). Hasil penelitian mengindikasikan bahwa isolat Sclerotium sp.yang berasal dari tanaman sambiloto mempunyai kemampuan bertahanhidup dan berkembang pada kondisi lingkungan yang luas (broadspectrum). Ketidakmampuan jamur tersebut menginfeksi tanaman jagungvarietas ketan, pematung, dan sokong dapat digunanakan sebagai salahsatu cara pengendalian patogen dengan sistem tumpangsari dan rotasi.Kata kunci : Sambiloto, Andrographis paniculata Ness, Sclerotium sp.,karakteristik, fisiologis, Jawa BaratABSTRACTPhysiological Characteristics of Sclerotium sp. Isolatedfrom SambilotoSclerotium sp. is a new destructive fungal patogen on sambiloto(Andrographis paniculata Ness.). The distribution of the patogen was stilllimited in Cicurug, Sukabumi and Cimanggu, Bogor, West Java. The aimof this experiment was to observe the growth of Sclerotium sp fromsambiloto under different environmental factors such as temperature,relative humidity, light condition, and pH on PDA medium as well as itshost range. The experiment was conducted in Indonesian Medicinal andAromatic Crops Research Institute (IMACRI) in 2005. The environmentalfactors tested were temperature (20, 28, 35, and 40) o C; relative humidity(55, 75, 85, and 100)%; pH (4-8); and light condition (continuosly on oroff and 12 hours on and off alternatively). The pathogenicity of theSclerotium sp. was tested against 3 varieties of corn (ketan, pematung, andsokong) and 3 varieties of peanut (jerapah, kelinci, and simpai) as well assambiloto as a comparison. Sclerotia of the fungus were inoculated on thestem base of the plant tested. Observation of the growth of the fungusunder different environmental factors and disease intensity on inoculatedplants was conducted everyday. The results showed that the growth ofSclerotium sp. isolate from sambiloto was affected by differentenvironmental factors. The isolate grew well at (20-35) 0 C, relativehumidity ranged from (55-100)%, pH ranged from 4-8, and lightcondition of both continuosly on or off as well as 12 hours on and offalternativelly. The isolate was pathogenic against sambiloto as well asagainst 2 varieties of peanut (simpai and jerapah), however, it was notpathogenic against all the corn varieties tested. The result indicated thatthe isolate of Sclerotium sp. from sambiloto was a broad spectrum fungalpathogen. The resistency of the corn varieties would be of value forcontrolling the disease through mixed cropping or rotation systems.Key words: Sambiloto, Andrographis paniculata Ness, Sclerotium sp.,physiological characteristics, West Java