Evaluasi Ketahanan Populasi Haploid Ganda Silangan IR64 dan Oryza rufipogon terhadap Hawar Daun Bakteri pada Stadia Bibit

Abstract

Evaluation of resistance of double haploid population of crosses between IR64 and Oryza rufipogon against Bacterial Leaf Blight (BLB) at seedling stage was conducted during dry season 2005/2006 in the screen house, at Rice Centre Research at Sukamandi. Inoculum was prepared by isolating BLB infected leaf in laboratory using Wakimoto’s media. Seeds were germinated in petri dish for 48 hours, and then were sown in the plastic boxes size of 40 cm x 30 cm, each family was planted in 10 cm long row. TN1, IRBB, Code, Angke, dan O. rufipogon were used as control. Leaf inoculation of isolates of Xanthomonas oryzae pv. oryzae (XOO) ras III, IV, and VIII with concentration of 108 cell/ml, were applied to the plants at 18-21 day old plants by cutting method. Fertilizer application as recommended. Pest and weed control were based on necessity. Observation of disease severity was carried out after a sensitive control, TN1, was a severely affected. Observation method based on SES IRRI (1996) which are 1 for plant showed 0-3% of leaf damage, 2(4-6%), 3(7-12%), 4(13-25%), 5(26-50%), 6(51-75%), 7(7-87%), 8(88-94%), and 9 for plant with 95-100% of leaf damage. Result showed that Bio50-ACBlas/ BLB03, Bio59-AC-BLB05 and Bio67-AC-BLB05 lines were resistant to phato-type III, 11 lines showed moderate resistant to phato-type IV, and Bio46-AC-Blas/BLB03, Bio47- AC-BLB05, and Bio48-AC-BLB05 lines were resistant to phato-type VIII. Apart of those, there were 2 lines, Bio38-ACBLB05, and Bio63-AC-Blas/BLB03 showed moderately resistance to three phatotypes tested. Abstrak Evaluasi ketahanan populasi haploid ganda silangan IR64 dan Oryza rufipogon terhadap hawar daun bakteri (HDB) pada stadia bibit telah dilakukan pada MK 2005/2006 di rumah kaca Balai Besar Penelitian Tanaman Padi, Sukamandi. Penyiapan inokulum dilaksanakan dengan mengisolasi daun yang terinfeksi HDB di laboratorium dengan menggunakan media Wakimoto. Tanaman dikecambahkan dalam petri selama 48 jam, kemudian ditanam dalam kotak plastik berukuran 40 cm x 30 cm. Tiap tanaman ditanam sepanjang 10 cm. Tanaman TN1, IRBB, Code, Angke, dan O. rufipogon, dipakai sebagai pembanding. Inokulasi dilakukan dengan konsentrasi 108 cell/ ml, dengan isolat Xanthomonas oryzae pv. oryzae (Xoo) ras III, IV, dan VIII, pada umur 18-21 hari setelah sebar dengan cara digunting. Pemupukan dilakukan sesuai rekomendasi. Pengelolaan hama dan gulma dilaksanakan berdasarkan keadaan. Metode pengamatan menggunakan SES IRRI (1996). Hasil pengamatan menunjukkan, galur yang tahan terhadap HDB ras III ialah Bio50-AC-Blas/BLB03, Bio59-AC-BLB05, dan Bio67-AC-BLB05. Untuk ras IV, terdapat 11 galur yang menunjukkan ketahanan moderat (agak tahan). Untuk ras VIII galur Bio46-AC-Blas/BLB03, Bio47-AC-BLB05, dan Bio48- AC-BLB05 bereaksi tahan. Galur Bio38-AC-BLB05 dan Bio63-AC-Blas/BLB03 agak tahan terhadap ketiga ras HDB.