Perkembangan Penelitian Pembentukan Galur Mandul Jantan pada Perakitan Padi Hibrida

Perakitan padi hibrida merupakan salah satu alternatif dalampenyediaan varietas unggul baru padi. Pembentukan hibrida padapadi melibatkan galur mandul jantan (GMJ atau galur A), galurpelestari atau galur B, dan galur pemulih kesuburan atau galur R.Pengembangan padi hibrida di Indonesia pada awalnya menggunakanGMJ yang diintroduksi dari China dan IRRI. Meskipunmemperoleh beberapa GMJ dengan kemandulan tepung sari yangtinggi (highly sterile), GMJ tersebut masih memiliki kelemahan,antara lain tingkat persilangan alaminya sangat rendah, dayagabungnya kurang baik, serta potensi heterosisnya belum cukuptinggi (< 15%). Penelitian lebih lanjut memperoleh sejumlah GMJdengan sifat kemandulan tepung sari yang lebih mantap dan stabil,serta memiliki beberapa kelebihan, antara tingkat persilangan yanglebih baik serta lebih tahan terhadap hama penyakit utama. Upayaperbaikan galur pelestari juga dilakukan untuk memperbaiki GMJ.Pemanfaatan teknik inkonvensional melalui kultur antera masihdalam tahap awal program pemuliaan padi

Pembentukan Galur Mandul Jantan Baru Padi Hibrida Tahan Penyakit Hawar Daun Bakteri Dan Hama Wereng Batang Coklat

The presently available cytoplasmic male sterile lines (CMS) commonly used to develop rice hybrids in Indonesia are susceptible to major pests and diseases. Research was conducted to develop new cytoplasmic male sterile lines which are highly resistant to major pests and diseases. Two new cytoplasmic male sterile rice lines, GMJ4A and GMJ5A, were developed using backcross method, derived from crosses of BP455G-PN-13-2-1-1-10-MR-3-1 and B11005E-MR-4-2-1, which were identified as completely sterile on a test cross nursery. The following season, sterile F1 generations were successively backcrossed until stable sterile plants were obtained in 2006. Seeds of the two cytoplasmic sterile lines were mass produced at Muara, Bogor, in 2006. GMJ4A and GMJ5A are resistant to bacterial leaf blight patotipe IV and VIII. Both lines are resistant to brown plant hopper in the green house test with scores of 1 to 3. The hybrid combinations involving GMJ4A and GMJ5A were evaluated in an observational yield test at Muara during dry season of 2007 and at Kuningan in dry season 2009. The level of grain yield heterosis were better than the check varieties. These two lines are expected to be used as a replacement for the existing CMS lines