<![CDATA[Blast Resistance Performance of Promising Lines Derived from Backcross and Double Haploid Population Between IR64 and Oryza rufipogon. Developing blast resistance varieties with superior agronomical performance has been the one of the important priorities in rice breeding program. Based on the purpose of this study the double haploid and backcross populations were developed using the most popular cultivar IR64 as recurrent parent and wild rice species Oryza rufipogon (Acc. IRGC 105491) as blast resistance donor parent. This study was initiated to analyze the blast resistance and agronomical performance of double haploid populations (DH_I, DH_II and DH_III) and backcross populations (BC2, BC3, and BC5), based on the green house and field screening tests. The results of statistical analysis showed that the blast resistance performance of DH population were diverse among DH_I, DH_II and DH_III. The smallest diversity was on the DH_III population. The same results were also detected on BC populations. The smallest diversity was on BC5 population. The diversity comparison between DH and BC population showed that DH_III population had smaller variation than BC5. Indicated that DH_III population has the most fixed population. The agronomic performance evaluation of DH_III population selected lines showed that Bio1, Bio2, and Bio8 qualitified as the candidate of promising lines. AbstrakPerakitan varietas tahan blas sebagai galur harapan, merupakan salah satu prioritas dalam program pemuliaan padi. Dalam rangka mendukung program tersebut, telah dilakukan pembentukan populasi haploid ganda (HG) dan silang balik (BC) dengan IR64 sebagai tetua berulang dan Oryza rufipogon (No. aksesi IRGC 105491) sebagai tetua donor gen tahan penyakit blas. Penelitian ini bertujuan menganalisis keragaan tingkat ketahanan galur-galur haploid ganda (HG_I, HG_II, dan HG_III) dan galur-galur silang balik (BC2, BC3, dan BC5) terhadap penyakit blas di rumah kaca dan lapang, sehingga diperoleh kandidat galur harapan. Hasil pengujian beberapa populasi HG dan BC menunjukan bahwa terdapat variasi keragaan yang berbeda-beda. Variasi paling kecil terdapat pada populasi HG_III. Hasil yang sama juga diperoleh pada populasi silang balik (BC2-BC5). Variasi paling kecil terdapat pada populasi BC5. Bila dibandingkan antar populasi HG dan BC, tingkat variasi pada populasi HG_III lebih kecil dibandingkan dengan tingkat variasi pada populasi BC5. Hal ini menunjukkan bahwa tingkat homosigositas paling tinggi terdapat pada populasi HG_III. Berdasarkan evaluasi penampilan agronomis beberapa galur HG_III terpilih, diperoleh tiga galur kandidat galur harapan Bio1, Bio2, dan Bio8.]]>
