Electronic Theses and Dissertation

Tinggong merupakan salah satu varietas padi lokal yang berasal dari wilayah Barat–Selatan Aceh. Varietas ini memiliki beberapa keunggulan, antara lain menghasilkan nasi dengan tekstur pulen serta memiliki toleransi yang baik terhadap cekaman abiotik, terutama kondisi kekeringan. Meskipun demikian, Tinggong masih memiliki beberapa kelemahan, seperti tinggi tanaman yang relatif tinggi, umur panen yang panjang, dan tingkat kerentanan yang tinggi terhadap penyakit hawar daun bakteri. Oleh karena itu, upaya perbaikan genetik dilakukan melalui persilangan dengan varietas introduksi IRBB27 untuk memperoleh galur yang memiliki karakter agronomi dan ketahanan yang lebih baik. Penelitian ini bertujuan untuk mengevaluasi karakter agronomi, potensi hasil, dan variabilitas genetik galur BC4F6 hasil perbaikan padi lokal Aceh Tinggong melalui persilangan dengan IRBB27. Penelitian ini dilaksanakan di Kebun Percobaan (lokasi 5°34'01LU – 95°22'24BT) dengan ketinggian 4,62 mdpl, Laboratorium Genetika dan Pemuliaan Tanaman, Laboratorium Ilmu dan Teknologi Benih, Departemen Agroteknologi Fakultas Pertanian Universitas Syiah Kuala, Darussalam Banda Aceh, berlangsung dari bulan bulan Juli – Desember 2025. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) nonfaktorial dengan 13 perlakuan dan 3 ulangan yaitu T35.12.8.2.1 (G1M1, G1M2, G1M3), T35.7.3.1.2 (G2M1, G2M2, G2M3), T36.10.3.19.1 (G3M1, G3M2, G3M3). Perlakuan terdiri atas 12 galur BC4F6 hasil persilangan Tinggong/IRBB27 dan satu tetua Tinggong (G5) sebagai pembanding. Parameter yang diamati meliputi tinggi tanaman, jumlah anakan, umur berbunga, umur panen, panjang malai, jumlah biji berisi per malai, bobot gabah berisi per rumpun, persentase gabah berisi, bobot total gabah per rumpun, bobot 1000 biji, kadar klorofil, estimasi potensi hasil, serta variabilitas genetik. Hasil penelitian menunjukkan bahwa galur BC4F6 berpengaruh sangat nyata terhadap sebagian besar karakter agronomi dan komponen hasil yang diamati. Tinggi tanaman saat panen berkisar antara 105,44–136,37 cm, lebih rendah dibandingkan tetua Tinggong yang mencapai 151,32 cm. Umur berbunga dan umur panen galur BC4F6 lebih genjah, yaitu 113–116 HSS, dibandingkan Tinggong yang berbunga pada umur 133 HSS dan panen pada umur 164 HSS. Produktivitas galur padi turunan Tinggong dengan IRBB27 lebih tinggi dijumpai pada galur T36.10.3.19.1(G3M3). Nilai heritabiitas parameter tinggi tanaman, umur panen, dan potensi hasil yaitu 0,94, 0,98, dan 0,87 menandakan efektivitasdalam proses seleksi galur turunan Tinggong/IRBB27.

Tinggong is a local rice variety originating from the West-South region of Aceh. This variety possesses several advantages, including producing rice with a soft, sticky texture and exhibiting good tolerance to abiotic stress, particularly drought conditions. However, Tinggong also has certain drawbacks, such as relatively tall plants, a long growth duration, and high susceptibility to bacterial leaf blight. Consequently, genetic improvement efforts were undertaken through crossing with the introduced variety IRBB27 to obtain lines with superior agronomic traits and resistance. This study aimed to evaluate the agronomic characteristics, yield potential, and genetic variability of BC4F6 lines derived from the improvement of the local Aceh rice variety Tinggong via crossing with IRBB27. The research was conducted at the Experimental Farm (coordinates 5°34'01" N – 95°22'24" E; elevation 4.62 m above sea level) and at the Genetics and Plant Breeding Laboratory and the Seed Science and Technology Laboratory—part of the Department of Agrotechnology, Faculty of Agriculture, Syiah Kuala University, Darussalam, Banda Aceh—from July to December 2025. A non-factorial Randomized Block Design (RBD) was employed, featuring 13 treatments and 3 replications: T35.12.8.2.1 (G1M1, G1M2, G1M3), T35.7.3.1.2 (G2M1, G2M2, G2M3), and T36.10.3.19.1 (G3M1, G3M2, G3M3). The treatments consisted of 12 BC4F6 lines resulting from the Tinggong/IRBB27 cross and the Tinggong parent (G5) as a control. The parameters observed included plant height, number of tillers, days to flowering, days to harvest, panicle length, number of filled grains per panicle, weight of filled grains per hill, percentage of filled grains, total grain weight per hill, 1000-grain weight, chlorophyll content, estimated yield potential, and genetic variability. The results showed that the BC4F6 lines exhibited highly significant effects on most of the observed agronomic traits and yield components. Plant height at harvest ranged from 105.44 to 136.37 cm, which was lower than that of the Tinggong parent (151.32 cm). The BC4F6 lines showed earlier maturity—flowering and harvesting at 113–116 days after sowing (DAS)—compared to the Tinggong parent, which flowered at 133 DAS and was harvested at 164 DAS. Among the rice lines derived from the Tinggong and IRBB27 cross, the T36.10.3.19.1(G3M3) line demonstrated the highest productivity. Heritability values ​​of 0.94, 0.98, and 0.87 for plant height, days to harvest, and yield potential, respectively, indicate the effectiveness of the selection process for the Tinggong/IRBB27 derived lines.