Keragaman Plasma Nutfah Padi Gogo Lokal Sumba Barat Daya, Provinsi Nusa Tenggara Timur (The Diversity of Upland Rice Landracs in South-West Sumba, East Nusa Tenggara Timur Province) Evert Y. Hosang*, Yermias Bombo, dan Tony Basuki Balai Pengkajian Teknologi Pertanian Nusa Tenggara Timur, Jl. Timor Raya Km 32 Naibonat, Kupang, Nusa Tenggara Timur, Indonesia Telp. (0380) 833766; Faks. (0380) 833766, 829537 *E-mail: yulianeshosang@yahoo.co.id Diajukan: 15 Juli 2016; Direvisi: 23 September 2016; Diterima: 25 November 2016 ABSTRACT Some cultivars of upland rice landraces in Nusa Tenggara Timur (NTT) Province had been collected and evaluated by a researcher team of Research Institute for Food Crop Biotechnology (RIFCB) in 1997. The team has collected 97 cultivars from 19 districts in NTT. The collection activity of upland landrace-rices in NTT was continued by Assessment Institute for Agricultural Technology (AIAT) NTT in 2013–2015, which collected 61 cultivars from 11 districts in NTT. South-West Sumba is a district that has the highest cultivar number of the collected landrace-rices with 20 cultivars. The cultivars from South-West Sumba have been characterised and evaluated using Standard Evaluation System. The results indicated that there were a high variability in agronomic and phenotypic characteristics among the 20 cultivars of the South-West Sumba District upland landrace-rices. The most agronomic and phenologyc diversity of the landraces are the leaf length, leaf surface texture, flag leaf angle, stem leaf’s colour, palea’s colour, lemma’s colour, rice grain skin, the number of productive tiller, and productivity. Based on the similarity of agronomic and phenotypic characteristics, there were four groups of South-East Sumba upland rices landraces; there are a high similarity group (more than 85% similarity), a medium similarity group (75–85% similarity), and a low similarity group (less than 75% similarity). Keywords: upland rice, landrace, diversity. ABSTRAK Plasma nutfah padi gogo lokal Nusa Tenggara Timur (NTT) sudah pernah dikoleksi dan dievaluasi oleh tim peneliti Balai Penelitian Bioteknologi Tanaman Pangan, Bogor pada tahun 1997 yang berhasil mengoleksi 97 aksesi dari 19 kabupaten di NTT dan dilanjutkan dengan kegiatan koleksi dan karakterisasi oleh Balai Pengkajian Teknologi Pertanian (BPTP) NTT yang telah mengoleksi 61 aksesi tanaman padi gogo lokal NTT dari 11 kabupaten di NTT. Kabupaten Sumba Barat Daya adalah salah satu wilayah yang memiliki aksesi padi gogo yang terbanyak, yaitu sebanyak 20 aksesi dan telah dievaluasi berdasarkan Standard Evaluation System. Dari hasil karakterisasi ini disimpulkan bahwa terdapat variasi karakteristik agronomi dan fenotipe yang sangat besar antar aksesi padi gogo lokal tersebut. Karakter yang paling menunjukkan keragaman antar aksesi adalah bentuk panjang daun, permukaan daun, sudut daun bendera, warna pelepah daun, warna gabah, warna kulit ari, jumlah anakan produktif, dan produktivitas padi. Sementara berdasarkan kemiripan karakteristik yang dievaluasi, t padi lokal Sumba Barat Daya dikelompokkan menjadi tiga kelompok, yaitu kelompok kemiripan tinggi (tingkat similarity >85%), kelompok kemiripan sedang (tingkat similarity antara 75–85%), dan kelompok kemiripan rendah (tingkat similarity <75%). Kata kunci: padi gogo, plasma nutfah, keragaman. Hak Cipta © 2016, BB Biogen Bul. Plasma Nutfah 22(2):93–100