Pendugaan Komponen Ragam dan Aksi Gen Karakter Agronomi Populasi F1 Kapas

Abstract

Penelitian ini bertujuan untuk (1) mengetahui keragaman genetik F1 kapas (Gossypium hirsutum),  (2) menduga karakter seleksi langsung dan tidak langsung, dan (3)  memperoleh informasi mengenai aksi gen yang mengendalikan karakter agronomi F1 kapas. Penelitian ini dilaksanakan di KP Sumberejo mulai Januari-Desember 2021. Bahan yang digunakan yaitu 38 generasi F1 dan Varietas Kanesia 10 (varietas pembanding). Sebanyak 38 hibrida F1 dan varietas pembanding disusun dalam RAK dan diulang sebanyak dua kali. Ukuran plot 5 x 6 m (30 m2), jarak tanam 100 cm x 30 cm dan menggunakan sistem tugal. Masing-masing lubang tanam terdapat satu tanaman (total luas netto 2340 m2). Karakter yag diamati dan diukur yaitu tinggi tanaman (cm), jumlah cabang per tanaman,  jumlah buah per tanaman (buah), bobot 100 buah (g), dan populasi tanaman per plot (tanaman), produksi tanaman/ha (kg), dan skor kerusakan daun akibat serangan Amrasca biguttula. Hasil penelitian menunjukkan semua karakter sangat berbeda sangat nyata pada taraf α 1% kecuali pada karakter tinggi tanaman.  Karakter jumlah cabang vegetatif, bobot 100 buah dan produksi/ha menunjukkan nilai heritabilitas yang tinggi dan KKG yang luas yaitu 60.32 dan 24.28, 94.15 dan 15.23 serta 89.26 dan 22.63. Karakter bobot 100 buah dan produksi/ha dikendalikan oleh banyak gen. Karakter bobot 100 buah diduga dapat digunakan sebagai karakter seleksi tidak langsung. Sedangkan, karakter produksi/ha diduga dapat digunakan sebagai karakter seleksi langsung populasi F1 kapas yang berproduksi dan mutu serat tinggi. This study aims to (1) determine the genetic diversity of F1 cotton (Gossypium hirsutum), (2) estimate the direct and indirect selection characters, and (3) obtain information on the action of genes controlling F1 cotton agronomic characters. This research was conducted at KP Sumberejo from January to December 2021. The materials used were 38 F1 generations and Kanesia 10 (comparison variety). A total of 38 F1 hybrids and comparison varieties were arranged in RAK and repeated twice. The plot size was 5 x 6 m (30 m2), the spacing was 100 cm x 30 cm and the tugal system was used. Each planting hole contained one plant (total net area of 2340 m2). The characters observed and measured were plant height (cm), number of branches per plant, number of fruits per plant (fruit), 100 fruit weight (g), and plant population per plot (plant), plant production/ha (kg), and leaf damage score due to Amrasca biguttula attack. The results showed that all characters were significantly different at 1% α level except for the character of plant height.  The characters of the number of vegetative branches, weight of 100 fruits and production/ha showed high heritability values and a wide GFC of 60.32 and 24.28, 94.15 and 15.23 and 89.26 and 22.63. The characters of 100 fruit weight and production/ha are controlled by many genes. The 100 fruit weight character is thought to be used as an indirect selection character. Meanwhile, the character of production/ha is thought to be used as a direct selection character.