Keragaman Karakter Kuantitatif dan Seleksi Segregan Transgresif Generasi F4 Sorgum Hasil Persilangan Bioguma 1 Agritan x Samurai 2

Abstract

Sorghum (Sorghum bicolor L. Moench) merupakan komoditas pangan potensial di Indonesia yang dapat dikembangkan melalui program pemuliaan tanaman. Penelitian ini bertujuan mengevaluasi keragaman genetik karakter kuantitatif, mengidentifikasi segregan transgresif, dan memperoleh diferensial seleksi pada populasi F4 hasil persilangan Bioguma 1 Agritan x Samurai 2. Penelitian dilaksanakan di Kebun Percobaan Leuwikopo IPB, Dramaga, Bogor pada November 2025 – April 2026 menggunakan 270 genotipe F4 serta tetua Bioguma dan Samurai 2 sebagai pembanding, dengan rancangan Single Seed Descent. Hasil penelitian menunjukkan populasi F4 memiliki keragaman fenotipe yang luas. Sebagian besar karakter dikendalikan oleh aksi gen epistasis dengan sebaran leptokurtik, kecuali diameter malai yang dikendalikan oleh aksi gen aditif. Sebagian besar karakter memiliki nilai heritabilitas arti luas kategori tinggi (>50%), menunjukkan keragaman fenotipe lebih dipengaruhi faktor genetik dibandingkan lingkungan. Bobot kering malai (r = 0,99) dan diameter malai (r = 0,76) berkorelasi sangat kuat dengan bobot biji per malai. Terdapat 13 genotipe yang teridentifikasi sebagai segregan transgresif dengan bobot biji per malai berkisar 82,2–154,5 g, melampaui kedua tetua. Perbandingan metode seleksi menunjukkan seleksi langsung paling efektif meningkatkan bobot biji per malai (76,24%), sedangkan seleksi Independent Culling Level (ICL) paling efektif menghasilkan genotipe unggul secara komprehensif. Genotipe-genotipe transgresif terpilih berpotensi dikembangkan lebih lanjut sebagai kandidat galur harapan sorgum berdaya hasil tinggi.

Sorghum (Sorghum bicolor L. Moench) is a potential food commodity in Indonesia that can be developed through plant breeding programs. This study aimed to evaluate the genetic diversity of quantitative characters, identify transgressive segregants, and obtain selection differentials in the F4 population derived from Bioguma 1 Agritan x Samurai 2 crosses. The research was conducted at the Leuwikopo Experimental Farm, IPB University, Dramaga, Bogor from November 2025 to April 2026 using 270 F4 genotypes and both parents as controls, with a Single Seed Descent design. Results showed that the F4 population exhibited broad phenotypic variation. Most characters were controlled by epistatic gene action with leptokurtic distribution, except panicle diameter which was governed by additive gene action. The majority of characters had broad-sense heritability values in the high category (>50%), indicating phenotypic variation was more influenced by genetic than environmental factors. Dry panicle weight (r = 0.99) and panicle diameter (r = 0.76) showed very strong correlations with grain weight per panicle. Thirteen genotypes were identified as transgressive segregants with grain weight per panicle ranging from 82.2 to 154.5 g, exceeding both parents. Direct selection was most effective in increasing grain weight per panicle (76.24%), while Independent Culling Level (ICL) was most effective for comprehensively identifying superior genotypes. The selected transgressive genotypes are promising candidates for further development as high-yielding sorghum lines.