Keragaan Agronomi Kacang Bambara (Vigna subterranea L.) Generasi M2 Hasil Iradiasi Sinar Gamma

Abstract

Kacang bambara (Vigna subterranea L.) merupakan tanaman pangan yang potensial untuk dikembangkan di Indonesia karena kandungan gizi dan daya adaptasi pada berbagai kondisi lingkungan yang tinggi. Penelitian ini mengevaluasi keragaan karakter agronomi, keragaman genetik, dan heritabilitas kacang bambara generasi M2 hasil iradiasi sinar gamma. Percobaan dilaksanakan di Kebun Percobaan Cikarawang IPB, Dramaga, Bogor, dari November 2024 hingga Mei 2025, menggunakan benih M2 dengan enam dosis iradiasi (0, 25, 50, 75, 100, 125 Gy). Hasil penelitian menunjukkan bahwa iradiasi sinar gamma menurunkan daya tumbuh benih, namun berhasil menginduksi keragaman genetik, ditunjukkan dengan munculnya mutan albino dan chimera, serta fenotipe baru seperti tipe pertumbuhan spreading type, bentuk polong without point, dan warna biji light brownish red pada M2 yang tidak ditemukan pada M0. Rata-rata komponen pertumbuhan dan produksi pada M2 umumnya menurun atau relatif sama dengan M0, tetapi Koefisien Keragaman Genetik (KKG) populasi M2 lebih tinggi dibandingkan M0. Heritabilitas tinggi teridentifikasi pada panjang daun terminal (0,54), panjang petiole (0,79), waktu berbunga (0,58), bobot polong cipo (0,84), jumlah polong cipo (0,75), dan jumlah biji per polong (0,65), menunjukkan potensi seleksi langsung yang efektif. Seleksi 20% individu terbaik berdasarkan komponen produksi menghasilkan peningkatan rata-rata populasi karakter komponen produksi pada genotipe M2 setelah seleksi yang lebih tinggi dibandingkan rata-rata populasi genotipe M0.

Bambara groundnuts (Vigna subterranea L.) are a promising food crop for development in Indonesia due to their high nutritional content and adaptability to various environmental conditions. This research evaluates the agronomic character performance, genetic diversity, and heritability of M2 generation bambara groundnut resulting from gamma ray irradiation. The experiment was conducted at the Cikarawang IPB Experimental Garden, Dramaga, Bogor, from November 2024 to May 2025, using M2 generation seeds with six irradiation doses (0, 25, 50, 75, 100, 125 Gy). Results showed that in general, irradiation reduced seed germination, but induced genetic diversity, as evidenced by the emergence of albino and chimera mutants, as well as new phenotypes such as the spreading type growth, pod shape without point, and light brownish red seed color in M2 that were not present in M0. The average growth and production components in M2 generally decreased or remained relatively the same as in M0, but the Coefficient Genetic of Variations (CGV) of the M2 population was higher compared to the M0 population. High heritability was found in terminal leaf length (0.54), petiole length (0.79), flowering time (0.58), cipo pod weight (0.84), number of empty pods (0.75), and number of seeds per pod (0.65), indicating the potential for effective direct selection. Selection of the best 20% individuals based on production components showed an increase in the average population of production component characters in M2 genotypes after selection (M2 S1) that was higher than the average population of M0 genotype.