Genetic parameter and yield potential of cassava clones on different soil fertility

إنجليزي. The aim of this research was to identify the genetic variability of several quantitative characters of cassava clones. The research was conducted in Muneng Experimental Station, Probolinggo, during rainy and dry seasons of 1998/1999, using a split plot design with two replications. The main plot was fertilizer (P), i.e. fertilizer applied were 200 kg urea + 100 kg SP36 + 100 kg KCl/ha (p1), and without fertilizer (P2), and as sub plot was 198 cassava clones. Each clone was planted in single row of 4 m length, distance between row was 1 m and within row was 0.8 m. Observation were number, length, diameter, and tuber weight per plant. The results showed that the number, length, diameter and tuber weight per plant were varied. Number and length of tuber had low genetic variability coefficient and heritability, so it was difficult to use as source of cassava clone yield potential improvement. Yield potential improvement using diameter and weight of tuber was very prospective. Those characters had moderate heritability and high genetic variability coefficient, it indicated the work of additive gene

مجهول. Penelitian bertujuan untuk menilai variasi genetik karakter-karakter kuantitatif pada klon-klon ubikayu. Percobaan dilaksanakan di Instalasi Penelitian Kacang-kacangan dan Umbi-umbian (Inlitkabi) Muneng, Probolinggo pada musim tanam 1998/1999, menggunakan rancangan petak terbagi, diulang dua kali. Petak utama adalah perlakuan pemupukan (P), yaitu dipupuk dengan 200 kg urea + 100 kg SP36 + 100 kg KCl/ha (P1), dan tidak dipupuk (P2). Anak petak adalah 198 klon ubikayu. Setiap klon ditanam dalam baris tunggal sepanjang 4 m, dengan jarak tanam 1 m x 0,8 m. Variabel yang diamati adalah jumlah, panjang, diameter, dan bobot umbi per tanaman. Hasil penelitian menunjukkan bahwa jumlah, panjang, diameter dan bobot umbi per tanaman beragam. Jumlah umbi dan panjang umbi memiliki koefisien keragaman genetik (KKG) rendah dan heritabilitas rendah, sulit untuk digunakan sebagai sumber perbaikan potensi hasil. Perbaikan potensi hasil dengan menggunakan populasi bahan genetik yang ada sangat prospektif melalui perbaikan diameter umbi dan bobot umbi. Kedua karakter tersebut memiliki heritabilitas (h pangkat dua) sedang dan KKG tinggi sebagai indikasi kerja gen aditif