Breeding grain sorghum pure lines through agronomic selection and feed quality evaluation

Abstract Background: The livestock industry in Malaysia relies heavily on feed imports, necessitating the development and exploration of a potential crop to produce sustainable germplasm, enabling growers to cultivate locally adapted animal feed. Sorghum ( Sorghum bicolor ) is a drought tolerant C4 crop cultivated in warm climates worldwide, representing a resilient feed option. The current study is the culmination of a breeding program aimed at developing high-yielding, feed-quality grain sorghum pure lines adapted to Malaysian conditions by combining field evaluation and biochemical analysis as selection criteria. Methods: To achieve this objective, the current research sourced germplasm from the Agrogene bank, Universiti Putra Malaysia. Ten out of fourteen pure lines had already undergone three selection cycles (V1–V10), while three pure lines were in their second selection (V11–V13), and one advanced forage sorghum pure line (Putra SB2) was used as a control. The experiment followed a randomized complete block design with three replicates at Field 10, Universiti Putra Malaysia. The experiment involved a two-stage selection process. Six F5 pure lines were selected from high-performing populations based on field study, while the final selection was made through biochemical analysis of feed quality. Results: The field experiment suggests that V9 (5-3-6-6) and V13 (Upms-1) were the highest yielding populations, producing grain yields of 2690.13 and 2567.7 kg/ha, respectively. V10 was also the earliest to mature at 95 days, while V9 matured at 97 days after sowing. Based on agronomic and genetic variability parameters, the other best-performing lines were V5 (1-3-1-8), V6 (1-3-1-25), and V7 (1-3-1-29); therefore, their F5 progenies were selected for further biochemical analysis. Biochemical analysis for feed quality revealed that the progenies of V9, V10, and V7 had type I tannin content, making them suitable for animal feed. G5 (5-3-6-9-8) had the least tannin content (4.362 mg CE/g), followed by G4 (5-3-6-6-3) with 4.489 mg CE/g and G3 (1-3-1-29-18) with 5.4 mg CE/g. Conclusion: The experiment concludes by identifying three superior grain sorghum pure lines, G3, G4, and G5, that prove to be promising options for animal feed under Malaysian conditions, provided further evaluation is conducted at multiple locations to achieve yield stability.