NUTRITIONAL EVALUATION OF MUTANTS AND SOMACLONAL VARIANTS OF SORGHUM (SORGHUM BICOLOR (L) MOENCH) IN KENYA

Abstract

Several improved sorghum varieties are adapted to semi-arid and tropic environments. Selection of varieties meeting specific local food and industrial requirements from this great biodiversity is important for food security in Kenya and other developing countries. More than 7000 sorghum varieties have been identified hence, need for further characterization with respect to nutritional traits. Sorghum bicolor (L) Moench mutants and somaclone lines (Seredo, Serena, Mtama 1 and El-gardam) were developed towards improvement for drought tolerance at the Jomo Kenyatta University of Agriculture and Technology. Using mutation techniques. X-ray with the dose of 15000R was used to induce genetic variation. Somaclones were produced through somatic embryogenesis on Linsmaier and Skoog’s (LS) media with 0.5 M concentration of Mannitol as an osmoticum to simulate drought conditions. The study was conducted to evaluate the chemical composition, B-vitamins, mineral profile, anti-nutrient content and levels of protein digestibility of somaclones, mutants and parents of the Sorghum bicolor  (L) Moench local cultivar in Kenya (namely Mtama 1, Seredo, El Gardam and Serena). The proximate composition, B-vitamins, anti-nutrient contents and levels of protein digestibility of the flour from the cultivars were determined. The chemical components did not vary among and within varieties (P ≥ 0.05). Serena and Seredo showed high levels of Anti-nutreint (phytates and Tannins) than Mtama 1 and El-dargam (tannin: 0.03-2.22%, Phytates: 124.3-374 mg/100  g) (P  ≥ 0.05). The somaclones and mutants of the sorghum cultivars except Mtama 1 were noted to have reduced quantities of tannin. Protein digestibility range,  between 39.1%-88.4% and were low in Seredo and  Serena  than in Mtama 1 and El-gardam. No differences (P ≥ 0.05) were observed among and within the treatments of the same varieties of the sorghum for  proximate composition, B-vitamins  and mineral compositions  (p <  0.05). It was concluded that  major variations among the varieties arose due to anti-nutrients. High anti-nutrient factors would affect the utilization of the Serena and Seredo varieties since these anti-nutrients reduced  the availability other nutrients.