Genetic divergence in northern Benin sorghum (Sorghum bicolor L. Moench) landraces as revealed by agromorphological traits and selection of candidate genotypes.

Sorghum [Sorghum bicolor (L.) Moench] is an important staple food crop in northern Benin. In order to assess its diversity in Benin, 142 accessions of landraces collected from Northern Benin were grown in Central Benin and characterised using 10 qualitative and 14 quantitative agromorphological traits. High variability among both qualitative and quantitative traits was observed. Grain yield (0.72-10.57 tons/ha), panicle weight (15-215.95 g), days to 50% flowering (57-200 days), and plant height (153.27-636.5 cm) were among traits that exhibited broader variability. Correlations between quantitative traits were determined. Grain yield for instance exhibited highly positive association with panicle weight (r = 0.901, P = 0.000) and 100 seed weight (r = 0.247, P = 0.000). UPGMA cluster analysis classified the 142 accessions into 89 morphotypes. Based on multivariate analysis, twenty promising sorghum genotypes were selected. Among them, AT41, AT14, and AT29 showed early maturity (57 to 66 days to 50% flowering), high grain yields (4.85 to 7.85 tons/ha), and shorter plant height (153.27 to 180.37 cm). The results obtained will help enhancing sorghum production and diversity and developing new varieties that will be better adapted to the current soil and climate conditions in Benin.

Glycaemic index and glycaemic load of sorghum products.

BACKGROUND: Sorghum, a small-seeded grass, is an important food crop and chief energy source for the people of semi-arid regions of the world. In India, sorghum production/consumption decreased after the 'green revolution', but it is now regaining momentum owing to numerous health and nutritional benefits. An understanding of the glycaemic index (GI) and glycaemic load (GL) of staples can help in choosing suitable foods for the prevention and control of diabetes. In view of this, the present study was undertaken to evaluate the GI and GL of different sorghum foods and compare them with those of wheat/rice based foods. RESULTS: The GI of sorghum-based foods such as coarse semolina upma (P < 0.05), fine semolina upma (P < 0.01), flakes poha (P < 0.01) and pasta (P < 0.01) was significantly lower than that of their respective control (wheat/rice-based) foods. All sorghum-based foods showed significantly lower GL (P < 0.01) than their respective control (wheat/rice-based) foods. CONCLUSION: A few sorghum-based products have low GI (<55; coarse semolina upma, fine semolina upma, flakes poha and pasta) and all sorghum-based products (with the exception of sorghum roti) tested in the present study have lower GL than their respective wheat/rice-based foods. Consumption of low-GI and low-GL sorghum-based foods may help in decreasing postprandial blood glucose levels.

Natural occurrence of aflatoxin B1 in sorghum grown in different geographical regions of India.

BACKGROUND: Sorghum (Sorghum bicolor (L.) Moench) is an important coarse cereal crop grown for grain and fodder in the semi-arid Tropics, mainly in Asian and African countries. In India sorghum is consumed as human food and poultry feed. Sorghum grain grown in the rainy season (kharif) is becoming severely affected by grain moulds, the major fungi involved being Aspergillus, Fusarium and Curvularia. If the extent of mould is severe, the grain is unsafe for consumption owing to contamination by mycotoxins. RESULTS: This paper presents a multi-centre study conducted in sorghum to evaluate natural contamination of aflatoxin B(1) in India. A total of 1606 grain sorghum samples were collected during the rainy (kharif) season across 4 years from seven states of India, representing different geographical regions of the country. Aflatoxin B(1) contamination during 2007-08 was the highest (13.1%), followed by samples from the year 2004-05 (2.85%). The samples collected in years 2005-06 and 2006-07 showed contamination below 1%. The number of samples (35) showing aflatoxin B(1) contamination above the safety limit was also highest during 2007-08 as compared to samples from the other years. CONCLUSION: This study, conducted for 4 years, showed that natural contamination of aflatoxin B(1) in sorghum grown in India is within safety limits (20 µg kg(-1)) recommended by the Codex Alimentarius Committee and 73% of samples were positive for toxin. However, 0.75% (12) of total samples contained aflatoxin above the safety limit. The overall occurrence of toxin from Madhya Pradesh and Rajasthan was below 5 µg kg(-1).