Diversity of Sorghum (Sorghum bicolor L. Moench) Germplasm from Tanzania

Sorghum (Sorghum bicolor L. Moench) is an important cereal crop cultivated in varied agro-ecological zones of Tanzania ranging from the southern highlands to coastal lowlands. Different cultivars and varieties of sorghum are needed for cultivation in such varied zones. Phenotypic properties of Tanzanian sorghums are not well-studied. Objective of this study was to phenotype some sorghum germplasm from Tanzania using morphological markers to establish their diversity for future use in breeding programs. Ninety-eight sorghum genotypes were evaluated at Bumala and Amagoro in Western Kenya during 2009 and 2010 seasons in a randomized complete block design. The International Plant Genetic Resource Centre descriptors of 1993 were used for data collection. Accession MCSR T29 was the earliest which took only 64 days while MCSR T80 was the latest taking 86 days to attain 50% flowering compared to the overall mean of 71 days. The MCSR T71 was the best yielder (114.6 g/ panicle) and MCSR T10 was the lowest (10.3 g/panicle) compared to overall mean of 92.4g/panicle. About 60% of the sorghums had brown and only 2.2% had black grains. MCSR T90 had bold grains with 1000 seed weight of 55.2g. Leaves per plant ranged from 7 in MCSR T69 to 17 in MCSR T25. Plant height ranged from 72.8 cm in MCSR T53 to 434.6 cm in MCSR T80. This study showed that, Tanzanian sorghums are diverse therefore could be used in future breeding programs for developing multipurpose and adapted cultivars. Keywords: Cultivars, Diversity, Phenotype, Varieties, SorghumSorghum (Sorghum bicolor L. Moench) is an important cereal crop cultivated in varied agro-ecological zones of Tanzania ranging from the southern highlands to coastal lowlands. Different cultivars and varieties of sorghum are needed for cultivation in such varied zones. Phenotypic properties of Tanzanian sorghums are not well-studied. Objective of this study was to phenotype some sorghum germplasm from Tanzania using morphological markers to establish their diversity for future use in breeding programs. Ninety-eight sorghum genotypes were evaluated at Bumala and Amagoro in Western Kenya during 2009 and 2010 seasons in a randomized complete block design. The International Plant Genetic Resource Centre descriptors of 1993 were used for data collection. Accession MCSR T29 was the earliest which took only 64 days while MCSR T80 was the latest taking 86 days to attain 50% flowering compared to the overall mean of 71 days. The MCSR T71 was the best yielder (114.6 g/ panicle) and MCSR T10 was the lowest (10.3 g/panicle) compared to overall mean of 92.4g/panicle. About 60% of the sorghums had brown and only 2.2% had black grains. MCSR T90 had bold grains with 1000 seed weight of 55.2g. Leaves per plant ranged from 7 in MCSR T69 to 17 in MCSR T25. Plant height ranged from 72.8 cm in MCSR T53 to 434.6 cm in MCSR T80. This study showed that, Tanzanian sorghums are diverse therefore could be used in future breeding programs for developing multipurpose and adapted cultivars. Keywords: Cultivars, Diversity, Phenotype, Varieties, Sorghu

Tolerance to aluminium toxicity in Tanzanian sorghum genotypes

Aluminium (Al) toxicity is a major abiotic constraint on grain sorghum (Sorghum bicolor L. Moench) production on acid soils in East Africa. Aluminium in acidic soil inhibits water and mineral uptake from and consequently, reduces plant vigour and yield. A study was done to determine genetic diversity of Tanzania's sorghum for response to Al toxicity. Five day old seedlings of 98 sorghum genotypes were subjected to 0, 148 or 222.25 moles of Al3+ supplied as Al2 (SO4)3.16H2O in Hoagland's nutrient solution. Seedlings were raised in a growth chamber for five days, after which root lengths were recorded. Net root growth was used to discriminate the germplasm into phenotypic groups. The genotype MCSR T33 exhibited highest net root length and was classified as tolerant. Wahi, MCSR T69 and MCSR T11 were moderately tolerant, while the rest were susceptible.La toxicit\ue9 aluminique est une contrainte majeur \ue0 la production du sorhgo (Sorghum bicolor L. Moench) sur les sols acides en Afrique de l'est. L'aluminium (Al) des sols acides inhibe l'assimilation d'eau et de min\ue9raux du sol, et r\ue9duit par cons\ue9quent la vigueur des plantes et le rendement.Une \ue9tude \ue9tait faite pour d\ue9terminer la diversit\ue9 g\ue9n\ue9tique du sorgho de la Tanzanie en r\ue9ponse \ue0 la toxicit\ue9 aluminique. Les plants ag\ue9s de 5 jours issus de 98 g\ue9notypes de sorgho \ue9taient soumis \ue0 0, 148 ou 222.25 moles de Al3+ fournis sous forme de Al2 (SO4)3.16H2O dans une solution de nutriment de Hoagland. Les plantules \ue9taient plant\ue9es dans la chambre de croissance pendant 5 jours apr\ue8s lesquels la longueur des racines \ue9tait mesur\ue9e. La croissance nette des racines \ue9tait utilis\ue9e pour s\ue9parer les racines en groupes ph\ue9notypiques. Le g\ue9notype MCSR T33 avait exhib\ue9 une longueur nette plus \ue9lev\ue9e des racines et \ue9tait classifi\ue9 comme tol\ue9rant. Wahi, MCSR T69 et MCSR T11 \ue9taient mod\ue9r\ue9ment tol\ue9rant, alors que les restes \ue9taient susceptibles

Tolerance to aluminium toxicity in Tanzanian sorghum genotypes

Aluminium (Al) toxicity is a major abiotic constraint on grain sorghum (Sorghum bicolor L. Moench) production on acid soils in East Africa. Aluminium in acidic soil inhibits water and mineral uptake from and consequently, reduces plant vigour and yield. A study was done to determine genetic diversity of Tanzania's sorghum for response to Al toxicity. Five day old seedlings of 98 sorghum genotypes were subjected to 0, 148 or 222.25 moles of Al3+ supplied as Al2 (SO4)3.16H2O in Hoagland's nutrient solution. Seedlings were raised in a growth chamber for five days, after which root lengths were recorded. Net root growth was used to discriminate the germplasm into phenotypic groups. The genotype MCSR T33 exhibited highest net root length and was classified as tolerant. Wahi, MCSR T69 and MCSR T11 were moderately tolerant, while the rest were susceptible.La toxicité aluminique est une contrainte majeur à la production du sorhgo (Sorghum bicolor L. Moench) sur les sols acides en Afrique de l'est. L'aluminium (Al) des sols acides inhibe l'assimilation d'eau et de minéraux du sol, et réduit par conséquent la vigueur des plantes et le rendement.Une étude était faite pour déterminer la diversité génétique du sorgho de la Tanzanie en réponse à la toxicité aluminique. Les plants agés de 5 jours issus de 98 génotypes de sorgho étaient soumis à 0, 148 ou 222.25 moles de Al3+ fournis sous forme de Al2 (SO4)3.16H2O dans une solution de nutriment de Hoagland. Les plantules étaient plantées dans la chambre de croissance pendant 5 jours après lesquels la longueur des racines était mesurée. La croissance nette des racines était utilisée pour séparer les racines en groupes phénotypiques. Le génotype MCSR T33 avait exhibé une longueur nette plus élevée des racines et était classifié comme tolérant. Wahi, MCSR T69 et MCSR T11 étaient modérément tolérant, alors que les restes étaient susceptibles