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 T69and MCSR T11 were moderately tolerant, while the rest were susceptible