Potassium and Phosphorus

Sorghum [Sorghum bicolor (L.) Moench] lines can be classified as glossy (light yellow green and shiny leaves) and nonglossy (normal dark green leaves) based on seedling morphology. Glossy lines are land races endemic to regions with low soil fertility and hot dry climates. Four glossy and four nonglossy sorghum lines were grown in nutrient solutions with different levels of phosphorus to determine genotype differences in P uptake, distribution and use. Glossy lines had higher root, shoot, and plant dry matter yields, and lower P concentrations than nonglossy lines. Glossy and nonglossy lines did not differ in plant P contents. Although glossy and nonglossy lines absorbed similar amounts of P from solution, glossy lines used P more efficiently. Glossy lines might adapt better to low P conditions than nonglossy lines, and provide sorghum breeders with germplasm for improving P efficiency.