Effects of Autoploidy on Grain Sorghum

Abstract

Early generation autotetraploid grain sorghum varieties were studied with special reference to the response of agronomically important characters to artificial autoploidy. Autoploidy substantially reduced fertility, head length, panicle branch number and length, stand and head number. Increased grain size failed to compensate for reductions in other yield components. Protein content increased by 20 per cent on average. but steady decreases occurred with increasing yield~. Differential genotypic responses to autoploidy suggested the need for cautious selection of material for inclusion in tetraploid breeding programmes. Feeding experiments and detailed biochemical studies of the grain are required to determine whether or not tetraploid sorghum is qualitatively superior to normal diploid sorghum.