Effects of amino acids on the development of spikelets in cultured tassels of Zea mays

Abstract

The effects of amino acids on spikelet development in in vitro cultured tassels of Zea mays inbred line Oh43 were studied. Single amino acids had differential effects on growth and differentiation of cultured tassels. While a few amino acids (arginine, lysine, valine, and proline) were stimulatory, most of the amino acids were either ineffective (serine, leucine, glycine, threonine, methionine, phenylalanine, histidine, aspartic acid, and tyrosine) or inhibitory (isoleucine, asparagine, tryptophan, glutamic acid, and alanine), at a concentration of 30 mg/L, to the development of "normal" spikelets and also to tassel growth. A mixture of the stimulatory amino acids at their optimal concentrations (arginine, 15 mg/L; lysine, 60 mg/L; valine, 120 mg/L; proline, 15 mg/L) produced the maximum number of "normal" spikelets, thereby duplicating the effect of an optimum concentration of casein hydrolysate.