Influence of nutrient deficiency on hair formation in the Rivulariaceae

Abstract

Thirteen out of 36 strains of Rivulariaceae were found to be able to produce hairs. In all 13 strains, abundant hair increase occurred under conditions of phosphate deficiency. Fe deficiency also led to hair formation in 8 strains, and Mg deficiency in one strain, but Ca, Mo and SO₄ deficiences had no such effect. Although the presence of combined nitrogen had a marked effect on the trichome morphology of the heterocystous strains, it reduced hair formation in only three strains, and the effect was only slight. Addition of the missing element to deficient cultures with hairs always eventually led to the loss of the hair. Two field materials were also studied, in crude culture. Both showed increased hair development with decreasing phosphate concentration.