Applicability of the term anthochron for representing the speed rate of flower opening on the inflorescence

Abstract

The objective of this work was to propose a term for representing the time interval between the opening of successive flowers on inflorescences and to verify the applicability of this term to gladiola. The term was built by joining the Greek combining forms antho‑ (anthos = flower) and chron‑ (chronos = time), to correspond to the time needed for successive flowers to open on floral stems (inflorescences), having time per flower as unit. In order to test the concept and applicability of the term, data on the accumulated number of opened florets on gladiola spikes were collected from two field experiments, in Santa Maria, in the state of Rio Grande do Sul, Brazil, from August 2011 to November 2013. For each plot with six plants, a simple linear regression was performed between the accumulated number of opened florets on the stem and the days after plant emergence. The term was called “anthochron”, and in gladiola, it was estimated as the inverse of slope of the linear regression, with the unit days per floret. Anthochron in gladiola depends on the cultivar and decreases with the increase of air temperature during the spike flowering period.