Abstract

Plant scientists usually record many indicators in their experiments. The common statistical management involves univariate analyses. Such analyses generally create a split picture of the effects of experimental treatments since each indicator is addressed independently. The Euclidean distance combined with the expert's criteria seems to show potential as an integrating indicator. The Euclidean distance has been widely used in many scientific fields nevertheless, as far as we know, it has not been frequently employed in plant science experiments. To exemplify the use of the Euclidean distance in this field, we performed an experiment focused on the effects of gibberellic acid on protease excretion during pineapple micropropagation in temporary immersion bioreactors. Five gibberellic acid concentrations were compared: 0.0, 1.4, 2.8, 4.2 and 5.6 mu M. Four dependent variables were recorded: increase in fresh shoot mass, protein concentration, proteolytic activity and specific activity in the culture media. The statistical protocol carried out integrated these four dependent variables to easily identify the best gibberellic acid treatment. Based on expert's criteria the integral analysis provided by the Euclidean distance indicated that 4.2 mu M gibberellic acid is the best treatment to produce proteases in the experimental conditions described here. This treatment showed the shortest (statistically significant) Euclidean distance to expert's criteria (0.61).