Relevance of tipburn incidence to the competence for Ca acquirement and Ca distributivity in lisianthus [Eustoma grandiflorum (Raf.) Shinn.] cultivars

Abstract

Tipburn is a severe problem that can occur during the propagation of several lisianthus [Eustoma grandiflorum (Raf.) Shinn.] cultivars. However, its incidence has not yet been established. Moreover, few studies have addressed the association between calcium (Ca) acquirement competence and the occurrence tipburn. The present study compared tipburn incidence and severity, plant growth rate, Ca acquirement competence (RGRCa), and Ca distributivity in 14 lisianthus cultivars. The influence of these traits on the occurrence of tipburn has also been discussed. To quantify Ca acquirement competence for each cultivar, plant growth and Ca content were analyzed together. It was determined that there were significant differences among lisianthus cultivars in terms of tipburn severity and incidence. However, these differences were not significantly correlated with either plant growth rate or Ca acquirement competence. In contrast, the parameters related to Ca distributivity to the upper leaf tips were significantly correlated with tipburn severity and incidence. Therefore, it became clear that the occurrence of tipburn in lisianthus cultivars is caused mainly by the inability of the plant to translocate adequate amounts of Ca to the tips of the upper leaves. Ca acquirement competence (RGRCa) were not significantly associated with tipburn severity and incidence in lisianthus cultivars. Nevertheless, growth analysis based on plant Ca content quantified Ca acquirement competence (RGRCa) and established the relevance of physiological (SARCa) and morphological traits (RMR and lCa−1) and RGRCa. This analytical method is a new approach towards understanding the nutrient economy of a plant at risk of deficiency.