Morphophysiology and quality of yellow passion fruit seedlings submitted to inhibition of gibberellin biosynthesis

Abstract

The aim of this study was to verify if a growth reduction of yellow passion fruit seedlings’ growth morphophysiology and quality could be changed by paclobutrazol applied through seedling immersion. The experiment was conducted in a greenhouse, with seedlings grown in polyethylene tubes (290 cm3), with substrate. At 40 days after sowing, the seedlings were immersed in an aqueous solution of paclobutrazol at concentrations of 0, 50, 100, 150, and 200 mg L-1. The experiment was conducted in a randomized block design, with five treatments (paclobutrazol concentrations) and four replicates. At 15 and 30 days after treatment, growth characteristics were evaluated. At the end of the assay, destructive evaluations related to mass determination, total leaf area, and seedling quality index were performed. Paclobutrazol treatment induced restrictions in seedling growth, except for fresh and dry mass of root and total fresh mass. Based on these characteristics, the increase in values induced by paclobutrazol was verified. The seedling quality, defined by the major value of the Dickson quality index and a smaller robustness index, was higher when submitted to paclobutrazol treatment.

Paclobutrazol as a strategy to induce reproductive precocity in sour passion fruit

“…The growth restriction of the shoot is the result of a set of phenological changes such as the reduction of the rod length, number of leaves, total leaf area, among others, already discussed previously for Passiflora edulis (TEIXEIRA et al, 2021). The lower gibberellins synthesis by PBZ and, eventually, the stimulation of other hormones in the plant result in physical and metabolic changes at cellular level (RADEMACHER, 2016), it can reduce the cells elasticity coefficient, limiting cell elongation (MARSHALL and DUMBROFF, 1999).…”

“…For Mango culture the PBZ is a regulator widely used in the flowering management (CAVALCANTE et al, 2020;SILVA et al, 2022). Currently, one of our research lines is to study the growth regulators in the seedlings species spread of the genus Passiflora in order to improve the quality and to induce resistance mechanisms to the main biotic and abiotic stresses (TEIXEIRA et al, 2019;TEIXEIRA et al, 2021;TEIXEIRA et al, 2023).…”

“…The percentage of water content in the roots (PWCR) was calculated by the ratio between the difference between fresh mass and dry mass by the dry mass, multiplied by 100, with the percentage unit being discriminated (TEIXEIRA et al, 2021).…”

“…The use of growth regulators, especially inhibitors of gibberellin biosynthesis, is a consolidated technology in many agricultural crops to promote the balance between vegetative/reproductive development (AJMI et al, 2020;AZARCON et al, 2022;AZARCON et al, 2022;HELMEY et al al., 2021). The management of sour passion fruit seedlings with paclobutrazol results in increased vigor, with restriction of excessive vegetative growth, intensification of root growth and promotion of physiological and anatomical changes, such as increased biosynthesis of reserve carbohydrates and secondary compounds (TEIXEIRA, et al, 2019;TEIXEIRA, et al, 2021).…”