Morpho-anatomical study of tomato seedlings (Solanum lycopersicum L.) under saline irrigation water

Abstract

Irrigation with high salt concentrations limits crop productivity. The objective of this study was to evaluate the effect of saline water irrigation on the growth and development of tomato seedlings, as well as histological changes. The trial was conducted in a metal greenhouse with 100 μm LD polyethylene cover at the FCA-UNLZ using expanded polystyrene trays. Treatments consisted of two saline solution levels (NaCl: EC 3 dS/m at 25 ºC and NaCl: EC 6 dS/m at 25 ºC) and a control using tap water (EC 0.8 dS/m at 25 ºC). Germination percentage, fresh weight, collar diameter, shoot height, root length, seedling length, and leaf area were evaluated when the control treatment reached the three-true-leaf stage. Anatomical studies of the leaf, stem, and root were also performed. The increase in irrigation water EC adversely affected seedling growth and development, observing that: the germination percentage decreased by 50% compared to the control; and total height, root length, shoot height, stem diameter, leaf area, stem and root dry weight, and total plant dry weight were significantly reduced. Anatomical studies reflected a more compact structure in the leaf mesophyll, as well as reduced development of vascular bundles in the stem and root.