Germination Attributes and Vegetative Growth Responses of TrueSeed-Derived Shallot under Salinity Stress

Abstract

Optimising non-productive land through the use of saline soils presents a significant challenge because elevated salt concentrations can inhibit shallot growth and development. This study aimed to determine the effects of NaCl concentration on seed viability and plant growth and to identify the salinity tolerance of TSS-derived shallot. The research was conducted in the greenhouse of the Agronomy Laboratory, Faculty of Agriculture, University of Bengkulu. The experiment comprised two stages: a germination test using Petri dishes containing NaCl solutions and a vegetative growth test. A completely randomised design was used with six NaCl concentrations: 0, 500, 1000, 1500, 2000, and 2500 ppm. The observed parameters included days to germination, seed vigour percentage, plumule length, radicle length, plant height, number of leaves, root length, number of roots, fresh weight, dry weight, leaf greenness, and plant mortality. Data were analysed using analysis of variance, followed by the least significant difference test at the 5% significance level. Increasing NaCl concentration significantly reduced seed vigour, plumule length, plant height, number of leaves, root length, number of roots, fresh weight, and dry weight, but did not significantly affect days to germination or radicle length. Plant mortality increased from 6.67% at 0 ppm to 48.00% at 2500 ppm; therefore, the LD₅₀ was not reached within the tested range. Overall, TSS-derived shallot remained viable under all treatments, although growth was progressively inhibited as salinity increased, particularly at concentrations above 1500 ppm.