Assessment of Kodo Millet (Paspalum scrobiculatum) Genotypes for Salt Stress Tolerance at the Seedling Stage Using Germination Tray

Abstract

An experiment was conducted in a poly house setup using germination trays to investigate the effects of salt stress on the seedling growth and germination of 42 genotypes of Kodo Millet (Paspalum scrobiculatum). This research, utilizing a Completely Randomized Design with three replications, was conducted at the Research Farm of RVSKVV in Gwalior. To ensure uniformity and manage variability, a consistent mixture containing equal parts of compost, vermiculite, and cocopeat in a 1:1:1 ratio was used. Salt stress levels were applied using NaCl solutions of concentrations 50 mM, 100 mM, 250 mM, and 500 mM. Increased emergence time and a lower final germination percentage were recorded at a 50 mM salt concentration compared to the control (0 mM). However, at higher concentrations, the effects were more severe, resulting in complete lethality with no recorded germination. At a 50 mM concentration, compared to the control, there was a decrease in shoot length, root length, seedling length, shoot fresh weight, root fresh weight, total fresh weight, total dry weight, vigour index, chlorophyll a, chlorophyll b and total chlorophyll concentration. Concurrently, an increase in proline concentration in the leaves was noted. The salt tolerance index and chlorophyll index was calculated to categorize genotypes based on their relative tolerance to salt-induced stress.