Relationships between cold‐ and salt‐tolerance during seed germination in tomato: Germplasm evaluation

Abstract Thirty tomato accessions representing six Lycopersicon species were evaluated for the rate of seed germination under no stress, cold‐stress and salt‐stress conditions. Most accessions responded similarly to both cold‐ and salt‐stress conditions (i.e. they were equally sensitive or tolerant to both stresses), however, a few accessions exhibited more sensitivity (or tolerance) to one stress than the other. In addition, some accessions that germinated relatively rapidly under non‐stress conditions exhibited great sensitivity to both cold stress and salt stress. Across accessions, significant (P < 0.01) positive phenotypic correlations were observed between germination rate under control and cold stress (r P = 0.89), control and salt stress (r P = 0.63) and cold stress and salt stress (r P = 0.77). The results indicate that the rate of tomato seed germination under non‐stress, cold‐ and salt‐stress conditions may be controlled by the same genes (or physiological mechanisms), but additional components may be involved which affect germination rate under specific stress conditions.