Relationship between survival and yield related traits in Solanum pimpinellifolium under salt stress

A subset of the Solanum pimpinellifolium collection maintained by AVRDC-The World Vegetable Center, Taiwan was evaluated to assess effects of salt stress on physiological traits and yield-related traits with the aim of identifying potential S. pimpinellifolium accessions useful for salt tolerance breeding in tomato. We undertook a comparative analysis of yield and plant survival traits under normal and salt stress conditions to obtain a first indication of the crucial traits associated with salt tolerance in S. pimpinellifolium. Although most traits of S. pimpinellifolium accessions showed a similar percent decrease in mean under salt stress compared with the cultivated checks, the former exhibited a wide range for all traits, suggesting great genetic diversity that can be exploited for the identification of salt tolerant genotypes. Genetic variability for yield and survival traits under salt stress was quantitative with low to moderate heritability. Results of correlation and path coefficient analysis revealed no correlation between any of the physiological traits with yield-related traits indicating that the ability to survive and yield under salt stress are two independent sets of traits in S. pimpinellifolium. Results of the path analysis along with heritability and genetic advance showed that shoot dry weight and K/Na ratio are the two most critical component traits for survival, while fruit number is critical for yield per plant. The large S. pimpinellifolium panel evaluated in this study revealed five genotypes possessing better survival traits, seven genotypes with good yield traits, and two genotypes combining both superior survival and yield traits under salt stress.