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

Eguru Sreenivasa Rao,Andreas W Ebert,Palchamy Kadirvel,Rachael C Symonds

doi:10.1007/s10681-012-0801-2

Abstract

AbstractA subset of theSolanum pimpinellifoliumcollection 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 potentialS. pimpinellifoliumaccessions 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 inS. pimpinellifolium. Although most traits ofS. pimpinellifoliumaccessions 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 inS. 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 largeS. pimpinellifoliumpanel 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.

Highlights

Salt stress caused by either saline or sodic soils is a major threat to global food production
While similar trends were observed in the S. pimpinellifolium accessions and the S. lycopersicum checks for most traits, shoot dry weight and mean fruit weight of the former showed less impact under salt stress compared with the cultivated checks
The results show 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

Summary

Introduction

Salt stress caused by either saline or sodic soils is a major threat to global food production. Sodicity and waterlogging of arable land is reaching serious proportions under irrigated conditions, affecting 20–33 % of all irrigated agricultural land worldwide (Ghassemi et al 1995; Foolad 2004; Munns 2012). Increased salinization may affect up to 50 % of arable land by the year 2050 (Wang et al 2003). The presence of increased salt in the soil solution leads to osmotic stress, restricting the ability of the plant to take up water and causing water deficit in plant tissues. Soil salinity disrupts homeostasis and ion distribution in the plant cell, as excessive amounts of salt are absorbed by the roots and channeled in the transpiration stream to the transpiring leaves (Greenway and Munns 1980; Serrano et al 1999; Zhu 2001). Ion imbalance and toxicity reduce nutrient uptake and transport capacity, and lead to nutritional imbalances (Ashraf 1994; Parida and Das 2005)

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Discussion

Conclusion