A comparative <i>in vitro</i> study of salt tolerance in cultivated tomato and related wild species

Abstract

Salinity stress is a major abiotic stress for plants worldwide. This study was carried out to determine the variation in salt tolerance for 12 different genotypes belonging to three different tomato species: Solanum lycopersicum (L), S. peruvianum (L) and S. pimpinellifolium (L). Shoot apices and callus cultures were exposed to different levels of salinity stress ranging from no salt (control) to 100, 200 and 300 mmol L −1 NaCl. All growth and physiological parameters were significantly affected by salt stress. Most shoot apices of S. lycopersicum did not develop roots when exposed to low NaCl levels, whereas apices of S. peruvianum and S. pimpinellifolium developed roots when exposed to all salt levels. This difference in salt tolerance was clearly shown on the basis of root fresh weights and root surface areas. Callus growth in response to increased salinity was much greater in S. peruvianum and S. pimpinellifolium than in S. lycopersicum. The Cl − and Na + concentrations increased significantly with increasing salt in the three species, although the S. peruvianum lines accumulated more ions compared with the others. As the salt concentration increased, less K + accumulated in S. lycopersicum compared to the related wild species. The results obtained in this study suggest that S. peruvianum line 0043-1 was the accession with the best salt tolerance. The most tolerant cultivated tomato (S. lycopersicum) cultivar was 'Rutgers. ' Both S. peruvianum line 0043-1 and S. lycopersicum 'Rutgers' are good candidates for inclusion in tomato breeding programs for salt-tolerance.

Novel Miscanthus genotypes selected for different drought tolerance phenotypes show enhanced tolerance across combinations of salinity and drought treatments

“…Many different traits contribute to salinity tolerance, which are species- and developmental stage-dependent (Munns, 2002; Jones et al , 2015). In glycophytes, salt tolerance also involves the accumulation of compatible solutes, such as proline, in the cytosol and organelles for osmotic adjustment and osmoprotection (Yokoi et al , 2002; Zaki and Yokoi, 2016).…”

An early ABA-induced stomatal closure, Na+ sequestration in leaf vein and K+ retention in mesophyll confer salt tissue tolerance in Cucurbita species

“…To date, most experimental work on salinity tolerance has focused on shoot Na + exclusion ( Møller et al , 2009 ; Huang et al , 2013 ; Niu et al , 2018 ). However, there is increasing evidence that this is not the sole mechanism for salinity tolerance ( Rajendran et al , 2009 ; Munns et al , 2016 ; Zaki and Yokoi, 2016 ). Some species or genotypes can maintain a relatively high Na + concentration in their shoots without major negative impacts on growth and yield.…”

“…This strategy, termed a tissue-tolerance mechanism ( Munns et al , 2016 ), is observed in both halophytes ( Wang et al , 2007 ; Adolf et al , 2013 ) and glycophytes (e.g. Triticum aestivum , Genc et al , 2007 ; T. monococcum , Rajendran et al , 2009 ; lettuce, Bartha et al , 2015 ; tomato, Gálvez et al , 2012 ; Zaki and Yokoi, 2016 ; rice, Prusty et al , 2018 ).…”

Utilization of Tomato Landraces to Improve Seedling Performance under Salt Stress

“…In order to cope with enriched salt conditions, plants implement a plethora of morphological, physiological and biochemical adaptations, with the effect of developmental stage and salt levels being critical in the efficiency of the activated defense mechanism to mitigate stress injury [26]. The adaptability of seedlings under salt stress may also reflect higher salt tolerance at advanced growth stages [27].…”