Agronomical and physiological characterization of salinity tolerance in a commercial tomato hybrid

Abstract

The salt tolerance of the commercial F1 tomato hybrid (Lycopersicon esculentum Mill) Radja has been agronomically and physiologically evaluated under greenhouse conditions, using a control (nutrient solution), a moderate (70 mM NaC1 added to the nutrient solution) and a high salt level (140 mM NaC1), applied for 130 days.The results show that Radja is a Na +-excluder genotype, tolerant to moderate salinity. Fruit yield was reduced by 16% and 60% and the shoot biomass by 30% and more than 75% under moderate and high salinities, respectively. At 90 days of salt treatment (DST), the mature leaves feeding the 4th truss at fruiting accumulated little Na + (178 mmol kg-l DW). At this time, the sucrose concentration in these leaves even increased with moderate salinity and the amino acid proline was not accumulated under salt conditions as compared to control. At 130 DST, Na + was accumulated mainly by the roots in proportion to the salt level applied, while in leaves appreciable amounts were found only at high salinity (452 mmol kg-I DW). In the leaves, CI-was always accumulated in proportion to the salt level and in a very much greater amounts than Na + (until 1640 mmol kg-I DW). The sucrose content was reduced in all plants by salinity, and was distributed preferentially toward the distal stem and peduncle of a truss at fruiting under moderate salinity, and toward the basal stem and root at high salinity. Moreover, proline was accumulated in different organs of the plant only at high salinity, coinciding with Na + accumulation in leaves. Attempts are made to find a clear relationship between physiological behaviour triggered by stress and the agronomical behaviour, in order to assess the validity of physiological traits used for salt-tolerance selection and breeding in tomato.

Effects of Saline Water on Tomato Under Subsurface Drip Irrigation: Nutritional and Foliar Aspects

“…This significant increase lead sharply to reduce the K + , Ca 2+ , Mg 2+ and P contents (Table 3) of the three cultivars. These results are in agreement with findings in tomato under saline stress (Pérez -Alfocea et al, 1996;Al-Karaki, 2000;Dasgan et al, 2002;Maggio et al, 2004), rice, maize and soybean under drought stress (Tanguilig et al, 1987) who reported that nutrients uptake by plants is decreased under drought stress conditions due to reduced transpiration, impaired active transport and membrane permeability, resulting in reduced root absorbing power. As observed in the present experiment, applying saline water continuously through DI might result in high salt accumulation in the three cultivars (Table 4).…”

“…These results corroborate previous data obtained with tomato (Alian et al, 2000;Kaya et al, 2001;Romero-Aranda et al, 2001;Maggio et al, 2007), melon (Botia et al, 1998;Sivritepe et al, 2003) as well as in celery (Pardossi et al, 1999), eggplant (Chartzoulakis and Loupassaki, 1997) and pepper (Chartzoulakis and Klapak, 2000;Kaya et al, 2009). Decrease of K + in roots may provide a mechanism by which the three cultivars of tomato, particularly Nemador, achieve ionic balance following uptake of high Na + concentrations in roots (Slama, 1986, Pérez-Alfocea et al, 1996, Al -Karaki, 2000Dasgan et al, 2002;Maggio et al, 2007 Calcium is important during salt stress, e.g. in preserving membrane integrity (Rengel, 1992), signalling in osmoregulation (Mansfield et al, 1990) and influencing K/Na selectivity (Cramer et al, 1987).…”

AMF Inoculation Enhances Growth and Improves the Nutrient Uptake Rates of Transplanted, Salt-Stressed Tomato Seedlings

“…The worldwide production has been estimated at 100 million t year´1 with a total production area of about 4.2 million ha [7]. Although considered moderately tolerant to salt stress, tomato fruit yield decreases by about 10% for each unit of soil EC above a threshold value of 2.5 dS¨m -1 [8]. Additionally to the development of salt-tolerant cultivars [1], three major cultivation techniques have so far proved useful to attenuate the effects of excess soil salinity: (i) subjecting seedlings to water-or NaCl-stress can facilitate the adaptation of salt-stressed adult plants; (ii) mist application improves vegetative growth and yield of salt-stressed tomato plants grown under Mediterranean conditions; and (iii) grafting tomato cultivars onto appropriate rootstocks can reduce the effects of salinity [3].…”

Growth of lulo (Solanum quitoense Lam.) plants affected by salinity and substrate

“…Also Savvas (2001) stated that there is a general consensus among the experimental results of many investigators that moderate levels of salinity affect the above-ground growth more than the root growth. To explain this opposite behavior of SRR, it should be taken into account that in 30 mM NaCl treatment in sand: (a) above ground growth was the lowest one among all treatments; (b) in spite of the negative effect of salt on the roots, root growth in lulo appears to be less affected by salt than shoot growth, similarly to tomato plants (Cuartero and Fernández-Muñoz, 1999); (c) a greater proportion of assimilates allocated to the roots and less to the shoot, as compared to control plants, could have influenced the decreased SRR of this treatment (Pérez-Alfocea et al, 1996).…”