Seedling emergence, growth, and mineral concentration of three citrus rootstocks under salt stress

Abstract

Salt tolerance of Carrizo citrange (CC), sour orange (SO), and Cleopatra mandarin (CM) rootstocks during emergence and early seedling stage of development was studied under greenhouse conditions. Increasing salt concentration in the nutrient solution delayed and depressed seedling emergence (SE), increased time to 50% emergence, reduced seedling growth (SD) but did not affect emergence spread. At the first salinity level (5 mmol), emergence of the first seedling (EFS) was delayed by 2-3 days in CC and one day in SO but was not affected in CM. At the two lowest salinity levels (5 and 10 mmol), final percent emergence (FPE) was not affected in CC but was reduced in SO and CM while shoot biomass was reduced in CC but was not affected in SO and CM. This study showed a non-consistent trend among citrus rootstocks concerning whether the delay in emergence is more sensitive to salt stress than final percent emergence. However, SG was generally more affected by salinity than SE, particularly at high salinity levels. Shoot and root N and Cl concentrations generally increased with increasing salt concentrations. Shoot Cl concentration was found to be a better tool than root Cl concentration in evaluating the extent of the injurious effect of salt stress and a better parameter in ranking salt tolerance of citrus rootstocks. This study also showed that salt tolerance is not a constant character in citrus rootstocks but varies with the stage of seedling development.

Fertilization at planting impairs root system development and drought avoidance of Douglas-fir (Pseudotsuga menziesii) seedlings

“…Tolerance to high salt concentrations varies with size of root stock and generally increases with age [61]. Thus, young Douglas-fir seedling roots may be highly vulnerable to injury associated with excessive fertilization, which may help to explain the poor root development of seedlings fertilized at a relatively high rate in this study.…”

Effect of NaCl concentrations in irrigation water on growth and polyamine metabolism in two citrus rootstocks with different levels of salinity tolerance

“…Shoot and root Cl À and Na + concentrations generally increase with increasing salt concentrations in the nutrient solution. Shoot Cl À concentration was found to be a better tool than root Cl À concentration in evaluating the extent of injurious effects of salt stress and a better parameter in ranking salt tolerance of citrus rootstocks (Zekri 1993b).…”

Osmotic and toxic ion effects on seedling emergence and nutrition of citrus rootstocks

“…Salinity has been found to reduce and delay seed germination and seedling emergence of citrus rootstocks (Mobayen and Milthorpe, 1978;Zekri, 1993aZekri, , 1993b. Furthermore, Zekri (1993aZekri ( , 1993b demonstrated that salinity tolerance varies with the stage of development of citrus rootstocks and did not find a consistent relationship between salt tolerance at seedling emergence and at later growth stages of citrus rootstocks.…”

“…Furthermore, Zekri (1993aZekri ( , 1993b demonstrated that salinity tolerance varies with the stage of development of citrus rootstocks and did not find a consistent relationship between salt tolerance at seedling emergence and at later growth stages of citrus rootstocks.…”