Combined Effects of Low Oxygen and Salinity on Germination of a Semi-dwarf Mexican Wheat1
- Everardo Aceves-N,
- L. H. Stolzy and
- G. R. Mehuys2
The simultaneous occurrence of low oxygen and high salinity conditions is common in a wide range of irrigated soils. The combined effects of O2 and osmotic potential stresses on germination of wheat (Triticum aestivum L. ‘Inia 66’) were tested under growth chamber conditions. A range of O2 concentrations and salinity levels were chosen to simulate soil aeration and salinity combinations that might be expected to occur in well-aerated, fine-textured, saline, and sallne.sodic soils. Daily observations of number of seeds germinated and days to first germination were recorded. Analysis of variance of percent germination was performed in three different ways: i) using the original data, ii) using the arcsine transformation, and iii) deleting most of the 0% germination values to get better estimates of the error terms.
Inia 66 showed tolerance to high salinity and low O2 during germination. Close to full germination occurred at a salinity level of −6 bars (21% 02) and at O2 (no salinity stress). However, the combination of high salinity with low O2 depressed germination below economic levels. Predicted osmotic potentials associated with a 50% decrease in germination ranged from −10.8 bars at 21% O2 to −3 bars at 1% O2. High salinity levels were more limiting than low O2 concentrations. Days to first germination were increased only at O2 concentrations lower than 5%. Apparently this concentration is the threshold at which germination is delayed at all the osmotic potentials tested. A function is proposed for predicting days to first germination under saline but good soil aeration conditions.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .