Some physiological responses of wheat and bean to soil salinity at low matric suctions

Abstract

A b s t r a c t. The effect of soil matric suction (2-33 kPa) and salinity (soil solution electrical conductivity 0.7-8 dS m -1 for bean and 2-20 dS m -1 for wheat) on some physiological characteristics of bean and wheat in a clay loam soil under greenhouse condition was investigated. The results showed that the leaf chlorophyll content index and potassium concentration decrease under salinity stress and increase with matric suction from 2 to 33 kPa suction for both plants. The wheat chlorophyll content index declines during the stress spell but bean chlorophyll content index remains nearly constant. The lowest values of the content of soluble sugars and the highest values of leaf proline content are observed at 2 kPa matric suction (highest aeration stress) for bean and wheat. As matric suction increases from 2 to 6 kPa, the soluble sugars increases and proline content decreases significantly and then soluble sugars decreases and proline content increases until 10 kPa suction, and the soluble sugars remains nearly constant at the higher matric suctions for both plants. While the electrical conductivity effect on the soluble sugars is not significant, the values of proline content for both crop increase significantly with electrical conductivity. It was shown that the aeration stress can result in more considerable and rapid physiological responses, in comparison with salinity stress. There is a strong correlation between wheat and bean chlorophyll content index and potassium concentration under salinity and aeration stresses.K e y w o r d s:

Soil salinity and matric potential interaction on water use, water use efficiency and yield response factor of bean and wheat

“…Soil aeration is an important factor affecting water uptake and growth in plants 1 . In wet soils (h > −10 to −30 kPa) aeration is limited, gas diffusion and transfer are insufficient, plants respiration is impeded and consequently water not absorbed efficiently 2 . As the frequency and connectivity of air filled pores increase, so does the soil matric suction, intensifying the uptake of water 2 .…”

“…In wet soils (h > −10 to −30 kPa) aeration is limited, gas diffusion and transfer are insufficient, plants respiration is impeded and consequently water not absorbed efficiently 2 . As the frequency and connectivity of air filled pores increase, so does the soil matric suction, intensifying the uptake of water 2 . Oxygen deficiency symptoms occur below the critical value of air content, depending on plant and soil types.…”

Germination of chia seeds submitted to saline stress

“…& Schult. (Rosa et al, 2015); Vigna sinensis (L.) Savi (Kandil et al, 2017); Phaseolus vulgaris L. (Khatar et al, 2017); Portulaca oleracea L. (Naik and Karadge, 2017).…”

The content of available macro- and microelements against the background of enzymatic activity in soils affected by the soda industry

“…This can affect water and air movement and root penetration (Crescimanno et al, 1995). Salt toxicity is one of the major edaphic factors limiting plant growth (Khatar et al, 2017). Natural and induced soil salinity reduce plant growth and the activity of microorganisms by lowering water availability (as a result of the high osmotic potential of the soil solution) and by raising ion toxicity (Wang et al, 2013).…”