COMPARATIVE EFFECT OF SALINITY ON GROWTH, IONIC AND PHYSIOLOGICAL ATTRIBUTES OF TWO QUINOA GENOTYPES

Soil salinization is a serious environmental menace that reduces the development, growth and yield of most of the plants. Growing halophyte crops such as quinoa (Chenopodium quinoa Willd.) is a promising way of productive utilization of saline soils. The present study was conducted during 2018-19, in which we investigated the comparative salt tolerance potential of two genotypes of quinoa (Puno and Al) on the basis of growth, ionic and physiological attributes. Five-week-old seedlings of both genotypes were exposed to different levels of salinity (0, 100, 200 and 400 mM NaCl) developed in Hoagland's nutrient solution. Results revealed that root and shoot growth, chlorophyll contents, membrane stability and relative water content remained unchanged at lower level of NaCl (100 mM). However, these attributes decreased significantly at higher level of NaCl (400 mM). The Na+ concentrations increased, whereas K+ concentrations and the ratio of K+: Na+ showed an inverse relation to the increasing salinity levels. The comparison of both genotypes indicated that physiological attributes and plant biomass were higher in Al than Puno due to less uptake of Na+ ions and higher K+: Na+ ratio. Therefore, Al is more suitable genotype than Puno to be grown on saline soils in arid regions of Pakistan.