Response of Different Soybean (Glycine Max L.) Genotypes Grown in Sand Culture to Salinity Stress
Elsayed A. A. Abdelraouf , Adel Elgarhy
The aim of this study was to evaluate eight soybean genotypes to salinity stress. Plants were grown in sand culture in a greenhouse experiment and irrigated with one-tenth strength modified Hoagland nutrient solution with or without 50 mM NaCl. The experimental design was split plot, arranged in randomized completely block design with three replications. Main plot factor was salt stress level (0 and 50 mM NaCl) and sub-plot factor was soybean genotypes (Giza21, Giza22, Giza35, Giza82, Giza83, Giza111, Clark, and Crawford). After four weeks from sowing, the whole plants were collected. The results indicated that salinity induced significant decrease in plant growth of all soybean genotypes, since, salt stress decreased shoot height, whole plant, shoot and root fresh and dry weight and leaf area of all soybean genotypes. However, salt stress increased shoot/root ratio on fresh and dry weight basis, plant moisture content and electrolyte leakage of all soybean genotypes. Chlorophyll content index no significantly decreased with salt stress. Salt stress increased shoot and root Na+ content while decreased K+ content and K+/Na+ ratio of shoot and root for all soybean genotypes. The obtained results showed that the eight soybean genotypes responded differently to salt stress. It seems that Giza82 was more tolerant and Clark was more sensitive to salinity than other genotypes. These genotypes can be arranged with respect to tolerance to salinity in the order: Giza82 > Giza35 > Giza21 > Giza22 > Giza111 > Crawford > Giza83 > Clark.
Keywords: salt stress, soybean genotypes, growth, electrolyte leakage, chlorophyll content index, sodium and potassium content.