Abstract:
Muskmelon is the most important fruit crop of arid and semi-arid regions and salinity as the most prevailing substance in such areas. Therefore, the present study was conducted to evaluate salt tolerance of muskmelon (Cucumis melo L.) genotypes based on some morphological, physiological and biochemical attributes in hydroponic system in the growth chamber of Plant Physiology Program, Crop sciences Institute, National Agricultural Research Centre, Islamabad, Pakistan during 2011-12. Seven muskmelon genotypes (T-96, Ravi, Mankera, White Candy, Bukhara, Surkh Kharboza and Adventa-1701) were sown in plastic trays for germination and then shifted to 3L nutrient solution in hydroponics containers. Fourteen days old plants were subjected to 0, 100, and 200 mM NaCl for sixteen days. Increasing levels of salt stress substantially declined the shoot and root biomass, plant height, root length and leaf area in all the tested muskmelon genotypes; however, genotypes differed in their response. Increasing level of salt also decreased the tested physiological and biochemical attributes; although genotypes T-96 and Mankera had higher photosynthesis (4.9 and 4.3 µmol m-2 s-1), stomatal conductance (142 and 132 mmol m-2 s-1), and higher K+/Na+ ratio (1.22 and 1.11 %) respectively at maximum salt level. Genotypes T-96 and Mankera were found salt tolerant, Ravi and White Candy as moderate and remaining genotypes as salt sensitive.
Keywords:
salt tolerance
,
K+ concentration
,
salinity
,
Na+ concentration