Effect of Salinity Stress on Growth, Physiology and Anatomy of Pumpkin (Cucurbita moschata Duchesne) cv. Kang Kog (Early view)

Abstract

Pumpkin is an important economic crop with high nutritional value. Different pumpkin varieties experience diverse growth problems due to soil salinity. This research studied the physiological and anatomical adaptations of the Kang Kog pumpkin cultivar to salinity stress. Pumpkin seedlings were grown under a hydroponic system using Hoagland's solution with NaCl concentrations of 0, 25, 50, 75, and 100 mM for four weeks. Results showed that pumpkin leaf number, leaf width, leaf length, root number, root length, plant height, stem diameter, fresh weight, and dry weight significantly decreased after exposure to high NaCl concentrations. Chlorophyll a and green intensity measured as SPAD units ??also significantly decreased, while chlorophyll fluorescence (Fv/Fm, Fv’/Fm’) and chlorophyll b content of all treated groups were not significantly different when compared to the control group. Fiber strands and cuticles in all treatments were significantly thicker compared to the control group, while vessel diameters and vascular bundle sizes of the treated groups significantly decreased compared to the control group. Results showed that salinity stress did not impact chlorophyll b, and chlorophyll fluorescence. Kang Kog pumpkins can adapt and grow in slightly saline environments. Our results provide important information for pumpkin breeding programs efforts that can be used in combining with other agronomic characters to improve tolerant cultivars under initial salinity stress tolerance.