Exploring the Genetic Diversity of Citrullus vulgaris L. Against Salinity Stress

| Salinity is a major issue for tinda gourd ( Citrullus vulgaris L.) production throughout the world. In a pot experiment, five selected tinda gourd genotypes i.e., Green ball, Dilpasand, Durga, Round gold, and Indian desi were sown. One month after emergence, the growing medium was supplied with the lowest NaCl level 2, two medium levels 4, 6, and the highest salinity level was 8 dS m -1 and was compared with the control (1.5 dS m -1 considered as normal). The Hoagland solution was applied every week as a nutrient solution. High sodium contents lead to sodicity. Finally, selected genotypes displayed significantly dissimilar responses toward the concentration of sodium ions according to their genetic potential. Various agronomic traits and physiological traits along with seedlings’ ionic content of sodium, phosphorous, potassium, and sodium in leaves revealed that ‘Round ball’ has better NaCl tolerance ability compared with other genotypes used in this study. The highest ionic sodium concentration (10.34 µg g -1 DW) was found in Green ball, whereas Round gold (8.92 µg g -1 DW) showed the minimum. NaCl-induced salinity leads to chlorophyll damage in Round gold (58.44 SPAD index) and ‘Green ball’ (50.55 SPAD index) accordingly. On an overall basis, ‘Round gold’ (12.1 µg g -1 ) had maximum followed by Indian desi (11.7 µg g -1 ) at the highest level of salinity (8 dS/m -1 ) with respect to control (6.9 µg g -1 ). It was revealed that the lowest ionic sodium concentration was observed in the Green ball (6.3 µg g -1 ). Considering the result of this study, the Round gold tinda gourd genotype may be used for cultivation in salt-affected soils.