Determination of influence as rootstock of salt and drought tolerant melon genotypes under salt stress

Salinity is one of the most severe environmental stresses and it affects over 20% of the world's irrigated land. Grafting method is known for a long time and be applied into vegetables. The purpose of this research; it was non-grafted and rootstock-grafted melon to conditions of salt stresses to investigate whether grafted plants could improve tolerance to salinity. In here, 2 tolerant and 2 sensitive melon genotypes and Albastros variety which is rootstock varieties were used. When the plants were reached with four leaves, they were subject to salt stress (200 mM NaCl) stress. The control plants were irrigated to nutrition solution. The end of the experiment, plants were evaluated according to growth parameters, relative water content (RWC), membrane injury index (MII), chlorophyll (SPAD) ration, shoot and root ion contents contents. In the results of study; 200 mM NaCl applications negatively affected plant growth in all genotypes, especially in sensitive genotypes in terms of plant growth parameters. However, in applications where tolerant genotypes are used as rootstocks, the reduction in plant growth parameters as a result of salt stress occurs as 20-38%, RWC 20%, shoot and root K and Ca ion contents 15-21%. Additionally, MII increased by 30%, shoot and root Na and Cl ion contents increased by 288-1096%. For sensitive melon genotypes, the use of tolerance genotypes increased the tolerance of plants to salt stress and improved plant growth parameters, RWC, SPAD, K and Ca contents of 73-391% compared to un-grafted control plants. Moreover, MII and, Na and Cl ion uptake is limited to 45% and 27-50%, respectively As a result of the study, it was determined that grafting which tolerant melon genotypes were used as rootstocks for sensitive genotypes was improved to salt tolerance, especially CU196 melon genotype and Albastros variety came to the forefront among these combinations.