In this study, grafted and ungrafted pepino (Solanum muricatum Ait.) plants were tested under different saline conditions. The nutrient solution experiment was conducted within October – November 2016, by employing the technique of Deep-Water Culture (DWC) in an entirely operated automatically climate chamber found in the Plant Physiology Laboratory of Erciyes University, Agriculture Faculty, Kayseri, Turkey. Plants were examined under three various salt levels (i.e., 1 dS m-1, 4 dS m-1 and 8 dS m-1) by growing them in a 8 liter pots loaded constantly in an aerated Hoagland solution. The study was organized with completely randomized block design through three repetitions. The climate chamber study was performed to investigate effects of salt stress on plant growth, shoot- root fresh- dry weights, photosynthesis, leaf area formation, chlorophyll content of leaf (SPAD), leaf and root electrolyte leakage, total length of root, volume of root, and diameter of root in grafted and ungrafted pepino plants. The results showed that shoot growth, root morphological and leaf physiological responses were considerably (p<0.001) influenced by various levels of salt conditions at the nutrient solution. Increased salt level of the nutrient solution decreased significantly root and shoot growth, area of leaf, photosynthetic activity of both grafted and ungrafted plants. Irrespective of being grafted, significant declines were observed in shoot fresh weight (23.6%, 52.1%), root fresh weight (24.8%, 52.8%), leaf area (21.3%, 51.9%), shoot dry weight (24.3%, 53.0%), root dry weight (15.4%, 45.1%), SPAD (5.7%, 18.7%), photosynthesis rate (24.6%, 42.1%), total root length (6.7%, 16.4%), and root volume (3.8%, 5.8%) of pepino plants under 4 dS m-1 salt applications and 8 dS m-1 salt applications, respectively. Grafting promoted growth of plant in pepino plants under both control and saline conditions, furthermore it was noticed that under saline conditions biomass production of both grafted and ungrafted ones were significantly depressed.
Grafted plants produced 54.1%, 43.0% and 9.6% higher shoot fresh weight; 52.0%, 42.0% and 12.8% higher root fresh weight; 52.5%, 40.7% and 8.7% higher leaf area; 60.0%, 46.6% and 11.1% higher shoot dry weight; 68.8%, 36.0% and 29.3% higher root dry weight; 19.9%, 9.2% and 8.2% higher SPAD; 8.0%, 5.1% and 10.8% higher photosynthesis rate; 8.6%, 3.6% and 6.6% higher total root length; 3.1%, 6.7% and 2.4% higher root volume than ungrafted plants under 1 dS m-1, 4 dS m-1 and 8 dS m-1 salt applications, correspondingly. Overall, our study showed that the effectiveness of grafting with respect to expansion of plants growth and development under salinity. Grafting was demonstrated to be an effective mean to achieve this goal.