Using grafting and salt tolerant rootstocks in order to obtain salt tolerance in tomato

Presented thesis study comprises two stages. While the first stage of thesis was carried out in early development stage of plants under climate chamber conditions, the second stage of thesis has been carried out in the mature stage of plants under greenhouse conditions to investigate their growth, yield and fruit characteristics. In this study, 22 different combinations of plants which were obtained by grafting with 4 salt tolerant and 2 salt sensitive genotypes which is known their responses to salinity stress were grown in climate chamber under control and saline conditions. A series of physiological and morphological measurements were done in grafted plants. In grafted plants which were grown under 150 mM NaCl treatment and control conditions in climate chamber, 1-5 scale evaluation, fresh and dry weight of vegetative part and roots of plants, plant height, number of leaves, leaf area, stomatal conductivity, leaf osmotic potential, leaf water potential, chlorophyll content, leaf membrane injury, Na, K, Ca, Cl ion concentrations of leaves, stem and roots, sucrose, fructose, glucose and total phenol contents of above and below of the graft union were measured and quantified. With regard to results of experiment in climate chamber, sensitive genotype were grafted onto tolerant genotype 174/121, their self-grafted plants 174/174 and 121/121 were grown under 50 mM NaCl treatment and control conditions in soilless culture greenhouse in the spring. In addition to the above mentioned physiological and morphological measurements, fruit yield and some physical fruit characteristics were measured such as average fruit weight, height, diameter and volume of fruit and some chemical fruit characteristics were quantified such as vitamin C, pH, electrical conductivity (EC), soluble solids content (SSC) and total dry matter in fruits. In the greenhouse experiment, when tolerant genotype 174 was used as rootstock , it was able to transport to sensitive scion the characteristic of being less influenced from salt stress. Tolerant rootstock reduced the yield reduction of sensitive scion from %44.38 to %2.53. Whereas fruit size, total dry matter, vitamin C was increased in sensitive scion grafted onto tolerant genotype, fruit pH was decreased under saline conditions. As a consequence, these characteristics raised the consumption and nutritional quality of tomato fruit.