Salt Stress Tolerance of 'Hatay' Clonal Apple Rootstock Candidate (Malus sylvestris L. Mill. Subsp. orientalis) Under in vitro Conditions

Abstract

Salt stress is an important environmental factor that negatively affects the growth and development of plants. The apple is one of the most sensitive plants to salt stress among fruit species. In this study, the tolerance of 'Hatay' clonal apple rootstock candidate to salt stress under in vitro conditions was investigated. Different salt concentrations (1/4 dilute MS, 1/2 dilute MS, MS (control), MS+1gL-1 NaCl, MS+2gL-1 NaCl, MS+4gL-1 NaCl, MS+6gL-1 NaCl, MS+8gL-1 NaCl, MS+10gL-1 NaCl) were used. Plant height, leaf area, stomatal conductance, fresh and dry weight, rooting rate, root number and root length were measured after salt stress. According to the study results, the highest plant height was determined in MS (control) medium and the lowest in 1/4 MS medium. The highest plant fresh weight was determined in MS (control) and MS+1gL-1 NaCl medium and lowest in 1/4 MS medium. The lowest plant fresh weight was determined in 1/4 MS medium. Leaf area was highest in MS medium and lowest in MS+1gL-1 NaCl medium. Stomatal conductance was highest in 1/2 MS medium and lowest in MS+1gL-1 NaCl medium. The rooting rate was highest in MS+1gL-1 NaCl medium and lowest in 1/4 MS medium. In terms of root number, root length, root fresh and dry weight, the best results were generally obtained in 1/2 MS medium, while the lowest results were obtained in 1/4 MS medium. The plants died in MS+2gL-1 NaCl, MS+4gL-1 NaCl, MS+6gL-1 NaCl, MS+8gL-1 NaCl, MS+10gL-1 NaCl environments. As a result, 'Hatay' clonal apple rootstock candidate was found to be sensitive to salt stress.