Assessment Results of Salinity Stressed F2 Population Originated from Interspecific Hybridization of Eggplant with Wild Relative Solanum incanum L.

Abstract

Salinity, which is one of the major abiotic stresses, prevails in mostly arid and semiarid areas that is nearly 20% of the world’s cultivated area. Excessive amounts of salt around the plant root zone are detrimental to vegetative growth and economic yield. Today salinization is still severely expanding and posing a great threat to the development of sustainable agriculture. Although eggplant (Solanum melongena L.) is considered moderately sensitive, soil salinity mitigates strictly the growth and yield. Eggplant has significant crop wild relatives (CWRs) which are thought to be more tolerant to abiotic stresses and it is substantial to exploit their potential against salinity in hybrid breeding studies. It has previously been proven that Solanum incanum L. has tolerance to salinity stress. This study aimed to improve salinity-tolerant pure eggplant lines. Therefore, the acquired F2 population from interspecific hybridization between the pure line (BATEM-TDC47) with distinctive features from BATEM eggplant gene pool and S. incanum L., were subjected to salinity stress at 150 mM NaCl level with its parents and F1 plants. On the 12th day after the last salt treatment, the plants were evaluated using a 0-5 visual scale. Among the 256 stressed plants, 50 F2 individuals were determined to be salt tolerant. Additionally, some of their morphological and physiological features, such as shoot length, stem diameter, number of leaves, anthocyanin presence, prickliness, malondialdehyde (MDA), and proline levels, were studied and compared to the controls of their parent and F1 plants. Results showed that shoot length and stem diameter decreased dramatically under salt stress. According to the analysis, the average MDA and proline levels of the F2 population were identified as 10.9 µ mol g-1 FW and 8.4 µ mol g-1 FW, respectively. The distinguished 50 F2 plants that showed salinity tolerance were transferred to the greenhouse and self-pollinated to produce the F3 generation.