关键词: 玉米; 自交系; 耐盐; 杂种优势

Abstract: 【Objective】 The identification of salt tolerance in maize inbred lines and hybrids is of great significance for breeding new varieties of salt-tolerant maize. In order to effectively analyze the response of maize inbred lines and hybrids under salt stress and to analyze the heterosis contribution of inbred lines, it is necessary to study the salt tolerance and heterosis performance of maize in-depth.【Method】The maize inbred lines B73, GEMS46 and B73×GEMS46F1 were used as testing materials to evaluate their salt tolerance. The trend and final difference of physiological indexes of inbred lines and hybrids under salt-tolerant conditions were analyzed and compared, thus reducing the contribution of inbred lines to heterosis under salt stress.【Result】The results showed that the treatment of 150 mmol/L NaCl in 3-leaf and 1-heart corn plants was a reasonable concentration. The fresh weight and dry weight of plant and Na⁺ and K⁺ content was criteria indicator. After salt treatment, the relative conductivity and H₂O₂ content of salt-tolerant inbred lines had the same trend as that of hybrids, and the response of salt-tolerant inbred lines and hybrids to salt stress was rapid. The accumulation of Na⁺ in salt tolerance inbred and hybrid was stronger than those of the sensitive inbred lines. In the process of breeding new salt-tolerant maize varieties, the response speed of maize inbred lines to salt stress and the content of Na⁺, K⁺ ions in the plants were analyzed synthetically. The salt-tolerant cross combinations could be quickly selected by using salt-tolerant inbred lines as parents. 【Conclusion】During the breeding of new salt-tolerant maize varieties the response speed to salt stress and the content of Na⁺, K⁺ in seeding stage of maize inbred lines were comprehensivery analyzed by using salt-toleant inbred lines as parents which can be quickly screened Salt out of the hybrid combination.

Key words: maize; inbred lines; salt tolerance; heterosis