Objectives Selecting crops with strong saline-alkali tolerance and high economic value is an important approach to utilizing saline-alkali arable land resources and increasing agricultural income. As a major cash crop, fresh waxy maize requires systematic investigation and analysis of the growth, yield, and quality of different varieties under saline-alkali stress, so as to select fresh waxy maize varieties with strong saline-alkali tolerance and excellent overall quality for saline-alkali areas.

Methods A field experiment was conducted in 2024 in Dafeng District, Yancheng City, Jiangsu Province, where the soil is moderately saline-alkali. Twenty-five waxy maize varieties from national and Jiangsu provincial regional trials were used as test materials. At the fresh-eating stage of each cultivar, plant and ear traits, fresh ear yield, fresh grain yield, dry matter and nitrogen accumulation, grain contents of soluble sugar, starch, and protein, and pasting and thermodynamic properties were measured. The saline-alkali tolerance of each variety was comprehensively evaluated using the membership function method, principal component analysis, and cluster analysis.

Results Under saline-alkali stress, significant differences in agronomic traits, yield, quality, and physiological indicators were observed among varieties. Sukenuo 236 had the highest fresh ear yield and fresh grain yield, being 51.6% and 67.3% higher than the average, respectively. Shancainuo showed the highest plant height, dry matter accumulation, and nitrogen accumulation, exceeding the average by 25.0%, 64.6%, and 97.6%, respectively. Sukenuo 1701 had the largest stem diameter, 28.0% above the average. Meiyushuangtiannuo 505 had the highest grain soluble sugar content, 60.5% above the average. JN10 had the highest grain starch content, 42.2% above the average. HN8 had the highest grain protein content, 23.3% above the average. Sukenuo 236 and Ruicainuo 61 had the highest peak viscosity and breakdown values. Sutiannuo 241 showed the lowest retrogradation enthalpy and setback values. Based on the comprehensive scores of principal component analysis, Sukenuo 236, Ruicainuo 61, and Shancainuo performed most prominently in yield and dry matter accumulation and were classified as yield-prominent varieties; Zhecaitiannuo 158 and Sutiannuo 241 were superior in pasting and thermodynamic properties and were designated as quality-prominent varieties; Shancainuo and Zhekenuo 818 showed superior combined yield and quality and were classified as comprehensive varieties. Furthermore, the 25 varieties were clustered into three grades using the weighted membership function method: five highly saline-alkali-tolerant varieties, sixteen moderately saline-alkali-tolerant varieties, and four saline-alkali-sensitive varieties.

Conclusions Under saline-alkali field conditions, significant differences in yield and quality traits were observed among the tested cultivars. Among them, Shancainuo, Sukenuo 236, Sukenuo 1701, Zhefengnuo 9, and Zhekenuo 818 showed high saline-alkali tolerance, excellent agronomic traits, high yield, and favorable pasting and thermodynamic properties of grain under saline-alkali stress, making them suitable for extension in saline-alkali areas.