To investigate the differences in grain yield and nitrogen use efficiency among different wheat varieties and their physiological mechanisms, this study was conducted at the experimental station of Henan Agricultural University in Yuanyang County, Xinxiang City, Henan Province, during the 2023—2024 wheat growing season. Forty approved wheat varieties were used as experimental materials. Principal component analysis and comprehensive scoring were performed on four key nitrogen efficiency indices: nitrogen recovery efficiency, partial factor productivity of nitrogen, physiological nitrogen use efficiency, and agronomic nitrogen use efficiency. Combined with grain yield, wheat varieties were screened for yield and nitrogen efficiency levels, and physiological indices of different yield-nitrogen efficiency types were further compared to reveal the physiological basis underlying the differences in yield and nitrogen use efficiency. The results showed that grain yield and the four nitrogen efficiency indices varied significantly among varieties, with coefficients of variation ranging from 11.61% to 46.73%. Based on principal component analysis, comprehensive scores of nitrogen use efficiency indices, and yield levels, the 40 wheat varieties were classified into four types: high-yield and high-efficiency (11 varieties), high-yield and low-efficiency (5 varieties), low-yield and high-efficiency (10 varieties), and low-yield and low-efficiency (14 varieties). Analysis of dry matter accumulation and translocation revealed that high-yield and high-efficiency varieties had significantly higher aboveground dry matter and nitrogen accumulation at anthesis and maturity than other types. Compared with high-yield and low-efficiency varieties, they also exhibited greater preanthesis nitrogen accumulation and preanthesis nitrogen translocation. In addition, the leaf area index (LAI) attenuation rate from anthesis to grain filling was lower in high-yield and high-efficiency varieties (18.77%) than in high-yield and low-efficiency varieties (22.67%). Meanwhile, high-yield types maintained significantly higher SPAD values during grain filling. Under the experimental cultivation conditions, high-yield and high-efficiency varieties maintained high dry matter and nitrogen accumulation at anthesis. By optimizing leaf spatial distribution and prolonging functional leaf longevity, they sustained dry matter production during grain filling, thereby achieving higher grain yield and nitrogen use efficiency.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |