Objectives This study aimed to clarify the sulfur (S) accumulation and distribution in the grain of new wheat cultivars, and investigate the differences of grain S concentration to grain yield, yield components and nutrient absorption and distribution, for the purpose to provide support for breeding and selecting elite cultivars to produce high-yield and high-quality wheat in major wheat production regions of China.

Methods Based on trials of 114 new wheat cultivars at 47 experimental sites across 13 provinces (municipalities) in major wheat production regions of China from 2021 to 2023, the wheat yield, yield components, and S concentration in each plant part were measured to analyze relationships of grain S concentration to grain yield, yield components, S uptake and distribution, and other nutrient concentrations.

Results Grain S concentration differed significantly among wheat production regions, with that in the Huang-Huai-Hai wheat region being significantly higher than in Yangtze-River-basin wheat region. The S concentration in grain, flour and bran of new wheat cultivars ranged from 1.00 to 2.27, 0.51 to 1.76 and 1.20 to 4.86 g/kg, respectively, with an average of 1.57, 1.16 and 2.50 g/kg in the major production regions of China. The average S concentrations of high-S, medium-S and low-S cultivars were 1.63, 1.57 and 1.47 g/kg in grain, 1.18, 1.16 and 1.10 g/kg in flour, and 2.65, 2.52 and 2.30 g/kg in bran, respectively. The S concentration in flour and bran showed a positive correlation with that in grain. For each 1.0 g/kg increase in grain S concentration, the S concentrations of high-S, medium-S and low-S wheat cultivars were increased by 0.59, 0.45 and 0.24 g/kg in flour, and by 2.33, 2.74 and 3.15 g/kg in bran, respectively. The yield, biomass, harvest index and spike number in the Huang-Huai-Hai wheat region were significantly higher than those in the Yangtze-River-basin, and the 1000-grain weight was significantly lower than in the Yangtze-River-basin. The S concentration in grain showed a positive correlation with the grain yield, biomass and spike number, with which of high-S, medium-S and low-S cultivars increased by 0.05, 0.08 and 0.04 g/kg for each 1.0 t/hm² increase in yield, by 0.03, 0.04 and 0.02 g/kg for each 1.0 t/hm² increase in biomass, and by 0.07, 0.06 and 0.05 g/kg for every 100×10⁴/hm² increase in spike number. The grain S concentration was also positively correlated with the S absorption in different parts of shoot and S distribution index in the straw, but negatively correlated with the S distribution index in the grain. As far as different nutrients were concerned, the grain S concentration was positively correlated with the N concentration for medium-S and low-S cultivars, with the K concentration for high-S and medium-S cultivars, and with the Ca and Mg concentrations for cultivars, while it was negatively correlated with Cu concentration for high-S cultivars, with Zn for high-S and medium-S cultivars.

Conclusions Among recently released Chinese wheat cultivars, high-sulfur-use-efficient genotypes exhibit enhanced S uptake, more effective allocation of absorbed S to the grain, and superior grain yield. In these elite cultivars, S acquisition is tightly coupled with K uptake, whereas in medium- and low-efficiency cultivars, grain S accumulation is primarily driven by N uptake. Notably, Ca and Mg exert significant synergistic effects on S uptake across all cultivars, irrespective of their S efficiency status. Consequently, agronomic strategies such as optimizing spike density, balancing N−P−K fertilization, and supplementing Ca and Mg are essential for improving grain S content and overall sulfur nutrition in wheat.