Abstract:

This study aimed to investigate the growth， physiological characteristics， nutrient accumulation， and yield performance of different maize varieties under saline-alkali stress conditions to address issues such as reduced maize （Zea mays） yields in such soils within the Ningxia Yellow River Irrigation District. By establishing a multi-trait evaluation system， the study sought to identify superior varieties suited to cultivation in saline-alkali soil， thereby providing a scientific basis for variety selection and cultivation management for efficient maize production on saline-alkali land. The experiment was conducted in Pingluo County， Ningxia， in 2023， with two main areas set up： mild saline-alkali （QS） and moderate saline-alkali （ZS） soil conditions. The varieties tested were Xianyu 335 （V₁）， Yinyu 238 （V₂）， Jindan 73 （V₃）， Deke 622 （V₄）， DK815 （V₅）， Heyu 157 （V₆）， Xianyu 1321 （V₇）， Jinrun 919 （V₈）， Tianci 19 （V₉）， and Xianyu 1225 （V₁₀）. It was found that under the tested contrasting saline-alkali stress conditions， the 10 maize varieties exhibit variety-specific differences in growth， physiology， nutrient accumulation， and yield， with different varieties demonstrating distinct advantages for various traits； Among them， under QS conditions， V₃ achieved optimal net photosynthetic rate （P_n）， kernel weight， and yield， with average increases of 4.90%-57.48%， 1.36%-35.97%， and 9.70%-40.26%， respectively， compared to other varieties； V₅ exhibited the highest PSⅡ potential maximum photosynthetic capacity （F_v/F_o） and K⁺ content， with increases of 3.50% to 27.29% and 2.54% to 6.02%， respectively， compared to other varieties； V₁₀ had the highest PSⅡ maximum photochemical efficiency （F_v/F_m）， proline （Pro） content， and total phosphorus content， with increases of 0.25% to 3.77%， 0.14% to 46.16%， and 12.59% to 48.48%， respectively， compared to other varieties. Under ZS conditions， the relative chlorophyll content （SPAD） and PS Ⅱ potential maximum photosynthetic capacity （F_v/F_o） of V₃ was increased by 2.88% to 35.30% and 4.30% to 35.37%， respectively， compared to other varieties； V₅ yield was increased by 3.56% to 61.80% compared to other varieties； P_n， peroxidase （POD） activity， and K⁺ content of V₁₀ were increased by 3.39% to 32.24%， 1.11% to 15.05%， and 1.32% to 5.19%， respectively， compared to other varieties. A multivariate evaluation was conducted using the entropy weight-TOPSIS method and principal component analysis （PCA）， with results showing consistent trends. Under the QS conditions， the three maize varieties with the optimal multivariate scores were V₃， V₅， and V₁₀， while under the ZS condition， the three maize varieties with the optimal scores were V₁₀， V₃， and V₅. Therefore， based on the combined score of the two statistical methods， Jindan 73 （V₃） demonstrated outstanding adaptability and stable yield under mild （QS） saline-alkali conditions， while Xianyu 1225 （V₁₀） performed relatively well under moderate （ZS）saline-alkali conditions. These two varieties provide a scientific basis for variety selection in saline-alkali maize cultivation in Ningxia and are suitable as core varieties for regional demonstration of contrasting saline-alkali soil tolerance and extension agency promotion.

Key words: maize, variety, saline-alkali stress, growth and physiological characteristics, nutrient accumulation, yield, comprehensive evaluation