The impact of increased shading stress on agronomic traits, photosynthetic performance and antioxidants activities in leaves of two soybeans cultivars (D16 and E93) was studied. Soybean seedlings were grown in pots and exposed to no shade (S0), slight shade (S1), moderate shade (S2), and heavy shade (S3). Our findings showed that under the S3 in both cultivars, leaf fresh weight (LFW), specific leaf area (SLA) and leaf thickness decreased significantly, accompanied by a reduction in photochemical parameters including the maximum quantum yield (F_v/F_m) and electron transport rate (ETR). Furthermore, compared to S0, S1 significantly increased the ETR, sucrose content and the activity of catalase (CAT) in both D16 and E93 cultivars while S2 and S3 decreased the activity. However, under all treatments of shading stress, the antioxidant activities of superoxide dismutase (SOD) and peroxidase (POD) were lowered in both cultivars. Such morphological and physiological plasticity to adapt S1 compensates for the decrease in biomass and leads to seed weight compared to that obtained with an amount of normal light. Through configuring the space in the intercropping systems, S1 could be helpful for optimum growth and yield. Redesigning photosynthesis through S1 for the intercropping systems could be a smart approach.

研究了遮荫胁迫增加对两个大豆品种（D16和E93）叶片的农艺性状，光合性能和抗氧化剂活性的影响。大豆幼苗在花盆中生长，没有遮荫（S0），没有遮荫（S1），中等遮荫（S2）和浓密遮荫（S3）。我们的研究结果表明，在S3下，两个品种的叶片鲜重（LFW），比叶面积（SLA）和叶片厚度均显着降低，并伴随着光化学参数的降低，包括最大量子产率（F _v / F _m）和电子传输速率（ETR）。此外，与S0相比，S1显着增加了D16和E93品种的ETR，蔗糖含量和过氧化氢酶（CAT）的活性，而S2和S3则降低了活性。然而，在所有遮光胁迫处理下，两个品种的超氧化物歧化酶（SOD）和过氧化物酶（POD）的抗氧化活性均降低。这种与S1相适应的形态和生理可塑性补偿了生物量的减少，并导致了种子重量（与普通光量相比）。通过配置间作系统中的空间，S1有助于最佳生长和产量。通过S1为间作系统重新设计光合作用可能是一种明智的方法。