Tolerance of soybean cultivars to flooding stress in vegetative growth stages

Abstract The objective of this work was to evaluate the tolerance of soybean (Glycine max) cultivars to flooding stress at different growth stages. The experiment was arranged in a 2x2x5 factorial arrangement, with two sowing dates (October and November), two soybean cultivars (TECIRGA 6070RR and NA 5909 RG), and five growth stages (SE-EM, EM-VC, VC-V2, V2-V4, and V6-V8) in the 2018/2019 and 2019/2020 crop years. The experimental design was completely randomized with four replicates. For both evaluated soybean cultivars, the growth stage most sensitive to soil flooding was SE-EM. After seedling emergence, the highest reductions in leaf area and shoot dry matter were observed in the V2-V4 stage, regardless of cultivar, sowing date, and crop year. From the V4 stage onwards, soybean shows a higher tolerance to flooding conditions. However, after seedling emergence, the TECIRGA 6070RR cultivar has a higher tolerance to flooding stress than NA 5909 RG. Sowing in October tends to reduce the impact of flooding stress on the plants.

摘要 本研究旨在评估大豆（Glycine max）不同生育时期对渍涝胁迫的耐受性。试验采用2×2×5三因素完全随机设计，设置2个播期（10月与11月）、2个大豆品种（TECIRGA 6070RR与NA 5909 RG）以及5个生育时期（SE-EM、EM-VC、VC-V2、V2-V4及V6-V8），于2018/2019和2019/2020两个作物年度开展，共设置4次重复。结果显示，供试的两个大豆品种中，对土壤渍涝最为敏感的生育时期为SE-EM。出苗后，无论品种、播期与作物年度如何，叶面积与地上部干物质降幅最大的阶段均为V2-V4时期。自V4生育时期起，大豆对渍涝环境的耐受性显著提升。但出苗后，TECIRGA 6070RR品种的渍涝胁迫耐受性优于NA 5909 RG。10月播种可有效降低渍涝胁迫对植株的负面影响。