Treatment of soybean seeds with mechanical damage: effects on their physiological potential

Abstract: Mechanical damage is a serious problem for the physiological potential of soybean seeds, especially when combined with chemical treatment. The aim of this study was to investigate the effects of chemical treatment on the physiological potential of soybean seeds with increasing levels of mechanical damage. Soybean seeds (cv. M6410 IPRO) of two lots with differences in vigor were subjected to five levels of mechanical damage (zero, one, two, three, and four impacts) brought about in a controlled manner. After characterization of the effect of the impacts on seed physical integrity (X-ray, X-ray microtomography, tetrazolium, and sodium hypochlorite), the seeds were subjected to four combinations of chemical treatment with fungicides (carbendazim and thiram), insecticides (imidacloprid and thiodicarb), micronutrients (cobalt and molybdenum), polymer (Peridiam®), and drying powder (Talkum Gloss®). Seed germination and vigor were evaluated sixty days after chemical treatment. A progressive increase in mechanical damage, especially that which causes cracks in the seed coat, reduces the physiological potential of soybean seeds and increases their sensitivity to the phytotoxic effect of the chemical treatment. The physical integrity of the seed coat is crucial for the success of technologies used for chemical seed treatment.摘要：机械损伤对大豆种子的生理潜能具有严重负面影响，尤其在配合化学处理时问题更为突出。本研究旨在探究化学处理对不同机械损伤梯度大豆种子生理潜能的影响。选取M6410 IPRO品种的两个活力存在差异的大豆种子批，以可控方式施加五个梯度的机械损伤（零次、一次、两次、三次、四次冲击）。在通过X射线成像（X-ray）、X射线显微计算机断层扫描（X-ray microtomography）、四唑染色法（tetrazolium）及次氯酸钠法表征冲击对种子物理完整性的影响后，对种子开展四类化学处理组合，涵盖杀菌剂多菌灵（carbendazim）与福美双（thiram）、杀虫剂吡虫啉（imidacloprid）与硫双威（thiodicarb）、微量营养元素钴（cobalt）与钼（molybdenum）、聚合物Peridiam®以及干燥粉剂Talkum Gloss®。于化学处理60天后对种子发芽率与活力水平进行评估。机械损伤程度逐步加剧，尤其是造成种皮开裂的损伤，会降低大豆种子的生理潜能，并提升其对化学处理药害效应的敏感性。种皮的物理完整性对于化学种子处理技术的实施效果至关重要。