烯效唑浸种对大豆苗期抗旱性的影响

为明确烯效唑对大豆苗期抗旱性的影响，以浙春3号为试材，采用不同浓度(0、0.05、0.1、0.2和0.4mg/kg)烯效唑浸种，探讨不同水分胁迫(正常供水、轻度胁迫和中度胁迫)下烯效唑对大豆苗期的抗旱效应。结果表明：烯效唑浸种降低了苗高，提高了大豆出苗率，茎粗和根冠比；同时还提高了叶片相对含水量，脯氨酸(Pro)含量和可溶性糖含量。烯效唑处理降低了丙二醛(MDA)含量，从而降低了脂质过氧化程度，提高了保护性酶的活性。正常供水下，SOD、POD和CAT酶活性均以0.1mg/kg处理最高，分别较对照提高了18.75%、8.43%和37.4%；轻度水分胁迫下，SOD、POD和CAT酶活性均以0.2mg/kg处理最高，分别较对照提高了23.53%、11.63%和47.5%；中度水分胁迫下，SOD、POD和CAT的酶活性均以0.4mg/kg处理最高，较对照分别提高了22.86%、11.2%和56.1%。可见，适宜浓度的烯效唑浸种可改善套作大豆苗期生长，提高抗旱能力。

Effects of uniconazole soaking on drought tolerance of soybean seedling

In order to understand the effects of uniconazole on drought tolerance of soybean seedlings,germination rate,morphological and physiological characteristics were studied using uniconazole soaked soybean cultivar Zhechun3 under different water stress.The result showed that seedling height was decreased,but germination rate, stem diameter and root to shoot ratio were increased after soaking.Relative water content,proline and soluble sugar were increased.Meanwhile, MDA (malondiadehyde) content was decreased followed by lipid peroxidation, although protective enzyme activity increased.The best response of the protective enzymes, including SOD (superoxide dismutase),POD (peroxidase) and CAT (catalase),increased up to 18.75%,8.43% and 37.4% under 0.1mg/kg uniconazole with normal irrigation,and up to 23.53%,11.63% and 47.5% under 0.2mg/kg uniconazole with slight water stress, and up to 22.86%,11.2% and 56.1% under 0.4mg/kg uniconazole with medium water stress,respectively.The results suggested that seed soaking with uniconazole at a suitable concentration could improve soybean seedling growth and strengthen seedling establishment during drought.