硝普钠浸种对紫花苜蓿种子萌发及幼苗生长的影响

通过不同浓度的外源一氧化氮（NO）供体硝普钠（Sodium Nitropprusside，SNP）对紫花苜蓿(Medicago sativa)种子进行处理，研究其对紫花苜蓿种子萌发、幼苗胚根与胚轴生长、MDA含量及POD活性的影响。结果表明，与不处理对照组相比，低浓度SNP(50~100 μmol·L-1)组的紫花苜蓿种子发芽率最高，为对照组的121%。幼苗胚根与胚轴的长分别是对照组的139%和145%，均显著高于对照组（P<0.05）；幼苗POD酶的活性也显著提高，MDA的含量仅为对照组的35%，显著低于对照组（P<0.05）。但较高浓度的SNP(＞100 μmol·L-1)浸种，其发芽率降低，与对照组差异不显著（P＞0.05）。胚根与胚轴增长趋势也变缓；幼苗POD酶活性增长速度也明显降低，MDA含量有所增加，但仍低于对照组。SNP浸种能促进紫花苜蓿种子的萌发和幼苗的生长，提高幼苗POD酶的活性，降低MDA的含量，其适宜浓度为50～100 μmol·L-1。

Effects of soaking seeds in SNP on seed germination and seedling growth of alfalfa

Effects of soaking seeds in sodium nitropprusside (SNP) on seed germination and seedling growth of alfalfa were studied. The results showed that， 1) seed germination rate and growth of radical and hypocotyls of soaking in 50－100 μmol·L-1 SNP treatments were significantly higher than those in control, and they were up to 1.21,1.39 and 1.45 times as control, respectively; 2) The activity of POD in seedling was enhanced significantly, and MDA content in seedling was decreased to 35%, and significantly lower than those in the control group. For the seeds soaking in SNP with high concentration (>100 μmol·L-1), the germination rate began to drop and had no significantly different with control. At the same time, the trend of growth of radical and hypocotyls was slowing down. MDA content was increasing, but still lower than that in control, while the activity of POD was reducing significantly. In conclusion, alfalfa seed soaking in SNP can promote alfalfa seed germination and seedling growth, improve seedling POD activity and reduce content of MDA. The appropriate concentration is 50－100 μmol·L-1.