摘要： 为研究淹水胁迫下褪黑素浸种对长短中胚轴水稻幼苗期生理和生化性状的影响，采用不同浓度梯度的褪黑素（MT）处理，测定中胚轴长、胚芽鞘长、芽长、鲜质量、成活率等相关农艺性状，测定过氧化物歧化酶（POD）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）的活性以及丙二醛（MDA）含量等生理生化指标。MT浸种对淹水胁迫下水稻生长的影响可分为低浓度缓解胁迫和高浓度加剧毒害；淹水处理下相比短中胚轴品种华航31、DH4040，长中胚轴品种鄂中4号、DH4038具有较高的成活率；在对4个品种添加10，100 μmol/L的MT浸种处理时，华航31中MT浸种效果表现均是最好的，其中100 μmol/L MT浸种处理在每个品种中均能显著提高幼苗的成活率。随着浓度提高到1 000 μmol/L，对所有的品种均表现为抑制成活；MT浸种可降低MDA含量，提高POD、SOD、CAT活性，促进中胚轴长、胚芽鞘长、芽长、鲜质量等农艺性状，100 μmol/L MT浸种处理效果最好；1 000 μmol/L MT浸种也可以促进相关农艺性状提升并提高酶活性，但成活率显著下降。适当浓度的褪黑素浸种，能提高淹水胁迫下水稻幼苗活力和出苗率，显著降低淹水胁迫对水稻幼苗的毒害作用。

关键词: 水稻, 中胚轴, 褪黑素, 浸种, 淹水胁迫

Abstract: The effects of melatonin-soaking seeds on physiological and biochemical characteristics of rice seedlings under submergence stress. Three concentration treatments of melatonin(10, 100, 1 000 μmol/L) were arranged. The agronomic traits such as Mesocotyl length, coleoptile length, shoot length, fresh weight and survival rate, and the physiological and biochemical indexes such as enzyme activity of peroxidase(POD), superoxide dismutase(SOD), catalase(CAT) and malondialdehyde(MDA) content were measured.The results showed that low concentration MT-soaking could alleviate the stress and high concentration MT-soaking aggravate the toxicity. Compared with short mesocotyl cultivars Huahang 31 and DH4040, long mesocotyl cultivars Ezhong 4 and DH4038 had higher survival rates under submergence stress. Among the four cultivars, Huahang 31 had the best effect of MT-soaking seeds in two treatments, i.e. 10,100 μmol/L MT. The treatment of 100 μmol/L MT-soaking seeds could greatly improve the seedling survival rate of all cultivars. When the MT-soaking concentration increased to 1 000 μmol/L, the survival rate of all cultivars was inhibited. MT-soaking seeds could reduce MDA content, increase POD, SOD and CAT activities, and promote agronomic traits such as mesocotyl length, coleoptile length, bud length and fresh weight, while 100 μmol/L MT-soaking seeds could also promote the related agronomic traits. While 1 000 μmol/L MT-soaking could also promote the related agronomic traits and enzyme activity,but the survival rate decreased significantly.It was concluded that soaking-seeds with appropriate concentration of melatonin could improve the vigor and emergence rate of rice seedlings under submergence stress, and significantly reduce the toxicity of submergence stress on rice seedlings.

Key words: Rice, Mesocotyl, Melatonin, Soaking-seed, Submergence stress

中图分类号: 

• S511