黄牡丹种子浸提液对白菜种子萌发及幼苗抗氧化酶活性的影响

摘要

研究黄牡丹种子浸提液对白菜(Brassica pekinensis)种子萌发、幼苗生长及几种主要抗氧化酶活性的影响,初步探讨黄牡丹种子休眠的原因.以野生黄牡丹(Paeonia delavay Franch.vat.lutea)种子为实验材料,提取种皮、胚乳水浸提物.黄牡丹种皮、胚乳中均含有抑制白菜种子萌发及幼苗生长的物质,且对白菜种子萌发及幼苗生长的抑制作用随着该物质浓度的增加而更为显著;相比种皮浸提液,相同浓度条件下的胚乳浸提液对白菜种子萌发及幼苗生长的抑制作用更加明显.几种主要抗氧化酶中,胚乳浸提液能够直接抑制白菜幼苗POD和CAT酶活性,间接影响SOD酶活性.黄牡丹种子浸提物可能通过影响白菜种子抗氧化酶活性从而影响其幼苗的正常生长,黄牡丹种子内存在抑制物质,从而影响黄牡丹种子的休眠.%To understand the cause of seed dormancy of Paeonia delavay Franch.var.lutea,the effects of water crude extracts of the seed coat and endosperm of P.delavayon the seed germination,seedling growth and antioxidant enzymes of Brassica pekinensis were examined in this paper.With wild P.delavay seed as the experimental material,the experiment extracted water crude extracts of the seed coat and endosperm.The results showed that the seed,especially the endosperm tissue of P.delavay contained substances that strongly suppressed seed germination.The crude extract of endosperm of P.delavay,which significantly reduced the activities of peroxidase and catalase,and indirectly affected the activity of superoxide dismutase,showed a more significant inhibition than that of seed coat at the same dose.It was concluded that the presence of inhibitory substances is one of important causes of seed dormancy in P.delavay.