脱蜡和低温湿沙处理对毛叶山桐子种子的萌发及相关酶生理生化特征的影响

Improvement of seed germination of Idesia polycarpa by dewaxing and low temperature treatment in moist sand

为探索毛叶山桐子种子的发芽技术,研究不同浓度的磷酸二氢钾(KH2PO4)溶液浸种脱蜡及不同的层积催芽时间对该种子的发芽率及酶活性的影响。结果表明,KH2PO4浸种脱蜡后低温层积催芽处理可显著提高毛叶山桐子种子的发芽势、发芽率及酶活性。种子的脂肪酶、过氧化物酶(POD)活性在层积60 d时与45 d对比无显著差异;过氧化氢酶(CAT)活性在30 d时已达到最高,45 d时无显著提高,60 d活性降低。比较不同处理下种子的脂肪酶、POD和CAT活性,结果显示毛叶山桐子种子最佳的预处理方法是在浓度为10.5 mmol·L-1的KH2PO4溶液浸种24 h后清洗脱除种皮蜡质层,之后置5℃恒温条件下层积催芽45 d,此时脂肪酶、POD和CAT生化活性最高,发芽率也最高(60%以上)。

The aim of this study was to improve the seed germination ofldesia polycarpa Maxim .var. vestita Diels. The seed were soaked in 10.5 mmol/L KH2PO4 solution to dissolve the surface wax and then stored in moist sand at 5 ℃ for a different time. Results showed that no significant differences in lipase and peroxidase activities were observed in the dewaxed seed stored in the moist sand at 5℃ for 45 d and 60 d. The activity of catalase reached the highest on the 30th day after the seed were stratified in moist sand and no significant improvement was seen on the 45th day. The catalase activity began to decrease on the 60th day of the stratification. The results indicated that the seed that were soaked in the KH2PO4 solution for 24 h and then stored in moist sand at 5 ℃ for 45 d showed the highest activities of lipase, peroxidase and catalase and the seed germination rate was greater than 60%.