牡丹叶及其不同溶剂提取物对生菜等幼苗生长的抑制效应

为了进一步明确牡丹叶及其不同溶剂提取物的化感活性大小,于室内采用琼脂混粉法测定了牡丹叶粉末在不同浓度下对生菜、小麦、黄瓜、稗、夏至草、播娘蒿和独行菜等7种受体植物幼苗生长的影响.结果表明,虽然在低浓度下牡丹叶粉末对各受体植物幼苗生长的影响差异较大,但在高浓度时均表现出了较高的抑制作用,且对胚根(或种子根)的抑制效果明显高于对胚轴或胚芽鞘的抑制.计算对各受体植物胚根或种子根、胚轴或胚芽鞘的有效中浓度(EC50),生菜为0.93～5.25 g/L、小麦为1.20 ～4.65 g/L)、黄瓜为3.58～＞10.0 g/L、稗为0.64～3.36 g/L、夏至草为1.09～5.27 g/L、播娘蒿为1.02 ～9.65 g/L、独行菜为0.79 ～6.84 g/L,以稗的敏感性最高,黄瓜最低.继而探索了牡丹叶乙醇、甲醇和蒸馏水3种溶剂提取物对生菜幼苗生长的抑制效果,发现乙醇提取物的活性最高,提取浓度以80％ (V/V)为宜.

Inhibitory Effects of Paeonia suffruticosa Leaves and the Extracts by Different Solvents on Sccdling Growth of Lactuca sativa and Some Other Plants

In order to further understand the allelopathic activities of Paeonia suffruticosa leaves, indoor test was carried out via agar mixed powder（PPA） method to detect effects of Paeonia suffruticosa leaf powder under different concentrations on seedling growth of 7 receptor plants including Lactuca sativa L. vat. ramosa Hort. , Triticum aestivum L. , Cucumis sativus L. , Echinochloa crusgalli L. , Lagopsis supine （ Steph. ） Ik. - Gal. ex Knorr. , Descuminia Sophia L. and Lepidium apetalum Willd. Results showed that influence of Paeonia suffruticosa leaf powder at low concentration on seedling growth of each receptor plant was quite different, but relatively high inhibition effects could be were observed at high concentration, and particularly inhibition effects on radicles （ or seminal roots） were significantly higher than that of hypocotyls or coleoptiles. The EC50 an effective dose for half lethal value corresponding to radicles （ or seminal roots）, and hypocotyls （or coleoptiles） respectively for each receptor plant, calculated as follows. L. sativa 0.93 -5.25 g/L. T. aestivum1.20-4.65 g/L, 6. sativus 3.58 - 〉10.0 g/L, E. crusgaUi 0.64 - 3.36 g/L, L. supine 1.09 - 5.27 g/L, D. Sophia 1.02 - 9.65 g/L, L. apetalum O. 79 - 6.84 g/L. Among them, E. crusgalli and C. sativus presented the highest and the lowest susceptibility to peony leaves respectively. Meanwhile, effect of peony leaves extract derived from different solvent （ethanol, methanol and distilled water） on seedling growth of L. sativa was tested respectively with a result that ethanol extract presented the highest inhibition activity on receptor plant seedling growth, and the optimum ethanol concentration for extraction was 80% （V/V）.