摘要
化感作用在植物入侵过程中具有重要意义。以裂叶月见草入侵早期直接与之竞争的草本植物(小蓬草和阿拉伯婆婆纳)以及农作物(小麦和小白菜)为受体植物,利用培养皿滤纸法研究裂叶月见草植株各器官浸提液对这4种受体植物种子萌发和幼苗生长的影响,探讨其化感作用的强弱、对农作物的影响以及化感作用与其入侵性的关系。结果表明,裂叶月见草具有化感物质,不同器官内化感物质含量不同,叶片和根内最多,茎次之,枯叶内含量最少;裂叶月见草提取液对4种受体植物种子萌发和幼苗生长均有化感作用;不同浓度浸提液对植物的化感作用强度不同,高浓度时较强,低浓度时较弱;高浓度(2.5%,m/V)的叶、根提取液显著降低受体种子的萌发率、发芽速率(小麦除外),化感效应指数(RI)可达-0.8018,甚至可使小蓬草种子不能萌发(RI=-1.0000)。在1.3%、2.5%叶、根和茎浸提液处理下,4种受体植物的胚根长度显著降低,且胚根出现畸形现象;在测试的4个指标中,发芽速率和胚根长度对化感物质更为敏感,可能是衡量化感作用的最敏感指标。化感作用是裂叶月见草干扰临近植物生长的一种重要的生态机制,是其成功入侵的重要原因。裂叶月见草可通过化感作用对农作物产生一定的危害,应采取措施防止其进一步扩散。
Allelopathy plays an important role in plant invasion.By studying the effects of aqueous extract of root,stem,leaf and withered leaf from Oenothera laciniata on seed germination and seedling growth in two herbaceous species（Triticum aestivum and Brassicav chinensis）,which compete directly with it during the early stage of its invasion,and two crops（Conyza canadensis and Veronica persica）,we probed the extent of allelopathy,effects on crops and the relationship between allelopathy and plant invasion.The results suggested that Oenothera laciniata has allelochemicals and different concentrations in different organs：leaves and roots have the most,stems have fewer and the withered leaves have the fewest.The aqueous extract of Oenothera laciniata could have allelopathy on seed germination and seedling growth in all the four species,and the effects were concentration-dependent,increasing with the increase of concentration.The high-concentrationed aqueous extract（2.5%,m/V） of leaves and roots could significantly reduce seed germination rate and germination speed（with Triticum aestivum as exception）.The RI of relative seed germination rates in high concentration extract（2.5%） of the leaves were-0.8018 and the seeds of Conyza canadensis can not germinate in high concentration extract of the roots（RI=-1.0000）.The radicle length of all the four species were remarkably reduced in the 1.3% and 2.5% of aqueous extract of the leaves,roots as well as stems,and abnormal radicle occurred.Among the four parameters mentioned above,seed germination speed and radicle growth were more sensitive to the extract,which might be used as the most sensitive index to judge allelopathy.The allelopathy of Oenothera laciniata served as a kind of important ecological mechanism to interfere the growth of plants around,which made great contribution to its successful invasion.Oenothera laciniata could impose a threat to crops through allelopathy.So it was suggested that measures should be taken to prevent its further spread.
出处
《中国农学通报》
CSCD
北大核心
2010年第16期256-261,共6页
Chinese Agricultural Science Bulletin
基金
河南科技大学人才基金资助(09001076)
河南科技大学科学研究基金项目资助(2007ZY025)
关键词
裂叶月见草
外来物种
化感作用
入侵机制
Oenothera laciniata
alien species
allelopathy
invasive mechanism
