尾巨桉叶片水浸提液化感作用的生物评价

以尾巨桉为研究对象,通过测定新鲜尾巨桉叶片水浸提液对菜心、白菜、水稻种子萌发及芽生长的影响,对其化感作用进行生物评价。结果表明,与对照相比,当尾巨桉叶片水浸提液质量浓度达到5%时,菜心和白菜的种子发芽率下降明显,产生显著或极显著的抑制作用,其他处理的作用不显著;尾巨桉叶片水浸提液质量浓度低于1%时,对水稻种子萌发具有一定促进作用。尾巨桉叶片水浸提液促进菜心、白菜的胚轴生长,而抑制胚根生长,且对胚轴生长的促进作用较明显;对水稻胚轴生长的作用不显著,而对其胚根生长有显著的抑制作用。尾巨桉叶片中存在某些化感物质,其化感效应因植物种类及器官不同而有所差别。

Bioassay of allelopathy of aqueous extracts from Eucalyptus urophylla×E.grandis's leaves

The bioassay of allelopathy of Eucalyptus urophylla×E.grandis was performed by measuring the effects of aqueous extracts from Eucalyptus urophylla×E.grandis′s leaves on seed germination and embryonic growth of Brassica parachinensis,Brassica pekinensis and Oryza sativa.The results showed that,in the treatment period,when the aqueous extracts from Eucalyptus urophylla×E.grandis′s leaves′ density reached 5%,the inhibited effects on the B.parachinensis.and B.pekinensis seed′s germination percentages were significant or extremely significant;The low concentration extracts(0.05%-0.1%) certainly promoted the germination of O.sativa.In addition,the aqueous extract stimulated the growth of B.parachinensis and B.pekinensis′s hypocotyl growth but inhibited their radicle growth.Significantly the O.sativa′s hypocotyl growth was promoted and the radicle growth was inhibited by the extracts.Accordingly,it is speculated that in E.urophylla×E.grandis fresh leaves,some substances have different allelopathic effects on plant by varied species and organs.