差巴嘎蒿叶浸提液对4种沙地草本植物种子萌发的化感作用

Allelopathic Effect of Foliage Water Extract of Artemisia halodendron on Seed Germination of Four Herbaceous Species in Sandy Land

差巴嘎蒿是沙地恢复过程中植被演替的重要物种,是半流动沙丘的优势物种之一。本文从化感作用角度,研究了不同浓度差巴嘎蒿叶浸提液（0、10、20、40、60、80 g·L^-1和100 g·L^-1）对狗尾草、达乌里胡枝子、大果虫实和冰草的种子萌发的影响。结果表明：差巴嘎蒿叶浸提液对狗尾草种子萌发的影响较小,低浓度浸提液处理对其萌发有一定的促进作用,而对其他3个物种均表现为显著的抑制效应,且随处理浓度增加,抑制效应增大。差巴嘎蒿对其他物种的种子萌发均具有强烈的化感作用,通过叶片凋落后的物质释放形成的化感作用可能是其保持竞争优势的重要方式之一。

Artemisia halodendron is one of the dominant species in vegetation succession for sand land restoration.At the initial stage of vegetation regeneration over sand land,A. halodendron was one of the dominant specie over semi-fixed dune. Thereafter it is replaced by other annual or perennial species,such as Lespedeza bicolor,Corispermum macrocarpum and Agropyron cristatum with the development of sand land recovery. However,the mechanism of its succession is still unclear. In this study,we focused on the allelopathic effect of leaf water extract with different concentrations（0,10,20,40,60,80 and 100 g·L^-1） from A. halodendron on seed germination of one symbiosis specie Seteria virids and three competitive species in terms of L. bicolor,C. macrocarpum and A. cristatum. The results showed that the leaf water extract of A. halodendron affected seed germination of S. virids slightly,and which was promoted under low concentration of the foliage water extract of A. halodendron. However,the seed germination was significantly inhibited by the foliage water extract of A. halodendron,and this allelopathic inhabitation was increased with the increase of the concentration. In conclusion,A. halodendron showed a strong allelopathic effect to other species in vegetation regeneration in the process of sand land restoration. Allelopathic effect was induced by the matters released from the fallen leaves,which may be one of the vital strategies to keep competitiveness.