羽枝青藓和瘤柄匐灯藓对入侵植物种子萌发和幼苗生长的影响

入侵植物会通过化感作用等手段抑制本地种的生存繁衍,但本土植物尤其是地被层的藓类植物对入侵植物有何影响尚不清楚。本文以本土羽枝青藓和瘤柄匐灯藓为供体材料,以恶性入侵杂草稗草和野胡萝卜为受试材料,从藓丛结构特征和化感作用角度探究藓类植物对入侵植物种子萌发和幼苗生长的影响。结果表明: 2种入侵植物种子落入藓丛后其发芽率、发芽势和发芽指数均受到显著抑制,抑制效果为藓丛上部>藓丛下部>无藓丛。稗草种子落入藓丛下部会显著影响其根长和根芽比。施加藓类浸提液均显著降低2种入侵植物的发芽率、发芽势及发芽指数,但呈现不同的浓度效应。施加浸提液在一定程度上增加了稗草幼苗芽长、根长和根芽比,但对野胡萝卜无明显的规律性影响。藓类植物对2种入侵植物种子萌发和幼苗生长的化感综合效应均表现为抑制作用,其中,野胡萝卜的敏感性大于稗草,且高浓度下更加明显。可见,藓类植物对入侵植物种子萌发和幼苗生长具有一定抑制作用。

Effects of Brachythecium plumosum and Plagiomnium venustum on seed germination and seedling growth of invasive plants

Invasive plants can inhibit the survival and reproduction of native species through alle-lopathy. It is not clear whether the native plants, especially the mosses in the ground layer, inf-luence the invasive plants. In this study, we examined the effects of two native moss species, Brachythecium plumosum and Plagiomnium venustum, on two malignant invasive plants, Echinochloa crusgalli and Daucus carota. The effects of mosses on seed germination and seedling growth of both invasive species were determined based on the clump structure and allelopathy of the mosses. The germination rate, germination potential and germination index of the two invasive species were significantly inhibited when seeds fallen on or into the moss clump, with an order of inhibition effect: above moss clump>below moss clump>no moss. Radicle length and radicle/plumule of D. Carota were significantly affected when seeds fallen into the moss clump. Moss water extracts significantly reduced germination rate, germination potential, and germination index of the two invasive plants, with these effects being concentration-dependent. To some extent, moss water extracts increased the plumule length, radicle length and radicle/plumule of D. Carota seedlings, but without effect on E. crusgalli. Both mosses showed inhibitory effects on seed germination and seedling growth of two invasive plants, with higher sensitivity of E. crusgalli than D. Carota. Along with the increases in concentration of water extract, stronger inhibitory effects were found. Therefore, mosses could partially inhibit seed germination and seedling growth of invasive plants.