外来植物日本落叶松凋落叶对卧龙乡土植物化感作用的研究

为了探究外来植物日本落叶松(Larix kaempferi)凋落叶对乡土植物的化感作用,本文以5种卧龙乡土植物为试材,采用培养皿滤纸法及盆栽土培法,研究了不同浓度(0.01、0.05、 0.1 g/mL)的日本落叶松凋落叶水浸提液对乡土植物种子萌发及幼苗生长的影响.结果表明:日本落叶松凋落叶水浸提液对5种乡土植物种子萌发及幼苗生长均有影响.1)浸提液对种子萌发的化感作用综合效应的强度依次为紫花苜蓿(Medicago sativa)夏枯草(Prunella vulgaris)草木犀(Melilotus officinalis)车前(Plantago depressa)披碱草(Elymus dahuricus).浸提液对紫花苜蓿、草木犀及夏枯草种子萌发主要表现出抑制作用,且抑制程度与浸提液浓度正相关;对披碱草及车前种子萌发表现出"低促高抑"的现象.2)浸提液对幼苗生长的化感作用综合效应的强度依次为紫花苜蓿草木犀夏枯草披碱草车前.其中浸提液对紫花苜蓿及草木犀幼苗生长主要表现出抑制作用且与浓度呈正相关;对披碱草及夏枯草幼苗生长表现出"低促高抑"的作用,对车前幼苗的生长始终表现为促进作用.研究结果为日本落叶松林下人工补植、增加植物多样性提出了营林管理措施.

Allelopathic effects of exotic plant Larix kaempferi litters on Wolong native plants

In order to explore the allelopathy of leaf litter of Larix kaempferi on native plants, the effects of different concentrations (0.01, 0.05, 0.1 g/mL) of water extracts of Larix kaempferi litters (LkLWE) on seed germination and seedling growth of native plants were studied using petri dish filter paper method and pot soil culture method with 5 native plants in Wolong. The results showed that LkLWE had an effect on the seed germination and seedling growth of 5 native plants.1) The intensity of the comprehensive effect of the allelopathy of LkLWE on seed germination was in order of M.sativa > P.vulgaris > M.officinalis > P.depressa > E.dahuricus. The LkLWE mainly inhibited the seed germination of M.sativa, M.officinalis and P.vulgaris, and the inhibition degree was positively correlated with the concentration of the extract; the seed germination of E.dahuricus and P.dipressa showed a phenomenon of low promotion and high inhibition. 2) The intensity of allelopathic comprehensive effect of LkLWE on the growth of seedlings was in the order of M.sativa > M.officinalis >P.vulgaris > E.dahuricus > P.depressa. Among them, the extract mainly inhibited the seedlings growth of M.sativa and M.officinalis, and was positively correlated with the concentration. The LkLWE has a lo-promoting and high-inhibiting effect on the seedlings growth of E. dahuricus and P. vulgaris, and has always been a positive effect on the growth of P.depressa seedlings. The results suggest some management measures for artificial replanting under Larix kaempferi forest and increasing plant diversity.