番茄对不同养分水平下南美蟛蜞菊和蟛蜞菊化感作用的响应

llelochemicals secreted by invasive alien plants can affect the growth and physiological characteristics of native plants, and nutrient availabilities have an important influence on the allelopathic potential of invasive plants. The Lycopersicon esculentum planted in situ was adjacent to the same species of L. esculentum, Wedelia trilobata and W. chinensis, and 15%, 25%, 50% and 75% Hoagland solution were simulated different nutrient availabilities in greenhouse control experiments, in order to investigate the allelopathic effects of the invasive plant W. trilobata and its native congener W. chinensis on leaf chlorophyll fluorescence parameters and biomass of the native plant L. esculentum under different nutrient availabilities. The results were as follows: (1) The chlorophyll fluorescence parameters and biomass of L. esculentum at 75% Hoagland solution were significantly higher than the other three nutrient availabilities. (2) As the nutrient availabilities decreased, PSII maximum photochemical efficiency (Fv/Fm), effective PSII quantum yield [Y(II)], photochemical quenching coefficient (qp) of L. esculentum leaves and the total biomass of L. esculentum plants were markedly reduced, whilenon-photochemical quenching coefficient (NPQ) and the biomass allocation to roots were increased. (3) Under 25% Hoagland solution, Fv/Fm, Y(II), qp and total biomass of L. esculentum planted with W. trilobata were remarkably lower than those of L. esculentum planted with W. chinensis, NPQ and the biomass allocation to roots were evidently higher than those of L. esculentum planted with W. chinensis. The above results demonstrate that W. trilobata and W. chinensis may inhibit the growth of L. esculentum through the secretion of allelochemicals in roots, and the allelopathic effect of W. trilobata is stronger than W. chinensis. Therefore, increasing nutrient availabilities in cultivation substrate can dramatically reduce the allelopathic effects of W. trilobata and W. chinensis on L. esculentum.