营养元素调控下南瓜组培根化感作用的初步研究

通过调节B5培养基中的组分,研究了金钩南瓜组培根在五种营养元素(P、Mg、Fe、Cu、B)四个浓度梯度(1/2 B5、B5、3/2 B52、B5)培养下化感作用的响应模式以及对黑籽和金钩南瓜两种受体幼苗生长的影响。结果表明:不同营养元素对受体植物幼苗生长的影响不一致,与元素含量显著相关,而且依赖于受体选择。五种营养元素在亏缺(1/2 B5)和正常(B5)条件下南瓜组培根过滤液对受体植物幼苗生长均表现为抑制作用;而适量增加营养元素的条件下(3/2 B5和2 B5),一般表现为促进作用,但2 B5含量下,B元素导致金钩南瓜的自毒作用,而Fe能引发金钩南瓜组培根过滤液对黑籽南瓜的抑制作用。因此理论上初步得出P和Mg元素可以降低南瓜根系的毒害作用,而Fe、Cu和B元素对南瓜根系的化感调控作用与品种选择有关,这对调控施肥、降低设施农业中葫芦科作物的连作障碍具有一定的参考意义。

A preliminary study on adjustment of nutrient elements for allelopathic effect of Cucurbita moschata M. cultured roots

By regulating components in B5 culture media,under four concentrations(1/2 B5,B5,3/2 B5,and 2 B5) of the five necessary elements(P,Mg,Fe,Cu,and B),allelopathic effect of pumpkin root culture(Var.Jingou) filtrates on the growth of two receiving plant seedlings(Cucurbita moschata M.Var.Jingou and Var.Heizi) were studied.The results indicated that different elements showed various effects on growth of receiving plant seedlings,which depended significantly on their corresponding contents and varieties of the accepting plants.Pumpkin cultured roots filtrates exhibited marked inhibition under deficit(1/2 B5) and normal(B5) nutrient circumstance.And under enhanced nutrients conditions (3/2 B5 and 2 B5),it generally showed significant stimulation effects.Fe and B redundancy would lead to certain inhibition.On the other hand,under the most redundant environment(2 B5),B element causes strong auto-toxic effects of Var. Jingou.Meanwhile,Fe would induce inhibitory effect of Var.Jingou cultured roots on seedlings growth on seedling growth of Var.Heizi.In conclusion,it was preliminarily derived that both P and Mg elements could eliminate phytotoxic activity of pumpkin cultured roots.However,Fe,Cu,and B elements showed allelopathy regulation of pumpkin,which depend on acceptors accessions.The results of this study could provide important reference and guidance for removing the obstacles of continuous cropping by fertilizer manipulations in modern sustainable agriculture.