老参地土壤提取液对水稻种子萌发及幼苗生长的化感效应

Allelopathic effects of extract from old ginseng soil on seed germination and seedlings growth in rice

【目的】探讨不同质量浓度老参地土壤提取液对水稻种子萌发、幼苗生长及光合作用的影响,为人参-水稻轮作体系研究提供参考。【方法】采用室内生物测定法及基质盆栽试验,以去离子水为对照(CK),研究低(10g/mL)、中(20g/mL)和高(40g/mL)3种质量浓度的老参地土壤水提液,对水稻种子萌发、幼苗生物量、根系活力、叶片可溶性蛋白和叶绿素合成、电导率及净光合速率的影响。【结果】与对照相比,不同质量浓度老参地土壤提取液处理后水稻种子萌发率、苗高及幼苗生物量均有不同程度的增加,其中随着老参地土壤提取液处理质量浓度的升高,水稻种子萌发率逐渐增加,中、高质量浓度处理与CK差异显著(P<0.05)。当老参地土壤提取液质量浓度为40g/mL时,单株鲜、干质量最大,分别为14.22和1.66mg。各质量浓度老参地土壤提取液处理对苗高影响不显著,却明显抑制了水稻幼根的生长。中、高质量浓度老参地土壤提取液处理均显著促进了幼苗叶片可溶性蛋白合成,低质量浓度老参地土壤提取液处理明显促进了根系活力的增加,而高质量浓度老参地土壤提取液处理则降低了根系活力;不同质量浓度老参地土壤提取液处理均显著降低了水稻叶片的叶绿素含量和绝对电导率;低、中质量浓度老参地土壤提取液处理下叶片净光合速率均有增加,而高质量浓度老参地土壤提取液处理则表现出微弱的抑制作用。【结论】老参地土壤水提取液对水稻早期萌发生长有一定的促进作用,且对部分生理指标(根系活力和净光合速率)表现为"低促高抑"的剂量相关性反应。

【Objective】The allelopathic effects of extract from old ginseng soil on seed germination and growth and photosynthesis of rice were investigated to provide reference for ginseng-rice rotation.【Method】The deionized water was used as the control,both bioassay methods and pot experiment were done to measure germination rate,root and shoot length,biomass,root vigor,electric conductivity,soluble protein and chlorophyll content,and net photosynthesis rate of rice seedlings under 10,20 and 40 g/mL water extract concentration.【Result】After treated with different concentrations of extract from old ginseng soil,rice seed germination rate,shoot height and biomass were all promoted than the control when the treatment concentration increased.Germination rate exhibited significant differences at 20 g/mL and 40 g/mL treatments（P〈0.05）.The biggest fresh quality and dry quality of single plant were respectively 14.22 mg and 1.66 mg when the concentration was 40 g/mL.The change of rice shoot height were unobvious compared with the control,but root lengths all were significantly inhibited after treated with different concentrations.The soluble protein contents gradually enhanced at middle and higher concentrations.However,root vigor of rice exhibited a dose-dependant treated with concentration changing.The chlorophyll synthesis was inhibited significantly with the increase of concentration from 10 g/mL to 40 g/mL of the control.Absolute EC of leaves all was lowered.The net photosynthesis rate showed stimulatory effect under 10 and 20 g/mL,and inhibitory effect under 40 g/mL slightly.【Conclusion】Taken together,extract from old ginseng soil had stimulating allelopathic effects on seed germination and seedling growth of rice but root length.Both root vigor and net photosynthesis rate exhibited promotion at lower concentration and inhibition at higher concentration.