三七根系分泌物的自毒作用及自毒物质研究-作物栽培学直与耕作学专业毕业论文.docxVIP

量最高的2种特有化学物质为苯甲酸和邻苯二甲酸。对这四种物质进 量最高的2种特有化学物质为苯甲酸和邻苯二甲酸。对这四种物质进 行生物测试，发现供试浓度越大自毒作用越强，主要表现出能明显抑 制三七幼苗根系生长，这4种物质对三七的自毒作用大小为邻苯二甲 酸棕榈酸苯甲酸硬脂酸。 关键词：三七；田七；连作障碍；根系分泌物；自毒作用 万方数据 AUToToⅪCITY AUToToⅪCITY IN P4川AXⅣD7D G!刀垤泣l?、临 oF RooT EXUDATES AND THEIR ALLELoCHEMICALS ABSTRACT Sanqi[Panax notoginseng(Burk．)F．H．Chen】was known of traditional herbal medicine in the Guangxi province of China,and had several hundred years of cultural history．In Guangxi，Sanqi was called Tianqi．Sanqi continuous planting was easy to cause serious succession cropping obstacle problem in the sanle field．This research on autotoxicity of root exudates was to study of succession cropping obstacle，and the results provided theoretic basis to solve the succession cropping obstacle problem． (1)Succession cropping soil significant autotoxicity against seed germination，and also showed a certain impact on the growth of Sanqi． Winl the increasing of time of harvest，autotoxicity went from strength to weakness．The soil conditions began to recover in six to nine years after harvest． (2)In the hydroponic conditions，the autotoxicity of Sanqi were investigated in hydroponics either with or without activated charcoal(AC) addition．The result showed that the root fresh weight and dry weight in the III 万方数据 hydroponic hydroponic condition with AC were significantly higher than the other． The CAT and POD activities and MDA content were lower than the other without AC，but the difference was not significant． (3)Based on GC／MS analysis results from new soil，rhizosphere soil and root exudates of Sanqi．The study found that there are lots of organic acids and esters in rhizosphere soil than new soil．The four kinds of chemical substances were found from the rhizosphere soil and root exudates of Sanqi，respectively benzoic acid，phthalic acid，palmitic acid and stearic acid．The four kinds of allelochemicals were selected to study their effect on the germination and growth．The test found that the higher concentration，the stronger of t