【作者】 叶陈英；

【导师】 林瑞余；

【作者基本信息】 福建农林大学 ， 植物学， 2010， 硕士

【摘要】 酚酸类物质是水稻化感作用形成的重要物质之一。本研究前期开发出一种有效的总酚酸测定试剂,并对该试剂的测定条件与方法进行优化。本研究使用该检测方法动态分析水稻根系分泌物中酚酸类物质的总量。使用该检测方法对标准样品酚酸进行检测的结果表明,在所测定的浓度范围内线形关系良好,相关系数符合性好,最低检出限在0.14μmol/L～0.61μmol/L之间,测定限在0.37μmol/L～1.00μmol/L之间,最低检出限和测定限已接近于液相色谱的相关指标数据。回收率分析结果表明,单一酚酸及混合酚酸的回收率在95.71%～122.52%范围内。可见,该检测方法具有操作简单、检测限低、检测速度快、测定条件限制少、显色范围宽且稳定性好等优点(专利申请号:2009103077540,作者排名第四)。此外,本研究运用此法动态检测不同化感潜力水稻根系酚酸类物质的释放总量,结果表明,两水稻品种的酚酸分泌总量随着时间的延长而增加,其中清种化感水稻PI312777酚酸分泌量比非化感水稻Lemont高。在移栽12天后化感水稻PI312777酚酸释放总量呈现出快速上升的趋势,而非化感水稻Lemont则是缓慢增长。进一步对两种水稻单株、每天的酚酸释放量进行曲线模拟结果表明,化感水稻PI312777酚酸的最小释放量为5.489μg/株·天,非化感水稻Lemont的最小释放量为1.791μg/株·天。以种植100天计算,化感水稻PI312777酚酸的最大释放量为19.451μg/株·天,而非化感水稻则为10.12μg/株·天。进一步以莴苣为受体分析不同酚酸类物质的化感潜力结果表明,不同酚酸类物质的化感潜力存在一定的差异,其表现为混合酚酸>对羟基苯甲酸>阿魏酸>水杨酸>香草酸。以混合酚酸为例,当混合酚酸的浓度在在0.3mg时对莴苣的抑制率可达50%以上。在此基础上,本研究进一步探讨外源添加单一酚酸类物质对土壤生理生化特性的影响及其在土壤中的降解速率。结果表明,酚酸类物质能够显著影响土壤微生物量碳(MBC)、土壤微生物呼吸强度(MBR),提高土壤微生物群落数量、土壤酶活性和土壤有效性氮、磷、钾含量。当不同酚酸处理后的第三天,土壤微生物量碳、微生物呼吸强度分别比对照提高了1.23~2.10倍和1.38~1.86倍。在微生物群落上,细菌数量则提高了1.43~3.54倍,真菌数量提高了1.16~1.50倍,放线菌数量提高了1.86~3.24倍。土壤酶方面,脲酶活性提高了1.58~2.66倍,蛋白酶活性提高了1.69~2.46倍,蔗糖酶活性提高了2.08~3.20倍。土壤营养物质循环中,有效氮增加了99%~168%,有效磷增加了135%~249%,有效钾增加了10%~15%。而不同酚酸对土壤各指标影响的大小趋势为对羟基苯甲酸>阿魏酸>香草酸>水杨酸>肉桂酸。此外,酚酸类物质在土壤中降解速率分析结果表明,酚酸处理后的第三天,土壤中酚酸含量下降了45%-75% ,第9天下降了55%-98%。从第3天到第9天,土壤剩余5种酚酸含量均明显下降,对羟基苯甲酸从132.3到2.65μg/g,阿魏酸从193.2到3.1μg/g,水杨酸从210.2到1.6μg/g,香草酸从271.3到32.3μg/g,肉桂酸从242.6到45.1μg/g。相关性分析结果表明,细菌数量、有效磷、钾含量与土壤中5种酚酸类物质的含量呈显著的正相关。放线菌数量、脲酶活性、有效氮含量与土壤中对羟基苯甲酸含量呈显著的正相关。真菌、放线菌数量、蛋白酶活性与土壤中阿魏酸含量呈显著的正相关。脲酶活性、蛋白酶活性、蔗糖酶活性、有效氮含量与水杨酸含量呈显著的正相关。放线菌数量、脲酶活性、蛋白酶活性、有效氮含量与香草酸含量和蛋白酶、蔗糖酶活性与肉桂酸含量均呈显著正相关。可见,酚酸类物质能有效刺激土壤微生物的增长,改变土壤酶活性,适当提高土壤有效营养物质的循环。综上,本研究开发了一种有效测定水稻根系分泌总酚酸含量的方法。本研究动态分析了水稻根系酚酸总量,并提出化感水稻种植后起化感作用的理论起始时间。其次本研究分析外源酚酸类物质对土壤生理生化特性的影响证实了,化感水稻分泌的酚酸类物质抑制了邻近杂草生长的同时,有利于改善自身生长的土壤环境,不仅起到抑草作用,还起到提高自身生存环境内所需营养物质循环的作用。总之,本研究为田间化感水稻栽培及深入揭示水稻化感作用形成的机理提供了一定的理论基础。更多还原

【Abstract】 Phenolic acid compound was one of the mainly allelochemical in rice. In this paper, a new method was developed to determine the total content of phenolic acid in aqueous by colorimetric analysis. Strictly linear correlation between absorption and the total content of phenolic acid was found in all the test concentration range by using single and mixture of standard chemicals. The lowest limit of determination was between 0.14μmol/L and 0.61μmol/L, and the limit of determination was between 0.37μmol/L and 1.00μmol. The lowest limit of determination and limit of determination were similar to that of high performance liquid chromatography (HPLC) method. Furthermore, the recovery rate of single and mixture phenolic acid was reached 95.71% to 122.52%. The method described above for total phenolic acid determination has many benefits, such as low detection limits, fast detection speed, low detection condition limit, wide range of chromogenic and good stability, et al (Patent applications number: 2009103077540).In this way, the dynamics of total phenolic acid in rice root exudates was detected . The results showed that the total phenolic acids in root exduates of two rice(allelopathic rice PI312777 and non allelopathic rice Lemont) enhanced across the culturing periods, showing the total phenolic acids in root exduates of allelopathic rice PI312777 was more higher than non allelopathic rice Lemont. After the rice was cultured for 12 days in hydroponics, the total phenolic acid in root extract of allelopathic rice PI312777 increased rapidly, while that in non allelopathic rice Lemont increased slowly. The fixed curve of total phenolic acids released by different allelopathic rice per plant per day indicated that the lowest total phenolic acid released of allelopathic rice PI312777 was 5.489μg/plant·day, while non allelopathic rice was 1.791μg/plant·day. The peak of released phenolic acids was 19.451μg/plant·day for allelopathic rice PI312777 and 10.12μg/plant·day for non allelopathic rice Lemont, when the rice was plant about 100 days in theory. Additionally, the lettuce was employed as the reciever plant to evaluate the allelopathic potential of phenolic acids. The results indicated that the allelopathic potential of mixture and single phenolic acid was showed in the order from higher to lower, mixture phenolic acid > p-hydroxybenzonic acid > ferulic acid > salicylic acid > vanillic acid. As example, the inhibition rate of mixture phenolic acids to receiver plant was about 50% at the concentration of 0.3mg·kg-1.The analysis of soil physiological and biochemical characteristics showed that 5 kind of phenolic acids, such as p-hydroxybenzonic acid, ferulic acid, salicylic acid, vanillic acid, and cinnamic acid, were employed to evaluate the effect of exogenetic phenolic acids on the microbial community, enzyme activities and nutrients available in paddy soil. The results showed that the application of phenolic acids could significantly enhance the soil microbial biomass carbon(MBC), soil microbial respiration rate(MBR), enrich soil microbial populations, impulse the soil enzyme activities, as well as be beneficial to available nutrients (nitrogen, phosphorous and potassium). After the soil was treated with phenolic acids, the highest promoting effect was found in the third day. showing that the soil MBC was ca 1.23 to 2.10 times, and the MBR was ca 1.38 to 1.86 times as higher as the control, and they were declined respectively later on The population of bacteria was ca 1.43 to 3.54 times as higher as the control, and it was ca 1.16 to 1.50 times for fungi, ca 1.86 to 3.24 times for actinomycete, respectively. The activity of urease was ca 1.58 to 2.66 times as higher as the control, and it was 1.69 to 2.46 times for protease, 2.08 to 3.20 times for sucrase. The contents of available nitrogen and phosphorus in the soils were significantly increased by 99% to 168% and 135% to 249%, and the contents of available potassium were enhanced by a range of 10%-15%. The promoting effect of exogenous phenolic acids showed in the order from higher to lower as p-hydroxybenzonic acid > ferulic acid > vanillic acid > salicylic acid > cinnamic acid. In addition, the residuals of the phenolic acids in the soil showed that the concentration of phenolic acid was decreased by 45%-75% detected on days 3, and further decreased by 55%-98% on days 9. From the third to the ninth day, the residuals of the five phenolic acids in soil were significantly decreased from 132.3 to 2.65μg/g, 193.2 to 3.1μg/g, 210.2 to 1.6μg/g, 271.3 to 32.3μg/g, and 242.6 to 45.1μg/g for p-hydroxybenzonic acid, ferulic acid, salicylic acid, vanillic acid and cinnamic acid, respectively, significant difference was also found among the five allelochemicals at the same incubating stages. Correlation analysis indicated that all the bacteria, available phosphorus and potassium were significantly positively correlated with the five exogenous phenolic acids, while the actinomycete, urease, and nitrogen had significantly positive correlation with p-hydroxybenzonic acid, the fungi, actinomycete, and protease had significant correlation with ferulic acid, the urease, protease, sucrase and available nitrogen were significantly positively correlated with salicylic acid, the actinomycete, urease, protease, and nitrogen had significantly positive correlation with vanillic acid. The protease and sucrase had significantly positive correlation with cinnamic acid. It suggested that phenolic acids are useful carbon resource to establish soil microbial community, enhance the activities of soil enzyme, and accelerate the cycling of nutrient in soil.In summary, we developed a effectively method to detect the total phenolic acid content in rice root exduates. Further, we used this method to detect the total content of phenolic acids released by different allelopathic potential rice. In addition, we analysed the effect of phenolic acid on soil physiological and biochemical characteristics , confirmed that allelopathic rice released phenolic acid not only inhibited the growth of company weed, but also benifitial to the nutrient cycling in the soil.更多还原