空心莲子草根系分泌物对无机磷细菌的负化感效应  

Negative Allelopathic Effects of Root Exudate of Alternanthera Philoxeroides on Growth and Phosphate Dissolution of Inorganic Phosphorus Bacteria

作　　者：王玉书[1] 刘海[1,2] 袁玲[1] 

机构地区：[1]西南大学资源环境学院,重庆400716 [2]贵州省农业科技信息研究所,贵阳550006

出　　处：《土壤学报》2017年第6期1486-1496,共11页Acta Pedologica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2013CB127405)资助~~

摘　　要：空心莲子草(Alternanthera philoxeroides Griseb)是全球难以根除的恶性杂草,能在有效磷较低的土壤中生长。了解空心莲子草对微生物转化土壤无机磷的影响,有益于揭示其入侵机制。利用固、液培养技术,以3株(B05、B07和B09)能溶解无机磷的伯克霍尔德氏菌(Burkholderia Yabunchi)为材料,研究了空心莲子草根系分泌物(Exudates from A.philoxeroides roots,EAR)对其生长繁殖和溶磷的化感作用。结果表明,在固体培养时,随EAR浓度提高,无机磷细菌(Phosphatesolubilizing bacteria,PSB)的菌落直径、溶磷圈直径和溶磷指数降低;在液体培养基中,EAR不同程度地抑制PSB繁殖生长,数量减少48.13%~73.03%。供试菌株均能分泌氢离子、草酸和柠檬酸,其中B05和B09还分别能分泌乙酸和苹果酸,B07能分泌乙酸和丁二酸,草酸和柠檬酸共占有机酸分泌总量的66.02%~74.72%。此外,有机酸分泌总量和氢离子分泌量分别与溶磷量呈显著正相关,相关系数依次为0.836和0.947(p<0.05,n=12)。EAR显著抑制PSB分泌有机酸和氢离子,与此同时溶磷量降低11.41%~47.32%。因此,EAR对PSB呈负化感效应,不同程度地抑制PSB繁殖生长、有机酸和氢离子分泌及无机磷溶解。【Objective】Alternanthera philoxeroides Griseb,a kind of ill weed hard to eliminate in the world,is able to grow in both soils and waters low in available phosphorus（P）and now widely distributed in over twenty provinces（regions or municipalities）in this country,causing enormous hazard to agriculture,forestry,animal husbandry and aquiculture. It is,therefore,essential to get to know how the weed affects microbes transforming inorganic P in soil. Hopefully,the knowledge will help understand its invasive mechanism,and serve as a scientific basis for effective control of the weed.【Method】 Plants of A. philoxeroides were gathered and cultured in deionized water（fresh root weight ：deionized water volume = 1∶1.5）for 48 hours formed of two cycles of day and night,12 hours each shift,at 25 ℃±2 ℃with light intensity being 15 000 Lex in the day shift. Then the plants were removed,leaving the water as root exudate solution of the plant for the follow-on experiment,which was designed to have two types of culture media,liquid and solid,inoculated with three P-dissolving strains of Burkholderia Yabunchi（B05,B07 and B09）and then amended with the root exudate solution at exudates of A. philoxeroides roots（EAR）0.000（CK）,0.013,0.025,and 0.050 g ml-1,separately. Bacterial colonies on the solid media were measured for diameters and diameters of their P-dissolving rings and then P-dissolving indexes worked out. And the liquid media were analyzed for proton,organic acids,and dissolved phosphorus with a p H meter,a high performance liquid chromatography（HPLC）,and the molybdenum blue colorimetric method,separately.【Result】Bacterial colonies,P-dissolving rings and P-dissolving indexes in the solid culture media decreased with increasing EAR concentration. The effect on was found the highest with Strain B09,which was followed by Strain B05 and B07. In the solid culture media amended with EAR 0.050 g ml^-1 of the root exudate,bacterial colonies decreased by 40.32%~50.00% in diameter,by 49.09%~

关 键 词：空心莲子草 化感效应 无机磷细菌 

分 类 号：S144[农业科学—肥料学]