连作草莓根系分泌物自毒作用的模拟研究  

SIMULATION OF AUTOTOXICITY OF STRAWBERRY ROOT EXUDATES UNDER CONTINUOUS CROPPING

作　　者：甄文超[1,2] 曹克强[1] 代丽[3] 张学英[3] 

机构地区：[1]河北农业大学植物保护学院 [2]河北省农作物病虫害生物防治工程技术中心,保定071001 [3]河北农业大学园艺学院

出　　处：《植物生态学报》2004年第6期828-832,共5页Chinese Journal of Plant Ecology

基　　金：河北省科技攻关项目 (0 12 2 0 173D);河北农业大学博士基金项目 (2 0 0 3 0 0 5 )

摘　　要：草莓 (Fragariaananassa)根系分泌物的自毒作用是草莓连作病害发生机理研究的重要内容之一。应用组织培养技术提取草莓根系分泌物 ,并对其自毒作用进行了测定。结果表明 ,在含有根系分泌物的生根培养基中定植的草莓组培苗 ,其生根、根系生长均受到不同程度的抑制 ,生物量显著下降 ,而且根系分泌物对草莓幼苗根系生理活性具有抑制作用。主要表现为根系TTC还原活性下降、相对电导率增大、SOD酶活性降低及MDA生成量增多等方面 ,并导致草莓幼苗生长发育不良、病害加重。说明草莓根系分泌物具有自毒作用 ,连作条件下田间根系分泌物逐年积累后产生的自毒作用 ,可能是草莓再植病害发生的重要原因。Replant disease is a serious problem for the development of sustainabl e cropping systems of strawberry, Fragaria ananassa. Previous studies have shown that auto-toxicoids secreted from roots play an important role in replant disease of some crops, and autotoxicity of root exudates is a very important asp ect of understanding replant disease mechanisms. In this paper, root exudates we re extracted and their autotoxicity was studied by using tissue culture methods in order to avoid interferences from external factors. Root tissue culture mediums (MS+BA 0.2 mg·L -1 ), in which one generation o f seedlings had been cultivated, were collected in a bio-clean cabinet and mixed with a new culture medium. Five treatments were set up in which the volume proportion of t he new culture medium to the used culture medium were 10∶30, 15∶25, 20∶20 , 25∶15 and 30∶10. Tissue culture seedlings of the same age and with the same app eara nce were chosen and inoculated in the five culture medium treatments. Our result s showed that on the 40th day after inoculation, development and growth of roots were inhibited in mixed tissue culture mediums, and the inhibitory effects were greater as the proportion of the used culture medium increased. As a result, in crements of plant height and leaves, number of roots, length of roots, and weigh t of plants were reduced in mixed culture mediums as compared to the pure new cu lture medium treatment. The vermiculite in which strawberry tissue culture seedlings had been cultivated for 60 days was collected and placed into 500 ml erlenmeyer flasks. The same qu a ntity of distilled water was added to each flask and then shaken on a shaker for 48 hours. After centrifuging (2 670×g) for 20 minutes, the supernatant was coll ected and evaporated on a rotary vaporizer at 42 ℃ to 1/10 volume, and then fil t ered through qualitative filter paper. The extract was diluted in a series of de nsity solutions of 50%, 40%, 30%, 20% and 10% (V%). Strawberry seedlings wer e tr eate

关 键 词：连作 草莓 根系分泌物 自毒作用 化感作用 组织培养 

分 类 号：S668.4[农业科学—果树学]