Autotoxicity Of Aquatic Extracts From Different Organs And Rhizospheric Soil Of Adzuki Bean

Adzuki bean is one of major food bean crops in China. People like it for its nutritionalvalue and healthcare value. In China, Adzuki bean production area are concentrating in certainregions and usually with serious continuous cropping, this is one of the main causes of itsyield and quality reduction and unstable. Therefore, to study the effects of the different organsand rhizospheric soil extracts on adzuki bean autotoxicity will provide a theoretical basis forrevealing the reasons of continuous cropping obstacle in adzuki bean and will have significantmeanings for production and industrial development of adzuki bean.High-yielding cultivars “Jihong9218” was used as a material and researched theautotoxicity of aquatic extracts from different organs and rhizospheric soil of adzuki bean bypot experiment and biological testing;Major autotoxicity were identified and tesed; Usingsand culture method, with P or K deficiency nutrition stress simulation, the autotoxicity ofleaf extract on bean were studied under nutrition stress. The major results were as follows:（1）Seed sprouting and seedling growth under autotoxicity were location difference ofadzuki beans, and autotoxicity of leaf aquatic extracts was significant.It indicated that toxicsubstances was mainly from bean leaves. Autotoxicity intensity order is as follows: Flag>fresh leaf> soil> root> stem.（2）Different concentrations of root, stem, and leaf extracts of adzuki bean have thedifferent influence on seed germination and seedling growth. The effects of flag, fresh leafextract on seed germination and seedling growth were inhibited, and as the concentrationincreased, the inhibitory effects were enhanced. The effects of flag, fresh leaf extract on seedgermination and seedling growth were inhibited, and the inhibitory effects were enhancedwith the concentration increased.The inhibitory effects of rhizosphere soil extract on seedgermination, growth of seedling leaves and stem fresh weight increased with theconcentration increased, while effects on seedling height, root length, root fresh weight werethe performance of " low promote high inhibition". The effects of root and stem extracts onseed germination and seedling growth showed a phenomenon of performance of “lowpromote high inhibition".（3）By GC-MS，55,43,40,33kinds of chemical substances were identified in aquaticextracts of leaf, root,rhizospheric soil,stem. Substances that detected simultaneously with high content were phthalic acid, cinnamic acid and p-hydroxybenzoic acid. The three acids wereimportant alleloehemieals by bioassay. Autotoxicity intensity order is as follows: phthalicacid> cinnamic acid> p-hydroxybenzoic acid.（4）Nutritional stress inhanced autotoxicity of leaf extract on adzuki beansseedling.Under nutrition stress, the content of chlorophyll and activity of root in adzuki beanwere decreaseing with increasing aquatic extracts density.The content of chlorophyll wassignificant difference （P<0.05） than CK under treatments of0.04g ml^-1.0.16g ml^-1in leafaquatic extracts. The content of MDA was increasing with increasing aquatic extracts density,and MDA accumulated gradually. The content of MDA was significant difference （P<0.05）than CK under treatments of0.16g ml^-1in leaf aquatic extracts. Compared aquatic extractswith P deficiency, there was more negative effect in K deficiency.