Induction Of Rice Allelopathy By Tissue Extracts And Hydroponics Solution Of Barnyardgrass(Echinochloa Crus-galli L.)

In this paper,the allelopathic rice PI312777(PI)and non-allelopathic rice Lemont(LE)were chosen as test material.The inhibitory rates(IRs)of two rice on barnyardgrass(Echinochloa crus-galli L.)(BYG)were explored by addition of seed extract,tissue extract and the concentrated hydroponic solution(CHS)of barnyardgrass.The results were shown bellow:By addition of seed extract,plant extract and CHS of BYG,the most effective method of increasing the inhibition of rice on BYG was the CHS.By CHS,the IRs of rice leaf-aqueous-extracts(LAE)on root length,plant height and dry weight of BYG were increased from 49.00%,44.07%and 48.27%,respectively of its control to 66.32%,58.24%and 64.82%,respectively of the treatments in PI,and were increased from 11.20%,9.18%and 10.72%,respectively of its control to 20.82%,17.55%and 21.74%,respectively of the treatments in LE.The IRs of the rice hydroponic solution on root length,plant height and dry weight of BYG were increased from 34.43%,33.76%and 38.36%,respectively of its control to 50.24%,44.93%and 53.06%,respectively of the treatments in PI,and were increased from 10.93%,10.79%and 14.21%,respectively of its control to 19.04%,16.16%and 21.14%,respectively of the treatments in LE.Under double treatment of the nutrient deficient(half-strength)and CHS addition,The IRs of rice LAE on root length,plant height and dry weight of BYG were increased by 80.99%,69.75%and 75.53%,respectively in PI,and increased by 38.88%,19.95%and 37.13%,respectively in LE.The results of the combination of dose and time effect showed that the optimal condition were 15mL of CHS treated 2d for PI,in which the IR on root length was 74.98%and 12.5mL of CHS treat 2d for LE,in which the IR on root length was 31.71%.The results of rice physiological indices showed that under CHS treatments,the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)were increased in both rice cultivars,compared with the controls.There was the similar tendency in contents of soluable proteins,solualbe sugar and proline.The content of malondialdehyde(MDA)was decreased in both rice cultivars,compared with the controls.In summary,the CHS addition in rice hydroponic solution could increase effectively the inhibition of rice on BYG.The results provide a novel approach for weed suppression in paddy field.