Allelopathy Of Aqueous Extracts Of Different Garlic Varieties

As one of the traditional vegetables in China, cultivated area and output of garlic rank the first place in the world. Because of the long-term large scale cultivation, it has become the main question which crop rotation and the cultivation system. Allelopathy is one of important bases of making plant culture system. But there are not many reports on garlic allelopathy until now. The paper has discussed the allelopathy of different garlic variety resources, and screened the variety with different allelopathy. It will establish the important foundation for garlic allelopathy further research and the garlic with other vegetables reasonable cropping system establishment. The main research results are showed as follows.1. Seed germination bioassay method and Q Cluster Analysis were used taking lettuce as the receiver plant. Finally selected 10 material with different allelopathy from 22 garlic variety resources for next research. The ten varieties of garlic are G84, G07, G89, G08, G09, G88, G64, G93, G57andG73.2. The allelopathy effect of garlic on germination, root and seedling of tomato or lettuce was studied with bioassay methods. The results indicate that:Allelopathy was different in the different donor crops. The allelopathy effect of straw aqueous extracts of different garlic varieties on tomato germinates, seedling and radicle growths have the significant difference. G64 garlic aqueous extracts is most remarkable in the 10 varieties.It inhibited tomato germinate and the seedling growth. The next are G84 and G57. The allelopathy effect of G73 straw aqueous extracts is weaker than others.The root aqueous extracts of G88 has obviously inhibited the lettuce germination tendency, germination rate, the seedling and the radicle growths. Its allelopathy effect is most conspicuous among 10 varieties. Then, they are G57,G89,G84,G08. The allelopathy effect of varieties of G07,G73,G93,G64 and G09 are weaker than others.The different concentration aqueous extracts of the same varieties was different in allelopathy effects on tomato and lettuce. The allelopathy effect of straw aqueous extracts of 0.02 g·mL^-1and 0.00 5 g·mL^-1on tomato radicle length have the significant difference.The activities of SOD and POD and the content of MDA in tomato and lettuce which treated with aqueous extracts of garlic were determined. The results showed that the effect of aqueous extracts on activities of SOD and POD in tomato or in lettuce were significant, and the balance of activate oxygen metabolism was broken, the cell membrane was destroyed, and the content of MDA had an increase.It is probably a kind of mode that phenolic acids of aqueous estracts destroyed the funtion of membrane and inhibited growth of receptor plants by allelopathy.By mensurating the pH and osmotic potential of garlic root aqueous extracts, it showed that the aqueous extracts concentration of garlic in this experiment haven't causes the lettuce's alkaline and osmotic stresses.