An investigation of salt stress on allelopathic effects of wheat and relationships between phenolic componds and allelopathy effects of wheat cultivars on Avena fatua and Lolium rigidium

Wheat is an important crop which grows in a large amount in all of the world and Iran. One thrid of the world and %25 of Iran’s land are saline. So salinity is an important problem for agriculture and crop production. Wheat phenolic compounds have allelopathic effects and different stress conditions affect their allelochemicals rates and composition. In this investigation we studied the effect of different NaCl concentrations (0, 50,150 and 200mM) on root and leave phenolic compounds rates of three cultivars of Triticum aestivum (Pastor, Tagan and Zagros) and T. durum. Avena fatua and Lolium rigidium treated by 10% water extract of wheat cultivars which grown under salt stress.Weed growth parameters (germination percent, root and leave lentgh and fresh and dry weight) were measured. As a result the phenolic compounds rates in roots and leaves were different between various cultivars and different concentrations of NaCl. The elevated levels of phenolic compounds were observed in leave. The allelopathy effects were significantly different among various organs and cultivars at different NaCl concentrations. Tagan and Zagros cultivars had the most phenolic compounds but Pastor and Durum had the high allelopathy effects. Thus there was no direct relation between the rate of phenolic compounds and allelopathic effects of these wheat cultivars. Probably phenolic compounds and allelophatic effects relationship are different between various cultivars of wheat and these properties depend on kind of phenolic compounds.