Evaluation the allelopathic power of wild mustard on germination characteristics of four wheat cultivars using Gas chromatography (GC- MS)

In order to evaluate the allelopathic effects of shoot and root water extract of wild mustard (Sinapis arvensis) on germination properties and seedling growth of wheat cultivars, an experiment was conducted in factorial based on completely randomized design with three replications at the physiology laboratory of Golestan Agriculture and Natural Resources Research Center, Iran in 2011. Experimental treatments were different consentations of water extract of  shoot and root Wild mustard(0, 2.5, 5 and 7.5%) and wheat cultivars (Morvarid, Moghan, Tajan and Arta). Also, in order to separate the osmotic effects of different concentrations of wild mustard water extract from allelochemicals effects, the polyethylene glycol 6000was used. The results showed that with increasing the concentration of shoot and root water extract of wild mustard, percentage and rate of germination, shoot and root length, shoot and root dry weight and seedling dry weight of different wheat cultivars decreased significantly., and it was different among the wheatvcultivars, whereas in the highest concentration, Moghan and Morvarid cultivars showed the least influence and Tajan and Arta cultivars showed the highest influence. Furthermore the different concentrations of polyethylene glycol had no effect on the traits mentioned above. This confirms that the osmotic potential of extracts had no influence in intensifing of allelochemicals effects. Fitting of three-parameter logistic model provided a successful estimation of the relationship between different levels of water extract and germination percentage. Generally, wild mustard shoot showed more inhibitory effect than the root.