Stimulatory effects of wheat (Triticum aestivum L.) on seed germination of Orobanche minor Sm

The effects of winter wheat varieties exudates were tested on the germination of Orobanche minor seeds through hydroponical culture and field experiments. The results indicated that allelopathic potential of wheat on stimulating O. minor seeds germination varied with tested varieties, growth stages, extraction solvents and extract concentrations. The methanolic extracts of all wheat varieties displayed a stronger induction of O. minor seeds germination than the aqueous extracts. The aqueous extracts at 10% and 1% effectively stimulated the germination, but the undiluted (100%) and 0.1% extracts did not induce the seed germination. Likewise, the methanolic extracts also induced the seeds germination. The methanolic extract of variety 'Xiaoyan No. 22' induced O. minor seed germination up to 56.8%. Thus O. minor seeds could be induced to germinate by the aqueous and methanolic extracts of winter wheat varieties. Winter wheat especially at the seedling and heading stages contained allelopathic substances to induce O. minor seeds germination. It is possible that wheat allelopathy could be used to stimulate the germination of O. minor, thereby rapidly depleting the seed bank of this problematic parasitic weed.