Allelopathy Of Wheat,Broad Bean And Rape On Sunflower Broomrape And Gentiana Macrophylla

Sunflower broomrape(Orobanche cumana Wallr.)is a kind of root parasitic plants,mainly distributed in the Northen part of China,is one of weeds which causes seriously damage to sunflower production,it was being listed as quarantine parasitic weed.At present,there is no effective method to control it.Gentiana macrophylla Pall.belongs to Gentianaceae and Gentiana L,are mainly distributed in high altitude in the Northwest China,is a kind of genuine medicinal plants in Qinghai area,it has been included in the national three level of protection of medicinal materials.Its big root could be used as medicine.In recent years,the demand of G.macrophylla increased year by year,and medicinal plants intercropping with crops is considered to be a very effective solution.This paper studies the possibility of wheat,broad bean which are the main food crops and rape which is economic crops in qinghai as a"trap crops" to sunflower broomrape;Also,we studied the effect of the three kinds of crops on the medicinal plant Gentiana macrophylla,in order to provide new ideas of gentiana macrophylla artificial cultivation.The main results are as follows:1.The result indicated that both root methanol extracts and exudates of wheat and broad bean were able to stimulate the germination of sunflower broomrape seeds.Root methanol extracts of wheat variety Ningdong 1 induced the highest seed germination rate(41.5%).The methanol extracts and the roots exudates of broad bean variety Qingcan 11 were also able to stimulate the germination of sunflower broomrape seeds,and extractions of roots exudates of broad bean induced higher germination rate(41.1%).In conclusion,extracts of wheat variety Ningdong 1 and broad bean variety Qingcan 11 roots may containing germination stimulants to induce the germination of sunflower broomrape seeds and might be used as trap crops for sunflower broomrape control.2.The results displayed that only the undiluted solution methanol extracts of root,root exudates and root volume for 0.4g and 0.6g of wheat weakly inhibited the germination of G G.macrophylla,but has no effect on the seedling growth of G.macrophylla.Compare to wheat,broad bean has stronger inhibitive effect on the germination of G.macrophylla,and broad bean shoot mulching,physiological indexes of G.macrophylla seedlings were significantly lower than control.Oilseed rape indicated a strongest inhibitory effect on both the germination of G.macrophylla and the growth of G.macrophylla no matter root exudates or root cutting and straw mulching.Brassica campestris L.and Brassica napus L.were mixed sown with G.macrophylla,and both in the seedling stage or bud stage,B.campestris displayed more stronger inhibition effect on the growth of G.macrophylla seedlings than that of B.napus.Therefore,in the artificial cultivation of G.macrophylla and G.macrophylla intercrop with oilseed rape should be avoided.