Effects Of Trace Elements And Exogenous Hormone On Growth And Concentrations Of Ergot Alkaloids Of Epichloe Endophyte Symbiotic Achnatherum Inebrians

Drunken horse grass(Achnatherum inebrians)is a perennial grass,widely distributed in northern China.Previous studies have revealed that a number of vertebrates have been poisoned by the endophyte(Epichloe gansuensis)infected grass.Seeds of A inebrians collected from field in Yuzhong Experimental Station of Lanzhou University,were used in this study.The drunken horse grass germination was tested in different individuals under different concentrations of two kinds of trace elements(Mn,Zn)and exogenous hormone(salicylic acid).The physiological and biochemical indexes,and contents of ergot alkaloids of the drunken horse grass were tested in different individuals under different concentrations of three kinds of trace elements(Mn,Zn,Fe)and exogenous hormone(ethephon,salicylic acid).The main results are as follows:,1.By recording and measuring germination percentage,germination index,vitality index,shoot and root lengths under different concerntrations of Mn and Zn,it was found that the treatment of Mn and Zn had significantly effect on the germination percentage and germination index of endophyte-infected or endophyte-free seed of A inebrians,but strong inhibition was only found in high concentration of Mn and Zn,and the growth of shoot and root also be restrained.While exogenous salicylic acid(SA)not only can promote the germination percentage and germination index,but also alleviate the negative effects caused by Mn stress.2.By measuring plant growth and contents of ergot alkaloids,it was found that under the high concerntrations of Mn,Zn,Fe,the plant height,tillering number and aboveground biomass of A inebrians were decreased,but the malonaldehyde(MDA),proline content and ergot alkaloids contents increased with the increasing concentration of heavy metals.At the same time,its antioxidant enzyme activity also increased accordingly.3.By measuring the effects of ethephon and salicylic acid(SA)on growth index and concentrations of ergot alkaloid of drunken horse grass,the results showed that plant height,above-ground biomass and the contents of ergine and ergonovine of enophyte-infected A inebrians increased under low concentrations of ethephon and SA treatment,but decreased under higher concentrations.