银胶菊的花对小麦的化感作用机制

采用温室盆栽法,研究了银胶菊的花水浸提液对小麦生长及其生理生化机制的影响,以明确其对小麦的化感作用。结果显示,花水浸提液抑制小麦种子萌发和幼苗生长,且抑制强度随浸提液浓度的升高而加强;随着花水浸提液浓度的增加,小麦叶片光合作用、光合色素含量和过氧化氢酶(CAT)活性下降,磷(P)和丙二醛(MDA)含量升高,氮(N)含量呈现先降低后趋于正常的变化趋势,硝酸还原酶(NR)活性呈现先降低后升高的变化趋势,谷氨酰胺合成酶(GS)活性没有显著变化,而过氧化物酶(POD)和超氧化物歧化酶(SOD)活性则呈现先升高后降低的变化趋势。表明银胶菊的花水浸提液抑制小麦叶片光合作用,提高了小麦叶片的MDA含量,并降低了小麦叶片SOD、POD和CAT的活性。

Allelopathy mechanism of flowers of Parthenium hysterophorus L. on wheat

In order to ascertain the allelopathy of Parthenium hysterophorus L. flowers on wheat, the greenhouse pot experiments were performed to investigate the effects of aqueous extract on the growth, physiological and biochemical mechanism in wheat. The results showed that aqueous extract of flowers inhibited the germination and growth of wheat, and the inhibition became stronger as the concentration of the extract increased. Some results from physiological and biochemical mechanism of treated wheat indicated that with the increase of extract concentration, photosynthesis, photosynthetic pigment contents and CAT activity decreased, while P and MDA contents increased; N content decreased first and then up to normal, while NR activity decreased first and then increased; GS activity kept normal, while POD and SOD activities increased first and then decreased. The results showed that aqueous extract of P.hysterophorus flower inhibited the photosynthesis, SOD, POD and CAT activities of wheat leaf, but increased the MDA content of wheat.