三裂叶蟛蜞菊对菜心化感作用的生理机理

Allelopathic Potentials of Wedelia trilobata on Brassica parachinensis and its Physiological Mechanism of Action

研究了三裂叶蟛蜞菊(WedeliatrilobataL.)各器官水提液对菜心(BrassicaparachinensisBailey)种子萌发、植株生长和一些重要生理过程的影响.结果表明,各器官水提液浸种显著降低了菜心种子的发芽率.在菜心生长过程中,浇淋各器官水提液极显著地减少了根系鲜质量和地上部鲜质量,使植株变矮,根系活力、叶片叶绿素含量和净光合速率降低.浇淋各器官水提液还极显著地抑制了叶片保护酶和硝酸还原酶活性,使植株自我保护机制降低,氮素代谢受阻.

The allelopathic potentials of aqueous extracts of Wedelia trilobata L. on Brassica parachinensis Bailey and its physiological mechanism of action were studied. The results showed that the aqueous extracts of root, stem, leaf and the whole plant of W. trilobata reduced the seed germination percentage of Brassica parachinensis. Watering Brassica paraohinensis seedlings with the aqueous extracts of W. trilobata resulted in the reduction of fresh root mass, fresh mass of aerial part and the plant height. It also reduced the root activity, leaf chlorophyll content and net photosynthetic rate. The aqueous extracts significantly inhibited the activities of protective enzymes, such as catalase, superoxide dismutase and peroxidases. They also significantly decreased the activities of nitrate reductase,the protective capability of plant itself, and inhibited nitrogen metabolism in plant.