[Effect of continuous cropping of Rehmannia on its morphological and physiological characteristics]

In contrast to the newly-planted plants, through measuring and analyzing the chlorophyll content, photosynthetic characteristics, root activity and enzyme activity of Rehmannia glutinosa in growth stages, the differentiation manifestation of R. glutinosa physiological activity mediated by continuous cropping was studied.

SPAD-502 chlorophyll meter was used to measure chlorophyll content and LI-6400 portable photosynthetic apparatus to determine plant photosynthetic characteristics. Plant root vigor and enzyme system were measured following reference literature.

The problems of Rehmannia caused by continuous cropping had happened since the early stage of its growth period, and lasted throughout the whole growth period. Under the condition of continuous cropping, the chlorophyll content, photosynthetic characteristics and root activity remained at a lower level compared with the newly-planted plants, among which, the chlorophyll content and the root activity (100 days after planting) had significant differences.

The insufficient photosynthesis source and the reducing of the storage capacity (root tuber) under the condition of continuous cropping might be the main reasons for these problems of R. glutinosa.