The experiment was conducted by using 1-year-old potted Salvia miltiorrhiza as research ob-ject,and setting the 13 C pulse labeling treatment and 12 C normal treatment.The 13 C pulse labeling method was used to study the photosynthetic carbon distribution patterns of continuous and non-continuous cropping S.miltiorrhiza.The morphological and physiological differences of the plants after 30 days of labeling were recor-ded.The aboveground,root and rhizosphere soil of S.miltiorrhiza were collected,and their 13 C abundance,C isotope ratio,13 C atomic percentage and total 13 C content per unit dry weight sample were compared and ana-lyzed to clarify the effects of continuous cropping on growth and photosynthesis of S.miltiorrhiza.The results showed that under continuous cropping conditions,the biomass and chlorophyll content of various parts of S.miltiorrhiza significantly decreased,and the activity of antioxidant enzymes increased.The content of tanshi-none Ⅰ,tanshinone ⅡA,dihydrotanshinone Ⅰ and rosmarinic acid in the active ingredients decreased.The dis-tribution ratio of photosynthetic carbon in different parts of S.miltiorrhiza was in the order of root>aboveground part>rhizosphere soil.Continuous cropping significantly affected the allocation proportion of 13 C photosynthetic carbon.The proportions of 13 C photosynthetic carbon in the aboveground part,root and rhizo-sphere soil of non-continuous cropping S.miltiorrhiza were 27.14%,72.80%and 0.06%respectively,while those of continuous cropping S.miltiorrhiza were 59.38%,40.59%and 0.03%,respectively.In summary,continuous cropping significantly affected the growth and secondary metabolism of S.miltiorrhiza.The photo-synthetic carbon transferred into the roots decreased with the extension of time in continuous cropping S.milti-orrhiza,which limited the growth and development of the roots.The strength of photosynthesis was an impor-tant indicator reflecting the growth status of S.miltiorrhiza.
关键词
13C脉冲标记法/光合碳/丹参/生长代谢/连作障碍
Key words
13 C pulse labeling method/Photosynthetic carbon/Salvia miltiorrhiza/Growth metabolism/Continuous cropping obstacle