ABSTRACT
AIM To explore the laws in accumulation of dry matter and medicinal ingredients of Isatis indigotica Fort.in Longdong area,and determine the best harvest time to obtain the high-quality and high-yield medicinal plant.METHODS The I.indigotica had its agronomic traits investigated regularly;the accumulation laws of its uridine,guanosine,(R,S)-geichan and adenosine measured by HPLC;and its comprehensive utilization value in different periods evaluated by grey correlation method.RESULTS There existed significant variations among the plant height,plant width,leaf length,leaf width,number of leaves,leaf weight,root length,root diameter,root weight,and the yields of uridine,guanosine,(R,S)-goitrin and adenosine at different growth stages,whose peak values appeared in different period.Additionally,there were also obvious differences in the aforementioned indexes levels among different strains.The highest weighted correlation degree of the comprehensive utilization value of Longde and 2008-6-2 on October 9,and of 2008-11 and 2016-2 on October 24.On the whole,the 2008-6-2 and 2016-2 were superior to 2008-11 and Longde.CONCLUSION It is suggested that the best harvest time of I.indigotica in Longdong area is in mid to late October.