The Influence Of Space Flight On Germplasm Of Glycyrrhiza Uralensis. Fish

In this project, the physiological and biochemical characters and the genome mutation of liquorice (Glycyrrhiza uralensis Fish) seeds carried by a recoverable satellite for 18 days'space flight (Weixing 1,WG1) were investigated. The content of bioactive compounds in liquorice roots were also determined and compared with those of the ground-based control and conventional breeding groups (Wuxing 1, WX1). The work could help to select high quality liquorice seeds and provided scientific basis for liquorice commercial cultivation. The main results were listed as follows:(1)Space environment affected the germination rate and radicel length index: under sufficient water condition, the germination rate and radicel length of WG1 showed no significant difference with ground control group (P>0.05), but the germination rate and radicel length of WX1 were higher than ground control group (P<0.05). However, under drought stress condition (moderate, -1.0MPa, the same as below), there was significant difference between WG 1 and ground control group, but there is no difference between WX1 and control group.(2)Space environment affected the metabolism of soluble protein, peroxidase (POD) and catalase (CAT) during germination: The change of soluble protein and the activities of POD and CAT were similar as those of the control group under sufficient water condition, while they were different from those of WX1 group. However, under drought stress condition, the content of soluble protein of WG1, POD activities and CAT activities were higher than those of control group on 3 and 5 day , respectively, after germination and showed significant difference (P<0.05). But the changes of WX1 group were similar to those of control group.(3)Space environment induced DNA mutation of liquorice: the results of ISSR analysis (inter-simple sequence repeat, ISSR) on WG1 indicated that 22 ISSR primers amplified 132 bands and 28 bands were found to be polymorphic with the percentage of polymorphism being 21.2%, which means that the genome of WG1 had changed after space flight. But the genome of WX1 has no significant difference with control group.(4)Space environment affected the the synthesis of effective compounds: The results of HPLC analysis shown that the content of Glycyrrhizic acid (GA) and Liquiritin(LQ) in roots of WG1 was 2.19 and 1.18 times higher than that of group control group, respectively. But compared with that of WX1, the content of GA, LQ and Polysaccharides (PC) was lower.