OBJECTIVEThe main aim of the research was to evaluate genetic variability and interrelationships of mainly quantitative traits in 2-year population, and provide a basis for high-yield breeding of Glycyrrhiza uralensis.

METHODFour genotype G. uralensis population were transplanting in four different environment using complete randomized block design with three replication, and the 10 quantitative traits, including plant height (PH), stem diameter (SD), tiller number (TN), taproot length (TRL), root length (RL), root diameter (RD), diameter of 20 cm below the root head (D20), taperingness (TR), lateral root number (LRN) and root fresh weight (RFW) were measured in field.

RESULTThe difference among population for all evaluated traits were significant (P<0.05) through Duncan's multiple range tests, and the coefficient of variation of RFW and LRN were above 25%. The analysis of variance was used to evaluate the traits of four populations across to four different environment Genotype, environment and their interaction effect were significant (P<0.05) or highly significant (P<0.01) for mainly evaluated traits. Simple correlation between traits showed that PH, SD, LRN, RL, RD and D20 had highly significant (P<0.01) and positive correlation with RFW. Results of the path coefficient analyses showed that D20 had the greatest positive direct effect on RFW, followed by the traits of PH and RL.

CONCLUSIONSelection for increased D20, RL and PH would be the best indirect selection traits for increasing root yield. Meanwhile, ample genetic variability exists in the G. uralensis 2-year population, it could be used for breeding improvement of root yield.