Objective: To evaluate genetic potential and selection index of yield-related traits in 2-year-old populations, and provide a basis for high-yield breeding of licorice (Glycyrrhiza uralensis).
Methods: Four genotype licorice populations were transplanting in four different environment using complete randomized block design with three replication, and the 10 yield-related 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. Genetic potential and selection index of yield-related traits were evaluated using theories of quantitative genetics.
Results: The genetic potential were higher for the three traits of PH (X1), TRL (X4) and RL (X5) that showed through genetic parameter of broad sense heritability (h2), genetic variation coefficient (GCV) and relative genetic advance (RGA). Among them, selection relative value increased by 45.94% through combination of PH and RL (Y1 = 0.21X1 + 0.08X5) compared with the direct selection for RFW (Y1).
Conclusion: It can realize effective indirectly selection for yield traits, RFW of licorice by PH and RL or their combination. That is, for selection of high-yield licorice, select big and high plants firstly, and then single out long root length materials.