Abstract: A random amplified polymorphic DNA (RAPD) marker linked to the precocious trait of walnut (Juglans regia L. ) , OPB208900, was identified with bulked segregant analysis ( BSA) . Two bulks of DNA samples were created from open2pollinated Liao 1 (an precocious cultivar) . The bulks were screened using 220 random primers (OP Kit) . OPB208 ( 5. GTCCA CACGG 3. ) generated a specific fragment with precocious individuals and without backward individuals. The specific fragment of approximately 900 base pairs ( bp) , was designated as OPB208₉₀₀. 22 DNAs from 19 cultivars and 3 clones were used as templates for RAPD analysis with primer OPB208 respectively. The specific band of OPB208₉₀₀ was present in 12 out of 17 precocious cultivars and absent in 5 backward cultivars/ clones. The RAPD marker OPB208₉₀₀ is related with precocious trait in walnut and
would be used to distinguish the precocious trait and backward trait in walnut.

Key words: RAPD, Precocious trait, Walnut (Juglans regia L.)