Abstract: Abstract：【OBJECTIVE】To identify the genetic distance between RAPD marker OPB-08900 and precocious gene of walnut (Juglans regia L.), and character the sequence of OPB-08900; 【METHOD】The template DNA extracted from precocious maternal parent Lüyuan、later mature paternal parent Lüfeng and 154 F1 hybrid plants were screened with OPB-08 primer (5′GTCCACACGG 3′). The genetic distance between OPB-08900 and precocious gene of walnut was calculated using Haldane function .DNA fragments of OPB-08900 derived from precocious F1 hybrid No.2 was retrieved from agarose gel and ligated into pMD18-T Vector, and then transformed into E. coli JM109. Sequencing of positive clones was carried out .The restriction sites of sequence OPB-08958 analyzed by DNAMAN and BLAST in nr database of GenBank;【RESULTS】The RAPD-PCR result showed that specific fragment OPB-08900 was presented in precocious maternal parent Lüyuan and 69 F1 hybrid plants, but was absented in later mature paternal parent Lüfeng and 82 F1 hybrid plants . The RAPD marker OPB-08900 was co-segregating with precocious trait of walnut and the genetic distance between OPB-08900 and precocious gene was 1.99 cM. The sequencing result showed the RAPD marker OPB-08900 was 958bp, so RAPD marker OPB-08900 should be renamed OPB-08958，GenBank accession number is DQ673614.There were 97 restriction sites in the sequence of OPB-08958, digested by 36 restriction enzymes; The sequence of OPB-08958 was not homologous with any plants in GenBank;【CONCLUSION】The precocious trait of walnut is controlled by more than 2 genes which were dominance. RAPD marker OPB-08958 linked to one of the precocious genes and the sequences of OPB-08958 is unique to Walnut genome.

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