Genetic Diversity of Juglans regia L. Cultivars Revealed by AFLP Analysis

【Objective】The genetic diversity and phylogenetic relationship of walnut cultivars were discussed at the molecular level,thus providing a scientific basis for more effective protection and use of these resources.【Method】The genetic diversity and relationship of 131 Juglans regia L.cultivars were analyzed by AFLP(amplified fragment length polymorphism)-silver staining protocol.The specific bands were counted and analyzed by NTSYSpc2.11a software.【Result】 AFLP fingerprinting of 131 Juglans regia L.cultivars with twenty pairs of EcoRⅠ/MseⅠ primers revealed a total number of 1 643 unambiguous bands,of which 1 512 ones were polymorphic and 82.15 polymorphic bands were detected by each pair of primer on average.The polymorphism frequency was 92.03%.This result showed the abundant diversities of enzyme digestion sites among Juglans regia L.cultivars.As analyzed by NTSYSpc2.11a,the similarity coefficient of 131 Juglans regia L.cultivars ranged from 0.637 to 0.928.These Juglans regia L.cultivars were divided into eight groups by UPGMA(unweighted pair group method with arithmetic aver age) based on similarity coefficient.The genetic relationship of 131 Juglans regia L.cultivars was analyzed according to the similarity coefficient.【Conclusion】 There are rich genetic diversity and complex genetic background in walnut germplasms,but it is difficult to distinguish distinctly the precocious walnut and serotinous walnut by cluster analysis.