Introduction
The selection and propagation of local apple seedlings and indigenous genotypes _ maintained by cuttings or grafting (True to Type) _ date back to 1560 BC in China. Gene flow originating  from Kyrgyzstan, the main center of apple diversity, passed through Iran along the Silk Road, and  contributed to the development of diverse centers of apple variation. As a result of natural selection, native genotypes have accumulated resistance genes providing adaptation to local biotic and abiotic stresses. While many traditional apple cultivars maintained in home orchards may smaller fruit size and lower productivity compared to modern commercial varieties, they exhibit greater resilience against pests, diseases, an fluctuating climatic conditions due to the diversity of microclimates in which they are grown. Collecting and conversing these indigenous varieties, as genetic resources is fundamental to national food security. Evaluating genetic diversity through morphological and pomological phenotyping remains a critical method for varietal identification and conservation. Such research activities are essential to prevent germplasm extinction, facilitate registration with National Office of Cultivars, and support breeding programs. without access to these genetic resources, fruit breeding research would be significantly hampered.  The value of rich germplasm collections becomes even more apparent with the emergence of pests and fungal or bacterial diseases triggered by climate change, highlighting the importance of genes conferring resistance. This imperative has led breeders to intensively survey and collect wild apple populations in Kazakhstan, Kyrgyzstan, and neighboring regions of  China, especially since the dissolution of the Soviet Union (Tian et al., 2022).
Materials and Methods
A comprehensive assessment of pheno-morphological and pomological traits, fruit physical characteristics, flesh firmness, fruit weight, and biochemical properties _ including russet disorder_ was conducted on 48 native apple cultivars and 2 imported varieties. All accessions, established as 14-year-old spindle-shped trees grafted onto MM111 rootstock, were cultivated at Kamalshahr Horticultural Research Station (Karaj, Iran) during 2020-2021. Both quantitative and qualitative fruit traits were measured using the International Apple Descriptor (UPOV) and in accordance with  the national DUS ( Distinctness, Uniformity, and Stability) testing guidelines.  Data collection included descriptive trait surveys,  followed by multivariate analyses such as factor analysis, cluster analysis and biplot visualization to elucidate patterns of genetic diversity.
Results and Discussion
Analysis of variance and mean comparisons tests revealed significant differences among the cultivars and genotypes for all quantitative traits assessed. Distinct differences were identified between traditional native cultivars and the promising genotypes, particularly regarding external fruit traits such as color and morpho-botanical characteristics, most notably fruit weight and flesh firmness. In addition, significant correlations were detected among several traits.
Assessment of qualitative traits revealed a high degree of diversity, as measured by the Shannon index. Cluster analysis further clarified the genetic relationships among accessions. Factor analysis identified four main and independent factors, fruit size, flesh firmness, length-to-diameter ratio, and external traits, which together explained 67% of the total variation observed in the dataset. On this basis, native apple cultivars and genotypes were divided into three distinct clusters. The accuracy of this classification was confirmed by diagnostic analysis, resulting in 100% correct assignment. 
Conclusion
These findings provide valuable information for the scientific identification, differentiation and registration of native apple cultivars and promising genotypes, supporting their official recognition by the Seed and Plant Certification and Registration Institute (SPCRI). The results also contribute to the conservation of native apple germplasm, helping to prevent genetic erosion. The detailed phenotypic profiling and diversity analysis offer essential resources for breeding programs, fascilitating the selection of parents for genetic improvement aimed at sustainability and resilience.