Document Type : Research Paper - Breeding and Biotechnology
Authors
1 Ph.D. Candidate of Biotechnology, Department of Horticulture, Abhar Branch, Islamic Azad University, Abhar, Iran.
2 Associate Prof. Temperate Cold Fruit Research Center, Horticultural Sciences Research Institute, (AREEO) Karaj, Iran.
3 Associate Professor, Department of Horticulture, Abhar Branch, Islamic Azad University, Abhar, Iran
4 Associate Professor, Department of Genetic Research and National Plant Gene Bank of Iran, Seed and Plant Breeding Research Institute, (AREEO) Karaj, Iran.
Abstract
The selection of local chance seedling of apple and autochthonous genotypes propagated by cuttings or grafting (True to Type) goes back to 1560 BC in China. The gene flow from Kyrgyzstan, the main habitat of apples, passing through Iran on the way of Silk Road, has led to the creation of different centers of apple diversity. Native genotypes as the result of natural selection carry resistance genes to the ruling a/biotic adversities in the region. May the native old genotypes of apple still cultivated a stain have small fruit and low productivity compared to new commercial cultivars but they surely present higher sustainability in front of pest, diseases and uneven climate adversities in diverse microclima. The collection of old indigenous varieties, as valuable genetic resources is assumed the bankroll of food security at the national level. Evaluation of genetic diversity through phenotyping based on systematic botany is still a fundamental method in identifying species and varieties. These research activities are aimed at preventing germplasm extinction and preservation in the collections, registration in the National Office of Cultivars and use in breeding programs. In absence of such plant material the fruit breeding researches would lose significance. Rich germplasm collection hides itself those resistance genes when and where climate change causes the unexpected advent of pest and fungal or bacterial diseases. That is why the more breeders have frequently studied the wild apple habitat in Kazakhstan and Kyrgyzstan confined with China to collect the desired genotypes (Tian et al., 2022) since the collapse of the Soviet Union.
Materials and Methods
Pheno-morphological and pomological traits, fruit physical characteristics, flesh firmness, weight and biochemical tests, plus russet disorder, harvested from 14-year-old trees spindle form onto MM111 of 48 local apple varieties were assessed plus 2 imported cultivars, all located in Kamalshahr Horticultural Research Station in 2020-2021Karaj-Iran. The quantitative and qualitative traits of the fruit were measured using the international apple descriptor (UPOV) according to the national guidelines for differentiation, uniformity and stability (D.U.S) of apple. Descriptive surveys of traits, multivariate analyzes including factor analysis, cluster analysis and drawing biplots were performed.
Results and Discussion
Based on the ANOVA and mean comparisons results, the assessed traits significant differences were found between cultivars and genotypes in terms of quantitative traits. Significant differences were also registered between the old native cultivars and the studied promising genotypes for the external fruit traits as the color, the morpho-botanical characteristics, especially the physical attributes of fruit weight and flesh firmness, as well as significant correlations between some traits. The studied qualitative traits showed high diversity in terms of the Shannon index. Cluster analysis shows the varietal genetic relationship. In the factor analysis, four main and independent factors of fruit size, flesh firmness, length/diameter and external traits explained 67% of the difference between the data, so the native apples and the studied genotypes were divided into three main groups, using the analysis of the diagnostic performance, this classification was confirmed with 100% accuracy.
Conclusion
The obtained information may be applied for scientific identification, differentiation and registration of the native varieties and promising genotypes impeding in Seed and Plant Certification and Registration Institute (SPCRI), impeding erosion of the native apple germplasm. The clear results of the gene expression level of the studied traits facilitate the necessary platform for a group of different goals in breeding programs.
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