نوع مقاله : پژوهشی
نویسندگان
1 گروه باغبانی، دانشکده تولید گیاهی، دانشگاه علوم کشاورزی گرگان
2 عضو هیات علمی دانشگاه علوم کشاورزی و منابع طبیعی گرگان
3 گروه باغبانی، دانشکده تولید گیاهی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، ایران
4 کروه زیست شناسی، دانشگاه گلستان
5 گروه باغبانی، دانشکده تولید گیاهی، دانشگاه علوم کشاورزی و ومنابع طبیعی گرگان
6 سازمان آموزش، تحقیقات کشاورزی، مرکز تحقیقات کشاورزی گرگان
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: Olive (Olea europaea L.), a member of the Oleaceae family, is one of the oldest cultivated fruit trees in the world, with a documented history of over 2000 years and a longstanding role in human civilizations. More than 1200 olive genotypes are currently under cultivation and utilization worldwide. Due to Iran's favorable climatic conditions, olive cultivation has significantly expanded over the past two decades. In this context, identifying and evaluating superior genotypes for improved yield, enhanced oil quality, and greater production efficiency has become a critical necessity. Accordingly, the present study was conducted to assess the impact of genotype on the morphological traits of olive, particularly those related to fruit, stone, and flower, across 20 commonly cultivated genotypes in Iran, including both native and introduced types.
Materials and Methods: This study was conducted in 2021 at the olive germplasm collection of the Golestan Agricultural and Natural Resources Research and Education Center, Iran. A total of 20 morphological traits related to flower, fruit, and stone were selected based on established standards and available facilities. These traits were evaluated in 20 olive genotypes currently cultivated in Iran, including: Koroneiki, Zard, Arbequina, Shiraz, Direh, Baladi, Shengeh, Zard Golouleh, Rowghani, Malekshahi, Conservolia, Caillet, Lemeski, Manzanilla, Amiygdalolia, Mari, Mission, Valanolia, Coratina, and Genotype One (a local genotype from Golestan). The experiment was laid out in a completely randomized design (CRD) with three replications. Statistical analyses were performed using SAS software. The Least Significant Difference (LSD) test was used to compare means and determine significant differences among genotypes. To visualize data patterns, a heatmap of traits was generated using PAST software. In addition, principal component analysis (PCA), correlation analysis, and hierarchical clustering were conducted to explore complex relationships among traits and reduce dimensionality in the dataset.
Results: The findings of this study revealed highly significant differences (p < 0.01) among the evaluated genotypes in terms of morphological traits related to fruit, stone, and flower. Mean comparisons indicated considerable genetic diversity, with genotypes such as Conservolia, Shiraz, Amiygdalolia, Malekshahi, and Manzanilla exhibiting superior performance in traits including fruit weight, fruit length, and flesh content highlighting their potential as promising candidates for breeding programs. In contrast, Genotype One, along with Arbequina and Koroneiki, recorded the lowest values in most fruit and stone-related traits. Regarding stone shape, Zard Golouleh and Arbequina were identified as more suitable for table olive processing due to their more spherical form. Inflorescence traits also varied significantly among genotypes, with Genotype One showing the lowest numerical values. Cluster and correlation analyses revealed that Lemeski, Amiygdalolia, and Malekshahi were grouped closely together, indicating minimal phenotypic distance, whereas Genotype One was phenotypically the most distinct. Correlation coefficients indicated strong positive associations among fruit and stone traits, while several inflorescence traits showed negative correlations with fruit-related traits. This inverse relationship may reflect a physiological trade-off in resource allocation between flower development and fruit growth, which warrants further investigation, particularly in the context of orchard management and genotype selection strategies.
Conclusion: This study, focusing on olive genotypes cultivated in Iran and employing a multivariate analysis of morphological traits, including fruit, stone, and especially inflorescence characteristics revealed a considerable level of genetic diversity among the evaluated genotypes. This diversity should be taken into account in future breeding and orchard management programs. The identified variability can play a critical role in improving productivity, enhancing oil quality, and contributing to the sustainable development of the olive industry in Iran. Moreover, the findings provide a valuable basis for the identification, selection, and improvement of superior cultivars adapted to the country’s agro-climatic conditions.
کلیدواژه‌ها [English]
)