ارزیابی تنوع ژنتیکی ژنوتیپ‌های مختلف زیتون در برخی از شهرستان‌های استان خوزستان با استفاده از نشانگر مورفولوژیکی

پژوهش‎ها نشان داده‎اند که برخی از صفات مورفولوژیکی میوه، هسته و برگ گیاه زیتون نظیر کمتر تحت تاثیر محیط قرار می‌گیرند و هر گونه تغییری در این صفات نتیجه تغییر در خزانه‌‎ژنی گیاه است لذا پژوهشی به ‌منظوربررسی تنوع ژنتیکی 50 ژنوتیپ زیتون در شهرستان‌های باغملک، اندیکا، ایذه و لالی استان خوزستان با استفاده از خصوصیات مورفولوژیکی میوه، هسته و برگ در قالب طرح آماری لانه آشیانه‌ای در سال 1395-1394 به اجرا درآمد. نتایج نشان داد که دامنه وسیعی ازتغییرات مورفولوژیکی در بین ژنوتیپ‌ها وجود داشت. نتایج تجزیه به عامل‌ها نیز نشان داد که 12 مولفه در مجموع 78.7 درصد از واریانس کل صفات را توجیه نمودند. اولین مولفه 13.42 درصد از واریانس کل را توجیه نمود و در این عامل، طول میوه (0.63)، عرض میوه (0.61)، وزن‌تر میوه (0.61)، شکل هسته (0.7)، عرض هسته (0.66)، طول هسته (0.44)، تعداد شیار (0.40) و طول برگ (0.5) ضریب بالایی داشتند. همچنین صفاتی نظیر طول و عرض میوه، هسته و برگ، شکل هسته و برگ، خمش برگ، تعداد شیار هسته، قاعده میوه در موقعیت a، وزن هسته، سطح هسته در موقعیت b، تقارن هسته در موقعیت a، اندازه عدسک روی میوه، توزیع شیار روی هسته، تقارن هسته در موقعیت b از جمله مهم‌ترین صفات در تفکیک ژنوتیپ‌ها و گروه‌بندی شهرستان‌های مورد مطالعه از یکدیگر بودند. بر اساس نتایج حاصل از تجزیه خوشه‌ای، ژنوتیپ‌ها به شش گروه مجزا تقسیم شدند. ژنوتیپ‎های متعلق به شهرستان باغملک دارای بیشترین یکنواختی اما ژنوتیپ‎های متعلق به شهرستان لالی، ایذه، اندیکا دارای بیشترین غیریکنواختی بودند.

Evaluation of Genetic Diversity of Different Olive Genotypes in Some Cities of Khuzestan Province Using Morphological Marker

Abstract Background and Objectives Olive (Olea europaea) is compatible with Mediterranean and Mediterraneanlike climates. Due to its high adaptability to different environmental conditions, this plant has adapted well to the varied climates in the world. It has extensively been cultivated in some regions of Iran to the extent that some cultivars do not have any identification. Therefore, a genotype/variety may be classified under several names and several varieties under a single name. Also, lack of garden information, renaming of imported cultivars, and nonstandard morphological traits for naming has led to fundamental problems in the pomology industry. Accordingly, it is necessary and inevitable to eliminate these ambiguities and accurately identify different olives’ genotypes in Iran. Hense, the first step in identifying the genotype is morphological identification. To this aim, the present research was conducted to investigate the genetic diversity and the relationship between the olive trees cultivated in some of the cities of Khuzestan through exploring morphological traits.   Materials and Methods This study was conducted in Indica, Baghmalek, Izeh, and Lali in 20152016. Fifty genotypes were collected from the orchards of the Andika, Baghmalek, Izeh and, Lali. The morphological traits of fruit, stone, and leaf were measured according to the IOOC guidelines and the Seed and Plant Certification and Registration Institute for Research (2007) guidelines. The variance analysis of the traits was performed using SAS 9.1 software as a nested design. Cluster analysis was used for the determination of the degree of relationship between genotypes. The main components and biplot analysis were used to reduce the number of variables.   Results The results showed that there was a wide range of morphological variations among genotypes. Factor and principal components analysis showed that 12 components could justify 87.7% of the variation among genotypes. The first component explained 13.42% of the total variance. In this factor, fruit length (0.63), fruit width (0.61), fruit weight (0.61), stone shape (0.7), stone width (0.66), stone length (0.44), and leaf length (0.5) had a high coefficient. Moreover, traits such as length and width of fruit, stone and leaf, stone and leaf shape, curvature of leaf, stone number grooves, fruit base in position A, stone weight, stone surface in position B,  stone symmetry in position A, fruit size of lenticels, stone distribution of grooves, stone symmetry in position B, were the most important traits in genotyping and grouping of the cities studied. Based on the results of cluster analysis, the genotypes were divided into six distinct groups.   Discussion In general, it was found that most of the genotypes in Baghmalek city are located in a separate cluster. In contrast, several genotypes in Lali, Izeh, and Indica are situated in a single cluster, which can be due to atmospheric differences in precipitation rates in these cities. Izeh, Lali, and Indica have lower temperatures and more atmospheric precipitation than Bagmalek. This important difference can cause the genotypes of these cities to be different compared to Baghmalek city.