Microsatellite Markers in Olives (Olea europaea L.): Utility in the Cataloging of Germplasm, Food Authenticity and Traceability Studies

One hundred single-copy nuclear sequence markers for olive variety identification: a case of fingerprinting database construction in China

Olive is an ancient oil-producing tree, widely cultivated in Mediterranean countries, and now spread to other areas of the world, including China. Recently, several molecular databases were constructed in different countries and platforms for olive identification using simple sequence repeats (SSRs) or single-nucleotide polymorphisms (SNPs). However, comparing their results across laboratories was difficult. Herein, hundreds of polymorphic single-copy nuclear sequence markers were developed from the olive genome. Using the advantage of multiplex PCR amplification and high-throughput sequencing, a fingerprint database was constructed for the majority of olives cultivated in China. We used 100 high-quality sequence loci and estimated the genetic diversity and structure among all these varieties. We found that compared with that based on SSRs, the constructed fingerprint database based on these 100 sequences or a few of them, could provide a reliable olive variety identification platform in China, with high discrimination among different varieties using the principle of BLAST algorithm. An example of such identification platform based on this study was displayed on the web for the olive database in China (http://olivedb.cn/jianding). After resolving redundant genotypes, we identified 126 olive varieties with distinct genotypes in China. These varieties could be divided into two clusters, and it was revealed that the grouping of the varieties has a certain relationship with their origin. Herein, it is concluded that these single-copy orthologous nuclear sequences could be used to construct a universal fingerprint database of olives across different laboratories and platforms inexpensively. Based on such a database, variety identification can be performed easily by any laboratory, which would further facilitate olive breeding and variety exchange globally.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11032-023-01434-9.

The Ancient Olive Trees (Olea europaea L.) of the Maltese Islands: A Rich and Unexplored Patrimony to Enhance Oliviculture

A prospecting campaign in the Maltese Islands has ensured the survival of several ancient olive trees (Olea europaea L.), genetically distant from known cultivars. Most of these plants were abandoned or partially cultivated. A two-year evaluation of fruit characteristics and compositions was performed on samples collected from the main representatives of these indigenous genotypes. Analyses were carried out using Gas Chromatography, High-Performance Liquid Chromatography and Near Infrared Spectrometry. Among the fruit samples, a wide range of variations was observed. Some of the genotypes showed fruit traits suitable for table olive production. This is the case of samples with a pulp/pit ratio higher than four, such as 1Wardija, 1Caritas, 1Plattini, 1Bingemma Malta and 3Loretu, whilst 1Bidni, 1Mellieha, 2Qnotta, 3Loretu, 1Bingemma Malta and 1Caritas were suitable for dual purpose. The total phenol content ranged from 6.3 (1Wardija) to 117.9 (2Mtarfa) g/kg of fresh pulp. The average percentage of MUFA was quite low for most of the varieties. These genotypes, which presumably originated in the Maltese Islands and are well adapted to the local pedo-climatic conditions, are being propagated for the following evaluation of their bio-agronomical performance (production, suitability to intensive cultivation, environmental sustainability, product quality, etc.). The purpose is to select, among these local genotypes, the most outstanding varieties, in terms of phenolic and FA profile and agronomical potential, to spread into cultivation, thereby contributing to an increase in the quality of the local table and olive oil production, strongly linked to the territory.

Techniques for Food Authentication: Trends and Emerging Approaches

Food producers and retailers are obliged to provide correct food information to consumers; however, despite national and international legislation, food labels frequently contain false or misleading statements regarding food composition, quality, geographic origin, and/or processing [...]

Biochemical Characterization of Six Traditional Olive Cultivars: A Comparative Study

Olives are an essential ingredient in Turkish food culture. Turkey has grown to become one of the top five producers of olives and olive oils in the world. Olive trees in general are found in the coastal parts of the country. The fruits of six traditional cultivars of olive (Gemlik, Domat, Memecik, Ayvalik, Cilli, and Adana Topagi), grown in Adana, were characterized based on their fruit skin color, the amount of chlorophylls, fatty acids, antioxidant activity, and total phenolic compounds, as well as volatile compounds. The international cultivar Manzanilla, grown in the same orchards as the traditional cultivars, was also included in the study to make a comparison. Compared to the Manzanilla cultivar, Memecik showed the highest amount of total phenolic content and antioxidant activity with the highest level of lightness, blueness/yellowness, and color intensity. Ayvalik presented the highest level of greenness/redness. Although the highest fruit lightness and darkness were found in the Cilli cultivar, with the highest amount of chlorophyll a (2.63 mgL−1), there was more chlorophyll b in Adana Topagi fruits (3.34 mgL−1). The highest percentage of fatty acids was found in the Gemlik cultivar of 66.81%, among which oleic acid was the major component. The total aldehydes ranged between 33.43% and 50.60%. Compared to Manzanilla and the traditional cultivars, the Domat cultivar had the highest amount of hexanal of 44.42%. Adana Topagi had the highest amount of alcohols (61.34%) and acids (1.31%). Memecik registered the highest amount of ketones (17.86%) and terpenes (20.34%). Among all cultivars, Manzanilla displayed the highest amount of esters (2.30%). In this study, traditional cultivars were found to be the richest in health-promoting chemicals. Furthermore, a significant variability among the cultivars was revealed, implying that metabolic fingerprinting approaches could be used to differentiate cultivars once more research into the effects of the growing conditions and environmental factors on the chemical profiles of each cultivar is carried out.