S. Pandolfi

Bio: S. Pandolfi is an academic researcher from National Research Council. The author has contributed to research in topics: Cultivar & Mediterranean Basin. The author has an hindex of 10, co-authored 17 publications receiving 296 citations.

Elucidation of the genetic architecture of self-incompatibility in olive: Evolutionary consequences and perspectives for orchard management

Abstract: The olive (Olea europaea L.) is a typical important perennial crop species for which the genetic determination and even functionality of self-incompatibility (SI) are still largely unresolved. It is still not known whether SI is under gametophytic or sporophytic genetic control, yet fruit production in orchards depends critically on successful ovule fertilization. We studied the genetic determination of SI in olive in light of recent discoveries in other genera of the Oleaceae family. Using intra- and interspecific stigma tests on 89 genotypes representative of species-wide olive diversity and the compatibility/incompatibility reactions of progeny plants from controlled crosses, we confirmed that O. europaea shares the same homomorphic diallelic self-incompatibility (DSI) system as the one recently identified in Phillyrea angustifolia and Fraxinus ornus. SI is sporophytic in olive. The incompatibility response differs between the two SI groups in terms of how far pollen tubes grow before growth is arrested within stigma tissues. As a consequence of this DSI system, the chance of cross-incompatibility between pairs of varieties in an orchard is high (50%) and fruit production may be limited by the availability of compatible pollen. The discovery of the DSI system in O. europaea will undoubtedly offer opportunities to optimize fruit production.

Qualitative evaluation of olive oils from new olive selections and effects of genotype and environment on oil quality

Abstract: In the dynamically changing olive oil industry, new cultivars with greateradaptability to modern cul - tivation techniques and with high quality oils are needed. In this paper, oil quality, in terms of fatty acid compo - sition and content in phenolic compounds, was analysed for many new genotypes previously selected in a bree- ding program and cultivated in three different locations of central and southern Italy. Data on some cultivars commonly grown in each area were included for comparison. The availability of data from many genotypes cul - tivated in all three locations allowed quantitative analyses of the genetic and environmental effects on the oil qua - lity traits studied. The acidic composition varied greatly both with genotype and with environment and so did the concentration in phenols, though the effect of genotype on phenols was not significant (P=0.09). The fatty acid composition, particularly the oleic/(palmitic+linoleic) ratio, appeared predominantly under genetic control, with a broad sense heritability of 0.58 while the environmental effect explained 0.31 of the total variance. The oil con - tent in phenolic compounds, instead, had lower heritability (0.29) and was more affected by the environment, which explained 0.50 of the total variance. Few genotypes were selected as the best for each location, but none performed best in all locations. This suggests that, in olive, the highest oil quality is difficult to achieve with a sin - gle genotype in different environments, due to a strong or even predominant effect of the environment on some quality traits. More likely, combinations of genotypes and territories can produce oils with high and typical qua - lity. In this paper, we provide information on potential new genotypes with promising performances in different Italian regions. Further testing of oil quality, together with agronomic performance, is necessary prior to any release of new cultivars.

The First Molecular Identification of an Olive Collection Applying Standard Simple Sequence Repeats and Novel Expressed Sequence Tag Markers.

Abstract: Germplasm collections of tree crop species represent fundamental tools for conservation of diversity and key steps for its characterization and evaluation. For the olive tree, several collections were created all over the world, but only few of them have been fully characterized and molecularly identified. The olive collection of Perugia University (UNIPG), established in the years ’60, represents one of the first attempts to gather and safeguard olive diversity, keeping together cultivars from different countries. In the present study, a set of 370 olive trees previously uncharacterized was screened with ten standard SSRs and nine new EST-SSR markers, to correctly and thoroughly identify all genotypes, verify their representativeness of the entire cultivated olive variation, and validate the effectiveness of new markers in comparison to standard genotyping tools. The SSR analysis revealed the presence of 59 genotypes, corresponding to 72 well known cultivars, thirteen of them resulting exclusively present in this collection. The new EST-SSRs have shown values of diversity parameters quite similar to those of best standard SSRs. When compared to hundreds of Mediterranean cultivars, the UNIPG olive accessions were splitted into the three main populations (East, Center and West Mediterranean), confirming that the collection has a good representativeness of the entire olive variability. Furthermore, Bayesian analysis, performed on the 59 genotypes of the collection by the use of both sets of markers, have demonstrated their splitting into four clusters, with a well balanced membership obtained by EST respect to standard SSRs. The new OLEST (Olea expressed sequence tags) SSR markers resulted as effective as the best standard markers. The information obtained from this study represents a high valuable tool for ex situ conservation and management of olive genetic resources, useful to build a common database from worldwide olive cultivar collections, also based on recently developed markers.

High genetic diversity detected in olives beyond the boundaries of the Mediterranean Sea.

Abstract: Background Olive trees (Olea europaea subsp. europaea var. europaea) naturally grow in areas spanning the Mediterranean basin and towards the East, including the Middle East. In the Iranian plateau, the presence of olives has been documented since very ancient times, though the early history of the crop in this area is shrouded in uncertainty. Methods The varieties presently cultivated in Iran and trees of an unknown cultivation status, surviving under extreme climate and soil conditions, were sampled from different provinces and compared with a set of Mediterranean cultivars. All samples were analyzed using SSR and chloroplast markers to establish the relationships between Iranian olives and Mediterranean varieties, to shed light on the origins of Iranian olives and to verify their contribution to the development of the current global olive variation. Results Iranian cultivars and ecotypes, when analyzed using SSR markers, clustered separately from Mediterranean cultivars and showed a high number of private alleles, on the contrary, they shared the same single chlorotype with the most widespread varieties cultivated in the Mediterranean. Conclusion We hypothesized that Iranian and Mediterranean olive trees may have had a common origin from a unique center in the Near East region, possibly including the western Iranian area. The present pattern of variation may have derived from different environmental conditions, distinct levels and selection criteria, and divergent breeding opportunities found by Mediterranean and Iranian olives.These unexpected findings emphasize the importance of studying the Iranian olive germplasm as a promising but endangered source of variation.

新しい国際学術雑誌"Forest Ecology and Management"の発行

Abstract: ING AND INDEXING

Olive domestication and diversification in the Mediterranean Basin

Abstract: Summary Olive (Olea europaea ssp. europaea) is the most important oil fruit crop in temperate areas, but the origin of the cultivated olive remains unclear. The existence of one or several domestication events in the Mediterranean Basin (MB) is still debated. We analyzed a dataset of 387 cultivated and wild accessions that were genotyped at 25 simple-sequence repeat (SSR) loci. The sample represented genetic diversity at the geographic extremes of the MB. We inferred relationships among samples and also applied approximate Bayesian computation to estimate the most probable demographic model of our samples. Cultivated olives clustered into three different gene pools (Q1, Q2 and Q3), corresponding loosely to the west, central and eastern MB, respectively. Q1 consisted primarily of accessions from southern Spain, retained the fingerprint of a genetic bottleneck, and was closely related to accessions from the eastern MB. Q2 showed signs of recent admixture with wild olives and may derive from a local domestication event in the central MB. Overall our results suggest that admixture shaped olive germplasm and perhaps also local domestication events.