ABSTRACT
Background and Aims: Wild olive ( Olea europaea subsp. europaea var. sylvestris ) is important from an economic and ecological point of view. The effects of anthropogenic activities may lead to the genetic erosion of its genetic patrimony, which has high value for breeding programmes. In particular, the consequences of the introgression from cultivated stands are strongly dependent on the extent of gene flow and therefore this work aims at quantitatively describing contemporary gene flow patterns in wild olive natural populations. Methods: The studied wild population is located in an undisturbed forest, in southern Spain, considered one of the few extant hotspots of true oleaster diversity. A total of 225 potential father trees and seeds issued from five mother trees were genotyped by eight microsatellite markers. Levels of contemporary pollen flow, in terms of both pollen immigration rates and within-population dynamics, were measured through paternity analyses. Moreover, the extent of fine-scale spatial genetic structure (SGS) was studied to assess the relative importance of seed and pollen dispersal in shaping the spatial distribution of genetic variation. Key Results: The results showed that the population under study is characterized by a high genetic diversity, a relatively high pollen immigration rate (0·57), an average within-population pollen dispersal of about 107 m and weak but significant SGS up to 40 m. The population is a mosaic of several intermingled genetic clusters that is likely to be generated by spatially restricted seed dispersal. Moreover, wild oleasters were found to be self-incompatible and preferential mating between some genotypes was revealed. Conclusions: Knowledge of the within-population genetic structure and gene flow dynamics will lead to identifying possible strategies aimed at limiting the effect of anthropogenic activities and improving breeding programmes for the conservation of olive tree forest genetic resources.
Subject(s)
Gene Flow/genetics , Olea/genetics , Pollen/genetics , Genetic Variation/genetics , Genetics, Population , SpainABSTRACT
The volatile profile of nine monocultivar chestnut flours, obtained from fruits grown in Italy (Parma province), was characterised by a head-space solid-phase microextraction (HS-SPME) coupled with GC-MS technique. The volatile fraction was composed of 44 main compounds belonging to different classes, mainly aldehydes, ketones, alcohols, furans and terpenes. Aldehydes, in particular hexanal, are the most abundant components. In order to better understand the origin of the different volatile compounds during the drying and milling processes, samples of fresh fruit were also analysed by the same technique and the data obtained were statistically and critically compared in order to get a picture of the volatile evolution in chestnut from fresh fruit to flour. Finally, the nine monocultivar flours were chemometrically classified on the basis of the main odour descriptors associated with the volatile fingerprinting.
