On the origin of the invasive olives (Olea europaea L., Oleaceae).

The olive tree (Olea europaea) has successfully invaded several regions in Australia and Pacific islands. Two olive subspecies (subspp. europaea and cuspidata) were first introduced in these areas during the nineteenth century. In the present study, we determine the origin of invasive olives and investigate the importance of historical effects on the genetic diversity of populations. Four invasive populations from Australia and Hawaii were characterized using eight nuclear DNA microsatellites, plastid DNA markers as well as ITS-1 sequences. Based on these data, their genetic similarity with native populations was investigated, and it was determined that East Australian and Hawaiian populations (subsp. cuspidata) have originated from southern Africa while South Australian populations (subsp. europaea) have mostly derived from western or central Mediterranean cultivars. Invasive populations of subsp. cuspidata showed significant loss of genetic diversity in comparison to a putative source population, and a recent bottleneck was evidenced in Hawaii. Conversely, invasive populations of subsp. europaea did not display significant loss of genetic diversity in comparison to a native Mediterranean population. Different histories of invasion were inferred for these two taxa with multiple cultivars introduced restoring gene diversity for europaea and a single successful founder event and sequential introductions to East Australia and then Hawaii for cuspidata. Furthermore, one hybrid (cuspidata x europaea) was identified in East Australia. The importance of hybridizations in the future evolution of the olive invasiveness remains to be investigated

A comparison between a new Ultra Fast Pressureless Sintering (UFPS) technology and Spark Plasma Sintering (SPS) for Barium AluminoSilicate metastable phase

Two processes to sinter monolithic hexagonal Barium AluminoSilicate (BAS) are compared in this study: Spark Plasma Sintering (SPS) and a new Ultra-Fast Pressureless Sintering (UFPS) technology developed by Galtenco Solutions®. For both, hexagonal BAS was sintered in its thermal stability range (between 1590 °C and 1760 °C). Results demonstrate that it is only possible to manufacture small parts (15 mm diameter/ 5 mm height) of hexagonal BAS with the SPS process. For larger or more complex shapes, a thermal gradient appears in the sample, leading to the partial melting of some of its body. On the other hand, the new UFPS technology enables the successful processing of large parts of hexagonal BAS with similar efficiency to SPS for small parts. This technology offers a better thermal control of the sintering and eliminates the thermal gradient issue that can be found in the SPS technique

Olive Genetic Resources

UMR AGAP - équipe AFEF - Architecture et fonctionnement des espèces fruitièresAs one of the most important and ancient fruit crops in the Mediterranean Basin, olive is characterized by a huge genetic patrimony, represented by cultivated and wild germplasm, ancient trees and related forms. The richness of this germplasm represents an unusual case among horticultural crops, due to species longevity, lack of new better performing genotypes, and the millennial tradition of cultivation. Focusing on a wide spectrum of genetic resources, their conservation, characterization, and management, this chapter tries to give an insight into the achievements and the necessities of this type of works in olive. Knowledge of existing diversity among the olive genetic resources is essential to maximize their conservation, safeguard, and exploitation