No abstract

13Inventorying, characterising and conserving on-farm ancient olive trees is a priority for 14 safeguarding their genetic, natural and agricultural value and for protecting ancient 15 genotypes threatened with extinction. In the "Taula del Sénia" (M-TdS) area (northeast 16 Iberian Peninsula) a highly important cultural landscape has been preserved, in which 17 the olive groves play an outstanding social and economic role: the ancient olive trees, 18 sustained by many local farmers, constitute a living heritage and provide a clear 19 example of High Nature Value (HNV). A total of 4,526 ancient productive olive trees, 20 with a trunk circumference (PBH) larger than 3.5 m, were inventoried and their spatial 21 localization and biometric measurements were collected. 41 olive trees have shown the 22 highest category in monumentality (PBH>8.1 m). The outstanding trees might be 634-23 1082 years old. The endocarp morphology of a representative sample of the most 24 ancient trees from this settlement resulted in 14 different profiles. The ancient trees 25 genotyped, through eight simple sequence repeat (SSR) markers, revealed 43 SSR 26 profiles. The use of SSR enabled us to verify that most of the trees (98%) belong to the 27 local cv. 'Farga', a male sterile variety with a rare chlorotype, only a few trees 28 corresponded with other local varieties, 'Morrut', 'Canetera' and 'Sevillenca', and ten 29 hitherto unidentified genotypes were distinguished, some with chloroplast lineages 30 different from the 'Farga' type. The M-TdS area holds a unique living and exploitable 31 heritage with the highest concentration of ancient olive trees worldwide. On-farm 32 conservation of this germplasm by the community of local growers is enabling 33 preservation of this important source of genetic variation, potentially holding traits of 34 resilience and adaptation to adverse soil and climatic conditions, demonstrated by the 35 survival of these trees over the centuries. Farmers have undertaken initiatives to valorize 36 the olive oil deriving from these M-TdS trees.37 38

Olive, the emblematic Mediterranean fruit crop, owns a great varietal diversity, which is maintained in ex situ field collections, such as the World Olive Germplasm Bank of Córdoba (WOGBC), Spain. Accurate identification of WOGBC, one of the world’s largest collections, is essential for efficient management and use of olive germplasm. The present study is the first report of the use of a core set of 96 EST-SNP markers for the fingerprinting of 1273 accessions from 29 countries, including both field and new acquired accessions. The EST-SNP fingerprinting made possible the accurate identification of 668 different genotypes, including 148 detected among the new acquired accessions. Despite the overall high genetic diversity found at WOGBC, the EST-SNPs also revealed the presence of remarkable redundant germplasm mostly represented by synonymy cases within and between countries. This finding, together with the presence of homonymy cases, may reflect a continuous interchange of olive cultivars, as well as a common and general approach for their naming. The structure analysis revealed a certain geographic clustering of the analysed germplasm. The EST-SNP panel under study provides a powerful and accurate genotyping tool, allowing for the foundation of a common strategy for efficient safeguarding and management of olive genetic resources.

The ancient ‘Corbella’ olive variety from the center-north of Catalonia is being recovered to obtain quality extra-virgin olive oil (EVOO) with unique organoleptic properties. The aim of this work was to determine the effect of agronomic and technical factors on the phenolic fingerprint of EVOO and to establish the optimum harvesting time and crushing and malaxation conditions for ‘Corbella’ olives. Therefore, three different ripening indices (0.3, 1.2, and 3.2) and three crushing temperatures (10, 18, and 25 OC) were studied. Additionally, a factorial design to optimize the phenolic concentration of the EVOO was developed, applying a range of sieve diameters (4 and 6 mm), and malaxation time (30 and 60 min) and temperature (27, 32, and 37 °C). The phenolic profile was analyzed by ultra-high performance liquid chromatography coupled to mass spectrometry in a tandem detector. The level of secoiridoids, the major phenolic compounds in the oil, was higher when using olives harvested earlier. Oleuropein aglycone and ligstroside aglycone were degraded during crushing at high temperatures, resulting in the formation of oleacein and oleocanthal. The best processing conditions in terms of total phenolic content were found to be 30 min of malaxation at 37 OC, the crushing size not having any affect.

Walnut blight, caused by Xanthomonas arboricola pv. juglandis, is currently controlled in western Europe through a standard schedule of seven applications of sprayed copper from bud break until harvest. A reduced spray schedule, with the last four applications omitted, was compared to the standard program in experimental plots for 3 years. Bacterial population levels in the spring were not significantly different between trees subjected to reduced sprays and those subjected to the standard schedule, but in summer they were higher in the trees that received fewer sprays compared with the standard program. However, disease control on nuts was similar or even better with the reduced spraying program than with the standard program, with the additional economic benefit of four fewer copper applications. After 3 years of using the reduced spray program, the amount of copper accumulated in the soil was significantly lower (about half) than that found in the soil where the standard spray program was implemented.