Intraspecific variation in pollen viability, germination and ultrastructure of Olea europaea L.

Variability of pollen morphology and ultrastructure of Olea europaea L. (Oleaceae) cultivars ‘Koroneiki’, ‘Mastoidis’ and ‘Kalamata’ was studied with scanning electron microscopy to identify genotype- distinguishing characters that could be employed for morphological cultivar discrimination. Pollen viability and germination was also measured for the three cultivars. Significant variation was observed in minimum diameter, maximum/minimum diameter (L/W) ratio and size index of pollen grain of ‘Mastoidis’ and the other two cultivars. Regarding the exine pattern, muri width of ‘Koroneiki’ and ‘Mastoidis’ pollen was similar and significantly lower than that of ‘Kalamata’. The highest values of maximum diameter were observed in ‘Kalamata’ and differed significantly with ‘Mastoidis’ but not with ‘Koroneiki’. No marked variation was noted in minimum diameter and L/W ratio. ‘Kalamata’ was characterized by higher size index than the other two cultivars, though statistical difference was observed only when compared with ‘Mastoidis’. Higher pollen viability and in vitro germination was recorded for ‘Kalamata’ and ‘Mastoidis’ compared to ‘Koroneiki’. Acquired information could contribute to the establishment of a database for future olive germplasm classification studies.Keywords: Floral biology, olive, pollen ultrastructure, scanning electron microscop

Driving the Ecological Transition of Agriculture through Voluntary Certification of Environmental Impacts: An Exploratory Literature Review on the Olive-Oil Sector

Human population growth has resulted in increased food consumption, followed by agrifood production intensification. Human activities have a significant impact on the environment, causing, among other things, air and water pollution and biodiversity degradation. In an international context where there is strong concern about environmental issues, it is also necessary to direct food production towards more sustainable models. In this context, the use of frameworks for certifying the environmental footprint of agrifood products can be a lever to promote sustainable production and consumption. The objective of this paper is to explore the opportunities for certifying the environmental footprint of products, focusing in particular on some of the main environmental claims: global warming, water depletion, and biodiversity loss. The olive sector was selected as a case study since it is the major tree crop in the Mediterranean countries, and it has strong impacts on human health and the environment. We employed a literature review in the SCOPUS database and the knowledge of experts in the main environmental certification sectors. The study revealed the possibility of adopting various mitigation strategies and improving environmental performance, while also pursuing certain market objectives related to certified products

Management options influence seasonal CO2 soil emissions in Mediterranean olive ecosystems

Field trials were conducted at traditional Mediterranean olive agro-ecosystems grown at two locations (Italy –IT, Greece –GR). Groves were managed for many years using sustainable (S, cover crops, compost application, mulching of pruning biomass) or conventional (C) practices (e.g., soil tillage, burning of pruning residuals). The IT grove was rainfed (RAIN) while the GR was irrigated (IRR). This study examined the seasonal variation of soil CO2 emission (Rs) to explore the effect of the management options (C, S) on Rs at both sites. The second aim was to test the hypothesis that the seasonal Rs is differentially modulated by soil temperature and moisture, namely that (i) soil moisture limits Rs when it is below the lower limit of the readily available water (RAWLLim) and (ii) soil temperature above a threshold (max_T) reduces Rs even if soil moisture is non limiting. On the whole-season basis, the mean Rs rate at the rainfed site was 2.17 ± 0.06 (SE) at CRAIN and 2.32 ± 0.06 μmol CO2 m−2 s–1 at SRAIN plot, while at the irrigated site Rs was about 3.64 ± 0.11 (CIRR) and 4.05 ± 0.15 μmol CO2 m−2 s–1 (SIRR). The seasonal oscillation of Rs was consistent across locations and partitionable in three periods according to DOY (Day of Year) interval: Phase I (DOY 20–103 –GR; 20–118 -IT), Phase II (DOY 141÷257, GR; 142–257, IT) and Phase III (DOY 291–357, GR; 286–350, -IT). Pooling all the Rs data across sites and managements, max_T was ∼ 20 °C discriminating a differential response of Rs when soil moisture was < or > RAWLLim. These differential modulations exerted by temperature and moisture were integrated into a conditional model developed with a repeated random subsampling cross-validation procedure to effectively (R2 = 0.84) predict Rs. This paper mechanistically describes the interaction of the environment (soil moisture and temperature) and the management options (S, C) under various moisture conditions on Rs and would support carbon flux accounting procedures (e.g., regulating ecosystem services) tailored to the estimation of sink/source capability of traditional olive agro-ecosystem within environmental-friendly agricultural domains

The issues of apricot (Prunus Armeniaca L.) Micropropagation

The effect of four modified mediums for apricot multiplication was observed in this study. A total number of 1864 single nodes of 20 Prunus armeniaca L.varieties were established. Explants surface was disinfected with 0.2 % mercuric chloride for 5 minutes. MS (1962) medium with 0.5 mg.l-1 BA, 0.01 mg.l-1 NAA and 0.5 mg.l-1 GA3 was used as a medium for primary culture. 'Velkopavlovická', 'Bergeron', genotype 1128 and genotype LE 2927 Š9 were successfully transferred to aseptic conditions and multiplied. Modified MS medium (1962), DKW/Juglans medium, Quoirin, Lepoivre (1977) medium and Marino et al. (1991) medium were used for multiplication. Modified MS medium and modified DKW/Juglans medium were not suitable for apricot multiplication at all and explants did not grow. The best results were observed in the case of Quoirin, Lepoivre (1977) medium with 0.4 mg. l-1 BA and 0.01 mg.l-1 NAA. Young plants multiplied well, were fresh and vital and no damage was observed. The highest number of new shoots was observed in the case of Marino et al. (1991) medium. The average growth of new shoots after the last passaging was 600 %, rate 7.33 (Velkopavlovická); 566 %, rate 7.0 (Bergeron); 475 %, rate 6.25 (1128) and 483 %, rate 6.33 (LE 2927 Š9)). However, new shoots in clusters were too dense and stunted and this medium is not recommended for apricot multiplication.O

Potential Fertilization Capacity of Two Grapevine Varieties: Effects on Agricultural Production in Designation of Origin Areas in the Northwestern Iberian Peninsula

In the present study, we analyzed the main parameters related with the potential fertilization ability of two grapevine varieties, Godello and Mencía, during the years 2017 and 2018. The research was carried out in two vineyards of the Galician winegrowing Designation of Origin areas of Ribeiro and Ribeira Sacra. Ten vines of each variety were selected for bunch and flower counting, pollen calculations, pollen viability studies by means of aceto-carmine (AC) stain and 2, 3, 5-triphenyl tetrazolium chloride (TTC) methods, and the determination of their germination rate. In all vineyards the 50% fruitset was reached, except for Godello in Cenlle during 2017. The mean coulure value was higher for Godello (40.5%) than for Mencía (31%). Analyzing the pollen production per plant and airborne pollen levels, we observed important discordances between them, which can be due to the influence of weather conditions and be related with self-pollination processes. We found important differences on pollen viability depending on the applied method and variety, with higher values for the AC method than the TTC for both varieties in all study plots, and higher values for Mencía variety than Godello. Regarding germination rates, we observed a marked reduction in 2017 with respect to 2018, in all study sites and for both varieties. The analyzed parameters were useful to explain the different productive abilities of Godello and Mencía varieties in the two studied bioclimatic regions of Ribeiro and Ribeira SacraThis research was funded by the Xunta de Galicia (Consellería de Educación, Universidade e Formación Profesional) through the recognition as Grupo de Referencia Competitivo de Investigación (GRC GI-1809 BIOAPLIC “Biodiversidad y Botánica Aplicada”, ED431C 2019/07), the Agrupación Estratégica de Investigación BioReDes (ED431E 2018/09) and the BV1 Reference Competitive Research Groups ED431C 2017/62 (Xunta de Galicia, Spain). This work was partially funded by Xunta de Galicia CITACA “Cluster de Investigación y Transferencia Agroalimentaria de Campus del Agua” Strategic Partnership (Reference: ED431E 2018/07) and the AGL2014-60412-R Economy and Competence Ministry of Spain Government project. Fernández-González M. was supported by FCT “Fundação para a Ciência e a Tecnologia” (SFRH/BPD/125686/2016) through the HCOP-Human Capital Operational Program, financed by “Fundo Social Europeu” and “Fundos Nacionais do MCTES (Ministério da Ciência, Tecnologia e Ensino Superior). González-Fernández E. was supported by the Ministry of Sciences, Innovation and Universities (FPU “Ayudas para la Formación de Profesorado Universitario” grant FPU15/03343)S

Whole genome scanning of a Mediterranean basin hotspot collection provide new insights into olive tree biodiversity and biology

Olive tree (Olea europaea L. subsp. europaea var. europaea) is one of the most important species of the Mediterranean region and one of the most ancient species domesticated. The availability of whole genome assemblies and annotations of olive tree cultivars and oleaster (O. europaea subsp. europaea var. sylvestris) has contributed to a better understanding of genetic and genomic differences between olive tree cultivars. However, compared to other plant species there is still a lack of genomic resources for olive tree popula-tions that span the entire Mediterranean region. In the present study we developed the most complete genomic variation map and the most comprehensive catalog/resource of molecular variation to date for 89 olive tree genotypes originating from the entire Mediterranean basin, revealing the genetic diversity of this commercially significant crop tree and explaining the divergence/similarity among different variants. Addi-tionally, the monumental ancient tree ‘Throuba Naxos’ was studied to characterize the potential origin or routes of olive tree domestication. Several candidate genes known to be associated with key agronomic traits, including olive oil quality and fruit yield, were uncovered by a selective sweep scan to be under selection pressure on all olive tree chromosomes. To further exploit the genomic and phenotypic resources obtained from the current work, genome-wide association analyses were performed for 23 morphological and two agronomic traits. Significant associations were detected for eight traits that provide valuable candidates for fruit tree breeding and for deeper understanding of olive tree biology.info:eu-repo/semantics/publishedVersio

OliveCan: a process-based model of development, growth and yield of olive orchards

Original ResearchSeveral simulation models of the olive crop have been formulated so far, but none of them is capable of analyzing the impact of environmental conditions and management practices on water relations, growth and productivity under both wellirrigated and water-limiting irrigation strategies. This paper presents and tests OliveCan, a process-oriented model conceived for those purposes. In short, OliveCan is composed of three main model components simulating the principal elements of the water and carbon balances of olive orchards and the impacts of some management operations. To assess its predictive power, OliveCan was tested against independent data collected in two 3-year field experiments conducted in Córdoba, Spain, each of them applying different irrigation treatments. An acceptable level of agreement was found between measured and simulated values of seasonal evapotranspiration (ET, range 393 to 1016 mm year1; RMSE of 89 mm year1), daily transpiration (Ep, range 0.14–3.63 mm d1; RMSE of 0.32 mm d1) and oil yield (Yoil, range 13–357 g m2; RMSE of 63 g m2). Finally, knowledge gaps identified during the formulation of the model and further testing needs are discussed, highlighting that there is additional room for improving its robustness. It is concluded that OliveCan has a strong potential as a simulation platform for a variety of research applicationsinfo:eu-repo/semantics/publishedVersio

Whole genome scanning of a Mediterranean basin hotspot collection provides new insights into olive tree biodiversity and biology

Olive tree (Olea europaea L. subsp. europaea var. europaea) is one of the most important species of the Mediterranean region and one of the most ancient species domesticated. The availability of whole genome assemblies and annotations of olive tree cultivars and oleaster (O. europaea subsp. europaea var. sylvestris) has contributed to a better understanding of genetic and genomic differences between olive tree cultivars. However, compared to other plant species there is still a lack of genomic resources for olive tree populations that span the entire Mediterranean region. In the present study we developed the most complete genomic variation map and the most comprehensive catalog/resource of molecular variation to date for 89 olive tree genotypes originating from the entire Mediterranean basin, revealing the genetic diversity of this commercially significant crop tree and explaining the divergence/similarity among different variants. Additionally, the monumental ancient tree ‘Throuba Naxos’ was studied to characterize the potential origin or routes of olive tree domestication. Several candidate genes known to be associated with key agronomic traits, including olive oil quality and fruit yield, were uncovered by a selective sweep scan to be under selection pressure on all olive tree chromosomes. To further exploit the genomic and phenotypic resources obtained from the current work, genome-wide association analyses were performed for 23 morphological and two agronomic traits. Significant associations were detected for eight traits that provide valuable candidates for fruit tree breeding and for deeper understanding of olive tree biology.This research was financed by Greek Public Investments Program (PIP) of General Secretariat for Research & Technology (GSRT), under the Emblematic Action ‘The Olive Road’ (project code:2018ΣE01300000). Sebastián Ramos-Onsins is supported by the grant PID2020-119255GB-I00 (MICINN, Spain) and the CERCA Programme/Generalitat de Catalunya and acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Programme for Centres of Excellence in R&D 2016–2019 and 2020–2023 (SEV-2015-0533, CEX2019-000917) and the European Regional Development Fund (ERDF).The publication of the article in OA mode was financially supported by HEAL-Link.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917).Peer reviewe