Heritability of seed weight in Maritime pine, a relevant trait in the transmission of environmental maternal effects

Quantitative seed provisioning is an important life-history trait with strong effects on offspring phenotype and fitness. As for any other trait, heritability estimates are vital for understanding its evolutionary dynamics. However, being a trait in between two generations, estimating additive genetic variation of seed provisioning requires complex quantitative genetic approaches for distinguishing between true genetic and environmental maternal effects. Here, using Maritime pine as a long-lived plant model, we quantified additive genetic variation of cone and seed weight (SW) mean and SW within-individual variation. We used a powerful approach combining both half-sib analysis and parent-offspring regression using several common garden tests established in contrasting environments to separate G, E and G x E effects. Both cone weight and SW mean showed significant genetic variation but were also influenced by the maternal environment. Most of the large variation in SW mean was attributable to additive genetic effects (h(2) = 0.55-0.74). SW showed no apparent G x E interaction, particularly when accounting for cone weight covariation, suggesting that the maternal genotypes actively control the SW mean irrespective of the amount of resources allocated to cones. Within-individual variation in SW was low (12%) relative to between-individual variation (88%), and showed no genetic variation but was largely affected by the maternal environment, with greater variation in the less favourable sites for pine growth. In summary, results were very consistent between the parental and the offspring common garden tests, and clearly indicated heritable genetic variation for SW mean but not for within-individual variation in SW.This study was financed by the Spanish National Research Grants RTA2007-100 and AGL2012-40151 (FENOPIN), both co-financed by EU-FEDER. The progeny trials and the clonal seed orchards are part of the experimental set up of the Maritime pine breeding programme developed by the Centro de Investigacion Forestal de Lourizan, Xunta de Galicia.Spanish National Research Grant RTA2007-100Spanish National Research Grant AGL2012-40151 (FENOPIN)EU-FEDERPeer reviewe

A stand-alone polarimetric acquisition system for producing a long-term skylight dataset

International audienceSkylight polarization phenomenon is at the origin of a recent growing interest for bio-inspired navigation. Skylightbased orientation sensors can be simulated on the basis of physical models. In parallel, machine learning algorithms require a large amount of data to be trained. However, while some simulated databases already exists in the literature, a public database composed of real-world color polarimetric images of the sky in various weather conditions does not. In this study, a long-term experimental device is presented, designed to be left in a distant roof to acquire data over several months, using a Division-of-Focal-Plane polarization imager with a fisheye lens mounted on a rotative telescope mount. An open-source mechanical and electrical design is proposed for easy replication at other locations, with an algorithm to get the sensor's orientation and geometrical calibration in the East-North-Up frame. A sample one-month long dataset is provided on a public archive

A stand-alone polarimetric acquisition system for producing a long-term skylight dataset

International audienceSkylight polarization phenomenon is at the origin of a recent growing interest for bio-inspired navigation. Skylight based orientation sensors can be simulated on the basis of physical models. In parallel, machine learning algorithms require a large amount of data to be trained. However, while some simulated databases already exists in the literature, a public database composed of real-world color polarimetric images of the sky in various weather conditions does not. In this study, a long-term experimental device is presented, designed to be left in a distant roof to acquire data over several months, using a Division-of-Focal-Plane polarization imager with a fisheye lens mounted on a rotative telescope mount. An open-source mechanical and electrical design is proposed for easy replication at other locations, with an algorithm to get the sensor's orientation and geometrical calibration in the East-North-Up frame. A sample one-month long dataset is provided on a public archive

Combined agro-ecological strategies for adaptation of organic horticultural systems to climate change in Mediterranean environment

Agricultural biodiversity and related agro-ecological measures could play a crucial role in the agro-ecosystems adaptation to climate changes, thus sustaining crop production. The objective of this study was to assess the suitability (and the best combination) of agro-ecological techniques as potential resilience strategies in organic horticultural systems in a Mediterranean environment. A long-term experimental device called MITIORG (Long-term climatic change adaptation in organic farming: synergistic combination of hydraulic arrangement, crop rotations, agro-ecological service crops and agronomic techniques) is set-up at Metaponto (MT), testing the following agro-ecological measures as well as organic and conservation farming best practices: i) hydraulic arrangement by a kind of ridge-furrow system; ii) cash crop rotations; iii) agro-ecological service crops (ASC) introduction; iv) ASC termination techniques (green manure vs roller crimper); and v) organic fertilisation. The research here reported was carried out during the 2014-2015 season in the MITIORG device, on a rotation of cauliflower (Brassica oleracea L.) and tomato (Solanum lycopersicum L.) crops. A detailed description of the scientific cognitive process that led to setup of the device, its components explanation, as well as preliminary yield results are reported. The outcomes suggest that organic vegetable cropping systems, designed following agro-ecological principles, are able to sustain yield of cash crops in rotation, in spite of changes in temperature and rainfall of the study site. Experimental data available in the next years will allow a deeper integrated analysis of the manifold effects of agro-ecological measures on horticultural systems

Itineraire du travail du sol comme revelateur du comportement du sol dans un dispositif experimental de longue duree avec rotations

National audienceIn the long term experimental device with crop rotation used in the National Agricultural Research Centre of Toulouse a differentiation of the « Technical Routes » of soil treatment appears under the influence of crop rotations. This differentiation reveals an evolution of the soil behaviour. We aimed at clearing these observations and if possible at explaining them. For this purpose the first part includes an analysis of the recording of the treatments and the notations of the quality of soil treatment. It takes also into account the energy used by the farming methods. This analysis relies on the method of the 2 i test. The second part deals with the results obtained by an experimental test carried out on some typical plots. This checking consists in a quantitative measurement of the structural state of the treated soil. The processing of these data occurs through factorial analysis of correspondences. The interpretation of the results uses the concept of technical route. A good agreement is observed between the facts observed on the spot contributing to the global estimation of the technicians and respectively the analysis of the notations of soil treatment and the quantitative measurement of the structural state. The agronomical, technical and methodological aspects of these results are discussed.Dans le dispositif expérimental de longue durée avec rotations de l’I.N.R.A. de Toulouse, une différenciation des « Itinéraires Techniques » du travail du sol se manifeste sous l’influence des rotations. Cette différenciation « révèle » une évolution du comportement des sols. On se propose d’expliciter ces observations et, si possible, de les expliquer. La première partie analyse, dans ce but, les enregistrements des travaux et les notations de qualité du travail du sol. Elle prend également en compte l’énergie consommée par les façons culturales. Cette analyse utilise la méthode du test 2 i. La deuxième partie examine les résultats obtenus par un contrôle expérimental effectué dans quelques parcelles typiques. Ce contrôle consiste dans une mesure quantitative de l’état structural de la terre travaillée. Le traitement de ces données utilise l’analyse factorielle des correspondances. L’interprétation des résultats fait appel au concept d’itinéraire technique. Une bonne concordance est constatée entre, respectivement, les faits observés sur le terrain concourant au jugement global des techniciens, l’analyse des notations de travail du sol et les mesures quantitatives d’état structural. Les aspects agronomiques, techniques et méthodologiques de ces résultats sont discutés