In southern Europe, rioe ißryza sativa L.) is grown as an irrigated crop in river deltas where it plays an ¡mportant role in the agroecological equilibrium through soil desalinization. In these regions, rice is at the northern limit of its natural area of adaptation. Special cultivars are needed for these challenging conditions. Using modelbased and distance-based approaches, we analyzed the genetic structure of the European Rice Germplasm Collection (ERGC), which is composed of 425 accessions, using 25 simple sequence repeat (SSR) markers. We compared it with a reference set of 50 accessions that are representative of the diversity of O. sativa. Most of the ERGC accessions (89%) clustered with japonioa types. The ERGC/apon/ca accessions were classified into three groups: one group close to rice types of tropical origin that are found in the United States and Argentina and two groups of temperate origin showing less differentiation. The three japonioa groups could be characterized according to their grain type and maturity class, which are the most strongly selected traits in European breeding programs. We extracted a core collection of 250 japónica accessions and characterized it using 70 single nucleotide polymorphisms (SNPs). The SSR and SNP dissimilarity matrices coincided reasonably well and for the best-supported structure, the percentages of admixture were highly correlated. The core collection can be used as an association panel to search for alíeles of interest for temperate areas or as a training population for genomic selection.

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During the last decade, a large number of QTLs and candidate genes for rice tolerance to salinity have been reported. Using 124 SNP and 52 SSR markers, we targeted 14 QTLs and 65 candidate genes for association mapping within the European Rice Core collection (ERCC) comprising 180 japonica accessions. Significant differences in phenotypic response to salinity were observed. Nineteen distinct loci significantly associated with one or more phenotypic response traits were detected. Linkage disequilibrium between these loci was extremely low, indicating a random distribution of favourable alleles in the ERCC. Analysis of the function of these loci indicated that all major tolerance mechanisms were present in the ERCC although the useful level of expression of the different mechanisms was scattered among different accessions. Under moderate salinity stress some accessions achieved the same level of control of Na(+) concentration and Na(+)/K(+) equilibrium as the indica reference variety for salinity tolerance Nona Bokra, although without sharing the same alleles at several loci associated with Na(+) concentration. This suggests (a) differences between indica and japonica subspecies in the effect of QTLs and genes involved in salinity tolerance and (b) further potential for the improvement of tolerance to salinity above the tolerance level of Nona Bokra, provided the underlying mechanisms are complementary at the whole plant level. No accession carried all favourable alleles, or showed the best phenotypic responses for all traits measured. At least nine accessions were needed to assemble the favourable alleles and all the best phenotypic responses. An effective strategy for the accumulation of the favourable alleles would be marker-assisted population improvement.

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This paper presents and evaluates multitemporal LAI estimates derived from Sentinel-2A data on rice cultivated area identified using time series of Sentinel-1A images over the main European rice districts for the 2016 crop season. This study combines the information conveyed by Sentinel-1A and Sentinel-2A into a high-resolution LAI retrieval chain. Rice crop was detected using an operational multi-temporal rule-based algorithm, and LAI estimates were obtained by inverting the PROSAIL radiative transfer model with Gaussian process regression. Direct validation was performed with in situ LAI measurements acquired in coordinated field campaigns in three countries (Italy, Spain and Greece). Results showed high consistency between estimates and ground measurements, revealing high correlations (R 2 > 0.93) and good accuracies (RMSE < 0.83, rRMSE m < 23.6% and rRMSE r < 16.6%) in all cases. Sentinel-2A estimates were compared with Landsat-8 showing high spatial consistency between estimates over the three areas. The possibility to exploit seasonally-updated crop mask exploiting Sentinel-1A data and the temporal consistency between Sentinel-2A and Landsat-7/8 LAI time series demonstrates the feasibility of deriving operationally high spatial-temporal decametric multi-sensor LAI time series useful for crop monitoring.

The ERMES agro-monitoring system for rice cultivations integrates EO data at different resolutions, crop models and user-provided in-situ data in a unified system which drives two operational downstream services for rice monitoring. The first is aimed at providing information concerning the behaviour of the current season at regional/rice district scale, while the second is dedicated to provide farmers with field-scale data useful to support more efficient and environmentally-friendly crop practices. In this contribution, we describe the main characteristics of the system, in terms of overall architecture, technological solutions adopted, characteristics of the developed products and functionalities provided to end-users. Peculiarities of the system reside in its ability to cope with the needs of different stakeholders within a common platform, and in a tight integration between EO data processing and information retrieval, crop modelling, in situ data collection and information dissemination. The ERMES system has been operationally tested in three European rice-producing countries (Italy, Spain and Greece) during growing seasons 2015 and 2016, providing a great amount of NRT information concerning rice crops. Highlights of significant results are provided, with particular focus on real-world applications of ERMES products and services. Although developed with focus on European rice cultivations, solutions implemented in the ERMES system can be, and are already being, adapted to other crops

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Rice by-products are extensively abundant agricultural wastes from the rice industry. This study was designed to optimize experimental conditions for maximum recovery of free and bound phenolic compounds from rice by-products. Optimized conditions were determined using response surface methodology based on total phenolic content (TPC), ABTS radical scavenging activity and ferric reducing power (FRAP). A Box-Behnken design was used to investigate the effects of ethanol concentration, extraction time and temperature, and NaOH concentration, hydrolysis time and temperature for free and bound fractions, respectively. The optimal conditions for the free phenolics were 41–56%, 40 °C, 10 min, whereas for bound phenolics were 2.5–3.6 M, 80 °C, 120 min. Under these conditions free TPC, ABTS and FRAP values in the bran were approximately 2-times higher than in the husk. However, bound TPC and FRAP values in the husk were 1.9- and 1.2-times higher than those in the bran, respectively, while bran fraction observed the highest ABTS value. Ferulic acid was most evident in the bran, whereas p-coumaric acid was mostly found in the husk. Findings from this study demonstrates that rice by-products could be exploited as valuable sources of bioactive components that could be used as ingredients of functional food and nutraceuticals.