E conomie and technical problems related to the redu ction of petroleum resources require the valorisation of renewable raw material. Re cently, microalgae emerged as promising alternative feedstock that represents an enormous biodiversity with multiple benefits exceeding the potential of conventional agricultural feedstock. Thus, this comprehensive review arti cle spots the light on one of the most interesting microalga Chlorella vulgaris. It assembles the history and a thorough des cription of its ultrastructure and composition a ccording to growth conditions. The harvesting te chniques are presented in relation to the nove! algo-refinery concept, with their te chnological advan cements and potential applications in the market.

International audienc

Twenty‐one durum wheat genotypes originating from different geographic areas were grown during 3 successive years. The trials were characterised by different precipitation regimes. Carbon isotope discrimination (Δ), carbon content (CC) and ash content (ma) were assessed in the flag leaf during anthesis, then in the kernel at full maturity. Differences between the 3 years, due to water availability, were noted for Δ, ma, CC and yield. Genotypic differences were also noted within each year for all the traits studied. Some genotypes from the Middle East exhibited higher flag leaf and kernel Δ than those originating from the West of the Mediterranean basin. The kernel Δ was strongly correlated with grain yield (GY). The leaf Δ correlated with GY only under strong water limitation and with biomass production (BP) in favourable water conditions. For the flag leaf, Δ was correlated with ma and with CC. Silicon content was then assessed in the flag leaf and in the kernel on a subset of 10 genotypes differing in their Δ values. Strong positive correlations were noted between silicon content and Δ and ma for the flag leaf. However, no clear relationship was found between silicon content and GY. The results obtained in this study confirm the validity of kernel Δ as a predictive criterion for GY under water stress and suggest the possible use of kernel ma as an alternative criterion to select genotypes with higher water stress tolerance.

In several crops including cereals, carbon isotope discrimination (Delta) has been associated with drought tolerance in terms of water-use efficiency and yield stability in drought-prone environments. By using a complete genetic map generated from 167 recombinant inbred lines from a cross between Tadmor and Er/Apm, QTLs associated with grain Delta have been detected in barley grown in three Mediterranean field environments, two differing only in water availability. Ten QTLs were identified: one was specific to one environment, two presented interaction with the environment, six presented main effects across three or two environments and one presented both effects. Heading date did not contribute to the environment (E) and G x E effects acting on Delta. Seasonal rainfall and the ratio of rainfall to evapo-transpiration made large contributions to the environmental effect, but their influence on G x E was weaker. Eight QTLs for Delta co-located with QTLs for physiological traits related to plant water status and/or osmotic adjustment, and/or for agronomic traits previously measured on the same population. Some perspectives in terms of characterising drought tolerance are evoked.