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High temperatures (HTs) during grain fi lling adversely impact grain yield and its end-use quality for wheat. HTs strongly reduce the expression of major enzymes associated with starch synthesis, whereas enzymes associated with defence against stress and protein folding are dramatically increased. Using proteomics tools, the effect of different temperature regimes on storage protein (SP) accumulation was investigated. HT signifi cantly decreased the quantity per grain of individual gliadin and glutenin spots, but at maturity the ratio of gliadin to glutenin was not modifi ed. HT during grain fi lling strongly reduced starch accumulation, modifi ed the size distribution of starch granules, and to a much lesser extent, reduced the quantity of total proteins per grain. The aggregation and polymerisation of SP was investigated using asymmetric fl ow fi eld fl ow fractionation. Previous analyses of near-isogenic hard/soft lines showed that characteristics of glutenin polymers were signifi cantly infl uenced by puroindoline alleles ( Pina-D1a and -D1b ), and proteomics analysis showed that a typical mechanism of unfolded protein response occurs in ER, resulting from stress during protein accumulation. Effects of alleles encoding puroindolines, HMW-GS and LMW-GS, and temperature during grain development on glutenin polymer characteristics, dough rheological properties, and bread loaf volume were investigated for 40 cultivars grown in six environments in France. A difference of only 2 °C in average daily air temperature between locations during the grain-fi lling period resulted in increased molecular mass of the glutenin

This study investigates genetic and environmental variation in starch content and characteristics of 14 French bread cultivars. Understanding the impact of these factors on wheat quality is important for processors and especially bakers to maintain and meet the requirements of industrial specifications. Different traits were evaluated: starch content, distribution of starch granules, percentage of amylose and amylopectin and their molecular characteristics (weight-average molar mass, number-average molar mass, polydispersity and gyration radius). Genetic, environment and their interaction had significant effects on all parameters. The relative magnitude of variance attributed to growth conditions, for most traits, was substantially higher (21% to 95%) than that attributed to either genotype (2% to 73%) or G × E interaction (2% to 17%). The largest environmental contribution (95%) to total variance was found for starch dispersity. The highest genetic influence was found for the percentage of A-type starch granules. G × E interaction had relatively little influence (≈7%) on total phenotypic variance. All molecular characteristics were much more influenced by environment than the respective percentages of amylose and amylopectin were. This huge difference in variance between factors obviously revealed the importance of the effect of growing conditions on characteristics of cultivars.

The levels of fumonisins (FUMO)—mycotoxins produced by Fusarium verticillioides—in maize for food and feed are subject to European Union regulations. Compliance with the regulations requires the targeting of, among others, the agroclimatic factors influencing fungal contamination and FUMO production. Arvalis-Institut du végétal has created a national, multiyear database for maize, based on field survey data collected since 2003. This database contains information about agricultural practices, climatic conditions and FUMO concentrations at harvest for 738 maize fields distributed throughout French maize-growing regions. A linear mixed model approach highlights the presence of borers and the use of a late variety, high temperatures in July and October, and a water deficit during the maize cycle as creating conditions favoring maize contamination with Fusarium verticillioides. It is thus possible to target a combination of risk factors, consisting of this climatic sequence associated with agricultural practices of interest. The effects of the various possible agroclimatic combinations can be compared, grouped and classified as promoting very low to high FUMO concentrations, possibly exceeding the regulatory threshold. These findings should facilitate the creation of a national, informative and easy-to-use prevention tool for producers and agricultural cooperatives to manage the sanitary quality of their harvest.