Yield and grain protein concentration in bread wheat: how to use the negative relationship between the two characters to identify favourable genotypes?

A study of the relationship between grain yield (GY) and grain protein concentration (GPC) in bread wheat was carried out on a 11-year series of trials conducted by the Groupement d'Etude des Varietes Et Semences (GEVES) for the registration of new cultivars on the French National List. Values for GY and GPC came from 458 individual trials, grouped together in 21 series of bi-annual and multi-site data. The correlations between the two characters, calculated environment by environment, appeared highly variable due to high "genotype x environment" interactions for GY and GPC. The use of mean values, calculated on the 21 series of GEVES trials, enabled a better assessment of the relationship between the two characters, and an algorithm was proposed to avoid bias due to potential outliers. Using the well-assessed relationship obtained, grain protein deviations (GPDs) were defined as the standardized residuals of the regression of GPC on GY. These deviations appeared to have a partly genetic basis, as the lines with high deviations were about the same in the two independent datasets constituted by the two consecutive years of GEVES experiments. Some lines used as standards in GEVES trials obtained significant GPD for different series of bi-annual and multi-site trials, confirming the genetic origin of high-GPD. Simulations made to determine the minimum experimental design, showed that at least five sites per year for two consecutive years, were necessary to have a good assessment of the GY-GPC relationship, and hence reliable estimates of GPD

Impact des nouvelles techniques de production, impliquant de faibles niveaux d'intrants, sur la quantité de protéines

La teneur en protéines est un critère de qualité majeur pris en compte lors de la commercialisation des céréales. Elle résulte d'un équilibre, au sein de la plante, entre la nutrition azotée et la nutrition carbonée, ces deux processus étant étroitement liés via la sénescence des feuilles. La fertilisation azotée tardive, en fournissant de l'azote à la culture à un moment où la demande des grains est fixée, permet en général d'accroître la teneur en protéines des grains. En raison des exigences environnementales nouvelles pour la production agricole française, des pratiques culturales moins dépendantes de l'utilisation d'intrants, et valorisant les régulations biologiques au sein des agrosystèmes, se développent. Ces pratiques ont des effets variés sur la teneur en protéines : baisse dans certains cas, hausse dans d'autres. Dans la majeure partie des situations, on peut raisonner les techniques de manière à maximiser les chances d'atteindre les teneurs seuils requises par l'aval. Le facteur le plus aléatoire reste souvent le climat

Sélection du blé tendre pour l'agriculture biologique

Face à une demande croissante des consommateurs pour des produits issus de l'agriculture biologique, l'INRA, organisme de recherche publique, contribue par ses travaux au développement de la filière. Cet article relate ce qu'a initié l'Institut en matière de sélection de variétés de blé tendre adaptées aux caractéristiques très particulières de ce mode de culture

How changes in climate and agricultural practices influence wheat production

How changes in climate and agricultural practices influence wheat production. 19. ICC Conference - Science meets Technolog

Conventional versus organic farming systems: dissecting comparisons to improve cereal organic breeding strategies

“Conventional” and “organic” farming systems have been compared in many studies. However, the lack of concern about the diversity of both conventional and organic farming systems can be imputed to the oft-quoted methodological difficulties of comparing conventional and organic systems. Indeed, the analysis of articles on genotype performance of small-grain cereals under conventional and organic management strategies revealed that there are significant variations in input levels within conventional systems and within organic farming. In addition, this could lead to conflicting results when attempting to identify the best breeding strategies for organic management systems. To boost breeding activities for the organic sector, our proposal is the establishment of an international classification of agroecosystem managements based on recognized agro-climatic and management indicators. Management classifications are proposed for both conventional and organic management strategies. This work would facilitate the sharing of new results among agronomists and breeders for designing adapted and efficient organic breeding strategies

How changes in climate and agricultural practices influence wheat production in Western Europe

Wheat is one of the main crops cultivated in nearly all regions of the world, from the equator to temperate lands. Since the early 1960s, grain yield has increased almost linearly. However, in several European countries, a stagnation is observed since the mid-1990s. Several studies have been carried out to analyse the possible causes of this stagnation, particularly in Western Europe and France. Three groups of factors are usually mentioned: a decrease in genetic progress, changes in agricultural practices for economic or regulatory reasons and, finally, more unfavourable biotic and abiotic environmental conditions. The vast majority of studies carried out in Europe and France show that the genetic progress has not slowed down since the 1980s. Among agricultural practices, a decrease in nitrogen fertilization and area of favourable preceding crops are often put forward. Finally, drought during the stem elongation and heat stress during grain-filling stages were mainly identified as environmental factors increasingly impacting yield. Besides average climate changes, extreme climatic years may have a large impact such as season 2015-2016 in France. Abnormally warm temperatures in late autumn, wet conditions and low solar radiations in spring explained this particularly low grain yield. Extreme events cause huge challenges to breeding that would require either adequate experimental conditions, trait assisted methods or genomic selection models that would enable to select for climatic scenarios that are very rare

Le facteur energie dans les exploitations de grande culture : impact des chocs petroliers et analyse prospective a l'horizon 2000

CNRS TD 15512 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Plus de protéines grâce à la génétique aujourd’hui et demain ?

National audienc

Conventional versus organic farming systems: dissecting comparisons to improve cereal organic breeding strategies

“Conventional” and “organic” farming systems have been compared in many studies. However, the lack of concern about the diversity of both conventional and organic farming systems can be imputed to the oft-quoted methodological difficulties of comparing conventional and organic systems. Indeed, the analysis of articles on genotype performance of small-grain cereals under conventional and organic management strategies revealed that there are significant variations in input levels within conventional systems and within organic farming. In addition, this could lead to conflicting results when attempting to identify the best breeding strategies for organic management systems. To boost breeding activities for the organic sector, our proposal is the establishment of an international classification of agroecosystem managements based on recognized agro-climatic and management indicators. Management classifications are proposed for both conventional and organic management strategies. This work would facilitate the sharing of new results among agronomists and breeders for designing adapted and efficient organic breeding strategies

Les limites de la comparaison « agriculture conventionnelle » versus « agriculture biologique » dans la définition de stratégies de sélection. Exemple des céréales à paille

National audienc