Changes in sunflower breeding over the last fifty years

Abstract

-This article discusses changes in sunflower breeding objectives since the introduction of hybrid varieties 50 years ago. After a reminder of the importance of some early programmes, Canadian in particular, the present situation for each breeding objective is compared with those encountered earlier. Breeding for yield has changed from maximum possible yield under intensive agriculture to yield with resistance to abiotic stresses, moderate droughts and shallow soils in particular, helped by collaboration with agronomists to produce crop models. Breeding for oil has changed from quantity to quality and the value of seed meal is again becoming economically important. Necessary disease resistances vary with agronomic practises and selection pressure on pathogens according to varietal genetics. The possibilities of new types of sunflower are also discussed. Advances in genomics will change breeding procedures, but with rapidly changing molecular techniques, international collaboration is particularly important.Keywords: Hybrid / yield / oil / disease resistance / genomics Résumé -Sélection du tournesol : tour d'horizon de 50 années d'évolution. Cet article discute des changements intervenus dans les objectifs de sélection du tournesol depuis l'introduction des variétés hybrides, il y a 50 ans. Après un rappel des premiers programmes, le canadien en particulier, la situation actuelle pour chaque objectif est comparée à celle rencontrée 50 ans auparavant. L'objectif de la sélection pour le rendement en grain ne vise plus en priorité un rendement maximum en conditions d'agriculture intensive mais un rendement maintenu sous stress abiotiques, séche-resses modérées ou sols peu profonds. Cette sélection est maintenant aidée par la collaboration avec des spécialistes en modélisation agronomique. La sélection relative à l'huile concerne maintenant plus souvent des qualités spécifiques que la teneur de la graine, tandis que le tourteau redevient de valeur économique significative. Les résistances aux maladies nécessaires pour les variétés actuelles varient selon les pratiques agricoles et les génétiques prépondérantes. La possibilité de changer radicalement d'architecture ou de cycle de culture est discutée. Les avances en génomiques vont modifier les procédures de sélection, mais une bonne collaboration internationale s'avère très importante vu les changements rapides dans les techniques moléculaires. Mots clés :Hybride / rendement / huile / résistance aux maladies / génomique

The sunflower crop in Argentina: past, present and potential future

“…are similar to those in other leading countries for the crop (USDA, 2017). Soybean became a highly competitive crop in Argentina and the sunflower crop was pushed towards less favorable regions and environments (ASAGIR, 2017), similar to what happened in Western Europe after 1992 (Vear, 2016). Sunflower was grown on soils of relatively low quality, compared to the other summer crops.…”

“…It should be possible to narrow this gap to obtain more stable yields over several years, of at least 2 ton/ha, as obtained in 2011, 2015 and 2016 (Fig. 1), and similar to those in France, Turkey and Ukraine but less than those reported in China (Vear, 2016;USDA, 2017).…”

Sunflower crop and climate change: vulnerability, adaptation, and mitigation potential from case-studies in Europe

“…During the past fifteen years, the sunflower yield increase through genetic advance has been slower than before, suggesting that current resources and breeding methods might not bring suitable solutions in a context of climate change (Vear, 2016). In order to face the challenges of delivering safe and high-quality food in a sustainable manner while maintaining yield and stability across different environments, a paradigm shift is needed in sunflower breeding.…”

“…But some dominance changes may occur between pathogens (and pathotypes) according to their thermal preferences and their dependency to free water. According to Vear (2016), climatic change may be involved in the recent development of Orobanche cumana in France, since higher temperatures and absence of rainfall could favor broomrape development in sunflower. Pathogens with long conservation forms in the soil (e.g., sclerotia) could better tolerate unfavorable periods.…”

Sunflower crop: environmental-friendly and agroecological

“…During the two previous decades, genetic control made a lot of progress for controlling sunflower diseases (Vear, 2016); nowadays, it is surely the most efficient, practical and repeatable method to control most of the diseases but breeders have to deal with new virulences that overcome specific resistance genes in farmers plots (e.g. downy mildew) and very polygenic resistances (e.g.…”