Helia 

About: Helia is an academic journal published by University of Novi Sad. The journal publishes majorly in the area(s): Sunflower & Helianthus annuus. It has an ISSN identifier of 1018-1806. Over the lifetime, 632 publications have been published receiving 5258 citations. The journal is also known as: international scientific journal of the F.A.O. European Cooperative Research Network on Sunflower and the International Sunflower Association.

Inheritance of imidazolinone-herbicide resistance in sunflower / herencia de la resistencia a imidazolinonas en girasol / hérédité de la résistance à l’herbicide imidazolinone chez le tournesol

Abstract: SUMMARY Broadleaf weeds cause considerable yield losses to sunflower production in all regions of the world. Resistance to the imidazolinone herbicides, imazethapyr and imazamox, found in a population of wild sunflower, could have great value for controlling many broadleaf weeds. The herbicide resistance was successfully transferred from resistant wild sunflower plants to a cultivated sunflower inbred line, HA 425. The objective of this investigation was to determine the inheritance of resistance to the herbicide imazamox in HA 425. Segregation ratios of plants in F2 and testcross populations indicated that resistance was controlled by two genes, a major gene having a semi-dominant type of gene action (Imr1), and a second gene (Imr2) with a modifier effect when the major gene is present. Resistance in sunflower can only be achieved with homozygocity (Imr1, Imr1, Imr2, Imr2) of both resistance genes in an inbred line or in a hybrid. Completely resistant hybrids require having resistance factors in both parents. RESUMEN Las malezas de hoja ancha causan perdidas de rendimiento considerables a los productores de girasol en todas las regiones del mundo. La resistencia encontrada en una población de girasol a los herbicidas de la familia imidazolinonas: imazethapyr e imazamox, podría ser de gran utilidad para controlar malezas de hoja ancha. La resistencia a herbicidas fué exitosamente transferida desde plantas de girasol silvestre a una linea endocriada de girasol cultivado, denominada HA 425. El objetivo de esta investigación fué estudiar la herencia de la resistencia al herbicida imazamox en la línea HA 425. El análisis de la segregación de plantas en una población F2 y cruzamientos de prueba, indicaron que la resistencia estaba controlada por dos genes, un gen mayor con un tipo de acción génica semi-dominante (Imr1) y un segundo gen (Imr2), con efecto modificador cuando el gen mayor estaba presente. La resistencia a herbicidas en girasol puede ser lograda solamente con completa homocigosis (Imr1, Imr1, Imr2, Imr2) de los genes de resistencia, por lo que híbridos completamente resistentes requieren tener los dos factores de resistencia en ambos padres. RÉSUMÉ Les plantes adventices à feuilles larges sont la cause d’importantes diminutions du rendement du tournesol dans toutes les parties du monde. La résistance aux herbicides basés sur l’imidazolinone, l’imazethapyr et l’imazamox, confirmée dans une population de tournesol sauvage, pourrait être d’une grande importance dans la lutte contre de nombreuses plantes adventices à feuilles larges. La résistance aux herbicides a été transmise avec succès du tournesol sauvage résistant à la ligne inbred de tournesol cultivé HA 425. Le but de cette expérience était d’établir l’hérédité de la résistance à l’herbicide imazamox dans la ligne HA 425. Les rapports de division dans les plantes F2 et dans les populations contrôle (cross-test) ont démontré que la résistance se trouve sous le contrôle de deux gènes, un gène principal avec un type semidominant d’action génétique (Imr1) alors qu’un deuxième gène (Imr2) a un rôle modificateur quand le gène principal est présent. La résistance du tournesol ne peut être atteinte qu’en transmettant les deux gènes de résistance (Imr1, Imr1,Imr2, Imr2) à l’état homozygote dans une ligne inbred ou hybride. Pour obtenir des hybrides tout à fait résistants, il est nécessaire que les deux parents possèdent les facteurs de résistance.

Correlation and path analysis in sunflower

Abstract: Fifty-one inbreds and three checks of sunflower were laid in a randomized complete block design following recommended package of practices. Correlation studies revealed that seed yield was positively and significantly associated with seed volume weight, hull percentage, percent autogamy, days to 50 percent flowering and oil yield. Oil content was positively associated with plant height, number of leaves per plant, seed volume weight, hull percentage, head diameter, percent' autogamy, days to 50 percent flowering, 100-seed weight, seed yield and oil yield. Path coefficient analysis for seed yield at phenolypic level showed that the direct effect was maximum for oil yield followed by 100-seed weight. The maximum indirect effect for seed yield was minimum through oil yield, while it was through yield per plant for oil.

Seed viability of oil crops depending on storage conditions

Abstract: Changes occurring in seed during aging are significant as far as seed quality and longevity are concerned and are a consequence of the effects of different storage conditions. The chemical composition of seed with high oil content is related to specific processes occurring in seed during storage. In this trial, sunflower and soybean genotypes developed in Novi Sad were submitted to accelerated aging for three and five days, and natural aging for six and twelve months, under controlled and conventional (non-controlled) conditions. The obtained results showed that preservation of seed viability depended on storage condition and duration, as well as plant species. Accelerated aging test can be used to predict the length of storage life of sunflower and soybean seed. In comparison to sunflower seed, soybean seed is more sensitive to damage and reduced germination during storage.

Recent Changes in the Pathogenic Variability of Plasmopara Halstedii (Sunflower Downy Mildew) Populations from Different Continents

Abstract: Abstract The obligate biotrophic Oomycete, Plasmopara halstedii, causal agent of sunflower downy mildew, is capable of producing new pathogenic races over time. Although changes in the P. halstedii race composition were reviewed for the first time in 2007, since then the pathogen has continued to change its virulence character dramatically. There was a need, therefore, to update information on pathogenic diversity of P. halstedii by making accounts of the temporal and spacial changes in the pathogen populations in North and South America and Europe. This paper, based on current publications and personal communications, attempts to present an accurate overview of races in Europe and Americas for the last 7 years.

Update on breeding for resistance to sunflower broomrape.

Abstract: Sunflower broomrape (Orobanche cumana Wallr.) is currently regarded as one of the most important constraints in sunflower (Helianthus annuus L.) production. In the last fifteen years, efforts to introduce genetic sources of resistance to this parasite in sunflower hybrids have been rapidly followed by the appearance of new virulent races that have overcome all known resistance genes. Due to this situation, most of the research efforts have focused on the development and characterization of new sources of genetic resistance to the most virulent races and also to investigate the genetic structure and variability of O. cumana populations and their evolution in order to develop long-term strategies for sunflower broomrape management. Results of evaluation of sunflower germplasm for resistance to different races have demonstrated that wild Helianthus species constitute the major reservoir of genes conferring resistance to new virulent races. Cultivated germplasms are also valuable sources of resistance genes. Most of the resistant sources have been found to be controlled by major genes, although quantitative resistance and epistatic effects have also been reported. Different dominance reactions depending on the race of broomrape, the source of resistance, and the susceptible parental line used for the cross have been observed. Molecular studies have shown that phenotypic variance for race E resistance was mainly explained by a major QTL associated with the resistance or susceptibility character, while race F resistance was explained by several QTLs with a small to moderate effect, mainly associated with the number of broomrapes per plant, suggesting the existence of a quantitative component in the resistance to race F. The relevance of these findings for sunflower breeding for resistance to broomrape is discussed.