Sunflower is grown in Argentina across a large and heterogeneous target population of environments. Weed control is one important challenge for this crop to keep it competitiveness with other production schemes. The role of herbicide tolerance research in the public and private sector in Argentina was critical for the development of new technologies across the last two decades, which had impact not only at the regional but also at the global level. The activities include development of initial elite germplasm carrying mutations in Ahal1, but also the discovery and creation of new mutations on the same locus to keep this technology evolving. To create a more efficient way for the deployment of these technologies the development of molecular markers is crucial, and this was attended by local teams too. Finally, the impact of this new technologies on the environment and the analysis of the gene flow from herbicide tolerant materials to sunflower wild relatives was conducted by public research teams in the country. These analyses must be done to create a safe way to translate this genetic modification into technologies than can be applied in every sunflower production area. The aim of this article was to review and highlight some of the milestones obtained by Argentinian researchers in the sunflower herbicide tolerance developments through the last decades.

Studying the full profile of fatty acids in seed oil from 52 lines of the VNIIMK sunflower genetic collection was the goal of this work. The composition of ten fatty acids in the seed oil was analyzed using gas-liquid chromatography of fatty acid methyl esters. The content of fatty acids (%) in the seed oil was: palmitic acid on average 6.3 with a range from 3.0 to 27.7; palmitoleic 0.3 (0.03-5.4); stearic 3.9 (1.1-10.4); oleic 51.5 (14.0-91.4); linoleic 32.2 (0.8-71.1); linolenic 0.05 (0.01-0.1); arachidic 0.3 (0.1-0.6); eicosenic 0.2 (0.1-0.3); begenic 1.0 (0.4-2.2); lignoceric acid 0.3 (0.1-0.6). The coefficient of variation ranged from 27% for lignoceric acid to 59% for palmitic acid, with an average CV of 40%. Of the 45 studied pairs of connections between fatty acids, reliable correlation coefficients were established for 20 pairs of characteristics, 10 positive (from 0.917 to 0.281) and 10 negative (from -0.974 to -0.315) values. The highest positive value of the correlation coefficient was noted for the palmitic-palmitoleic acid pair, and the most negative for the oleic-linoleic acid pair. The discovered wide variation in the content of each fatty acid in the lines of the sunflower genetic collection will allow the lines to be used both in research on biochemical genetics and in practical breeding for oil quality.

Sunflower is the fourth-largest global source of vegetable oil (after soybean, palm, and rapeseed) that is primarily used for human consumption. Argentina ranks  as the third-largest producer of sunflower oil in the world. Breeders have developed genotypes with varying fatty acid compositions to provide alternatives to conventional sunflower oil and to replace trans fatty acids. High oleic and high stearic-high oleic genotypes have expanded the range of sunflower oil compositions available. High oleic oil presents greater oxidative stability than conventional sunflower oil, due to its lower content of polyunsaturated fatty acids. High stearic-high oleic oil and its fractions exhibit even greater stability and plasticity, making them suitable alternatives to high-melting animal fats, tropical oils, or hydrogenated lipids. Additionally, sunflower oil can modify its fatty acid composition based on the environmental conditions during grain filling, mainly conditioned by the temperature. This aspect is crucial for sunflower cultivation in Argentina, given the country’s extensive production area. The oxidative stability and technical functionality of these oils are mainly determined by their fatty acid composition; thus, different food applications of sunflower oils are described based on their specific characteristics.

Sunflower broomrape (Orobanche cumana Wallr.) is an obligate parasite known for significantly reducing sunflower yield. The most widespread and virulent race of broomrape in the Russian Federation is the G race. The most ecologically and economically effective strategy for its control involves breeding genetically resistant sunflower varieties and hybrids. The use of DNA markers in the selection of resistant plants significantly enhances the efficiency of the breeding process. Two genetic markers, RORS1 for the HaOr7 gene, and the wild-type allele marker, SORS9, were designed to detect the presence or absence of a specific DNA fragment. A codominant marker system for multiplex PCR was developed from these markers. An analysis of 57 plants derived from the progeny of two heterozygous F1 hybrids revealed that the frequencies of phenotypic segregation aligned fully with the marker system, following the 3:1 model. All resistant plants exhibited amplification of the RORS1 marker, indicating the presence of the HaOr7 gene, while susceptible plants lacked this marker. Association analysis was conducted using the marker system, screening 90 susceptible and resistant sunflower lines and hybrids of different origins. Susceptible lines and hybrids were characterized by the amplification of the SORS9 marker only, whereas resistant lines exhibited amplification of the RORS1 marker only. Additionally, screening of resistant hybrids from eight different breeding companies cultivated in the Russian Federation revealed that all hybrids resistant to G and G+ races of broomrape carried the HaOr7 gene in a heterozygous state.

Sunflower is grown in Argentina across a large and heterogeneous target population of environments. From the beginning of sunflower breeding activities in 1931 until the present day, the evolution of planted area, pathogen populations, market demands, and management practices posed challenges to the local breeding community. In the first part of this review, we have divided the national sunflower production history into three periods to analyze the past contributions of local breeding to the local and global sunflower industries. Special emphasis is placed on the role played by the National Institute of Agriculture Technology. The first period was characterized by the development of open pollination varieties which became the germplasm foundation on which the Argentine sunflower hybrid industry was later developed. From 1975 onwards, the genetic gains achieved by sunflower breeding programs have strongly contributed to the increase in farmers’ yields (second and third periods). Production per unit area was sustained during the phase of displacement of the crop to more marginal environments pushed by the explosive growth of soybeans (third period). In the second part of this study, we used a holistic approach to analyze the present challenges of sunflower breeding in Argentina, addressing (1) the complexity of the target genotype-environment system, (2) the genetic resources available to the breeding programs, (3) the clarity of the breeding objectives and strategy, and (4) the resource capability to implement, evaluate and manage the necessary breeding strategies.

Wild sunflower species have many sources of genes resistant to abiotic and biotic stresses, broomrape parasite as well as having higher quality traits. The transferring of these useful genes to the cultivated sunflower is so important issue to obtain a continuous resistance and then develop better quality and yielding cultivars in sunflower. The molecular methods in the plant breeding studies shortens the breeding cycles by providing an accurate and effective selection as well as saving time. The study was conducted in wild sunflower garden which set up via a project in previous years in Trakya University Edirne, Turkey. Fatty acid compositions of all wild species materials were determined in Trakya University laboratory for the first time in the world largely via Gas Chromatography (GC). The molecular analysis was performed in the lab to identify individuals with high oleic acid trait containing the homozygous oleic gene with 4 molecular markers (3 INDEL markers F4-R1, F4-R2 and F4-R3) and an SSR marker N1-3F) / (N2-1R HO). Based on GC analysis; no species with a high oleic rate (80% or more oleic acid) was found. However, among the examined wild species, three of them were found having mid oleic acid content (between 60 - 80% oleic acid). Among these species, Helianthus annuus species ranked first with the highest oleic acid content of 77.46%, followed by H. hirsutus with 69.71% and H. floridanus with 67.19%. On the other hand; Helianthus californicus, Helianthus exilis, Helianthus giganteus, Helianthus gracilentus, Helianthus grosseseratus, Helianthus laciniatus, Helianthus mollis, Helianthus neglectus, Helianthus petiolaris, Helianthus petiolaris subsp. petiolaris were determined as high oleic based on molecular 3 INDEL markers. However, these were not determined higher oleic acid content based on GC analysis. In conclusion; there was no genotype containing high oleic acid among the wild species based on GC analysis but high oleic species found in marker analysis; therefore, selectivity of the markers may not be accurate or new markers need to be used for the analysis of further researches.