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The development of durable resistance to broomrape (Orobanche cumana Wallr.) in sunflower (Helianthus annuus L.) requires detailed characterization of the genetic and physiological bases of resistance. The objective of the present study was to map the resistance gene accurately, and to characterize the mechanism of resistance to broomrape observed in a sunflower inbred line (PHSC1102). PHSC1102, which was consistently resistant against race F and race G populations of broomrape, was crossed with PHSC1201, which was susceptible to races F and G. A mapping population of 150 F2 genotypes was phenotyped by evaluating F2:3 families for resistance to broomrape races FGV and GTK. The use of single nucleotide polymorphism (SNP) markers mapped the OrSII gene to Linkage Group 4 (LG4) of the sunflower genome. Mini‐rhizotron and histological studies of the resistant line revealed that the attachment of broomrape to host roots was similar in both the resistant and susceptible lines and that the resistance was observed at a late stage (i.e., after tubercle development). Interestingly, the resistance of the PHSC1102 line was associated with the production of phenolic compounds, which were hypothesized to restrict the parasite's growth. This research provides novel and valuable information about the host–parasite interactions between sunflower and broomrape.

Three virulent populations (CU194, SE193, and SE194) of the parasitic plant Orobanche cu-mana were inoculated onto four lines (KA-41, J-8281, HA-89, and RHA-273) of sunflower (Helianthus annuus L.). Pots were transferred to growth chambers set at 15, 19, 23, and 27°C. Emergence of broomrape plants and infection incidence were determinants of disease reaction. All broomrape populations were pathogenic to the sunflower lines KA-41, HA-89, and RHA-273, although differences in virulence were found. At 15 to 23°C, the populations of broomrape infected these three sunflower lines, but a delay in emergence of broomrape was found at 15°C; whereas, at 27°C, the level of infection was restricted. Only population CU194 infected the resistant line J-8281, with infection occurring mainly at 23 and 27°C, but few broomrape plants emerged. Our results suggest that the effect of temperature on the host-parasite relationship is complex.

The parasitic weed Orobanche cumana Wallr. (broomrape) constraints sunflower production in eastern and southern Europe and in the Middle East. Resistance of sunflower hybrids to O. cumana race F, which is widespread in the main sunflower growing countries including Spain, is not complete. The infection of six populations of O. cumana (races B and F) in four sunflower genotypes in greenhouse (10 to 32oC) and in growth chamber (20 to 25oC) was studied. Also the effect of four sowing dates (SD) on the intensity of the attack of sunflower genotypes by O. cumana race F at three inoculum densities was investigated in an irrigated field in 2000 and 2001. Greenhouse was more favorable than growth chamber for O. cumana infection, which was highest by race F populations. In the field experiment, the reduction of the attack in the moderately resistant hybrid was significant at all SD and higher at late SD as compared to early sowings in both growing seasons. Late sowings (from the end of March until the beginning of April) favor an enhanced expression of the resistance of sunflower to O. cumana race F irrespective of seedbank, and can be therefore recommended, under irrigation and together with the use of moderately resistant sunflower hybrids, as part of an efficient strategy on the control of this parasitic weed.

[EN] Sunflower broomrape (Orobanche cumana Wallr.) parasitization on sunflower was first observed at the end of the 19th century and has continued since then jeopardizing sunflower cultivation in many areas of Europe and Asia. A distinctive characteristic of the O. cumana-sunflower parasitic system is that it is mainly governed by a gene-for-gene interaction. This determines complete resistance in the host controlled by dominant alleles at a single locus, which facilitates the management of the resistance for hybrid seed production. But on the other hand avirulence in the parasite is also controlled by dominant alleles at a single gene. Monogenic, dominant resistance exerts a strong selection pressure on the parasite that maximizes the probability of overcoming resistance mechanisms in a short period of time. This has in fact resulted in a number of physiological races that periodically surpass all the available resistance sources. The spread of populations to new areas and the subsequent hybridization between populations is another mechanism creating genetic diversity in sunflower broomrape and allegedly recombination of avirulences genes. After more than one century of coexistence, genetic resistance to broomrape in sunflower has to be focused under an integrated approach that considers not only the characterization of resistance mechanisms in the host, but also the genetic and physiological bases of avirulence in the parasite. From the perspective of genetic resistance in sunflower, most important is not relying only on single dominant genes, but following instead pyramiding strategies. These should give priority to combining complementary mechanisms of resistance under both qualitative (vertical) and quantitative (horizontal) genetic control. These aspects are discussed in the paper., [FR] Le parasitisme de l’orobanche du tournesol (Orobanche cumana Wallr) a été observé à la fin du 19e siècle et a continué depuis lors, mettant en péril la culture du tournesol dans de nombreuses régions d’Europe et d’Asie. Une caractéristique spécifique de l’interaction O.cumana-Tournesol est qu’elle est principalement régie par une interaction gène pour gène. Elle détermine une résistance totale de l’hôte contrôlée par des allèles dominants à un seul locus, ce qui facilite la gestion de la résistance pour la production de semences hybrides. Mais d’un autre côté, l’avirulence du parasite est également contrôlée par les allèles dominants d’un seul gène. Monogénique et dominante, la résistance exerce une forte pression de sélection sur le parasite qui maximise la probabilité de surmonter les mécanismes de résistance dans un court laps de temps. Cela a en fait abouti à un certain nombre de races physiologiques d’orobanche qui contournent régulièrement toutes les sources de résistance disponibles. La propagation des populations en de nouveaux lieux et l’hybridation ultérieure entre populations est un autre mécanisme qui favorise la diversité génétique de l’orobanche du tournesol et la prétendue recombinaison des gènes d’avirulences. Après plus d’un siècle de coexistence, la résistance génétique à l’orobanche chez le tournesol doit être envisagée via une approche intégrée qui tient compte non seulement de la caractérisation des mécanismes de résistance chez l’hôte, mais aussi des bases génétiques et physiologiques de l’avirulence du parasite. Du point de vue de la résistance génétique du tournesol, le plus important est de ne pas seulement considérer les gènes dominants simples, mais davantage des stratégies pyramidales. Celles-ci devraient laisser la priorité à la combinaison de mécanismes complémentaires de résistance, via un contrôle génétique à la fois qualitatif (vertical) et quantitatif (horizontal). Ces aspects sont abordés dans cet article., Authors’ research on sunflower broomrape is being supported by research project AGL2014-53886-P funded by the Spanish Ministry of Economy and Competitiveness and European Union FEDER funds.

Sunflower (Helianthus annuus L.) seed oil with high palmitic acid content has enhanced thermo-oxidative stability, which makes it well suited to high-temperature uses. CAS-5 is a sunflower mutant line that accumulates over 25 % palmitic acid in its seed oil, compared to 5–8 % in conventional cultivars. The objective of this study was to investigate the molecular basis of the high-palmitic acid trait in CAS-5 through both candidate gene and QTL mapping approaches. An F2 population derived from the cross between CAS-5 and the conventional line HA-89 was developed. A 3-ketoacyl-ACP synthase II (KASII) locus on a telomeric region of linkage group (LG) 9 of the sunflower genetic map was found to co-segregate with palmitic acid content in this population. The KASII locus explained the vast majority of the phenotypic variation (98 %) of the trait. Two minor QTL affecting palmitic acid content were also found on the lower half of LG 9 and on LG 17. Additionally, QTL associated with other major fatty acids (stearic, oleic, and linoleic acid) were identified on LG 1, 6, and 10. This result may reflect untapped genetic variation that could exist among sunflower cultivars for genes determining fatty acid composition. In addition to demonstrating the major role of a KASII locus in the accumulation of high levels of palmitic acid in CAS-5 seeds, this study stressed the importance of characterizing genes with minor effects on fatty acid profile in order to establish optimal breeding strategies for modifying fatty acid composition in sunflower seed oil., The research was partially funded by Junta de Andalucía support program to research group AGR-118.

The research was funded by the Spanish Ministry of Science and Innovation and the European Union FEDER (research project AGL2007-62834).

The research was funded by FEDER funds (European Union), the Spanish Ministry of Science and Innovation (research project AGL2007-62834) and Dow Agrosciences LLC.

[EN] 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. [ES] El jopo de girasol ( Orobanche cumana Wallr.) está considerado en la actualidad como uno de los problemas mas importantes del cultivo de girasol ( Helianthus annuus L.). En los últimos quince años, los esfuerzos realizados para incorporar fuentes de resistencia genética a este parásito en híbridos de girasol han estado acompañados por la rápida aparición de nuevas razas viru- lentas que superaban todos los genes de resistencia conocidos. Debido a esta situación, la mayoría de los esfuerzos de investigación se han centrado en el desarrollo y caracterización de nuevas fuentes de resistencia genética a las razas más virulentas del parásito, así como en la investigación de la estructura genética y variabilidad de las poblaciones de Orobanche cumana y de su evolución, con el objetivo de desarrollar estrategias duraderas a largo plazo para el control del jopo de girasol. Los resultados de evaluación de germo- plasma de girasol para resistencia a diferentes razas han demostrado que las especies silvestres de Helianthus constituyen la mayor fuente de genes de resistencia a las nuevas razas virulentas. El germoplasma cultivado es también una valiosa fuente de genes de resistencia. La mayoría de las fuentes de resist- encia están controladas por genes mayores, pero tanto resistencia cuantitativa como efectos epistáticos han sido tambié n identificados. Se han observado dif- erentes reacciones de dominancia dependiendo de la raza de jopo, la fuente de resistencia y la línea util izada como parental suscep tible. Estudios molecu- lares han mostrado que la varianza fenotípica para la raza E se explica princi- palmente por un QTL mayor asociado con la resistencia o susceptibilidad del carácter, mientras que la resistencia a la raza F estuvo controlada por varios QTL de efecto pequeño o moderado asociados principalmente con el número de jopos por planta, lo que sugiere la existencia de un componente cuantitativo en la resistencia a la raza F. Se discute la relevancia de estos resultados en la mejora para resistencia al jopo de girasol.

Contact: Marie-Helene.Muller@supagro.inra.fr; International audience; We made a first descriptive study of weedy sunflowers infesting sunflower crop fields in one Spanish and three French regions. Overall, weedy sunflowers affected around 15% of sunflower fields. Infested fields were most often dispersed over the study areas without evident geographical clustering. In France, five weedy populations were surveyed more intensively. They were composed of a large diversity of morphotypes showing a combination of typical wild and domesticated traits in proportions that differed between populations. Yield losses reached 50% in heavily infested patches. Our results suggest that weedy sunflowers may have arisen through the hybridization of cultivated and wild sunflower, potentially during the seed production process. Such crop-wild hybrids would have been introduced recurrently into fields through the seed lots, where they evolved to locally invasive weedy populations

Spanish sunflower acreage is basically divided into three main and isolated areas, the Guadalquivir valley, southern Spain, represents 37% of the total acreage, the Cuenca area located in Spain's central plateau, 28%, and the Castilla-Leon area, northern Spain, 29%. Sunflower broomrape (Orobanche cumana Wallr.) has been present in Spain since the 1960's. From that time on, different waves of dissemination and dispersion of the parasite have been registered. The latest correspond to the broomrape race E dispersal in the early 1990's and race F dispersal in the first few years of this century. These broomrape dissemination waves have been limited only to the Guadalquivir and Cuenca areas. In the Castilla-Leon area, the presence of broomrape had not been noticed until now. In 2008, a highly virulent broomrape infection focal point (about 300 m2) was detected in a sunflower plot near Medina del Campo (Valladolid), south of the center of the Castilla-Leon area. Racial determination has proved that this broomrape inoculum belongs to race F.

Sunflower broomrape (Orobanche cumana Wallr) continues to be one of the most important constraints in sunflower production in Spain. In the last ten years, genetic resistance has been the predominant control strategy against O. cumana. However, the introduction of new resistance genes has been frequently followed by the occurrence of new virulent races overcoming their resistance. In this report, a combined control strategy against O. cumana is discussed, including: a) the use of IMI sunflower cultivars to control winter and early spring weeds and sunflower broomrape; b) the combination of vertical and horizontal resistance mechanisms in the same genotype, supported by molecular markers in order to develop a more durable resistance; c) the study of the variability and racial composition of Spanish sunflower broomrape populations using classical and molecular approaches with the objective to learn about population dynamics in this parasitic weed. The combination of such strategies is expected to contribute to improved sunflower performance in areas infested by broomrape in the Mediterranean area.

The objective of the study was to investigate the performance at frying temperature of a new sunflower oil with high content of oleic and palmitic acid (HOHPSO) and containing γ-tocopherol as the most abundant natural antioxidant. HOHPSO either containing α- or γ-tocopherol (HOHPSO-α and HOHPSO-γ, respectively) were obtained from genetically modified sunflower seeds and refined under identical conditions. The oil stability against oxidation, as measured by Rancimat at 120 °C, was much higher for the oil containing γ-tocopherol, suggesting the higher effectiveness of γ-tocopherol as compared to α-tocopherol to delay oxidation. Experiments at high temperature (180 °C) simulating the conditions applied in the frying process clearly demonstrated that, for the same periods of heating, the oil degradation and the loss of natural tocopherol were significantly lower for the oil containing γ-tocopherol. Comparison of different genetically modified sunflower oils with different fatty acid compositions confirmed that oil degradation depended on the fatty acid composition, being higher at a higher degree of unsaturation. However, the loss of tocopherol for a similar level of oil degradation was higher as the degree of unsaturation decreased. Overall, the results showed that HOHPSO-γ had a very high stability at frying temperatures and that mixtures of HOHPSO-α and HOHPSO-γ would be an excellent alternative to fulfill the frying performance required by the processors and the vitamin E content claimed by the consumers., This work was supported by research funds from Ministerio de Educación y Ciencia (AGL 2004-00148) and Junta de Andalucía

Sunflower oil with increased levels of saturated fatty acids has important applications in food industry. The objective of this research was to develop novel variations with increased saturated fatty acid levels by chemical mutagenesis. Seeds of four different accessions of Peredovik were treated with a solution of ethylmethane sulfonate. M2 seeds from a single M1 plant exhibited a large variation (5-29%) for palmitic acid content. The progenies of all selected M2 seeds showed again continuous ranges of variation (10-30%) for palmitic acid content. Similar continuous segregation was observed in some M3:4 and M4:5 families derived from high palmitic half seeds (>25%), although other families had uniformly high palmitic acid content. Previous genetic studies of CAS-5, a high palmitic acid mutant which showed clear bimodal distributions in the M2 generation, concluded that the trait was genetically controlled by alleles at three loci. The different segregation patterns observed in NP-40, the new high palmitic acid mutant, suggested that it was genetically different from CAS-5.

The high stearic acid sunflower mutant CAS-3 is characterized by a low seed oil content, which might represent a constraint for the commercial production of high stearic acid sunflower oil. The objective of the present research was to investigate the relationships between fatty acid profile and seed oil content in CAS-3. Plants of CAS-3 were reciprocally crossed with plants of breeding line ADV-37, with high oil content and standard fatty acid profile. Oil content and fatty acid composition were measured in individual F 2 seeds and F 2 plants (F 3 seeds averaged). Both F 2 seeds and F 2 plants from the cross ADV-37 x CAS-3 had a significantly higher oil content than those from the reciprocal cross, which indicated the existence of cytoplasmic effects in the genetic control of the trait. A consistent negative correlation between oil content and palmitic acid and a positive correlation between oil content and oleic acid were detected both in F 2 seeds and F 2 plants. Conversely, no consistent correlation between oil content and stearic acid was observed, which suggested the feasibility of simultaneous selection for both traits.

Genetic resistance to broomrape (Orobanche cumana Wallr.) race F in sunflower line Jl, derived from the wild perennial species Helianthus grosseserratus Martens and Helianthus divaricatus L., has been reported to be controlled by dominant alleles at a single locus, Or6. However, deviations from this monogenic inheritance have been observed. The objective of the present study was to gain insight into the inheritance of resistance to broomrape race F in the sunflower line Jl. F 1 , F 2 , F 3 and BC generations from crosses between Jl and three susceptible lines, P21, NR5 and HA821 were evaluated. F 1 hybrids showed both resistant (R) and moderately resistant (MR) plants, the latter having a maximum of five broomrape stalks per plant compared with > 10 in the susceptible parents. This indicated incomplete dominance of the Or6 alleles. F 2 plants were classified as R, MR or susceptible (more than five broomrape stalks per plant). Three different segregation ratios were observed: 3:1, 13:3 and 15:1 (R + MR: S), suggesting the presence of a second gene, Or7, whose expression was influenced by the environment. A digenic model was confirmed, based on the evaluation of F 2:3 families.

Oil quality in vegetable oils is a relative concept that depends on the enduse of the oil. Vegetable oils are intended for food applications (salads and cooking oils, margarines, shortenings, etc) and nonfood industrial applications (biodiesel, lubricants, surfactants, etc). Sunflower (Helianthus annuus L.) oil has been traditionally appreciated in the world oil market. However, new emerging markets are demanding changes in oil quality for both food and nonfood applications. Nutritional and functional properties determining oil quality are primarily determined by the fatty acid composition of oil and the total content and composition of natural antioxidants, especially tocopherols. During the last 30 years these components have been extensively modified in sunflower through conventional selection from naturally occurring variation and trough mutagenesis. As a result, together with the standard sunflower oil whose fatty acid profile is made up of 11% saturated fatty acids, 20% oleic acid, and 69% linoleic acid, there is currently available a vast diversity of other sunflower oil types, for example low saturated ( 25%), high stearic (>25%), high oleic (>85%), high linoleic (>75%) as well as a number of oils with intermediate levels and combinations among them. Similarly, the standard sunflower oil with 95% of the tocopherols in the alpha-tocopherol form has been modified to produce oils with high levels of betatocopherol (>75%), gamma-tocopherol (>95%), and delta-tocopherol (>65%). The novel fatty acid and tocopherol traits are in all cases governed by a reduced number of genes, which facilitates considerably their management in plant breeding programs aimed at developing cultivars with improved oil quality. .

Publisher Summary In Western Europe, sunflower production started to extend to Spain in the late 1960s and to France in the late 1970s. Sunflower plays a major role in rotations with cereals in the European Union (EU). Having a deeper root system than cereals, sunflower uses a part of the fertilization not taken by cereals; thus, preventing leaching and subsequent groundwater contamination. Therefore, it is expected that sunflower will continue being a key crop in the EU regions where it is currently grown. The evolution of sunflower acreage would depend on several factors. The incorporation of a green direct payment in the new Common Agricultural Policy (CAP) would favor sunflower cultivation but also other groups of crops such as legumes, which would compete with sunflower in rotations with cereals in some regions. Public and private research has played and will continue to play an important role in the development of sunflower in the EU. Breeding advances will also determine the evolution of sunflower acreage and yields in the EU.

Publisher Summary The closely related genera Orobanche and Phelipanche, known as broomrapes, encompass around 170 holoparasitic plant species mainly distributed in the northern hemisphere, with greatest diversity in the Mediterranean region and Western Asia. One of the most important weedy species is O. cumana Wallr., which parasitizes exclusively sunflower crops. Due to its host specificity, O. cumana is commonly named as sunflower broomrape. Broomrapes are very destructive weeds, with yield losses close to 100% under high infestations. Sunflower broomrape has great capacity of dispersion and mutation. Sunflower broomrape can be controlled by post-emergence application of Imidazolinone (IMI) herbicides on non-Genetically Modified Organism (GMO), IMI-tolerant hybrids, derived from resistance alleles identified in wild populations or developed by mutagenesis. This chapter discusses the current status of sunflower broomrape infestations and race evolution around the world, recent research advances in the biology and genetics of the parasite, and current strategies and future prospects for sunflower broomrape control through exploiting sunflower genetic resistance to either broomrape or IMI herbicides.

Sunflower (Helianthus annuus L.) seeds contain alpha-tocopherol as the major tocopherol derivative, which accounts for more than 900 g kg 21 total tocopherols. However, four sources of high gammatocopherol content (.850 g kg 21 ) have been developed. First studies on the lines LG-17 and T2100 concluded that the trait in both lines was determined by recessive alleles at the Tph2 locus. The objectives of the present research were (i) to conduct an allelic study on the other two lines, IAST-1 and IAST-540, (ii) to identify markers linked to the Tph2 gene, and (iii) to map this gene. Plants of T2100 were crossed with plants of the other three lines, which resulted in F1 and F2 populations with uniformly high gamma-tocopherol content in the seeds, indicating the presence of tph2 alleles in the four lines. Genetic mapping of the Tph2 gene was conducted with an F2 population from the cross between CAS-12, with standard tocopherol profile, and IAST540. F2 seeds segregated following a 3 low to 1 high gamma-tocopherol ratio. Bulked segregant analysis identified two simple sequence repeats (SSR) markers on linkage group (LG) 8 linked to Tph2. A large linkagegroupwasconstructedbygenotypingadditionalmarkers.Tph2 mapped between markers ORS312 (3.6 cM proximal) and ORS599 (1.9 cM distal). The availability of closely linked PCR-based markers and the location of the Tph2 gene on the sunflower genetic map will be useful for marker-assisted selection and further characterization of tocopherol biosynthesis in sunflower seeds.

Tocopherols are a family of fat soluble antioxidants of great value for both nutritional and technological properties of seed oils. The four naturally occurring tocopherols (alpha-, beta-, gamma- and delta-tocopherol) widely differ for their relative in vivo (vitamin E) and in vitro antioxidant properties. Sunflower (Helianthus annuus L.) seeds mainly contain alpha-tocopherol (95% of the total tocopherols), which has a great vitamin E value but a low in vitro activity. Conversely, beta-tocopherol shows more balanced in vitro and in vivo antioxidant properties, which is desired for specific uses of the oil. The sunflower line T589 is characterised by an increased beta-tocopherol content in the seeds ( >30%), which is determined by the single gene Tph1. The objectives of this study were to map the Tph1 gene by molecular markers (SSRs) and to develop a linkage map of the Tph1-encompassing region. High performance liquid chromatography (HPLC) was used to phenotype 103 F2 and 67 F3 progeny from the mapping population CAS-12 × T589, which segregates for Tph1. Bulk segregant analysis identified two SSR markers on linkage group (LG) 1 linked to Tph1. A large linkage group was constructed by genotyping additional SSRs and INDEL markers. Tph1 mapped to the upper end of LG 1 and cosegregated with the SSR markers ORS1093, ORS222, and ORS598. The availability of tightly linked PCR-based markers and the location of the Tph1 gene on the sunflower genetic map will be useful for marker-assisted selection in sunflower and provides a basis for the physical mapping and positional cloning of this gene.

A sunflower (Helianthus annuus L.) oil with high concentration of stearic acid has important applications in the food industry. Two sunflower mutants with high stearic add content, CAS-3 and CAS-14, have been developed. In contrast to CAS-3, high stearic acid expression in CAS-14 seeds is temperature dependent and nonuniformly distributed in the seed. The trait in CAS-3 has been found to be governed by two genes, Es1 and Es2. The objective of the present research was to study the inheritance of high stearic add content in CAS-14 through crosses with P21, a nuclear male sterile (NMS) line with a wild-type fatty add profile, and CAS-3. The genetic analysis included the evaluation of the F 1 , F 2 , F 3 , BC 1 F 1 , and BC 1 F 2 seed generations. Crosses between P21 and CAS-14 revealed that the high stearic add trait was recessive and controlled by a single gene, designated Es3. The analysis of the F 3 and BC 1 F 2 to P21 generations demonstrated a repulsion-phase linkage between the Es3 and the Ms loci, the latter conferring the NMS trait. The frequency of recombination between Es3 and Ms was estimated to be 0.09. Crosses between CAS-3 and CAS-14 demonstrated that both lines possess alleles for high stearic acid content at different lod, as transgressive segregants with low stearic acid content were observed in all generations. Genetic recombination of es1 and es3 alleles did not result in an increment of the maximum stearic add content in the seeds compared with the maximum levels produced by the es3 alleles alone.

Increasing the stearic acid content to improve sunflower (Helianthus annuus L.) oil quality is a desirable breeding objective for food-processing applications. CAS-14 is a sunflower mutant line with a high stearic acid content in its seed oil (>35% vs.

SUMMARY Two different sunflower lines with increased beta-tocopherol concentration in the seeds, LG-15 and T589, have been developed. The objective of the present research was to conduct a comparative genetic study of the increased beta-tocopherol concentration in both lines. Plants of LG-15 were reciprocally crossed with plants of T589 in 2003. The F1, F2, BC to LG-15 and BC to T589 seed generations were produced in the same environment in 2004 and analyzed for tocopherol profile. The results indicated a strong environmental effect on the increased levels of beta-tocopherol concentration in LG-15 and T589, which averaged 30.5% and 25.8%, respectively, in 2003 and 43.2% and 54.0%, respectively, in 2004. The comparison of individual plant means and standard errors of individual plant means for the F2 and BC generations with those in the non-segregating parental and F1 generations indicated no transgressive segregation for beta-tocopherol concentration in F2 or BC seeds. These results suggested that increased beta-tocopherol concentration in both lines is the result of genetic alterations at the same locus.

Increased stearic acid (C18:0) content in the seed oil of sunflower would improve the oil quality for some edible uses. The sunflower line CAS-20 (C18:0 genotype Es1Es1es2es2), developed from the high C18:0 mutant line CAS-3 (C18:0 genotype es1es1es2es2; 25% C18:0), shows increased C18:0 levels in its seed oil (8.6%). The objective of this research was to map quantitative trait loci (QTL) conferring increased C18:0 content in CAS-20 in an F2 mapping population developed from crosses between HA-89 (wild type Es1Es1Es2Es2; low C18:0) and CAS-20, which segregates independently of the macromutation Es1 controlling high C18:0 content in CAS-3. Seed oil fatty acid composition was measured in the F2 population by gas-liquid chromatography. A genetic linkage map of 17 linkage groups (LGs) comprising 80 RFLP and 19 SSR marker loci from this population was used to identify QTL controlling fatty acid composition. Three QTL affecting C18:0 content were identified on LG3, LG11, and LG13, with all alleles for increased C18:0 content inherited from CAS-20. In total, these QTL explained 43.6% of the C18:0 phenotypic variation. Additionally, four candidate genes (two stearate desaturase genes, SAD6 and SAD17, and a FatA and a FatB thioesterase gene) were placed on the QTL map. On the basis of positional information, QTL on LG11 was suggested to be a SAD6 locus. The results presented show that increased C18:0 content in sunflower seed oil is not a simple trait, and the markers flanking these QTL constitute a powerful tool for plant breeding programs.

Half-seed analysis by gas-liquid chromatography (GLC) allows a nondestructive evaluation of the fatty acid composition of oilseeds, since in most cases the analyzed portion is representative of the whole seed. However, the sunflower (Helianthus annuus L.) mutant CAS-14 exhibits a high stearic acid concentration nonuniformly expressed along the longitudinal axis of the seed. No analytical technique is available for nondestructive selection at the single seed level in this mutant. The objective of the present research was to study the potential of near-infrared reflectance spectroscopy (NIRS) for analyzing the fatty acid composition of single husked achenes of sunflower and to evaluate its performance in a selection program for high stearic concentration in materials derived from CAS-14. A calibration set containing 2510 single husked achenes from a broad spectrum of breeding materials was developed. Reliable equations were developed for stearic acid, with r 2 = 0.80 and ratio of the standard error of cross validation (SECV) to the standard deviation (SD) of 0.45, oleic acid (r 2 = 0.89, SECV/SD = 0.34), and linoleic acid (r 2 = 0.91, SECV/ SD = 0.30). The calibration equations were applied to the analysis of 8109 husked achenes within a selection program for high stearic acid concentration, 503 of them being further analyzed by GLC to monitor the performance of NIRS. The results revealed a close relationship between NIRS and GLC data, with r 2 of 0.83 for stearic acid, 0.92 for oleic acid, and 0.93 for linoleic acid concentration. It was concluded that NIRS can be used reliably for nondestructive selection for these major fatty acids at a single-seed level.

SUMMARY The holoparasitic angiosperm sunflower broomrape (Orobanche cumana Wallr.) is currently regarded as one of the most important constraints of sunflower production in many areas in Southern Europe and the Black Sea region. Breeding for resistance is considered to be the most effective and feasible method of controlling sunflower broomrape. Commercial hybrids cultivated in Spain carry the Or1 to Or5 genes that confer resistance to races A to E. However, a new race, designated F, has been identified. Germplasm with race F resistant genes derived from wild and cultivated sunflowers has been developed. Dominance reaction of these genes is an essential feature that determine the breeding method to produce race F resistant sunflower hybrids. Crosses between different sources of race F resistant lines, including those derived from wild and cultivated sunflower, and different susceptible parental lines were made. Allelic crosses between race F resistant lines, as well as crosses between race F resistant lines and race E resistant lines were also carried out. F1 plants, F2 plants, and their parental lines were evaluated for their disease reaction to race F or race E of broomrape. Different dominance reactions and inheritance mechanisms for broomrape resistance were observed. These depended on the race of broomrape, the source of race F resistance, and also the susceptible parental line used for the cross. The relevance of the results obtained for sunflower breeding for resistance to sunflower broomrape is discussed.

Sunflower (Helianthus annuus L.) genotypes with increased stearic add (C18:0) content in their seed oil may be useful for food and industrial applications. The objective of this study was to isolate and characterize mid-stearic acid sunflower lines homozygous recessive for single genes from the high stearic acid mutant CAS-3 (250 g kg -1 ). Crosses between CAS-3 (genotype eslesles2es2), and the inbred line HA 89, with standard low stearic add levels (50 g kg -1 ; Es1Es1Es2Es2), were made to obtain F 3 families segregating for either the Esl or Es2 loci. From these families, F 3 half-seeds with putative genotypes esleslEs2Es2 (188 g kg -1 ) and Es1Es1es2es2 (90 g kg -1 ) were selected. F 7 -lines homozygous for esl or es2 were developed. These lines were named CAS-19 (es1es1Es2Es2) and CAS-20 (EslEsles2es2) and showed mid-stearic acid levels of 168 g kg -1 (CAS-19) and 83 g kg -1 (CAS-20). The fatty acid content was evaluated in all generations by gas-liquid chromatography. The genetic composition of CAS-19 and CAS-20 was verified by evaluating progenies from crosses between both mid-stearic acid lines, and from crosses between the mid-stearic acid lines and HA 89. The new Es1Es1es2es2 and es1es1Es2Es2 genotypes expressing mid-stearic acid levels represent a further advance for the development of sunflower lines for specific edible purposes, and constitute a unique source for agronomic and genetic studies on single alleles controlling increased stearic acid content in sunflower.

SUMMARY Wild Helianthus species are an important reservoir of useful genes for sunflower breeding. The objective of the present research was to evaluate the existing variability for tocopherol content and composition in a germplasm collection of wild sunflower species. The germplasm evaluated consisted of 257 accessions from 36 Helianthus species, including both annual and perennial species. Eight seeds per accession were randomly picked and bulked for tocopherol analysis conducted by HPLC with fluorescence detection. Tocopherol content averaged 328 mg kg -1 seed in the analyzed accessions, with an average profile of 99.0% alpha-tocopherol, 0.7% beta-tocopherol, and 0.3% gammatocopherol. In cultivated material, an average tocopherol content of 669.1 mg kg -1 seed have been reported, made up of 92.4% alpha-tocopherol, 5.6% betatocopherol, and 2.0% gamma-tocopherol. The maximum total tocopherol content in wild sunflower germplasm corresponded to an accession of H. maximilianii, with 673 mg kg -1 seed. Increased levels of beta-tocopherol were identified in one accession of H. praecox (11.2% of the total tocopherols) and one accession of H. debilis (11.8%). All other accessions contained less than 6.5% betatocopherol. Increased gamma-tocopherol levels were identified in one accession of H. exilis (7.4%) and two accessions of H. nutalii (11.0% and 14.6%, respectively). All other accessions contained less than 2% gamma-tocopherol. Although further research at an intrapopulation level is needed to confirm and isolate variants, the results of the present research indicated that wild Helianthus germplasm contains useful variability for tocopherol content and composition.

Tocopherols are the most important compounds having antioxidant activity in sunflower seeds. The objective of the present research was to study the genetic and environmental variation for tocopherol content and composition in sunflower. Thirty-six sunflower hybrids were grown at 13 locations across all major areas of sunflower cultivation in southern Spain. Seed yield, 100 seed weight, oil content and tocopherol content and composition were determined. Tocopherol content ranged from 314·5 to 1024·5 mg/kg seed and from 562·8 to 1872·8 mg/kg oil. The tocopherol fraction was largely composed of alpha-tocopherol, which accounted for 88·4% to 96·3% of the total tocopherols. Both genotypic and environmental effects were significant for tocopherol content and composition. For alpha-, beta- and total tocopherol content, the effect of the genotype was larger than that of the environment, whereas the latter had a greater effect on gamma-tocopherol content. Genotype×location interaction was significant for alpha-, gamma- and total tocopherol content. Tocopherol content was not correlated with seed oil or seed yield, indicating the possibility of selecting for this trait without affecting the performance of the genotypes.

CAS-12 is a sunflower mutant with increased levels of palmitic (C16: 0 = 30%) and oleic (C18: 1 = 55%) acids in its seed oil, hence it has a reduced linoleic acid content (C18: 2 < 5%). This study was conducted to determine the inheritance of high C16: 0 content and its relationship with high C18: 1 content in CAS-12. Reciprocal crosses involving CAS-12, CAS-5 (high C16: 0 content), HAOL-9 (high C18: 1 content) and HA-89 (standard fatty acid profile) were made. The F 1 , F 2 and BC 1 F 1 generations were obtained. The genetic control of the high C16: 0 trait in CAS-12 was partially recessive and gametophytic. In all cases, this character segregated in the ratio 19: 38: 7 (low: intermediate: high C16: 0 content) in the F 2 generation. These results, together with the lack of segregation for C16: 0 content in crosses between CAS-12 and CAS-5, indicated that the genetic control of the high C16: 0 trait in CAS-12 was similar to that in CAS-5 in being controlled by partially recessive alleles (pl, p2, and p3) at three loci. Crosses between HA-89 and CAS-12, and HAOL-9 and CAS-5 (segregating for C16: 0 and C18: 1) demonstrated that the high C16: 0 and the high C18: 1 traits were independently inherited. However, C18: 1 segregation in these crosses exhibited reversal of dominance. Apparently, the low C18: 1 parental lines carried modifier genes causing the deviation.

Confectionery sunflower (Helianthus annuus L.) has been cultivated in Spain for many years in small vegetable gardens for self-consumption, and this has created a vast genetic diversity of local landraces. The objective of this research was to assess variation in seed quality traits in a germplasm collection of Spanish local landraces of confectionery sunflower. Seed weight, kernel percentage, oil content, fatty acid composition, squalene, tocopherol and phytosterol contents, and tocopherol and phytosterol composition, were analysed in 137 landraces grown for 2 years in Córdoba, Spain. The evaluation was hindered by large differences for flowering time between accessions (>90 days), which made it difficult to separate genetic from environmental effects. The collection contained large variability for all traits evaluated. Of particular relevance were the ranges of variation (2-year averages) for squalene content (12-128mgkg-1 seed kernel), tocopherol content (114-423mgkg-1 seed kernel) and Δ7-stigmastenol content (7.1-35.2% of total phytosterols). Some traits were associated with specific locations; for example, all seven accessions collected in Espiel (Córdoba province) had high Δ7-stigmastenol content, although they differed for other traits. Some of the accessions evaluated in this research are valuable genetic sources for breeding programs focusing on seed and oil quality in sunflower. © CSIRO 2014.

Orobanche cumana is a holoparasitic plant naturally distributed from central Asia to south-eastern Europe, where it parasitizes wild Asteraceae species. It is also an important parasitic weed of sunflower crops. The objective of this research was to investigate genetic diversity, population structure, and virulence on sunflower of O. cumana populations parasitizing wild plants in eastern Bulgaria. Fresh tissue of eight O. cumana populations and mature seeds of four of them were collected in situ on wild hosts. Genetic diversity and population structure were studied with SSR markers and compared to weedy populations. Two main gene pools were identified in Bulgarian populations, with most of the populations having intermediate characteristics. Cross-inoculation experiments revealed that O. cumana populations collected on wild species possessed similar ability to parasitize sunflower to those collected on sunflower. The results were explained on the basis of an effective genetic exchange between populations parasitizing sunflower crops and those parasitizing wild species. The occurrence of bidirectional gene flow may have an impact on wild populations, as new physiological races continuously emerge in weedy populations. Also, genetic variability of wild populations may favour the ability of weedy populations to overcome sunflower resistance mechanisms., The research was partially funded by Fundación Ramón Areces, Madrid. R. Pineda-Martos was the recipient of a PhD fellowship from the Spanish National Research Council (CSIC) (JAEPre_08_00370).

SUMMARY The genetic control of the high saturated fatty acid content in sunflower seed oil has been studied in the high palmitic acid (C16:0) mutant line CAS-5, and in the high stearic acid (C18:0) mutant line CAS-3. This review summarizes the pertinent results. The high saturated fatty acid content in sunflower seed oil is controlled by partially recessive alleles at two loci (Es1, Es2) for the high C18:0 content and at three loci (P1, P2, P3) for the high C16:0 content. The high C16:0 and the high C18:0 traits are not inherited independently. When their combined segregation was studied, the expected phenotypic expression of both high C16:0 and high C18:0 levels was not observed. This fact was attributed to the existence of an epistatic effect of the loci controlling the high C16:0 trait on the loci controlling the high C18:0 trait. The results obtained indicate that sunflower hybrids with a high saturated fatty acid content in their seed oil can be developed and will be in cultivation in a few years.

SUMMARY A review of the racial situation of Orobanche cumana in Spain and of several studies on sunflower resistance to broomrape is presented. In the nineties, populations of O.cumana attacking sunflower crops in Spain have evolved first towards the increase in frequency of race B simultaneous to the decrease of race A. Later, race E has appeared with increasing frequency. However, the subsequent change to resistant hybrids carrying the Or5 gene has prompted the recent appearance of a new race (race F) that overcomes this resistance gene, and is expanding mainly in southern Spain. Collections of cultivated P.I. accessions tested for resistance to races E or F indicated a low frequency of entries resistant or segregating for resistance. A low frequency of resistance was also observed in accessions of wild annual species. Among 18 species, only H.agrestis and H.anomalus showed full resistance to both races, whereas H.debilis ssp. cucumerifolius and H.exilis segregated. Lines breeding true for resistance, derived from H.anomalus, H.exilis and H.debilis have been produced. In contrast, inoculation of races E and F to wild perennials resulted in complete resistance in 74% of the species, and segregation for resistance to race F in 11%. The transference of resistance from wild perennial species into cultivated sunflower is, however, much more difficult than that of annuals. Embryo rescue and chromosome doubling techniques were often required. Although inheritance studies indicated dominance and one single gene involved in the resistance to races A and E in most crosses, two dominant genes, epistatic interactions and reversal in the dominance were observed in some cases.

Broomrape (Orobanche cernua Loefl., syn. O. cumana Wallr.) populations belonging to a new race F in Spain have overcome all known resistance genes Or1 to Or5 in cultivated sunflower (Helianthus annuus L.) and are spreading rapidly. All hybrids currently grown in Spain are susceptible to race F, and sources of resistance genes for this race are needed to develop new resistant cultivars. The objective of this study was to evaluate sunflower germplasm for resistance to race F (virulent population SE296). Using artificial inoculation with broomrape seed, 54 accessions of wild Helianthus spp. representing 27 perennial and four annual species and 55 cultivated accessions of sunflower were evaluated after incubation for ≃1 mo in a growth chamber. Helianthus seedlings were transplanted to the greenhouse for an additional ≃3 mo to evaluate the broomrape infection. Most perennial species of wild Helianthus were completely resistant to race F, but some accessions of the species H. divaricatus, H. maximiliani, and H. pauciflorus subsp. pauciflorus showed different proportions of susceptible plants, with a disease incidence varying from 10 to 80%. The annual wild species, H. anomalus and H. agrestis, were fully resistant, while segregation was observed in H. debilis subsp. cucumerifolius and H. exilis. Only 7.2% of the accessions of cultivated sunflower tested were fully resistant, with 20% of them segregating for resistance. The high frequency of broomrape resistance to race F observed in the perennial wild species, as well as the resistance found in wild annual and cultivated germplasm, indicates that development of sunflower cultivars resistant to this new race of the parasite is feasible.

Two sunflower (Helianthus annuus L.) mutants with high concentrations of saturated fatty acids in their seed oil have been identified and studied extensively. The mutant line CAS-5 has high concentrations of palmitic acid (C16:0) (>25% compared with 7% in standard sunflower seed oil) and low-C18:0 values (3%). CAS-3 is characterized by its high levels of stearic acid (C18:0) (>22% compared with 4% in standard sunflower seed oil) and a low-C16:0 content (5%). CAS-5 also possesses elevated levels of palmitoleic acid (C16:1) (>5%), which is absent in standard sunflower seed oil. The objective of this study was to determine the relationships between the loci controlling the high-C16:0 and the high-C18:0 traits in these mutants. Plants of both mutants were reciprocally crossed. Gas chromatographic analyses of fatty acids from the seed oil of F1, F2, F3 and the BC1F1 to CAS-5 generations indicated that the loci controlling the high-C16:0 trait exerted an epistatic effect over the loci responsible for the high-C18:0 character. As a result, the phenotypic combination containing both the high-C16:0 levels of CAS-5 and the high-C18:0 levels of CAS-3 was not possible. However, phenotypes with a saturated fatty acid content of 44% (34.5% C16:0+9.5% C18:0) were identified in the F3 generation. These are the highest saturated (C16:0 and C18:0) levels reported so far in sunflower seed oil. When F3 C16:0 segregating generations in both a high- and a low-C18:0 background were compared, the high-C16:1 levels were not expressed as expected in the high-C18:0 background (CAS-3 background). In this case, the C16:1 content decreased to values below 1.5%, compared with >5% in a low-C18:0 background. As the stearoyl-ACP desaturase has been reported to catalyze the desaturation from C16:0-ACP to C16:1-ACP, these results suggested that a decrease in its activity was involved in the accumulation of C18:0 in the high-C18:0 mutant CAS-3.

Sunflower (Helianthus annuus L.) is severely affected by broomrape (Orobanche cernua Loefl.) in the main crop areas of the Old World. The appearance of new virulent broomrape populations has prompted the search for new sources of resistance. The objectives of this study were to elucidate the inheritance of sources of resistance from different origins and to determine allelic relationships between the resistance genes. Six resistant sunflower lines (one of them with resistance gene Or 5 ), two susceptible lines, the F 1 crosses between resistant and susceptible lines and resistant and resistant lines, and the F 2 and BC 1 generations were evaluated for broomrape resistance with the widespread highly virulent population SE 194. Genetic ratios from segregating generations indicated that resistance to O. cernua in these lines was conferred by a single dominant gene. None of the crosses between resistant lines produced susceptible F 2 or BC 1 plants. However, the reaction of the resistant lines to broomrape populations from different areas and years showed differences to new highly virulent populations. Only two lines were resistant to all populations, indicating that resistance in these lines was conferred by additional dominant alleles at the Or locus or by a cluster of very tightly linked non-allelic genes. The resistance found in the two cultivated lines against the new populations, which overcome the Or 5 resistance gene, is an important finding and will aid the development of new resistant cultivars since the current resistant hybrids are based on this gene. Results from this study can also be used to establish differential lines against the new broomrape populations.

Sunflower genotypes with increased levels of palmitic acid (C16 : 0) in the seed oil could be useful for food and industrial applications. The objective of the present study was to determine the inheritance of the high C16 : 0 content in the sunflower mutant line CAS-5 (>25% of the total oil fatty acids). This mutant was reciprocally crossed with the lines HA-89 (5.7% C16 : 0) and BSD-2-691 (5.4% C16 : 0), the latter being the parental line from which CAS-5 was isolated. No maternal effect for the C16 : 0 content was observed from the analysis of F1 seeds in any of the crosses. The inheritance study of the C16 : 0 content in F1, F2 and BC1F1 seeds from the crosses of CAS-5 with its parental line BSD-2-691 indicated that the segregation fitted a model of two alleles at one locus with partial dominance for the low content. The analysis of the fatty acid composition in the F2 populations from the crosses with HA-89 revealed a segregation fitting a ratio 19 : 38 : 7 for low ( 25%) C16 : 0 content, respectively. This segregation was explained on the basis of three loci (P1, P2, P3) each having two alleles showing partial dominance for low content. The genotypes with a high C16 : 0 content were homozygous for the recessive allele p1 and for at least one of the other two recessive alleles, p2 or p3. This model was further confirmed with the analysis of the F3 and the BC1F1 generations. It was concluded that both the recessive alleles p2 and p3 were already present in the BSD-2-691 line, the allele p1 being the result of a mutation from P1. This genetic study will facilitate breeding strategies associated with the incorporation of the high C16 : 0 trait into agronomically acceptable sunflower hybrids.

Current breeding programs dealing with the modification of oleic and linoleic add concentrations in sunflower (Helianthus annuus L.) require large numbers for chromatographic analyses of half seeds The objective of this research was to study the potential of near-infrared reflectance spectroscopy (NIRS) to estimate the oleic and linoleic add concentrations of intact single sunflower achenes. Spectra from intact achenes were collected with a specially designed adapter and a standard monochromator instrument Calibration equations for oleic and linoleic add were developed from a calibration set including 465 intact achenes with a large range of variation for both fatty acids and were validated with an external set of 100 intact achenes. The coefficient of determination between NIRS and gas-liquid chromatography (GLC) was 0.88 for both fatty acids in external validation, demonstrating the high reliability of NIRS to predict oleic and linoleic add concentrations of intact, single sunflower achenes. The calibration equation for oleic acid was used to evaluate two F 2 populations segregating for this fatty add, which were further analyzed by GLC. The use of NIRS predictions permitted the discrimination of the majority of the high oleic acid achenes (>700 g kg -1 ), demonstrating the use of NIRS for selecting sunflower achenes with specific oleic and linoleic acid concentrations.

Interspecific crosses were made between the cultivated sunflower inbred line HA89 and accessions of five wild perennial Helianthus species (H. giganteus L., H. laevigatus T. & G., H. resinosus Small, H. pauciflorus Nutt. and H. decapetalus L.) resistant to broomrape ( Orobanche cernua Loefl.). Using the genetic male-sterile isogenic version of that line as female, successful reciprocal crosses were also obtained with all these wild species except with H. decapetalus. Five-day-old hybrid embryos were excised and cultured in vitro. In all cases, few mature plants were obtained from embryos in early developmental stages (early heart and globular) but up to 28% mature plants were obtained from embryos in later stages of development. Very immature embryos were difficult to excise without damage. Hybrid embryos and mature plants were obtained from all five wild species. Interspecific hybrid embryos from different wild species showed distinct developmental potentials, the proportion of hybrid embryos in different developmental stages varying among species. Differences in the proportion of hybrid embryos at the several developmental stages were also obtained for the reciprocal crosses (cultivated × wild), which showed higher proportion of fully developed embryos. Hybrids involving H. giganteus and cultivated sunflower were difficult to obtain without the use of embryo culture. Embryo culture proved to be an useful tool to overcome post-zygotic hybrid incompatibility in different Helianthus spp., and facilitated interspecific transfer of resistance to O. cernua.

A methodological study was conducted to test the potential of near-infrared reflectance spectroscopy (NIRS) to estimate the oil content and fatty acid composition of sunflower seeds. A set of 387 intact-seed samples, each from a single plant, were scanned by NIRS, and 120 of them were selected and further scanned as husked seed, meal, and oil. All samples were analyzed for oil content (nuclear magnetic resonance) and fatty acid composition (gas chromatography), and calibration equations for oil content and individual fatty acids (C16:0, C16:1, C18:0, C18:1, and C18:2) were developed for intact seed, husked seed, meal, and oil. For intact seed, the performance of the calibration equations was evaluated through both cross- and external validation, while cross-validation was used in the rest. The results showed that NIRS is a reliable and accurate technique to estimate these traits in sunflower oil (validation r 2 ranged from 0.97 to 0.99), meal (r 2 from 0.92 to 0.98), and husked seeds (r 2 from 0.90 to 0.97). According to these results, there is no need to grind the seeds to scan the meal; similarly accurate results are obtained by analyzing husked seeds. The analysis of intact seeds was less accurate (r 2 from 0.76 to 0.85), although it is reliable enough to use for pre-screening purposes to identify variants with significantly different fatty acid compositions from standard phenotypes. Screening of intact sunflower seeds by NIRS represents a rapid, simple, and cost-effective alternative that may be of great utility for users who need to analyze a large number of samples.

The definition of a suitable breeding strategy in drought-prone environments is an important task for sunflower breeders. To achieve this task, reliable information on heritability and gene effects on yield and related traits under these conditions is necessary. Thirty six sunflower hybrids were produced by factorial cross of six male-sterile and six restorer lines. Parents and their hybrids were evaluated in eight environments. Six environments consisted of two adjacent trials in the experimental area, the first under irrigation and the second under dryland conditions, during 1987, 1988 and 1992. The other environments were: one early planting trial in dryland conditions, conducted during 1987, and a winter trial planted in January during 1988. Estimates of female variance (σf) were significant for seeds per head, seed weight, head sterile center, days to blooming and oil content. Female × male interactions (σ2fm) were significant for all characters except harvest index and index of susceptibility to drought. Estimates of narrow sense heritabilities, calculated with information from analyses combined across environments, were 0.65 for yield, 0.80 for seeds per head, 0.84 for seed weight, 0.81 for head diameter, 0.60 for sterile head center, 0.72 for oil content, 0.61 for harvest index, 0.72 for biomass, 0.94 for days to bloom, and 0.42 for drought susceptibility index. Heritability estimates for individual environments showed more variation for yield than for other traits. Estimates for heritability of canopy temperature were high (0.68–0.79). Rainfed yield was positively correlated with yield components and negatively correlated with canopy temperature and susceptibility index. It is concluded that an efficient breeding strategy for sunflower under moderate drought-stressed conditions is the simultaneous selection for seed yield in both rainfed and irrigated environments together with selection for canopy temperature and stem diameter.

Orobanche cumana is a weed that grows as a root parasite on sunflower. In general, the O. cumana-sunflower parasitic system is regarded to follow the gene-for-gene model, although this has never been demonstrated at the genetic level in O. cumana. The Or5 dominant gene in sunflower confers resistance to O. cumana race E, but not to race F. The objective of this research was to study the inheritance of avirulence/virulence in crosses between plants of O. cumana lines classified as races E and F. Four race E and three race F lines were developed, from which four race E × race F cross-combinations were made, in three cases including reciprocals. In all cases, F1 seeds did not have the ability to parasitise sunflower line P-1380 carrying the Or5 gene, indicating dominance of race E avirulence allele(s). Five F2 populations comprising a total of 387 F2:3 families were evaluated on sunflower line P-1380. In all cases, one-fourth of the F2:3 families did not possess the ability to parasitise P-1380 plants, suggesting that race E avirulence and race F virulence on P-1380 are allelic and controlled by a single locus. This study demonstrated the gene-for-gene interaction in the O. cumana-sunflower parasite system and provided useful information to identify genes involved in O. cumana virulence. The approach followed in this research can contribute to define precisely races of the parasite on the basis of the presence of avirulence genes. © 2013 European Weed Research Society., The research was partially funded by Fundacio ́ n Ram on Areces. Madrid. R. Pineda-Martos was the reci- pient of a PhD fellowship from the Spanish National Research Council (CSIC) (JAEPre_08_00370).

Phytosterols are important dietary components. This research was aimed at estimating genetic variation and genotype × environment interactions for phytosterol content and profile in sunflower (Helianthus annuus L.). Twenty-two commercial hybrids were grown in six locations in southern Spain. The effect of genotypes was significant for phytosterol content and concentration of most phytosterols. Genotype × location interaction was significant for the concentration of campesterol, stigmasterol, Δ7-stigmastenol, and Δ7-avenasterol. Estimates of broad-sense heritability were high (0.85 to 0.97) for phytosterol content and concentration of major phytosterols. These results suggest the feasibility of selecting for both phytosterol content and profile in sunflower. © Crop Science Society of America.

Sunflower broomrape (Orobanche cumana Wallr.) is considered a self-fertilizing species, but there is no indication as to whether it is strictly self-fertilized or that it presents some extent of cross-fertilization. The objective of this research was to measure the rate of cross-fertilization in O. cumana using an unpigmented recessive mutant as a visual marker. A pot and a field experiment in which single unpigmented plants were surrounded by a large number of pigmented plants were conducted. Occurrence of F1 hybrids, readily distinguishable from unpigmented plants in the progenies of unpigmented plants provided a direct measurement of the cross-fertilization rate. Progenies of unpigmented plants contained 21.5 % of F1 hybrids in the pot experiment and 28.8 % in the field experiment. The results revealed that O. cumana is a partially allogamous species, which has great relevance for understanding the genetic structure and dynamics of populations and, ultimately, race evolution in this parasitic plant. © 2012 Springer Science+Business Media Dordrecht., The research was funded by Fundación Ramón Areces, Madrid, Spain.

Sunflower (Helianthus annuus L.) seeds have a tocopherol profile dominated by alpha-tocopherol. The objective of this research was to study the dynamics of tocopherol accumulation in sunflower lines with altered total tocopherol content or tocopherol profile. Developing seeds were sampled at regular intervals in two lines with reduced and increased total tocopherol content, respectively, and six lines with modified tocopherol profiles. The line with reduced tocopherol content showed a tocopherol accumulation rate reduced by half, whereas the line with increased tocopherol content showed a tocopherol accumulation rate twofold higher than the control. In the three cases, alpha-tocopherol followed a sigmoid accumulation pattern. Modified tocopherol profiles were expressed at early stages of tocopherol accumulation. In most lines with modified profiles, tocopherol accumulation pattern differed from the alpha-tocopherol lines, with maximum tocopherol content at 18 or 21 days after flowering (DAF) that was reduced to reach a plateau from 33 or 36 DAF onward. Such a reduction was caused by continued dry matter accumulation after tocopherol accumulation ceased or slowed down. In lines with increased levels of beta-tocopherol or both gamma- and delta-tocopherol, the synthesis of beta- and delta-tocopherol started and stopped earlier than the synthesis of alpha- and gamma-tocopherol, respectively. © 2013 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.

Sunflower (Helianthus annuus L.) seeds and oils are rich sources of phytosterols, which are important compounds for human nutrition. There is limited information on variability for seed phytosterols in sunflower germplasm. The objective of this research was to evaluate kernel phytosterol content and profile in sunflower germplasm and to confirm phytosterol traits under several environments. Kernel phytosterol content in a collection of 985 accessions ranged from 1319 to 5119 mg kg-1. Large variation was also observed for the concentrations of campesterol (32 to 197 g kg-1 phytosterols), stigmasterol (41 to 128 g kg-1), β-sitosterol (448 to 755 g kg-1), and Δ7-stigmastenol (8 to 274 g kg-1). Seventy-two accessions selected for high phytosterol content and/or different profiles were evaluated for 2 yr under sib-pollination. From these, 20 accessions were selected based on phytosterol traits and further evaluated in two replicated field trials. Lines HA 89 and IASP-18, with conventional and high phytosterol content, respectively, were used as controls. Phytosterol traits such as high phytosterol content (up to 3682 mg kg-1 compared to 2686 mg kg-1 in HA 89 and 4957 mg kg-1 in IASP-18) as well as high concentrations of campesterol (180 g kg-1compared to a maximum of 66 g kg-1 in control line IASP-18), stigmasterol (161 g kg-1compared to 64 g kg-1 in HA 89), and Δ7-stigmastenol (300 g kg-1 compared to 163 g kg-1in HA 89) were confirmed. Selected accessions will be of great value for future basic and applied research on phytosterols in sunflower. © Crop Science Society of America., The research was supported by research project P07- AGR-03011 from Junta de Andalucía and EU FEDER funds.

alpha-Tocopherol is the main tocopherol in sunflower seeds (> 90%). Because it exerts a weak antioxidant action in vitro, its partial replacement by other tocopherols is an important breeding objective in this crop. The objective of this research was to develop novel tocopherol profiles in sunflower through mutagenesis and genetic recombination. Seeds of four 'Peredovik' accessions were used for chemical mutagenesis with ethyl methane sulfonate (EMS). Single-seed screening in the M2 generation resulted in two M2 seeds, derived from different M1 plants, with increased gamma-tocopherol contents of 19.2% and 96.7%, respectively. M3 progeny from the M2 seed with the 96.7% content bred true for high gamma-tocopherol content, containing more than 90% gamma-tocopherol. M3 progeny from the M2 seed with only 19.2% gamma-tocopherol segregated in a range from 0 to 84.6%. Selection for high gamma-tocopherol content produced an M(4 : 5) line, designated IAST-1, with a stable high concentration of gamma-tocopherol. Crosses between IAST-1 and T589, with an increased beta-tocopherol content, produced F2 segregants with transgressive levels of up to 77% beta-tocopherol or up to 68% delta-tocopherol. Both novel tocopherol profiles were confirmed in the F3 generation.

The objective of the present research was to study the inheritance of reduced plant height in the sunflower line Dw 89. Plants of the cytoplasmic male sterile version of this line, cmsDw 89 (mean plant height of 47.4 cm) were crossed with plants of the restorer line RHA 271 (mean of 120.9 cm). F 1 plants averaged 120.4 cm, which indicated dominance of standard over reduced plant height. F 2 plants followed a segregation pattern of 1 : 15 (reduced : normal height), suggesting that reduced plant height in Dw 89 is controlled by alleles at two loci, designated Dw1 and Dw2. Class assignment in the F 2 was confirmed through the evaluation of the F 3 generation. Backcrosses to Dw 89 segregated with 1 : 3 (reduced : normal height) ratios, which confirmed the digenic inheritance of the trait. The evaluation of plant height distributions in F 3 families suggested possible genetic interaction between the Dw1 and Dw2 loci.