Achene Oil Research Articles

Foliar Application of Glycinebetaine and Salicylic Acid Improves Growth, Yield and Water Productivity of Hybrid Sunflower Planted by Different Sowing Methods

Improved planting methods and foliar application of glycinebetaine (GB) and salicylic acid (SA) can improve the water productivity in field crops under limited water supply conditions. A 2-year field study was conducted to evaluate the possible role of different planting methods and foliar applications of GB and SA in improving the yield, quality and water productivity of hybrid sunflower (Helianthus annuus L.). The crop was planted by flat sowing (75 cm spaced rows) and ridge sowing (75 cm spaced ridges), with GB and SA applied exogenously at 100 and 0.724 mm, respectively, at both budding and flowering stages, while control plots received distilled water. Ridge sowing, rather than flat sowing, improved the biological yield, oil yield, leaf area index (LAI), crop growth rate (CGR), plant height, water-use efficiency and final achene yield during both the years. Foliar applications of GB and SA at both the stages improved the achene yield, although foliar application of GB at flowering was the most effective. Neither the planting methods nor the foliar application of GB and SA altered the achene oil contents during both the years. Foliar application of GB and SA increased the free proline content of the leaf and GB contents at flowering but reduced the achene protein contents, whereas planting method had no effect on these attributes across the years. Of the foliar applied chemicals, GB was more effective in improving sunflower growth and yield and water productivity than SA. To conclude, ridge sowing coupled with foliar application of GB at flowering stage could be beneficial for achieving maximum yields of hybrid sunflower under relatively water limited conditions in the field.

Exogenous glycinebetaine application improves yield under water-limited conditions in hybrid sunflower

Limited water availability is a severe threat to the sustainability of crop production. Exogenous application of glycinebetaine (GB) has been found very effective in reducing the adverse affects of water scarcity. This study was conducted to examine the role of exogenous GB application in improving the yield of hybrid sunflower (Helianthus annuus L.) under different irrigation regimes. There were three levels of irrigation: Control (four irrigations), three irrigations (irrigation missing at budding stage) and two irrigations (irrigation missing at budding and grain formation stage) in the experiment. While GB was applied exogenously at 100 mM GB each at budding and grain formation stages, the Control treatment did not receive any GB application. Data regarding yield, yield components and quality parameters showed that water stress reduced the head diameter, number of achene per head, 1000-achene weight and yield. Nonetheless, it was significantly improved by the exogenous GB application. Among the qualitative characteristics, protein contents were significantly increased by water stress at different growth stages but were reduced by exogenous GB application. Whilst oil contents were reduced by drought at different stages, GB application, however, did not ameliorate the negative effect of drought stress on achene oil contents. The effects of water stress and foliar application of GB were more pronounced when applied at vegetative stage than at the reproductive stage. Moreover, exogenous GB application was only advantageous under stress conditions.

Improving Drought Tolerance by Exogenous Application of Glycinebetaine and Salicylic Acid in Sunflower

AbstractWater shortage is a severe threat to the sustainability of crop production. Exogenous application of glycinebetaine (GB) and salicylic acid (SA) has been found very effective in reducing the adverse affects of drought stress. This study was conducted to examine the possible role of exogenous GB and SA application in improving the yield of hybrid sunflower (Helianthus annuus L.) under different irrigation regimes. There were three levels of irrigation, viz. control (normal irrigations), water stress at vegetative stage (irrigation missing at vegetative stage) and water stress at flowering stage (irrigation missing at flowering stage). GB and SA were applied exogenously at 100 and 0.724 mm, respectively, each at the vegetative and at the flowering stage. Control plants did not receive application of GB and SA. Water stress reduced the head diameter, number of achene, 1000‐achene weight, achene yield and oil yield. Nevertheless, exogenous GB and SA application significantly improved these attributes under water stress. However, drought stress increased the free leaf proline and GB, and were further increased by exogenous application of GB and SA. However, exogenous GB application at the flowering stage was more effective than other treatments. Oil contents were also reduced under water stress; however, GB and SA application could not ameliorate the negative effect of water stress on achene oil contents. The effects of water stress and foliar application of GB were more pronounced when applied at the flowering stage than at the vegetative stage. Moreover, exogenous GB application was only beneficial under stress conditions.

Characterization of oil bodies in jelly fig achenes

Thin-layer chromatography analysis revealed that the contents stored in oil bodies isolated from jelly fig (Ficus awkeotsang Makino) achenes were mainly neutral lipids (>90% triacylglycerols and approximately 5% diacylglycerols). Fatty acids released from the neutral lipids of achene oil bodies were highly unsaturated (62.65% alpha-linolenic acid, 18.24% linoleic acid, and 10.62% oleic acid). The integrity of isolated oil bodies was presumably maintained via electronegative repulsion and steric hindrance provided by their surface proteins. Immunological cross-recognition using antibodies against sesame oil-body proteins indicated that two oleosin isoforms and one caleosin were present in these oil bodies. MALDI-MS analyses confirmed that the three full-length cDNA fragments obtained by PCR cloning from maturing achenes encoded the two jelly fig oleosin isoforms and one caleosin identified by immunological screening.

Yield and quality response of autumn-planted sunflower (Helianthus annuus L.) to sowing dates and planting patterns

Sowing time and sowing methods are often used to overcome environmental constraints on crop production. Information on the effect of these agronomic techniques on sunflower (Helianthus annuus L.) oil quality is, however, scarce. A field study was conducted to evaluate the effect of sowing dates and planting patterns, and their interaction, on seed yield and oil quality of hybrid sunflower. Sunflower hybrid Hysun-33 was sown at four dates beginning with the first week of August with fortnightly intervals under three planting patterns, viz., flat sowing (60 cm apart lines), ridge sowing (60 cm apart ridges) and bed sowing (90/30 cm) for 2 yr (2002 and 2003). The performance of the August sowing dates was significantly better with respect to yield and yield components than the September-sown crop. Among the three sowing dates in August, there was variable performance of the crop in the 2-yr study. On average, the sowing of sunflower from mid-August to the last week of August yielded better than early August sowing dates. The evaluation of quality parameters revealed greater content of achene oil in the September-sown crop followed by the crop sown in the last week of August. Delayed sowing lowered oleic acid content, but increased stearic and linoleic acid levels. Planting pattern treatments affected head diameter, achenes per head, 1000-achene weight and achene yield. Conclusively, sunflower sown on ridges during the second fortnight of August encountered favourable environmental conditions and gave significantly higher economic yield. Key words: Helianthus annuus , plantingg eometry, plantingpatterns, quality, sowingdates, sunflower yield

Efeito de NPK na produtividade e componentes químicos do girassol

The objective of this work was to evaluate the NPK influence on yield and oil, proteins and phytochemical contents in sunflower grain and to explore the potential of mathematical model of marginal contributions of fertilization effects. The field experiment was conducted in 3 3 incomplete factorial model, in two randomized blocks, with 15 parcels for block. The treatments were zero, 30 and 60 kg ha -1 of N, P and K. The achene yield increased with fertilizer doses until 55 kg of N ha -1 , 41 kg ha -1 of K 2 O and 46 kg ha -1 of P 2 O 5 . The achene oil content answered positively to increased K 2 O and P 2 O 5 . Proteins content decreases as K 2 O rate increases. No influence of the fertilization was observed in concentrations of chlorogenic acid, total sterols and total phosphorus on achene.

Achene Structure, Development and Lipid Accumulation in Sunflower Cultivars Differing in Oil Content at Maturity

Sunflower cultivars exhibit a wide range of oil content in the mature achene, but the relationship between this and the dynamics of oil deposition in the achene during grain filling is not known. Information on the progress, during the whole achene growth period, of the formation of oil bodies in the components of the achene and its relationship with variations in final oil content is also lacking. The biomass dynamics of achene components (pericarp, embryo, oil) in three cultivars of very different final oil concentration (30-56 % oil) were studied. In parallel, anatomical sections were used to follow the formation of oil and protein bodies in the embryo, and to observe pericarp anatomy. In all cultivars, oil bodies were first observed in the embryo 6-7 daa after anthesis (daa). The per-cell number of oil bodies increased rapidly from 10-12 daa until 25-30 daa. Oil bodies were absent from the outer cell layers of young fruit and from mature pericarps. In mature embryos, the proportion of cell cross-sectional area occupied by protein bodies increased with decreasing embryo oil concentration. The sclerenchymatic layer of the mature pericarp decreased in thickness and number of cell layers from the low-oil cultivar to the high-oil cultivar. Different patterns of oil accumulation in the embryo across cultivars were also found, leading to variations in ripe embryo oil concentration. In the high-oil cultivar, the end of oil deposition coincided with cessation of embryo growth, while in the other two cultivars oil ceased to accumulate before the embryo achieved maximum weight. Cultivar differences in mature achene oil concentration reflect variations in pericarp proportion and thickness and mature embryo oil concentration. Cultivar differences in protein body proportion and embryo and oil mass dynamics during achene growth underlie variations in embryo oil concentration.

Influence of water stress and exogenous glycinebetaine on sunflower achene weight and oil percentage

The study was carried out to assess whether exogenously applied glycinebtaine has any role in reducing the adverse effects of water stress on sunflower achene yield and oil contents. Two sunflower lines, Gulshan-98 and Suncross were subjected to water stress at the vegetative and reproductive stages of plant growth. Three levels of glycinebtaine (0, 50 and 100 mM) were applied before sowing (seed treatment) and at the time of initiation of stress at the vegetative and reproductive stages. A marked adverse effect of water stress on 100-achene weight and achene oil contents were observed in both sunflower lines. Exogenous supply of glycinebtaine was not effective in alleviating the adverse effects of water stress on achene oil percentage. Foliar spray of glycinebtaine, however, significantly reduced the negative effects of water stress on achene weight. Seed treatment with either level of glycinebtaine was not effective in increasing the 100-achene weight and achene oil percentage under both normally irrigated and water stress conditions. The sunflower line, Suncross produced higher oil yield than that of Gulshan-98.

Wild helianthus annuus, a potential source of reduced palmitic and stearic fatty acids in sunflower oil

The current trend in human diets is to decrease consumption of the saturated palmitic and stearic fatty acids. Healthy diets restricting not only total fat, but the saturated portion of that fat, would decrease blood serum cholesterol and the risk of coronary heart diseases. Edible vegetable oils are the principal source of fats in many diets. Sunflower oil, which is fifth in production among edible vegetable oils in the world, contains 65 g kg-1 saturated palmitic and 45 g kg-1 saturated stearic acids. These concentrations are high compared to rapeseed oil with 40 g kg-1 palmitic and 20 g kg-1 stearic acids. A reduction of saturated fats in traditional sunflower oil would lead to a healthier edible oil. The objective of this preliminary study was to search the vast genetic diversity available from wild Helianthus annuus, the closest relative of the cultivated sunflower, for potential sources of reduced saturated fatty acids; less than 70 g kg-1 combined palmitic and stearic fatty acids. Achenes of eighty-two populations of wild H. annuus were collected from the central Great Plains of the USA. Composited 20-achene samples from each population were analyzed for saturated fatty acids using organic base-catalyzed transesterification of fatty acid methyl esters and capillary gas chromatography. The average palmitic acid concentration ranged from 39 to 65 g kg-1 for the populations. Average stearic acid concentrations ranged from 19 to 37 g kg-1. Achene oil of one population of wild H. annuus from Holmquist, South Dakota, USA had a palmitic acid concentration averaging 39 g kg-1, while stearic acid averaged 19 g kg-1. The combined 58 g kg-1 palmitic and stearic acids is almost 50% lower than the present level of these fatty acids in sunflower oil. The level of saturated fatty acids observed in the population remained low when plants were grown in the greenhouse under uniform conditions. In the greenhouse palmitic acid concentration of this population averaged 40 g kg-1, while stearic acid averaged 19 g kg-1. Crosses between this population and an inbred cultivated line produced F1 plants with an achene oil that averaged 39 g kg-1 palmitic and 21 g kg-1 stearic acid. In comparison, the inbred cultivated parent averaged 61 g kg-1 palmitic and 51 g kg-1 stearic acid. F2 plants produced achene oil that averaged 45 g kg-1 palmitic and 23 g kg-1 stearic acid, for a total of 68 g kg-1. When F1 plants were backcrossed to the cultivated inbred, BC1F1 plants produced an achene oil that averaged 45 g kg-1 palmitic and 26 g kg-1 stearic acid for a total of 71 g kg-1. In comparison, the inbred cultivated parent averaged 65 g kg-1 palmitic and 42 g kg-1 stearic acid, for a total of 107 g kg-1. Preliminary information indicates that palmitic and stearic fatty acids in sunflower oil can be reduced by introducing genes from a wild annual population into cultivated sunflower. Further research will be needed to determine the inheritance of these fatty acids. Other agronomic traits will also have to be monitored during introgression of the fatty acids genes.

Dwarf sunflower response to row spacing, stand reduction, and defoliation at different growth stages

Growth compensation of dwarf sunflower (Helianthus annuus L.) hybrids to low initial stands, later stand losses, or plant defoliation has not been reported regarding replanting decisions and crop insurance yield loss assessment. Three experiments were conducted to study the affect of stand reduction, defoliation, and row spacing on dwarf sunflower yield and quality when grown in eastern North Dakota. Experiment 1 evaluated stand reduction (0, 25, 50 and 75%) applied at growth stages (V4, R1 and R6) in 15, 45 and 76 cm spaced rows. Row spacing interactions with stand reduction and growth stage were not significant for yield indicating growth stage and stand reduction effects on yield response were independent of row spacing. In exp. 2, significant growth stage (V4, V8, R1, R2, R3, R5 and R6) by stand reduction (0, 12, 25, 37, 50, 62 and 75%) interaction showed stand reduction at vegetative growth stages not influencing yield, but as maturity progressed yield reductions became greater with increased stand reduction. Achene weight increased with increasing stand reduction at vegetative and early reproductive stages. A reciprocal relationship was noted between achene weight and achene oil content where oil content decreased as achene weight increased. Interaction of growth stage (R1 and R6) and defoliation (0, 25, 50, 75 and 100%) in exp. 3 indicated greater reduction in yield, test weight, 1000-achene weight, and achene oil conte nt as defoliatin increased at growth stage R6. Yield compensating ability of dwarf sunflower is dependent on type and level of damage and growth stage of occurrence, with total yield reduction considering all effects. Key words: Sunflower, Helianthus annuus L., row spacing, stand reduction, defoliation

COBERTURA NITROGENADA EM GIRASSOL SOB PLANTIO DIRETO NA PALHA: I - RENDIMENTO DE GRÃOS E SEUS COMPONENTES, ÍNDICE DE COLHEITA E TEOR DE ÓLEO

O trabalho teve como objetivo avaliar o efeito de diferentes doses de nitrogênio em cobertura no cultivo do girassol (Helianthus annuus L.) em sistema plantio direto na palha. O experimento foi conduzido no ano agrícola de 1998/99, na Fazenda Agripastos, em Palmeira, região dos Campos Gerais do Paraná, em um argissolo vermelho-amarelo, cultivado em sistema plantio direto na palha desde 1976. O delineamento experimental foi blocos ao acaso com quatro repetições. Os tratamentos foram: doses de nitrogênio (0, 25, 50, 75, 100 e 125 kg.ha-1), na forma de uréia, aplicados em cobertura quando as plantas se encontravam no estádio V8. O híbrido M734 foi semeado em setembro de 1998. Por ocasião da colheita, foram avaliados: rendimento de grãos, índice de colheita aparente, massa média de 1000 aquênios, número de aquênios por capítulo e teor de óleo nos aquênios. A adubação nitrogenada em cobertura, nas condições do experimento, não alterou rendimento de grãos, seus componentes e o teor de óleo nos aquênios.

Wild perennial sunflower as a potential source of reduced palmitic and stearic fatty acids in sunflower oil

The trend in healthier human diets is to decrease the consumption of the saturated fatty acids. Sunflower oil, which is fourth in production among edible vegetable oils in the world, contains 65 g kg-1 palmitic and 45 g kg-1 stearic acids, both saturated fatty acids. These levels are high compared with rapeseed (Brassica napus L) oil with 40 g kg1 palmitic and 20 g kg-1 stearic acids. A reduction of saturated fats in traditional sunflower oil would lead to a healthier edible oil. The objective of this preliminary study was to search the vast genetic diversity available from wild ancestors of cultivated sunflower for potential sources of reduced palmitic and stearic fatty acids. Achene oil of one population of wild H. giganteus L. (GIG-102) from INRA, Montpellier, France, had 47 g kg-1 palmitic acid and 18 g kg-1 stearic acid. The combined 65 g kg-1 palmitic and stearic acids is 40% lower than the present level of these fats in sunflower oil. The level of saturated fatty acids observed in the population remained low when plants were grown in the greenhouse under uniform conditions. In the greenhouse, palmitic acid averaged 48 g kg-1, while stearic acid averaged 16 g kg-1. This would indicate that palmitic and stearic acid concentrations are under genetic control with potential for incorporation into cultivated sunflower. Crossing this population with an inbred cultivated line produced F1 plants with an achene oil that averaged 39 g kg-1 palmitic and 26 g kg-1 stearic acid. The inbred cultivated parent averaged 55 g kg-1 palmitic and 51 g kg-1 stearic acid. F2 plants produced an achene oil that averaged 47 g kg-1 palmitic and 29 g kg-1 stearic acid, for a total of 76 g kg-1. When F1 plants were back-crossed to the cultivated inbred, BC1F1 plants produced an achene oil that averaged 47 g kg-1 palmitic and 28 g kg1 stearic acid for a total of 75 g kg-1. The inbred cultivated parent averaged 54 g kg-1 palmitic and 56 g kg-1 stearic acid, for a total of 110 g kg-1. Preliminary information indicate that palmitic and stearic fatty acids in sunflower oil can be reduced by introducing genes from a wild perennial progenitor into cultivated sunflower. Further research will be needed to determine the inheritance of these fatty acids. Other agro-nomic traits will also have to be monitored during the introgression of genes for reduced saturated fatty acids into cultivated sunflower.

NITROGÊNIO EM COBERTURA NO CULTIVO DE GIRASSOL EM SISTEMA DE PLANTIO DIRETO NA PALHA

O presente trabalho, conduzido no ano agrícola de 1998/99, teve como objetivo avaliar o efeito de diferentes doses de nitrogênio em cobertura no cultivo do girassol (Helianthus annuus L.) em sistema de plantio direto na palha. O experimento foi conduzido na Fazenda Agripastos, em Palmeira, região dos Campos Gerais do Paraná, em um latossolo vermelho-amarelo, cultivado em sistema de plantio direto na palha desde 1976. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. Os tratamentos testados foram: doses de nitrogênio (0, 25, 50, 75, 100 e 125 kg.ha-1), na forma de uréia, aplicados em cobertura quando as plantas encontravam-se no estádio V8. A variedade M734 foi semeada em setembro de 1998. Para as avaliações foram amostradas cinco plantas por unidade experimental nos estádios V8, V17, R1, R5.5 e R7, analisando as variáveis: número total de folhas, altura da planta, diâmetro do caule, área foliar, índice de área foliar, diâmetro do capítulo e partição de matéria seca. Por ocasião da colheita, foram avaliados: rendimento de grãos, índice de colheita aparente, massa média de 1000 aquênios, número de aquênios por capítulo, teor de óleo nos aquênios, número de plantas acamadas, quebradas e com sintomas de podridão do capítulo. Complementarmente, foi realizada análise foliar para obtenção dos teores de N, P, K, Ca, Mg, Fe, Mn, Cu e Zn. A adubação nitrogenada em cobertura, nas condições do experimento, não alterou o rendimento de grãos, seus componentes, o teor de óleo nos aquênios, a partição de matéria seca e as características morfológicas do girassol. Não foi comprovado aumento no percentual de plantas acamadas, quebradas ou com sintomas de podridão do capítulo, mesmo na aplicação das maiores doses de nitrogênio. O N aplicado em cobertura no cultivo de girassol sob sistema de plantio direto na palha alterou o teor de N nas folhas, mas não alterou os teores de P, K, Ca, Mg, Fe, Mn, Cu e Zn.

Análise da capacidade combinatória entre linhagens de girassol

A capacidade geral (CGC) e a capacidade específica de combinação (CEC), entre duas linhagens macho-estéreis (mãe) e um grupo de sete linhagens S4 restauradoras de fertilidade (pai), foram estimadas para estudar o potencial desses materiais em programas de melhoramento de girassol (Helianthus annuus L.). O método IV de Griffing, adaptado para cruzamentos dialélicos parciais, foi usado na análise das combinações híbridas. Considerando a CGC para rendimento de aquênios e teor de óleo, os progenitores com maior potencial para o melhoramento foram CMS HA 302 (originária de uma população norte-americana) para ser usada como mãe, e as linhagens 89V2345)3382 e 89V2345)3311 (derivadas da população V2000, obtida por seleção sobre a população Issanka, originária da França) como pais nos cruzamentos. Para o rendimento de aquênios, os efeitos gênicos não aditivos foram importantes na determinação das diferenças entre progenitores. Considerando-se os efeitos gênicos aditivos e não-aditivos conjuntamente, as melhores combinações são CMS HA 302 x 89V2396)5333 para rendimento de aquênios e CMS HA 30379NW22 x 89V2345)3382 para teor de óleo e rendimento de óleo.

Interhybrid Competition Affects Sunflower Character Expression

AbstractField researchers are confronted with selection of the proper plot design to assure agreement of small‐scale experimental plot results with large‐scale commercial field production. The objective of this research was to investigate the effect of plot design on expression of hybrid sunflower (Helianthus annuus L.) characters. Field studies were conducted in North Dakota at three dryland sites: Carrington, Fargo, and Prosper. lnterhybrid and intrahybrid competitive situations were attained by using one‐row or two‐row hybrid arrangements with three hybrids as possible borders. Competitive effects were determined on achene yield, achene oil concentration, achene weight, test weight, days to anthesis, head diameter, plant height, and leaf number. Plot achene yield was 20% greater when the border hybrid was a semidwarf than when border hybrids were of more conventional height. Border hybrid competitive influences on achene yield were approximately twice as great for one‐row as for two‐row arrangements. Other characters influenced by interhybrid competition were test weight, head diameter, and plant height. Characters not influenced by interhybrid competition included achene weight, achene oil concentration, days to anthesis, and leaf number. Plot border rows are recommended when evaluating characters subject to interhybrid competitive influences. An alternative approach is using one‐row or two‐row arrangements and grouping hybrids similar in plant height and maturity in the same field proximity.

Fatty acid composition of Achene oils from five Moroccan climatic cultivars of <i>Cannabis</i>.

The fatty acid composition of achene oil from five Cannabis climatic cultivars cultivated in the nort of Morrocco is determined. Linoleic acid predominated (40 to 45%), followed by linolenic (12 to 17%) and oleic (7 to 10%) acids. Differences in the fatty acid composition of oils are attributed to environmental factors.

Association of sunflower achene color with other achene characters and bird preference

The association of achene color with other achene characters and bird preference was investigated in segregates of a striped Yugoslavian line NS 39 and in 12 crosses of various genotypes. In the NS 39 segregates, the strongest association of achene color was with kernel content (r = 0.606), bird preference (r = 0.610) and achene oil (r = 0.445). Birds preferred lines with darker achene color which in turn was linked with higher oil and nutmeat content. In the crosses of various genotypes, achene color was strongly associated with achene oil content in segregates of two grey × black achene color crosses (r = 0.436 and 0.292) and in segregates of anthocyanin-containing × black achene color cross (r = 0.419). Key words: Sunflower, color association, achene characters, bird preference, achene oil, nutmeat anthocyanin

Response of Hybrid and Open‐Pollinated Safflower to Plant Population

AbstractFour safflower (Carthamus tinctorius L.) cultivars were evaluated at five plant populations in experiments over 2 yr at three North Dakota locations. Differences in achene yield due to plant population were not significant. Hybrid AGC‐353 produced significantly higher achene yield than the other cultivars. Number of capitula per plant and achenes per capitulum were the yield components most influenced by plant population. Cultivar effects were significant for all yield components. Plant population did not influence achene oil content; however, significant differences among genotypes occurred. Cultivar S‐541 and hybrid AGC‐353 produced significantly higher and lower achene oil percent, respectively, than the other cultivars. The significantly higher hull content of hybrid AGC‐353 compared with the other cultivars caused the low oil content.

Genetic analysis of hullability in sunflower

Significant increase in sunflower meal protein content could be achieved by a decrease in seed crude fibre through seed dehulling before oil extraction. In order to evaluate the presence of genetic variability suitable for the establishment of a breeding programme to improve the character of hullability, crosses were made in 1989–1990 among eleven randomly chosen inbred sunflower lines, according to a diallelic schema. In the following growing season the 55 F1 hybrids obtained and the eleven parental lines were sown according to a randomized block design with three replications. The following characters were determined: achene yield, weight of 1000 achenes, % achene oil and hull (HC), mechanical hull extraction (FH) and hullability (H) obtained from the ratio FH/HC. Analysis of variability of the character demonstrated that both additive and non-additive variability were significant with moderate heritability in a narrow sense. Hullability is shown to have a strongly positive correlation with mechanical hull extraction and with % achene hull. The biological negative correlation existing between % achene hull and % achene oil leads to serious complications in selection for high hullability without decreasing oil yield. A very promising inbred line (L3) was identified, with positive GCA effects for hullability, oil content and seed yield, suggesting new breeding strategies to overcome the barriers in simultaneous improvement of the above characters. A genetic improvement programme must therefore take into account both intrinsic parental characteristics (GCA) and also those of the different hybrid combinations (SCA). Furthermore, a very useful contribution to hullability could come from a global study in which genetic effects are considered together with effects linked to the mechanical process, pedoclimatic conditions, crop management techniques and possible interaction between these factors.

Estudio proteico de híbridos de girasol cultivados en Argentina

Protein content of residual meals of two sunflower cultivar during two harvest are evaluated. The relation between this component and the oil content of hull, achene and seed are showed. Negative tendency of correlation are observed between hull oil content and hull protein content, on achene oil content and achene protein content and on seed oil content and seed protein content along the harvest studied. Although the protein content for second harvest studied was lower, the apparent competitive behaviour between oil-protein was ratified.