Confection Sunflower Research Articles

Evaluation of Shearing Rolls for Hulling Confectionary Sunflower Seed for Precision Planting

<abstract> <bold><sc>Abstract. </sc></bold>The planting of sunflower seed has always used intact inshell seed. However, consumer demand for extra-large (XL) confection sunflower seed has led to new hybrid varieties, and much of the seed is now too large for current planting technologies and has poor germination. One alternative may be to use hulled kernels. Unfortunately, the impact hullers used in the snack food industry cause very high kernel breakage and poor germination. Thus, the effectiveness of shearing rolls was evaluated across several process conditions including: seed moisture content (6.1%, 7.8%, and 8.5%), differential roller speed (1.29, 1.55, and 1.68), roller gap distance (0.14 and 0.21 cm), and number of roller passes. Overall hulling effectiveness increased with decreased seed moisture content, and increased roller speed. At 6.1% moisture content, 0.21 cm roller gap distance, and 1.29 roller speed, proportion of dehulled seed increased by 54%, but the fraction of intact seed decreased by 19% when number of passes increased from 1 to 5. Although intact kernel yield improved with increasing pass number, germination and vigor index declined when the number of passes exceeded five, regardless of seed moisture and roller speed. The highest intact kernel yield of 68% with 88% germination and overall hulling efficiency of 4.9 was obtained using 7 passes, seed moisture content of 6.1%, and differential speed of 1.68. The results suggest shearing rolls provide a vast improvement of intact kernel yield and germination when compared to impact hulling used in the industry.

Registration of Two Confection Sunflower Germplasm Lines, HA-R10 and HA-R11, Resistant to Sunflower Rust

Two confection sunflower (Helianthus annuus L.) germplasm lines, HA-R10 (Reg. No. GP-327, PI 670043) and HA-R11 (Reg. No. GP-328, PI 670044), developed by the USDA–ARS Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station were released in December 2013. Both lines have resistance to sunflower rust (caused by Puccinia helianthi Schwein.), which is an emerging production issue for confection sunflower in North America due to the spread of new rust races and the lack of resistance sources. HA-R10 is a BC3F3–derived BC3F4 maintainer line of confection sunflower selected from the cross CONFSCLB1*4/HA-R2, and HA-R11 is a BC4F3–derived BC4F4 restorer line of confection sunflower selected from the cross CONFSCLR5*5/HA-R3. The rust resistance genes R5 in HA-R10 and R4 in HA-R11 were introduced from oilseed lines HA-R2 and HA-R3, respectively, with the two confection sunflower genetic stocks CONFSCLB1 and CONFSCLR5 as the recurrent parents. Greenhouse testing of rust resistance and DNA marker-assisted selection were used during development and progeny testing of the germplasm lines. HA-R10 and HA-R11 are morphologically similar to the recurrent parents but possess the rust resistance gene(s) transferred from oilseed sunflower. These sources will afford confection sunflower breeders an opportunity to incorporate rust resistance genes into their parental lines, thus facilitating the development of disease-resistant hybrids.

Do wild bees complement honeybee pollination of confection sunflowers in Israel?

Complementarity between species in the use of flower resources can enhance the pollination services of diverse pollinator communities. To test for complementarity, we studied fine-scale patterns of flower visitation and contribution to seed set of the three locally dominant bee species (commercially managed honeybees and two wild, non-managed Lasioglossum species) visiting confection (non-oil) sunflower in central Israel. The three species differed in their temporal (time of day) and phenological (head bloom stage) visitation patterns but generally showed niche redundancy. Moreover, honeybees strongly outperformed the wild species in both visitation rates and single-visit contributions to seed set. We conclude that the present communities and densities of wild bees do not complement honeybee sunflower pollination in the studied system. Sunflower seed production in central Israel is currently dependent solely upon the high stocking rate and pollination efficiency of honeybees.

Genetic mapping of rust resistance genes in confection sunflower line HA-R6 and oilseed line RHA 397

Few widely effective resistance sources to sunflower rust, incited by Puccinia helianthi Schwein., have been identified in confection sunflower (Helianthus annuus L.). The USDA inbred line HA-R6 is one of the few confection sunflower lines resistant to rust. A previous allelism test indicated that rust resistance genes in HA-R6 and RHA 397, an oilseed-type restorer line, are either allelic or closely linked; however, neither have been characterized nor molecularly mapped. The objectives of this study are (1) to locate the rust resistance genes in HA-R6 and RHA 397 on a molecular map, (2) to develop closely linked molecular markers for rust resistance diagnostics, and (3) to determine the resistance spectrum of two lines when compared with other rust-resistant lines. Two populations of 140 F2:3 families each from the crosses of HA 89, as susceptible parent, with HA-R6 and RHA 397 were inoculated with race 336 of P. helianthi in the greenhouse. The resistance genes (R-genes) in HA-R6 and RHA 397 were molecularly mapped to the lower end of linkage group 13, which encompasses a large R-gene cluster, and were designated as R 13a and R 13b, respectively. In the initial maps, SSR (simple sequence repeat) and InDel (insertion and deletion) markers revealed 2.8 and 8.2cM flanking regions for R 13a and R 13b, respectively, linked with a common marker set of four co-segregating markers, ORS191, ORS316, ORS581, and ZVG61, in the distal side and one marker ORS464 in the proximal side. To identify new markers closer to the genes, sunflower RGC (resistance gene candidate) markers linked to the downy mildew R-gene Pl 8 and located at the same region as R 13a and R 13b were selected to screen the two F2 populations. The RGC markers RGC15/16 and a newly developed marker SUN14 designed from a BAC contig anchored by RGC251 further narrowed down the region flanking R 13a and R 13b to 1.1 and 0.1cM, respectively. Both R 13a and R 13b are highly effective against all rust races tested so far. Our newly developed molecular markers will facilitate breeding efforts to pyramid the R 13 genes with other rust R-genes and accelerate the development of rust-resistant sunflower hybrids in both confection and oilseed sunflowers.

Molecular mapping of the Rf 3 fertility restoration gene to facilitate its utilization in breeding confection sunflower

The inheritance of a previously identified dominant Rf gene in the confection sunflower line RHA 280 has been determined and designated as Rf 3 . This study reports the mapping of the Rf 3 locus using an F2 population of 227 individuals derived from CMS HA 89-3149 × RHA 280. Bulked segregant analysis with 624 pairs of simple sequence repeat (SSR) primers and sequence tagged site (STS) primers identified two polymorphic SSR markers each of linkage groups (LGs) 7 and 11 from a previous map. Results on 90 F2 individuals with 42 polymorphic markers of LGs 7 and 11 indicated that the Rf 3 gene was linked with eight markers on LG 7, including five SSR markers (ORS328, ORS331, ORS928, ORS966, and ORS1092) and three expressed sequence tag (EST)-SSR markers (HT619-1, HT619-2, and HT1013). Further analysis of the total F2 population of 227 individuals identified a co-dominant marker, ORS328, linked to Rf 3 at a genetic distance of 0.7 cM on one side, and a female-dominant marker HT1013 at 12.6 cM proximal to Rf 3 on the other side; a genetic distance of 47.1 cM for LG 7 was covered. This is the first report of an Rf gene from the confection sunflower. The closely linked marker to Rf 3 will facilitate marker-assisted selection, and provide a basis for cloning of this gene.

First Report of Phomopsis Stem Canker of Sunflower in Illinois Caused by Phomopsis helianthi.

Stem cankers were observed on confection sunflower (Helianthus annuus) plants growing in a field in Champaign County, Illinois in August 2008. Lesions were brown to reddish brown, elongated (approximately 10 to 15 cm long), and centered over the area where leaf petioles connected to the stems. Stem tissues underneath the lesions were degraded. Lesions from diseased stems were cut into 5- to 7-mm pieces and immersed in a 0.5% NaOCl solution for 1 min, rinsed with sterilized distilled water, and placed into petri dishes containing acidified potato dextrose agar (APDA; 4 ml of 25% lactic acid per liter). Fungal colonies that grew from the stem lesion pieces on APDA were white, floccose, and dense with dark colored substrate mycelia. On the basis of the symptoms on sunflower plants and the growth characteristics on APDA, the fungus was tentatively identified as Phomopsis helianthi (1). To confirm the identity of the fungus, PCR amplification of the small subunit rDNA and internal transcribed spacer (ITS) region with primers EF3RCNL and ITS4 was done (2). The PCR product was sequenced with these primers at the Keck Biotechnology Center at the University of Illinois, Urbana. The resulting nucleotide sequence was compared with small subunit rDNA and ITS sequences deposited in the nucleotide database ( http://www.ncbi.nlm.nih.gov ) and showed highest homology to sequences of Diaporthe helianthi, teleomorph of P. helianthi. To confirm pathogenicity of the fungus, sunflower plants (cv. Cargill 270) were grown in the greenhouse and inoculated with the isolated fungus. The stems of sunflower plants between the V2 and V4 growth stages (3) were excised just below the uppermost node. Mycelia plugs of the fungus were placed into the large end of disposable micropipette tips (200 μl). The micropipette tip containing the fungus was subsequently placed over a cut sunflower stem. The fungal isolate was used to inoculate five stems. To serve as controls, five cut sunflower stems were inoculated with micropipette tips containing plugs of noninfested PDA and five cut stems were not inoculated. Mean lesion length on the stem was measured from the inoculated tip toward the soil line 7 days after inoculation. The experiment was replicated over time. Mean lesion length over both replications averaged 24 mm on the fungus-inoculated plants, 2 mm on the noninfested PDA-inoculated control plants, and no lesions were present on the noninoculated control plants. The fungus was reisolated on PDA from the inoculated plants in the greenhouse. To our knowledge, this is the first report of P. helianthi causing a stem canker of sunflower in Illinois. Although commercial sunflower production in Illinois is currently limited, it is being evaluated as a potential crop to follow winter wheat in portions of the state. If sunflower production were to increase in the state, growers may have to monitor for and manage Phomopsis stem canker.

Mapping quantitative trait loci (QTL) controlling seed morphology and disk diameter in sunflower (Helianthus annuus L.)

SUMMARY Seed morphology and disk diameter are agronomically most important traits for the confection sunflower. This paper reports the results of an analysis of quantitative trait loci (QTLs) underlying 10 seed morphological traits including seed and kernel size, shape and stripe, and disk diameter in both F 2 population and F 2:3 families derived from an oilseed by confection cross. A linkage map containing 165 target region amplification polymorphism (TRAP) and 44 simple sequence repeat (SSR) markers was constructed from 120 F 2 plants. This map contained 17 linkage groups and spanned a total genetic distance of 1784.3 cM. A total of 51 QTLs were detected and 32 of them were identified in both generations. Each QTL explained 5.1-29.3% of the phenotypic variation, suggesting these traits were controlled by multiple genes. Most of the QTLs were clustered in six chromosomal regions. Two of the three QTLs identified for disk diameter were also located in two of the six regions. Moreover, alleles from the confection line at these QTLs had positive effects on these traits. Both QTL congruence and correlation analysis revealed that different genetic bases are responsible for seed shape, stripe, and other confection traits. The information generated by this study will facilitate confection sunflower breeding. RESUMEN La morfología de las semillas y el diámetro del disco son los caracteres agronómicos más importantes para el girasol confitero. Este trabajo informa los resultados del análisis de los loci para caracteres cuantitativos (QTLs) que subyacen 10 caracteres morfológicos de las semillas, incluyendo tamaño de aquenio y pepita, forma y estriado y diámetro del disco en una población F 2 y las familias F 2:3 derivadas de un cruzamiento entre un material del tipo oleaginoso y uno confitero. Se construyó un mapa de ligamiento consistente en 165 marcadores de polimorfismo de amplificación de regiones objetivo (TRAP) y 44 marcadores de repetición de secuencias simples (SSR) a partir de 120 plantas F 2 . Este mapa contiene 17 grupos de ligamiento y explora una distancia genética total de 1784.3 cM. Se detectó un total de 51 QTLs, 32 de los cuales de identificaron en ambas generaciones. Cada QTL explicó un 5.1-29.3% de la variación fenotípica, lo que sugiere que estos atributos están controlados por múltiples genes. La mayoría de los QTLs están agrupados en seis regiones cromosómicas. Dos de los tres QTLs identificados para diámetro del disco están localizados en dos de las seis regiones cromosómicas. Además, alelos de la línea confitera en dichos QTLs presentaron efectos positivos sobre estos atributos. Tanto la congruencia de QTLs como los análisis de correlación revelaron que bases genéticas diferentes son responsables de la expresión de los atributos forma de semilla, estriado y otros caracteres de los confiteros. La información generada por este estudio facilitará el mejoramiento del girasol confitero. RÉSUMÉ La morphologie de la graine et le diamètre du capitule sont les caractères agronomiques les plus importants pour le tournesol de bouche. Cet article rapporte les résultats d’une analyse de LCQ associés à 10 caractères morphologiques parmi lesquels la taille du grain, sa forme et ses stries et le diamètre du capitule, à partir d’une population F 2 et de sa descendance F 2 :F 3 issue d’un croisement entre une lignée de type “huile” et d’une lignée de type “de bouche”. Une carte de liaison a été établie à partir de 165 marqueurs TRAP (target region amplification polymorphism) et de 44 marqueurs microsatellites (SSR), et sur 120 individus F 2 . Cette carte comporte 17 groupes de liaison et couvre une distance génétique totale de 1784.3 cM. Au total, 51 LCQ ont été mis en évidence et 32 d’entre eux l’ont été pour les deux générations. Chaque LCQ explique 5.1 à 29.3% de la variance phénotypique totale, ce qui suggère un contrôle multigénique. La plupart des LCQ se concentre sur six régions chromosomiques. Deux des trois QTL identifiés pour le diamètre du capitule co-localisent avec deux de ces six régions chromosomiques. De plus, le parent de type “de bouche” apporte les allèles favorables à ces caractères. La cohérence des résultats obtenus sur les LCQ et les analyses de corrélations mettent en évidence l’existence de bases génétiques distinctes pour la forme de la graine, ses stries, et les autres caractères d’intérêt pour le tournesol de bouche. L’information produite par cette étude facilitera l’amélioration génétique des tournesols de bouche.

Preliminary investigations into the significance of floral applications of calcium, boron and polyphenols for increased seed set in confection sunflowers ( Helianthus annuus L.)

One of the major problems of confection sunflowers is low seed set. We studied the relationship between seed set and the origin of pollen, either self or cross, and the effects of stigmatic sprays of calcium nitrate, boric acid and polyphenols on seed set. In a screen-house experiment, seed set was analyzed for three predetermined regions in the sunflower capitulum: distal, median and proximal. Cross-pollination combined with calcium nitrate or boric acid spray significantly improved seed set in the distal region compared with cross-pollination alone or with cross-pollination combined with self-pollination. Neither spray had a significant effect on seed set in the median or proximal regions. Cross-pollination of the proximal region only, with either fresh pollen or 24-h-old pollen, did not improve seed set compared with cross-pollination of the whole capitulum. We found no direct link between pollen germination on the stigma and seed set. However, each region of the capitulum responded differently to self- or cross-pollination. In two open-field experiments, stigmatic applications of calcium nitrate significantly increased seed set by approximately 9% compared with open pollination alone, while stigmatic applications of polyphenols significantly increased seed set by approximately 9% only once, suggesting that commercial yields may be increased by using similar applications.

Registration of Three Low Cadmium (HA 448, HA 449, and RHA 450) Confection Sunflower Genetic Stocks

Registration of Three Low Cadmium (HA 448, HA 449, and RHA 450) Confection Sunflower Genetic Stocks

Influence of Planting Date on Sunflower Stem Weevil (Coleoptera: Curculionidae) Larval Density and Parasitism in Oilseed and Confection Sunflower in Western Kansas

The sunflower stem weevil infests stalks of cultivated sunflower and can cause lodging resulting in loss of the head prior to harvest. Our objective was to determine whether altered planting periods could reduce weevil densities in confection and oilseed sunflower in the central High Plains production region. We evaluated impact of planting date by measuring larval density within sunflower stalks, larval parasitoid species present, and parasitization rates. Trials were conducted at Colby, KS from 1999 to 2001, with plots seeded in four planting periods. Results, although inconsistent over years and between the two sunflower types, showed that later planting dates reduced weevil density in stalks. Weevil numbers in stalks from the first seeding period until the last had decreased by 10% to 50%. The third planting date in each year coincided with cumulative degree-days (581) for the predicted emergence of 90% of adult sunflower stem weevils. Yields were not reduced as planting was delayed. Fewer weevils were observed in oilseed than in confection hybrids. Lower densities of sunflower stem weevils in the stalk can reduce losses from lodged plants. Seven hymenopteran parasitoid species were reared from sunflower stem weevil larvae. Nealiolus curculionis (Fitch) and Neocatolaccus tylodermae (Ashmead) were the most common species. Parasitization rates were low, but wasps actively attacked the weevil throughout the growing season. Research showed that delaying planting until after the early and later May planting periods reduced weevil densities in western Kansas.

Plant stage susceptibility and economic injury level for tarnished plant bug, Lygus lineolaris (Heteroptera: Miridae), on confection sunflower

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), feeding on developing sunflower seed causes kernel brown spot, a serious problem in confection sunflower. The purpose of this research was to determine the economic injury level and plant stage susceptibility for confection sunflower in greenhouse and field studies using sunflower heads artificially infested with L. lineolaris adults. Greenhouse experiments showed each adult damaged 38 seeds per head. Field studies showed a lower average damage in heads infested with seven adults compared with heads with five adults, possibly due to interference among the adults and nymphs. The regression equation used to predict the number of kernel brown spot damaged seeds per head based on adults per head was Y=-0.86+33.54X. Thus, feeding resulted in 32.7 damaged seeds per head per adult. Approximately 5% of seeds in a head were damaged per adult. Damage to sunflower heads was approximately twice as severe when L. lineolaris infestation occurred at growth stages R4 and R5 compared with stages R6 and R7. Thus, protection of sunflower plants from infestation by tarnished plant bug, until they have completed blooming, may prevent economic loss. The economic injury level for tarnished plant bug was one adult per 10 to 15 plants, each head averaging 500 to 600 seeds, for a damage level of 0.5%. Thus, tarnished plant bug management should be initiated between the R4 to R5.1 stage if adult densities approach the economic injury level. Also fields need to be monitored until bloom is completed to reduce incidence of kernel brown spot damage to confection sunflower.

First Report of Albugo tragopogonis on Cultivated Sunflower in North America.

White rust, caused by Albugo tragopogonis (Pers.) S.F. Gray, was observed on a few plants of both oilseed and confection sunflowers (Helianthus annuus L.) in northwestern Kansas (Cheyenne County) in 1992. The disease was observed again from 1993 to1995 in nine counties in western Kansas, with incidence per field ranging up to 35%. White rust was found only on late-planted fields in 1996 and 1997 and was not found at all from 1998 to 2001. White rust was also observed on cultivated and wild sunflower (H. annuus) for the first time in eastern Colorado (Kit Carson and Yuma counties) from 1994 to 1997, but was absent from 1998 to 2001. Leaf pustules on both cultivated and wild sunflowers were similar in appearance. Pustules were convex, chlorotic on the upper side of the leaf, and concave and dull white on the under side of the leaf. Pustules on cultivated sunflower were generally limited to three to six leaves in the middle of the plant and affected 10 to 40% of the leaf area. Sporangial dimensions fell within the reported dimensions for A. tragopogonis (2). In 1997, water-soaked lesions 1 to 2 cm long containing oospores of A. tragopogonia were observed on the lower to middle portions of stems of cultivated sunflower in western Kansas and the adjacent area of Colorado. Stem lesions were observed much less frequently than foliar lesions and only in 1997. Sporangia were not observed in stem lesions, nor were any other fungi isolated from these lesions. To our knowledge, this is the first report of white rust occurring on cultivated sunflower in any production area of North America; the disease has not been observed in the major U.S. sunflower production area of North Dakota, South Dakota, and Minnesota. Foliar white rust lesions generally have little economic impact on sunflower, but the presence of stem lesions is significant because stem lesions may lead to lodging (3). Lodging due to A. tragopogonia was not observed in either Kansas or Colorado. White rust has previously only been reported on wild H. annuus in Wisconsin and on perennial Helianthus spp. in Missouri and Illinois (1).

Large Sunflower Seeds are Characterized by Low Embryo Vigor

The cause for the differences in germination ability of large and small confection sunflower (Helianthus annuus L.) seeds was investigated over 3 years. The source-sink relationship was manipulated to better explore the differences between seeds of various sizes and to study the role of the embryo and the pericarp (hull) in controlling germination ability. Percent germination of large seeds was significantly lower than that of small seeds when tests were performed at 15 °C. Increasing the ratio of leaf area to number of developing seeds caused an increase in mean seed mass, but resulted in a lower percentage of germination. Seed vigor, as measured by mean time to germination or to emergence of hulled seeds or by rate of root elongation, was negatively correlated with embryo mass, indicating that the low vigor of large seeds is not due to the mechanical barrier imposed by the hull. Analysis of electrolyte leakage confirmed the hypothesis that the low quality of large seeds results from a disturbance during the process of seed development.

Inhibitory Effects of Confection Sunflower Hulls1

Abstract Sunflower hull material from Sunflower (Helianthus annuus L.) was unsuccessful as an amendment in potting mixtures because of inhibition to top and root growth. Aqueous and methanol extracts from sunflower hulls reduced the rate of germination with lettuce and radish seeds and reduced primary root elongation with lettuce in bioassay tests.