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The present study was conducted to determine the yield and quality characteristics of oil sunflower genotypes as candidates for registration under Konya and Karaman conditions, in 4 replications according to the "Random Blocks Trial Design". The differences between the cultivars used in both locations of the study in terms of the number of days to bloom, the number of days to physiological maturity, the diameter of the tray, the thousand seed weight, seed moisture, seed yield, oil content, and oil yield were found to be statistically significant. The number of flowering days of the genotypes was found to be 64.5-60.8 days (H412; P63LLE113), the number of days to physiological maturity was 113.9-110.3 days (H412; P63LLE113), plant height 169.0-164.6 cm (M94S35; P63LE113), head diameter 20.9-17.3 cm (H412; P63LLE113), thousand-seed weight 60.3-47.4 g (H408; P64LE119), seed moisture 7.8-5.9 % (H408; P63LE113), seed yield 43.6-43.2 t ha-1 (H412; P64LE119), oil content 44.2-41.8 (H412; M94S35), and oil yield 19.2-17.0 t ha-1 (H412; P63LE113). The study showed that high yields could be achieved by using newly-developed hybrid sunflower genotypes in the conditions in the region. According to the averages of the location, it can be argued that the H412 hybrid that has high seed and oil yield can be successfully grown in regional conditions. [ABSTRACT FROM AUTHOR]

This research was conducted to determine the yield and quality characteristics of oil sunflower genotypes as candidates for registration under Konya and Karaman conditions, in four replications according to the "Random Blocks Trial Design". The differences between the cultivars used in both locations of the study in terms of the number of days to bloom, the number of days to physiological maturity, plant height, the diameter of the head, the thousand seed weight, seed moisture, seed yield, oil rate, and oil yield were found to be statistically significant. The number of flowering days of the genotypes was found to be 65.6-60.6 days (H194; P63MM54), the number of days to physiological maturity was 116.9-109.0 days (Tunca; P63MM54), plant height 172.0-143.3 cm (Tunca; H249), head diameter 18.8-15.9 cm (H250; P63MM64), thousandseed weight 43.4-54.2 g (H250; Gibraltar), hectoliter weight 32.3-30.3 kg (P63MM54; H194), seed moisture 7.1-8.4 % (H250; P63MM54, Gibraltar), seed yield 4.37-3.82 t ha-1 (H194; H249), oil rate 47.8-42.9 % (H250; H55), and oil yield 2.04-1.64 t ha- 1 (H250; H249). According to the averages of the locations, it can be argued that the H194, H250, H55, and H5 hybrids that have high seed and oil yield can be successfully grown in regional conditions. [ABSTRACT FROM AUTHOR]

Many of the current hybrids of sunflower are based on only one CMS source (i.e., PET-1) identified from Helianthus petiolaris, resulting in a crop with an extremely narrow genetic base. Therefore, the present study was conducted to evaluate different cytoplasmic combinations in sunflower hybrids using cytoplasmic male sterile (CMS) sources as female parents. There were 40 single cross hybrids produced by crossing among four diversified cytoplasmic male sterile lines from Helianthus argophyllus and H. annuus with ten restorer lines evaluated in kharif 2016 and rabi / summer 2016-17. For earliness hybrids ARG-2-1-2 x GKVK 2, ARG-2-1-2 x RHA 93 and MUT2-8-3-2 x M-17R can be exploited while for seed yield (kg/ha) hybrid MUT-2-8-3-2 x GKVK 3 exhibited significant positive standard heterosis followed by cross combination ARG-2-1-2 x LTRR-822. As sunflower is an oilseed crop high heterosis for oil content is desired, hybrid ARG-2-1-2 x RHA 6D-1 showed significant positive heterosis for this trait. There was considerable heterosis in desired direction for other phenological and agronomic traits too which indicated that highly heterotic crosses may be selected to expand yield potential and cytoplasmic base of the sunflower hybrids. [ABSTRACT FROM AUTHOR]

In south-east of Romania is present the most dangerous races of parasite Orobanche cumana and because of that, who want to cultivated sunflower hybrids, has low seed yield do to broomrape attack. In year 2019, in Braila area, in sunflower fields natural infested with the new races of broomrape from Romania, we tested many sunflower genotypes for resistance/tolerance to this parasite. We want to identifying sunflower genotypes who are resistant/tolerant to broomrape present in Brăila area and from 20 sunflower experimental hybrids tested in natural infested field in three epochs, no one was resistant at broomrape attack. The highest intensity of broomrape attack was in epoch I who was sowing on date May 3, 2019 and sunflower hybrid H2 has 520 broomrape\44 sunflower plants. The lowest intensity of broomrape attack was in epoch II who was sowing on date May 17, 2019 and sunflower hybrid H19 has 40 sunflower plants\13 broomrapes. Sunflower hybrid H17 has a better tolerance at broomrape then other 19 sunflower hybrids tested in field with natural infestation with parasite Orobanche cumana, from Brăila area, Romania where is present races G and H. Regarding plant height of sunflower hybrids tested, was between 90 cm (H10) and 135 cm (H6) in first epoch and between 145 cm (H2) and 200 cm (H9) in the second epoch. [ABSTRACT FROM AUTHOR]

Natural hybridization occurred frequently in the sunflower family. To date, however, no study on natural hybridization involving in Ligularia and Cremanthodium has been reported. Here, we presented the molecular evidence for natural hybridization between Ligularia nelumbifolia (Bureau & Franch.) Hand.-Mazz. and Cremanthodium stenoglossum Ling & S.W.Liu. Four nuclear DNA regions were sequenced to test the natural hybridization hypothesis, and three chloroplast DNA regions were sequenced to determine the direction of hybridization. Analyses of the investigated DNA data suggested that all of the putative hybrid individuals were derived from hybridization between L. nelumbifolia and C. stenoglossum and that bidirectional hybridization occurred. Moreover, sympatric Ligularia tsangchanensis (Franch.) Hand.-Mazz. and Ligularia virgaurea (Maxim.) Mattf. ex Rehder & Kobuski were not apparently involved in the hybridization. Although NewHybrids analysis showed that all the putative hybrid individuals were F1 class, a low frequency of backcrossing to C. stenoglossum might exist in the hybrid swarm. In such a case, hybrids might serve as a bridge facilitating gene flow between L. nelumbifolia and C. stenoglossum, and hybrid speciation is unlikely to happen for these hybrid individuals without asexual reproduction. Given the poorly resolved phylogenetic relationship between Ligularia and Cremanthodium, the occurrence of natural hybridization between L. nelumbifolia and C. stenoglossum might provide new insights into the recircumscription and redelimitation of these two genera. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) is known as one of the most important and preferred vegetable oil producing plants. In recent years, new cultivars with high oleic acid contents have been developed because of their health effects, extended frying and shelf life. On the other hand, nutrition of the plants is important for healthy growth, high yield, and oil quality and their nutrient needs may differ between the plant species and varieties. We aimed to determine the effects of increasing application doses of nitrogen (N) (0, 16, 32, 48, and 64 mg.kg-1 N) on growth and on some nutrient element uptake of four sunflower hybrids and compare the nutritional differences of linoleic (ESNovamis CL, and LG 5542 CL) and high-oleic (Oliva CL and ESGrafic CL) type sunflower hybrids in a greenhouse. The experiment was conducted in randomized factorial design with three replicates. Increasing doses of N effected the dry matter and nutrient uptake of sunflower hybrids significantly (p<0.01). Increasing doses of N elevated the dry weight, N, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and boron (B) uptake of all tested sunflower hybrids. The increases were found maximum at 32 mg.kg-1 N dose. Significant differences were also established between the hybrids. Among the tested hybrids, ESGrafic CL a high oleic type sunflower has higher nutrient uptake capacity so much more nutrients might be supplied to this new generation sunflower hybrids according to the soil and plant analysis results. [ABSTRACT FROM AUTHOR]

The wastewater treatment and sludge production sectors in Morocco are recent. Considered as waste, no management strategy for sewage sludge (SS) has been implemented. Thus, its disposal definitely represents a major environmental problem since sludge is either incinerated, used as landfill or simply deposited near wastewater treatment plants. The objective of this study was to determine the effects of dehydrated SS on certain soil properties (pH, electrical conductivity (EC), Mineral nitrogen, available phosphate P 2 O 5 , and soluble potassium K 2 O), and also on growth and yield components of the sunflower ( Helianthus annuus L.). An experiment was conducted using six treatment rates (0; 0 + NPK; 15; 30; 60 and 120 t ha −1 ). The results showed that soil pH was significantly affected by SS, becoming less alkaline compared to the control, while electrical conductivity increased significantly when the applied doses were above 30 t ha −1 . Also, a significant enrichment in mineral N and available phosphorus was detected in amended soil. However, no differences were found between pots having received the mineral fertilization and the SS at 15 t ha −1 . Stem height growth of the sunflower seedlings receiving SS increased significantly compared to the two controls. For both the aerial and root parts, significant increases in dry biomass accumulation were observed compared to the unamended plants. Net CO 2 assimilation (A n ) increased, while stomatal conductance (g sw ) and transpiration rates (T r ) decreased with increasing SS rates. SS application at 15 t ha −1 presented similar values of the yield components compared to plants fertilized chemically. However, grain yield (in quintals ha −1 ) was noted to be 2.4, 5 and 8 times higher in treatments receiving SS respectively at the rate of 30, 60 and 120 t ha −1 . [ABSTRACT FROM AUTHOR]

Cytoplasmic male sterility (CMS) systems represent ideal mutants to study the role of mitochondria in pollen development. In sunflower, CMS PET2 also has the potential to become an alternative CMS source for commercial sunflower hybrid breeding. CMS PET2 originates from an interspecific cross of H. petiolaris and H. annuus as CMS PET1, but results in a different CMS mechanism. Southern analyses revealed differences for atp6, atp9 and cob between CMS PET2, CMS PET1 and the male-fertile line HA89. A second identical copy of atp6 was present on an additional CMS PET2-specific fragment. In addition, the atp9 gene was duplicated. However, this duplication was followed by an insertion of 271 bp of unknown origin in the 5' coding region of the atp9 gene in CMS PET2, which led to the creation of two unique open reading frames orf288 and orf231. The first 53 bp of orf288 are identical to the 5' end of atp9. Orf231 consists apart from the first 3 bp, being part of the 271-bp-insertion, of the last 228 bp of atp9. These CMS PET2-specific orfs are co-transcribed. All 11 editing sites of the atp9 gene present in orf231 are fully edited. The anther-specific reduction of the co-transcript in fertility-restored hybrids supports the involvement in male-sterility based on CMS PET2. [ABSTRACT FROM AUTHOR]

Pakistan is facing a chronic deficiency of edible oil and imports around 75% of its edible oil from other countries which is a huge burden on our national economy. The situation thus requires for enhancing the indigenous oilseed production through different possible approaches. Development and promotion of local sunflower hybrids can be one of the options. Local sunflower hybrids with higher yield and wider adoptability can make Pakistan self sufficient in edible oil. Therefore a study was carried out at National Agricultural Research Centre Islamabad, to evaluate the performance of 12 locally developed sunflower Hybrids. Twelve sunflower hybrids including two checks viz., SMH 1006, SMH 0907, SMH 0932, SMH 1208, NKS-278, SMH 1001, SMH 0917, SMH 1401, Hysun-33, SMH 0927, SMH 0909 and SMH 1215 were studied in the experiment. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Data regarding Agronomic parameters was collected on days to flower initiation, days to flower completion, stem diameter, number of leaves per plant, plant height, head diameter, days to maturity, 100 seed weight, number of seeds per head and seed yield per hectare. Quality parameters were consisted upon oil content (%), protein content (%) and Fatty acid profile. Results showed that SMH-1001 and SMH-1215 hybrids performed best for yield and quality parameters, whereas, SMH-1006 and SMH-0909 were considered best for early maturing traits. [ABSTRACT FROM AUTHOR]

Key message: This study compares five models of GWAS, to show the added value of non-additive modeling of allelic effects to identify genomic regions controlling flowering time of sunflower hybrids. Abstract: Genome-wide association studies are a powerful and widely used tool to decipher the genetic control of complex traits. One of the main challenges for hybrid crops, such as maize or sunflower, is to model the hybrid vigor in the linear mixed models, considering the relatedness between individuals. Here, we compared two additive and three non-additive association models for their ability to identify genomic regions associated with flowering time in sunflower hybrids. A panel of 452 sunflower hybrids, corresponding to incomplete crossing between 36 male lines and 36 female lines, was phenotyped in five environments and genotyped for 2,204,423 SNPs. Intra-locus effects were estimated in multi-locus models to detect genomic regions associated with flowering time using the different models. Thirteen quantitative trait loci were identified in total, two with both model categories and one with only non-additive models. A quantitative trait loci on LG09, detected by both the additive and non-additive models, is located near a GAI homolog and is presented in detail. Overall, this study shows the added value of non-additive modeling of allelic effects for identifying genomic regions that control traits of interest and that could participate in the heterosis observed in hybrids. [ABSTRACT FROM AUTHOR]

In this paper, the behavior of 15 sunflower hybrids was observed at the attack of the main pathogens (Phomopsis helianthi, Sclerotinia sclerotiorum, Alternaria helianthi) on demonstrative plots set up at S.C. SPORT AGRA SRL in Amzacea, Constanta County, within the climate conditions of year 2018. The hybrids taken into account come from seed companies: Ciproma, Syngenta, Euralis, Limagrain and Pioneer. Sunflower culture technology was the same for all hybrids. Foliar treatments with Pictor 0.5 l/ha fungicide were performed against pathogens. Observations were performed between July and August 2018. Crop technology included preemergent herbicide Gardoprim Plus 3.5 l/ha and post-emergent herbicid, Listego PLUS 2 l/ha which limited the weed and Orobanche cumana attack. [ABSTRACT FROM AUTHOR]

Prediction of hybrid performance using incomplete factorial mating designs is widely used in breeding programs including different heterotic groups. Based on the general combining ability (GCA) of the parents, predictions are accurate only if the genetic variance resulting from the specific combining ability is small and both parents have phenotyped descendants. Genomic selection (GS) can predict performance using a model trained on both phenotyped and genotyped hybrids that do not necessarily include all hybrid parents. Therefore, GS could overcome the issue of unknown parent GCA. Here, we compared the accuracy of classical GCA-based and genomic predictions for oil content of sunflower seeds using several GS models. Our study involved 452 sunflower hybrids from an incomplete factorial design of 36 female and 36 male lines. Re-sequencing of parental lines allowed to identify 468,194 non-redundant SNPs and to infer the hybrid genotypes. Oil content was observed in a multi-environment trial (MET) over 3 years, leading to nine different environments. We compared GCA-based model to different GS models including female and male genomic kinships with the addition of the female-by-male interaction genomic kinship, the use of functional knowledge as SNPs in genes of oil metabolic pathways, and with epistasis modeling. When both parents have descendants in the training set, the predictive ability was high even for GCA-based prediction, with an average MET value of 0.782. GS performed slightly better (+0.2%). Neither the inclusion of the female-by-male interaction, nor functional knowledge of oil metabolism, nor epistasis modeling improved the GS accuracy. GS greatly improved predictive ability when one or both parents were untested in the training set, increasing GCA-based predictive ability by 10.4% from 0.575 to 0.635 in the MET. In this scenario, performing GS only considering SNPs in oil metabolic pathways did not improve whole genome GS prediction but increased GCA-based prediction ability by 6.4%. Our results show that GS is a major improvement to breeding efficiency compared to the classical GCA modeling when either one or both parents are not well-characterized. This finding could therefore accelerate breeding through reducing phenotyping efforts and more effectively targeting for the most promising crosses. [ABSTRACT FROM AUTHOR]

Nine CMS analogues from different cytoplasmic sources and their common maintainer were crossed with four perfect restorers from PET-1 source to develop of 40 sunflower hybrids. The experiment was conducted during spring season 2011 and 2012 two years continuously, under two different water environments, normal irrigated and water stress environment, where irrigation was stopped after the anthesis. The analysis of variance revealed significant differences among the sources for day to flowering, days to maturity and seed yield under both the environments, both the years and pooled over the years. The variance due to GCA and SCA showed that gene action was additive for maturity whereas, non-additive genetic effect was observed for days to flowering and seed yield under both the environments. The CMS analogues E002-91A (H. annuus), PKU-2A (H. annuus), and ARG-3A (H. argophyllus) were recorded as good combiner for early flowering in both the environments. The CMS analogs E002-91A and ARG-3A were observed good combiners for early flowering, early maturity and high seed yield, whereas, NC-41B from conventional CMS source H. petiolaris (PET-1) was recorded good combiner for late flower and early maturity and poor combiner for seed yield under both the environments. Among testers P69R was recorded good combiner for late flowering under normal water environment while, in water stress it was good combiner for early flowering but it was not good for seed yield. RCR-8297 was recorded for good combiner for late maturity and high seed yield under both the environments. The SCA estimates were highest in cross E002-91A× RCR-8297 and PKU-2A × P124R and ARG-6A × RCR-8297 for early flowering and early maturity under both the environments. These new cytoplasmic male sterility sources can be substitute of the classical (PET-1) source with added advantage for early maturing and high yielding. [ABSTRACT FROM AUTHOR]

Sunflower is an important oilseed crop, which shows susceptibility to heat stress. In this study, 63 single cross hybrids were evaluated under heat stress condition for 2 years and compared with the two commercial hybrids. Genotype and genotype × environment (GGE) was used to differentiate single cross hybrids on the basis of multiple traits. GGE biplot showed that several single cross hybrids had higher seed yield potential than standard check. Moreover, seed yield per plant (SYP) was related to pollen viability percentage, showing that achene yield was the product of high gametophytic fertility under heat stress. Hybrids having high seed yield potential under heat stress had lower cell membrane injury. GGE biplot for SYP and its components showed that single cross hybrids were characterized into two major groups. Group I was further characterized into two sub group. Group Ia included hybrids with high 100-SW, while group Ib had the hybrids with high number of seeds per head and head diameter. Group II had the hybrids with high kernel weight and kernel to seed ratio. The hybrids could be recommended according to their potential utilization in the seed industry. [ABSTRACT FROM AUTHOR]

High oleic hybrids of sunflower are widely cultivated around the world. The effect of temperature on oleic acid percentage of these hybrids is a concern, since oils with oleic acid percentage above a threshold receive a prime over the regular price. The objective of this work was to identify the main avenues for the genetic improvement of oleic acid percentage of high oleic hybrids of sunflower, both in current and future global warming scenarios. A data set obtained in a trial network allowed to explore the oleic acid percentage response to temperature of high oleic hybrids in the argentine sunflower growing region (between 29 and 38° LS, 46 trials in 15 locations during the period 2005/06–2012/2013). A similar data set was used to evaluate the variability in phenology. Mean values and stability across environments of oleic acid percentage differed among the studied high oleic hybrids. Differences in the parameter values of a sigmoid equation evidenced the variability in the response of oleic acid to temperature. Oleic acid percentage was simulated with a model that included this equation coupled to a phenology module, for different sowing dates and locations with contrasting temperature, under current conditions and a global warming scenario. It was possible to identify a low number of temperatures and field environments useful to reproduce the rankings of hybrids obtained with a wide range of temperatures. This information could be used to phenotype for high oleic percentage with a low number of experiments and reduce the efforts to identify better high oleic genotypes. Simulations show that the maximum oleic acid percentage is currently not attained in 50% of the studied hybrids in some sowing dates, even at the warmest locations, while in a future global warming scenario it would not be attained in 30% of the studied hybrids in the colder locations. Sensitivity analysis was performed for parameters of the sigmoid equation and the phenology module determining when the critical period for fatty acid composition occurs. In both in current and future scenarios, phenology parameters showed a null or low effect on oleic acid percentage. Two parameters of the sigmoid equation showed a significant impact, which differed between current and future scenarios. Simulations suggest that the stability of oleic acid percentage could still be a concern in the future. However, selecting for key parameter values for a given scenario could help to obtain better high oleic hybrids of sunflower. [ABSTRACT FROM AUTHOR]

Irrigation method has the potential to directly or indirectly influence populations of wild bee crop pollinators nesting and foraging in irrigated crop fields. The majority of wild bee species nest in the ground, and their nests may be susceptible to flooding. In addition, their pollination of crops can be influenced by nectar quality and quantity, which are related to water availability. To determine whether different irrigation methods affect crop pollinators, we compared the number of ground-nesting bees nesting and foraging in drip- and furrow-irrigated hybrid sunflower fields in the Sacramento Valley. We found that irrigation method did not impact wild bee nesting rates or foraging bee abundance or bee species richness. These findings suggest that changing from furrow irrigation to drip irrigation to conserve water likely will not alter hybrid sunflower crop pollination. [ABSTRACT FROM AUTHOR]

This study involved a set of 40 sunflower hybrids developed by crossing nine CMS analogues from different cytoplasmic sources and their maintainer (NC-41B) with 4 perfect restorers from PET-1 source. The analysis of variance revealed significant differences among the cytoplasmic sources for traits studied under both the environments, both the years and pooled over years. CMS ARG-3A (Helianthus argophyllus), DV-10A (H. debilis ssp. vestitus) and PRUN-29A (H. praecox ssp. runyonii) recorded significantly higher seed yield as well as oil content as compared to common maintainer NC-41B under both normal and stress environments respectively. DV-10A (H. debilis ssp. vestitus) had bigger head size in normal and higher 100 seed weight under stress environment as compared to NC-41B. Significant increase in seed yield and oil content for all CMS analogues as compared to conventional H. petirolasis source was observed which may be attributed to the effect of cytoplasmic genes or nuclear cytoplasmic interactions. CMS ARG-3A from H. argophyllus and CMS-XA (unknown source) may be designated as potential CMS sources for normal and water stress environments respectively. The CMS analogues E002-91A (H. annuus), ARG-3A (H. argophyllus) and ARG-6A (H. argophyllus) and tester RCR-8297 were recorded as very good combiners for seed yield under both the environments. CMS-XA × P124R, CMS-XA × P100R, PKU-2A × P124R, ARG-2A × P100R, ARG-3A × P124R, ARG-6A × P69R, DV-10A × P100R and PRUN-29A × RCR-8297 were identified with high SCA effects for seed yield per plant under both the environments. Non additive component of the genetic variance was observed for all the traits studied. [ABSTRACT FROM AUTHOR]

To know the genetic variations for some sunflower (Helianthus annuus L.) traits under the influence of three plant population (40000, 50000 and 60000 plants.ha-1 ) for tow varieties (oil and non-oil) of sunflower. The experiments were conducted during spring and fall seasons of 2013, using factorial experiment within RCBD. The plant spaces between the furrows 90 cm and within furrows 27.8, 22.2 and 18.5 cm, which variable due to plant population. The field was fertilized using compound fertilizer (18% N: 18% P2O5) and urea (46%N)at 350 kg. ha-1 . The results revealed that there are genotypic and phenotypic homogeneity in both varieties, according to the lowest S ̅, CV, GCV and PCV for most of studied traits. The broad sense heritability values (83-98%) and the 60000 plant population in fall season for most of traits that cause to increase genetic gain (16-42%). It was concluded that number of seeds.head -1 and seeds weight can be used as selection index to improve both varieties. [ABSTRACT FROM AUTHOR]

During invasion, colonizing species can hybridize with native species, potentially swamping out native genomes. However, theory predicts that introgression will often be biased into the invading species. Thus, empirical estimates of gene flow between native and invasive species are important to quantify the actual threat of hybridization with invasive species. One classic example of introgression occurs in California, where Helianthus bolanderi was thought to be a hybrid between the serpentine endemic Helianthus exilis and the congeneric invader Helianthus annuus. We used genotyping by sequencing to look for signals of introgression and population structure. We find that H. bolanderi and H. exilis form one genetic clade, with weak population structure that is associated with geographic location rather than soil composition and likely represent a single species, not two. Additionally, while our results confirmed early molecular analysis and failed to support the hybrid origin of H. bolanderi, we did find evidence for introgression mainly into the invader H. annuus, as predicted by theory. [ABSTRACT FROM AUTHOR]

The application of biological active preparations (BAPs) and remote-sensing control in the management of agronomic intervention are an important part of successful crop cultivation. The effects of foliar application of two BAPs (containing amino acids or Abiestins®) on yield and yield-forming, as well eco-physiological traits calculated from infrared thermographs data (crop water stress index, CWSI and index of stomatal conductance, Ig) of three hybrids of sunflower were studied in field poly-factorial experiments, realised during two years (2012 and 2013). The results showed that the application of selected BAPs has contributed to an increase of the sunflower yield, in particular through an increase in the weight of thousand seeds ( rp = 0.761, P < 0.001). Similarly, oil content in achenes was significantly higher in treatments with BAPs, mainly with preparation containing free amino acids. The study describes the quantitative relationship between yield and quality of sunflower production ( rp = −0.41, P < 0.01). Selected hybrids of sunflower in two growth stages showed the significant differences in CWSI and Ig (both at P < 0.01), respectively. An analysis of negative linear relation between the yield of achenes and CWSI ( rp = −0.654, P < 0.001) confirmed that higher value of plant stress resulted in a smaller yield and vice-versa. The opposite trend was observed between yield and Ig index ( rp = 0.576, P < 0.001). The data obtained from IR thermography can be used for monitoring the physiological health of sunflower plants, as well in potential prediction and control of yield. [ABSTRACT FROM AUTHOR]

Sunflower occupies main position among oil seed crops in Pakistan. Mostly indigenous sunflower hybrids are cultivated which give low achene and fodder yields. The issue related with these hybrids ascribed to lack of information about use of inputs and cultural practices. Judicious nitrogen use and suitable high yielding hybrid play key role in increasing sunflower productivity. Protein is the basic requirement of the metabolic processes for the vegetative, reproductive growth and yield of the crop. The protein is wholly dependent upon the amount of nitrogen fertilization available in soil for the plant use. A two year study was conducted in 2012 and 2013 at National Agricultural Research Centre (NARC), Islamabad, Pakistan. The experiment was aimed to evaluate the effect of different nitrogen (N) levels (N0 = 0 kgha-1, N1 = 60 kgha-1, N2 = 0 1 2 80 kgha-1, N3 = 120 kgha-1, N4 = 180 kgha-1 and N5 = 240 kgha-1) on two sunflower 3 4 5 hybrids, SMH-0907 and SMH-0917 to optimize the N levels for obtaining maximum yield on sustainable basis. Both hybrids were kept in the main plot while N levels in the sub plot in a randomized complete block design with three replications. The results showed that the number of achene head-1, 100-achene weight and achene yield increased with increased N application. The increased levels of N also enhanced the achene yield. The maximum achene yield (3170.8 kg ha-1) was recorded at 180 kg N ha-1 followed by 240 kg N ha-1. Minimum achene yield (2115 kg ha-1) was observed in control treatment (N ). Polynomial regression line showed 0 that the rate of yield increase was higher up to 180 kg N ha-1 and become slow thereafter. The hybrid SMH-0907 produced more achene (2736 kg ha-1) as compared to the hybrid SMH-0917 (2694 kg ha-1). Results revealed that economized application of different doses of N can boost up the yield in both sunflower hybrids SMH-0907 and SMH-0917. These findings could be helpful in rationalizing most valuable inputs such as nitrogen in sunflower crop. It can be deduced that the application of 180 kg N ha-1 can provide the best combination for good yield in sunflower crop under the prevailing humid conditions of Pakistan. [ABSTRACT FROM AUTHOR]

The aim of this research was to investigate the effect of stand density on seed yield and protein content in sunflower hybrids. The field experiment was carried out at Rimski Šanèevi location. Six NS sunflower hybrids were examined. Five hybrids are confectionery (NS Goliat, NS Slatki, NS Gricko, Vranac and Cepko), and one is used for bird food (NS-H-6485). The trial was arranged as randomized complete block design (RCBD) with four replications. Sowing was done with six different densities (from 20,000 to 70,000 plants per hectare, with an increment of 10,000 plants per hectare). Analysis of variance (ANOVA) showed that the effect of hybrid, stand density and hybrid × stand density interaction were highly significant for seed yield and protein content. The highest seed yield, on the basis of average for all densities, was found in NS-H-6485 (4.77 t ha-1) and in NS Gricko (4.43 t ha-1). Average seed yield of hybrids significantly increased up to 50,000 plants per ha-1, when it reached the value of 4.50 t ha-1, and then decreased. Significantly higher protein content, taking into account all stand densities, showed hybrid Cepko (16.94%). Protein content, above the overall average value, was achieved in hybrid Vranac (16.11%). The highest protein content in the average for all six hybrids was at the lowest stand density (20,000 plants per ha-1), and then decreased up to higher densities. The results showed that stand density had significant effect on seed yield and protein content in sunflower hybrids. [ABSTRACT FROM AUTHOR]

Evaluation and characterization of sunflower hybrids using morphological, physiological and biochemical data are necessary and essential in sunflower breeding programs. The aim of this paper was to evaluate the productive possibilities of some sunflower hybrids grown in Macedonian environmental conditions. The experiment was carried out during the period 2013 and 2014 on the research field of the Faculty of Agriculture, 'Goce Delchev' University - Shtip, in Ovche Pole locality, Republic of Macedonia. Total 20 sunflower hybrids were used as an experimental material. The trial was arranged as randomized complete block design (RCBD) with three replications. The average content of oil and oleic acid were 45.6 and 65.2%, respectively. The highest seed yield from all sunflower hybrids was obtained for the hybrid NLK12M144 (3,344 kg ha-1) and the lowest for hybrid NLK12S126 (2,244 kg ha-1). Cluster analysis classified the sunflower hybrids into four groups based on agronomic traits and seed yield. Most of the hybrids were included in cluster I and III (7 hybrids) followed by cluster IV. Using principal component analysis two main components have been extracted, with eigenvalue greater than one. They account for 72.99% of the variability in the original data. Only four hybrids had positive values for both main components (NLK12M144, NLK12S070, NLK12S125 and NLN12N011 DMR). The results from this study can be used to identify the best sunflower hybrids grown under Macedonian environmental conditions and to select the superior hybrids for future exploitation. [ABSTRACT FROM AUTHOR]

In breeding process it is important to know the extent of association between the traits that affect the yield. Objective of this study was to determine genotypic and phenotypic correlation and path coefficients in 50 sunflower hybrid combinations in order to identify research priorities in sunflower breeding. Relationships between seed yield and five bio-morphological traits in sunflower (oil content, protein content, 1,000-seed weight, head diameter and plant height) were studied. Head diameter had the highest correlation coefficient with seed yield, at phenotypic and genotypic level. Path analysis revealed that all evaluated traits had positive influence on seed yield at both, genotypic and phenotypic, levels. The highest direct effect on seed yield was found for head diameter, while protein content had the lowest direct effect on seed yield. Study has shown that the greatest improvement in sunflower seed yield can be achieved through selection on head diameter. [ABSTRACT FROM AUTHOR]

The present study was under taken to examine the modic effects of salicylic acid and ascorbic acid on mineral elements and leaf proline contents of two drought stressed sunflower hybrids (Hysun-33 and Hysun-38). Drought stress was imposed at vegetative and reproductive growth stages. Two concentrations of salicylic acid and ascorbic acid (100 and 200 mg L-1) were applied as a foliar spray at vegetative and reproductive stages and root treatment. Results revealed that imposition of drought stress at both the growth stages of both hybrids caused significant reduction for shoot nitrogen, potassium and calcium contents, whereas non significant reduction for phosphorous contents was noted. However, in contrast significant increase was noted for proline contents. However, exogenous application of all the (0, 100 mgL-1 and 200 mgL-1) concentrations of salicylic acid and ascorbic acid applied by either mode had a significant drought stress alleviative effects and increased the values of all the attributes, whereas, non significant increase was noted for phosphorus contents. Effect of foliar spray application was significantly higher for calcium and leaf proline than root treatment. Salicylic acid proved more effective than ascorbic acid, particularly, when applied at vegetative stage. Most effective concentration was 200 mg L-1 and maximum increase was recorded in Hysun-33. [ABSTRACT FROM AUTHOR]

The most important criteria for introducing new confectionary hybrids into the production is high protein yield. Path coefficient analysis was used to obtain information on direct and indirect effects of studied traits (seed oil content, kernel oil content, seed yield, kernel protein content, mass of 1000 seeds, kernel ratio and hull ratio) on protein yield. The research was conducted during three vegetation seasons, on 22 experimental confectionary sunflower hybrids created in the breeding program at the Institute of Field and Vegetable Crops. Strong and very strong correlations were found among the largest number of examined traits. A weak negative interdependence was determined between kernel oil content, kernel protein content, mass of 1000 seeds, hull ratio, and protein yield using the analysis of simple correlation coefficients. Positive but weak correlation was determined between protein yield and seed oil content, and kernel ratio. Very strong positive correlation was determined between protein yield and seed yield (0.468**). The seed oil content had a very strong direct negative effect on protein yield (DE=-0.734**). The mass of 1000 seeds had a weak negative direct effect on protein yield. Kernel protein content and kernel oil content demonstrated a weak direct positive effect on protein yield. Path coefficient analysis of protein yield showed a very strong positive direct effect of kernel ratio (DE=1.340**), seed yield (DE=0.657**) and hull ratio (DE=0.992*). These findings confirm the effect of seed yield, kernel ratio, and hull ratio on protein yield, and their importance as the selection criteria in confectionary sunflower breeding. [ABSTRACT FROM AUTHOR]

Three block design field experiments were carried out in the period 2012 - 2015, following the same methods, on three different sites in the country, which differ significantly in the spectrum of the available weeds. The subject of the experiments was the improved version of the Clearfield Plus technology. In all the three years the sunflower hybrid ES Candimis CL Plus was planted on the three sites. The major aim of the experiments on the three sites was to establish the selectivity for sunflower and the efficacy of Pulsar 40 (40 g/l imazamox) against almost all the economically important weeds in that crop. The reported phytotoxicity caused to sunflower on the three sites in the three years was expressed in a slight discoloration of the treated sunflower plants, which was totally overcome between the 14th and 20th day. The results of the experiments show that the greatest differences in the efficacy of Pulsar 40 were reported about its activity against perennial weed species. When Pulsar 40 was applied separately without DASH, its efficacy against Johnson grass, corn thistle, field bindweed, hemp agrimony, rough cocklebur, white goosefoot, purslane and broomrape was significantly reduced. Referring to its efficacy against the annual broad-leaved weed species redroot pigweed, charlock mustard, wild radish, clea-vers, black nightshade, etc., it was 100% and no differences were observed between the rates of 80, 100 and 125 ml/da. The separate use of the herbicide at a rate of 125 ml/da shows the same efficacy against more stubborn weeds, as that of Pulsar applied at the rate of 80 ml/da together with 80 ml/da of the adjuvant DASH. [ABSTRACT FROM AUTHOR]

The wild North American sunflowers Helianthus annuus and H. debilis are participants in one of the earliest identified examples of adaptive trait introgression, and the exchange is hypothesized to have triggered a range expansion in H. annuus. However, the genetic basis of the adaptive exchange has not been examined. Here, we combine quantitative trait locus ( QTL) mapping with field measurements of fitness to identify candidate H. debilis QTL alleles likely to have introgressed into H. annuus to form the natural hybrid lineage H. a. texanus. Two 500-individual BC1 mapping populations were grown in central Texas, genotyped for 384 single nucleotide polymorphism ( SNP) markers and then phenotyped in the field for two fitness and 22 herbivore resistance, ecophysiological, phenological and architectural traits. We identified a total of 110 QTL, including at least one QTL for 22 of the 24 traits. Over 75% of traits exhibited at least one H. debilis QTL allele that would shift the trait in the direction of the wild hybrid H. a. texanus. We identified three chromosomal regions where H. debilis alleles increased both female and male components of fitness; these regions are expected to be strongly favoured in the wild. QTL for a number of other ecophysiological, phenological and architectural traits colocalized with these three regions and are candidates for the actual traits driving adaptive shifts. G × E interactions played a modest role, with 17% of the QTL showing potentially divergent phenotypic effects between the two field sites. The candidate adaptive chromosomal regions identified here serve as explicit hypotheses for how the genetic architecture of the hybrid lineage came into existence. [ABSTRACT FROM AUTHOR]

The purpose of the work was to research various systems of bee families placement at the sunflower pollination, to distinguish the advantages of this crop conducted pollination, with the help of the bees and to develop some streamline suggestions to increase the amount of seed production.It was conducted an experiment to test three systems (scheme) of bee families exploitation at the pollination of early hybrid sunflower "El Passo 199" on three agricultural land of 30 hectares each, which were placed at a distance of over 600 - 1000 m from each other. The load of bee families at the pollination was 1 ha per each family. In the first scheme (batch I, witness) – the hives with bee families were placed traditionally in a hearth, at one side (edge) of the field with blooming plants. In the second scheme (batch II) – the bee hives were placed in two hearths at the two opposite sides of the field. In the third scheme (batch III) – the bee hives were placed in four hearths, proportionally at the four sides of the field.The research results have shown that the bee hives placement at the sunflower pollination, proportionally at those 4 symmetrically opposite sides of the field, provides a significant increase of bee visits to the flowers, compared to the witness batch – with 1.4 bees/ 5 min, or 82.5 % (td = 14.2; P < 0.001) and, compared to batch II – with 0.4 bees/ 5 min, or 14.8 % (td = 2.8; P < 0.01). By the total pollen amount collected in the nest daily, on average, bee families from batch II exceeded their fellows of witness batch with 25 g/day, or 16.8 % (td = 4.3; P < 0.001), and those of batch III exceeded their fellows of batch I - with 46 g, or 30.9 % (td = 5.9; P < 0.001). By flight intensity, the bees without pollen balls of batch III exceeded their fellows of witness batch with 46 bees/10 min, or 9.5 % (td = 2.1; P < 0.05), and those with pollen balls – with 35 bees/10 min, or 17.8 % (td = 3.1; P < 0.01). The seeds fertilization degree, in case of isolated pollination was very low, and was 13.1 – 15.8 %. In case of free pollination (entomophilous), contrary, the most sun flower inflorescence seeds were fertile (full), The number of fertile seeds, in this case, exceeded 5.7 – 7.2 times compared to the isolated pollination (P < 0.001). The seeds pollination degree, in case of free pollination, was 88.6 – 92.1 %. The seeds pollination degree from batch III, was higher, compared with witness batch– with 3.5 percentual units, or 4.0 % (td = 2.6; P < 0.01). The total weight of harvested seeds, on average, at one sun flower inflorescence, in case of entomophilous pollination, exceeds compared to the isolated pollination, in all batches and examined sectors 1.8 – 2.2 times more (P<0.001), and by fertile seed weight–2.3 – 2.6 times (P < 0.001). By the quantity (weight) of fertile (full) seed production, sun flower inflorescences of batch II exceeded their fellows of batch I with 11.9 g, or 18.5 % (td = 5.6; P < 0.001), and the sun flower inflorescences of batch III exceeded their fellows of batch I with 16.1 g, or 23.8 % (td = 6.7; P < 0.001). From the obtained information, were deduced the conclusions that the conducted pollination of early sunflower hybrid El Passo-199 with the help of the bees, provides, compared to the isolated pollination, an increase of seeds fertilization degree and of the seed production weight with 2.3 – 2.6 times. The proportional placement of the bee hives at the pollination, as close to the picking source, at the four opposite sides of the sunflower field, contributes to a significant increase of the bees visits frequency to the flowers – with 82.5 %, of the flight intensity of the bees without pollen balls – with 9.5% and of those with pollen balls – with 17.8 %, of the collected pollen amount – with 39.6 %, of the seeds fertilization degree – with 4. 0%, and of the seeds production – with 23.8%. [ABSTRACT FROM AUTHOR]

Phenolic compounds such as polyphenols, tannins and flavonoids as well as antioxidant activity, play an important role in the plant defense mechanisms. The above mentioned parameters were measured in four sunflower hybrids (NORH-34, HOB-2, IMI-3-911 and NS-H-111) inoculated with broomrape (sunflower root parasitic plant). The synthesis and accumulation of these compounds depended on genotype and broomrape inoculation. Total phenolic content in healthy sunflower root tissue ranged from 2.87 up to 10.53 mg, while in infected root tissue this parameter ranged from 6.06 to 12.66 mg gallic acid equivalents/g dry root weight. Total tannins content in healthy root ranged from 2.01 to 6.74 and in infected root from 4.30 to 8.17 mg gallic acid equivalents/g dry root weight. Total flavonoids in healthy root tissue were within the range 3.36-44.94 and in infected root tissue 35.35-83.89 mg of rutin equivalents/g dry root weight. Antioxidant activity in sunflower roots correlated with the total phenolic and total tannins and flavonoids content. [ABSTRACT FROM AUTHOR]

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Potassium (K) nutrition ensures optimum yield and quality of crops. This polyethylene bag study was conducted to evaluate the impacts of varying levels of K on the growth, yield and K accumulation of two sunflower hybrids. The experiment was conducted in a two factor randomized complete block design with three replications. Two sunflower hybrids (Hyson-33 and Hyson-39) were grown in main plots on five different rates of K (0, 30 through 120 kg ha-1). The soil of the experimental soil was a non-saline and alkaline heavy clay texture, low in organic matter but sufficient in K. It was observed that K application did not affect plant height (cm) of sunflower hybrids across genotypes, it significantly enhanced plant weight (g) (207%), number of leaves plant-1 (101%), stem diameter (mm) (207%), head diameter (mm) (215%), head length (cm) (150%), achene yield (g) (100%) and K accumulation (216%) at 120 kg K ha-1, as against its control (0 kg K ha-1). Across K application rates, sunflower hybrids significantly varied from each other for their different traits. As compared to Hyson-33, Hyson-39 had more plant weight 207%), number of leaves (96%), stem diameter (206%), head diameter (215%), head length (248%), and seed yield (110%). Contrarily, Hyson-33 accumulated more K (22%) than Hyson-39. Sunflower genotypes behaved differently at different K rates for their various traits, except for number of leaves and stem diameter. Biomass yield, head diameter, head length, head weight and seed yield were lowest in case of Hyson-33 at 0 kg K ha-1 while highest in case of Hyson-39 at 120 kg K ha-1. Moreover, K accumulation was lowest at 0 kg K ha-1 and highest at 120 kg K ha-1, in case of Hyson-39. This study concluded that the hybrid sunflower Hyson 39 should be cultivated with K application at 120 kg ha-1. [ABSTRACT FROM AUTHOR]

Seven cytoplasmic male sterile lines were crossed with six restorers in line x tester fashion to estimate the heterosis for seed yield and its component traits in sunflower. The result revealed that seed yield and its components showed highly significant differences for all the traits. The extent of heterosis in 42 hybrids over better parent (BP) ranged from 6.15 to 317.28% for seed yield and from -11.42 to 10.18% for oil content. The superiority of hybrids over standard check (PAC-1091) ranged from -58.41 to 24.63% and from -5.92 to 14.88% for seed yield and oil content respectively. The hybrids CMS 234A x RHA-6D-1R, CMS 852A x RHA-6D-1R and ARM 243A x 3376R were the best for seed yield, oil content and yield characters. These hybrids may be exploited for heterosis breeding and need to be screened for yield stability. [ABSTRACT FROM AUTHOR]

Hybrid sterility is an important species barrier, especially in plants where hybrids can often form between divergent taxa. Here we explore how life history affects the acquisition of hybrid sterility in two groups in the sunflower family. We analyzed genetic distance and F1 pollen sterility for interspecific crosses in annual and perennial groups. We find that reproductive isolation is acquired in a steady manner and that annual species acquire hybrid sterility barriers faster than perennial species. Potential causes of the observed sterility pattern are discussed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 F 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 F 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. [ABSTRACT FROM AUTHOR]

Heterosis is a main force leading the development of the hybrid seed industry in sunflower. The purpose of this study is to evaluate if heterosis effects for morphological traits among sunflower hybrids can be related to differences in the repetitive component of the genome of parental lines. The assumption is that, at least for certain traits, heterosis results from mutations in the cis-regulatory elements of genes, largely related to retrotransposon insertions and/or removals. Our experimental approach consists of a correlation study between hybrid performance and retrotransposon-related genetic distances between inbreds. Six sunflower inbred lines of different origin were crossed in a half diallel fashion; comparing parental lines and hybrids, mid parent heterosis of F hybrids was evaluated for six traits. We estimated the parental genetic distances between the six inbreds on data gathered by the inter-retrotransposon-amplified-polymorphism (IRAP) protocol. Different retrotransposons previously isolated in sunflower were targeted by 11 primer pairs designed on conserved LTR domains. As a control, genetic distances were also calculated using 86 genic SNPs. We analysed the correlation between the mid-parent heterosis for each of the six traits analysed and the genetic distance (calculated on data obtained by SNP or IRAP analyses) between the parental lines. Differences between parents showed to be largely related to variations in the retrotransposon component of the genome. Retrotransposon-related genetic distance between parents resulted to be larger than that related to genic SNPs, and significantly correlated to seed yield and, at a lesser extent, to plant height and stem diameter in hybrids. The hypothesis that variations in the repetitive component of the genome, especially LTR-retrotransposons, affect the displaying of heterosis is discussed. [ABSTRACT FROM AUTHOR]

This investigation was directed to sunflower improvement using hybrid forms resulted from wide hybridization. The aim was to create new B/A and R lines from interspecific and intergeneric hybrids resistant to diseases, parasite broomrape, herbicides, other stress factors and with high combining ability in highly productive oil-type sunflower hybrids with varied fatty acid contents. The confectionary hybrids should have a high kernel protein content and amino acid content. The investigation was carried out during the period 1983-2010. The programme included 16 cultivars and 18 B lines with their analogues. Interspecific, intraspecific, and intergeneric hybridization produced hybrid materials originating from 38 Helianthus species with different ploidy levels, 9 annuals and 29 perennials, and 28 species from other genera of family Compositae. New sunflower forms and lines created possessed resistance to downy mildew, Phomopsis, Phoma and Alternaria, tolerance to Sclerotinia and total resistance to the different races of parasitic broomrape. The new forms had distinctive plant architecture, different vegetation periods, and seeds of different sizes and coloration. New B/A and R lines, characterized with high combining ability, seed oil, and fatty acid content and varying protein amino acid contents were obtained. Fifteen sources of cytoplasmic male sterility ( cms) were obtained from interspecific hybrids and 271 sources of fertility restoration ( Rf) genes from interspecific and intergeneric hybrids. Five new oil type hybrids and one confectionery type were developed and registered. The results from this investigations showed that by wide hybridization new genetic material can be transferred to the cultivated sunflower. These results supplemented the contribution of interspecific and intergeneric hybridization for sunflower breeding. [ABSTRACT FROM AUTHOR]

Extension of areas cultivated with sunflower within our country during the last decade to over 800 ths. Ha and up to over 1 million Ha in 1999, as consequence of the high demand on the internal and external market, is representing a real danger. This is due to the fact that the 6-7 years return period for the same lot can no more be observed. Such a return period is required due to the continuance in the soil of the several pathogen agents as Plasmopara helianthi Novot, Sclerotinia sclerotiorum (Lib) de Bary, Sclerotinia bataticola Taub. Research has been performed on a brown luvic soil. The precursory culture has been wheat. The experiments have been tri-factorial, factor A has been the cultivated hybrid (a1 -- RP64F50 --; a2 PR64A89, factor B -- the agricultural fond (b1 -- N50P100K100; b2 -- N100P100K100), and factor C cultivation density (c1 -- 45.000 plants/ha; c2-50.000 plants/ha). Experiences have been performed during the experimental cycle 2010-2012. The studied hybrids have genetic strength to blight attacks (Plasmopara helianthi), species 304, already existing in our country. These hybrids are tolerant to Phomopsis and Sclerotinia, resistant to fall and breakage, resistant to dryness and heat, highly productive and having high content of oil. The crop results are revealing the superiority of PR64A89 hybrid that has overcome by 9% the crop of PR64F50.n Increasing of nitrogen dose from N50 to N100 on the constant usage of P100K100 has increased the crop by 14%. Increasing the density from 45,000 to 50,000 plants/ha has lead to crop decreasing by 12%. Thousand seeds mass has been negatively influenced by increasing the density, on both fertilization levels, on both hybrids, oscillating between 58 and 61 g. at PR64F50 hybrid and between 60 and 65 g to PR64SA89 hybrid. A similar tendency has been manifested and the hectoliter mass has been situated between 43 - 45 kg/hl at PR64F50 and between 38-43 kg/hl at PR64A89. The content of oil in PR64F50 hybrid has decreased following the doubling of nitrogen dose from 45 to 42% and to PR64A89 46-44 %. [ABSTRACT FROM AUTHOR]

The genomics of local adaptation is an increasingly active field, providing insights into the forces driving ecological speciation and the repeatability of evolution. Demography and gene flow play an important role in determining the paths by which parallel evolution occurs and the genomic signatures of adaptation. In the annual sunflowers, hybridization between species has repeatedly led to the colonization of extreme habitats, such as sand dunes. In a new case of adaptation to sand dunes that occurs in populations of H. petiolaris growing at Great Sand Dunes National Park and Preserve (Colorado), we wished to determine the age and long-term migration patterns of the system, as well as its ancestry. We addressed these questions with restriction-associated DNA ( RAD) sequence data, aligned to a reference transcriptome. In an isolation with migration model using RAD sequences, coalescent analysis showed that the dune ecotype originated since the last ice age, which is very recent compared with the hybrid dune species, H. anomalus. Large effective population sizes and substantial numbers of gene migrants per generation between dune and nondune ecotypes explained the highly heterogeneous divergence observed among loci. Analysis of RAD-derived SNPs identified heterogeneous divergence between the dune and nondune ecotypes, as well as identifying its nearest relative. Our results did not support the hypothesis that the dune ecotype has hybrid ancestry, suggesting that adaptation of sunflowers to dunes has occurred by multiple mechanisms. The ancestry and long-term history of gene flow between incipient sunflower species provides valuable context for our understanding of ecological speciation and parallel adaptation. [ABSTRACT FROM AUTHOR]

Hybridization and abiotic stress are natural agents hypothesized to influence activation and proliferation of transposable elements in wild populations. In this report, we examine the effects of these agents on expression dynamics of both quiescent and transcriptionally active sublineages of long terminal repeat (LTR) retrotransposons in wild sunflower species with a notable history of transposable element proliferation. For annual sunflower species Helianthus annuus and H. petiolaris, neither early generation hybridization nor abiotic stress, alone or in combination, induced transcriptional activation of quiescent sublineages of LTR retrotransposons. These treatments also failed to further induce expression of sublineages that are transcriptionally active; instead, expression of active sublineages in F1 and backcross hybrids was nondistinguishable from, or intermediate relative to, parental lines, and abiotic stress generally decreased normalized expression relative to controls. In contrast to findings for early generation hybridization between H. annuus and H. petiolaris, ancient sunflower hybrid species derived from these same two species and which have undergone massive proliferation events of LTR retrotransposons display 2× to 6× higher expression levels of transcriptionally active sublineages relative to parental sunflower species H. annuus and H. petiolaris. Implications and possible explanations for these findings are discussed. [ABSTRACT FROM AUTHOR]

Interspecific hybridization is frequently restricted by genetic cross incompatibilities, genetic distances and different ploidy levels. To overcome this incompatibility a direct organogenesis method has been used successfully. Different molecular methods have been used for verification of success interspecific and intergeneric crosses. It could be demonstrated by results of RAPD fingerprinting that interspecific hybridization is also a valuable tool for broadening genetic variability in sunflower. The successful hybridization between ( H. annuus (cv. Albena) × H. salisifolius) was achieved. In total 21 RAPD primers (10 bp) length were used for the characterization of interspecific progenies. We were able to demonstrate that RAPD could be used for characterization of interspecific progenies in sunflower at a late stage of selection (F9). It was possible to discriminate between the H. annuus parents and their progenies, where an increased genetic variability was detected. Results of UPGMA cluster analysis confirmed the hybrid nature of the interspecific lines and showed that hybrid progenies which originate in the same cross combination formed specific cluster each, i.e., distinct genetic pools. [ABSTRACT FROM AUTHOR]

Abstract: The response of the imazamox resistant and susceptible sunflower hybrids Rimi and S to imazamox and of tribenuron-methyl resistant and susceptible hybrids Rsu and S to tribenuron-methyl was investigated both in a whole-plant bioassay and in field experiments. Plants were treated post-emergence with imazamox/tribenuron-methyl at four true leaves (grown in pots) and at four–six true leaves (grown in field). Visual injury estimation and vegetative parameters (plant height, fresh weight, dry weight, leaf area) were recorded. ALS (acetolactate synthase) enzyme activity in different herbicide concentrations was determined in vitro. Pronounced differences were noted between Rimi and S hybrids and between Rsu and S hybrids in the vegetative parameters and ALS activity. Namely, Rimi hybrid was 9–64-fold more resistant than S for vegetative parameters and about 3000-fold for ALS activity, while Rsu hybrid was 14–56-fold more resistant than S for vegetative parameters, and about 2600-fold for ALS activity. [Copyright &y& Elsevier]

Sunflower rust, caused by the fungus Puccinia helianthi Schwein., was not a serious problem for many decades because of successful deployment of effective resistance genes in commercial sunflower ( Helianthus annuus L.) hybrids in North America. In the 1980s and early 1990s, however, a shift in virulence of the rust race population in North America rendered most of the commercial hybrids susceptible to new virulent races. A germplasm line, HA-R2, carrying the rust resistance gene R was released as a multi-race rust-resistant line in 1985 but has not been widely used in commercial hybrid production. R remains effective against the prevalent rust races of sunflower in North America. This gene was previously reported to be associated with two simple sequence repeat (SSR) markers, ORS316 and ORS630, which were mapped to linkage group (LG) 13 of sunflower. However, out of the 63 markers of LG13 screened in the present study, only 18, including ORS316 and ORS630, were polymorphic. These markers, which covered all of LG 13, were assayed in 94 individual F2 progenies derived from the cross of HA 89 with HA-R2. All failed to detect any locus in LG13 associated with the gene R . Subsequently, a bulked segregant analysis was employed with an additional 510 SSR markers selected from the remaining 16 LGs of the sunflower genome. This analysis demonstrated that the LG2 markers showed association with rust resistance . Genotyping of the 94 F2 individuals with 23 polymorphic SSR markers from LG2 confirmed the R location on LG2, flanked by two SSR markers, ORS1197-2 and ORS653a, at 3.3 and 1.8 cM of genetic distance, respectively. The markers for R developed in this study will provide a useful tool for speeding up deployment of the R gene in commercial sunflower hybrid production. [ABSTRACT FROM AUTHOR]

Hybrid species provide a unique opportunity to examine trait evolution. We previously demonstrated that the hybrid species Helianthus anomalus is more fit than its ancestral parents, Helianthus annuus and Helianthus petiolaris, in its habitat and hypothesized that nutrient limitations have been a major selective agent in that adaptive evolution. In this glasshouse study, we asked whether H. anomalus has more conservative growth and resource use traits than its ancestral parents, as expected for low-nutrient-adapted species. Helianthus anomalus had a lower maximum relative growth rate, leaf area ratio, and specific leaf area as well as less of a decrease in relative growth rate with nitrogen limitation than its ancestral parents. Helianthus anomalus also had higher nitrogen use efficiency, largely because of a longer mean residence time, as well as greater leaf toughness and longer leaf life span. However, H. anomalus did not have a lower photosynthetic rate, higher ratio of fine root length to leaf area, or higher nitrogen resorption before leaf senescence. Thus, H. anomalus has acquired several conservative growth and resource use traits consistent with low nutrients as a selective agent during speciation and adaptation, but this leaves open the question of which growth and resource use components are the actual targets of selection. [ABSTRACT FROM AUTHOR]

The article discusses the ecological importance of gene flow from transgenic crops. It mentions the empirical research which shows that wild plants can benefit from a bacterial transgene undercaged, natural conditions. It examines the crop-developed Bacillus thuringiensis (Bt) transgene in a backcrossed wild sunflower populations.

Sunflower (Helianthus annuus L.) is economically one of the most important annual crops in the world grown for edible oil and for bio-energy purposes. Due to the high cost and the environmental concern, fertilization is among the agronomic inputs that ought to be reconsidered and further studied. The objectives of the present study were to evaluate the growth and productivity of three sunflower hybrids under several fertilization regimes. The experiment was conducted in Agricultural University of Athens according to the split-split plot design (randomized complete block) with three replicates, three main plots (inorganic, organic and untreated) and three subplots (sunflower hybrids: Neoma, P64HE39, P64LL62). Several growth and yield parameters were measured. The results indicated that Neoma was the most productive hybrid and the one which reacted better in terms of its vegetative growth in the incorporation of the organic compost. Organic fertilization had a significantly positive effect on yield and seed number of P64HE39 and P64LL62. Conclusively, organic fertilization of sunflower hybrids can result to high yields and it can be suggested as a successful practice to sunflower growers as long as the interactions between fertilization regime and hybrid are going to be taken into account. [ABSTRACT FROM AUTHOR]