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The paper deals with the effect of mineral fertilizers on the dynamics of total phosphorus in the aboveground mass of sunflower in gray-brown soils. It is determined that the use of mineral fertilizers in sunflower crop has a significant effect on the accumulation of total phosphorus in the aboveground mass on the phases of growth. Total phosphorus increases by 0.02-0.11% in stem, 0.02-0.13% in receptacle and 0.03-0.12% in seed compared to the control (no fertilizer) option at the end of vegetation under the influence of mineral fertilizers. The highest amount of total phosphorus is observed in the N120P120K120 option at each growth phase. As a result of the use of mineral fertilizers in sunflower crops, it is found that there is a high correlation between the amount of total nitrogen, phosphorus and potassium (%) in the stem, receptacle, seeds and the yield (c/ha) in the ripening phase on options. [ABSTRACT FROM AUTHOR]

Sunflower is an important crop that its oil has high nutritional and economic value. In this study, genotype-trait biplot method was used to study interrelationships between different traits and new sunflower hybrids. For this study, 24 new sunflower hybrids along with Golsa cultivar were evaluated in a simple lattice design with two replications in Gorgan Agriculture Research Station, Gorgan, north of Iran, during 2020 cropping season. The results showed that thousand seed weight, head diameter, seed number per head, stem diameter, leaf length, leaf width and petiole length had a positive correlation with seed yield. Also, a negative correlation was observed between seed yield and phonological traits and plant height. Therefore, it can be concluded that improving seed yield may simultaneously lead to improve in the early maturity and dwarfism. Based on biplot polygon view, the genotypes No. 5 and 19 had superior characteristics in terms of seed yield and its attributes. Also, based on a hypothetical ideal genotype biplot, the genotypes No. 3, 2 and 10 outranked the other genotypes in terms of all examined traits. A majority of the examined traits had high discriminating ability and were able to show differences between genotypes. The stem diameter was the nearest trait to an ideal trait and, therefore, it has the highest discriminating ability and representativeness. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the correlation between agronomic traits and seed yield of sunflower hybrids and also to determine the direct and indirect effects of analysed traits on seed yield. Correlation studies revealed that days to 50% flowering, plant height, head diameter, volume weight, seed yield per plant and oil content were important selection indices for both oil and seed yield improvement. Alternaria leaf spot severity had negative and significant correlation on seed yield per plant, oil content and oil yield per plant. This indicated the importance of resistance breeding for Alternaria leaf spot disease. The path analysis revealed that traits namely; days to 50% flowering, head diameter, oil content, plant height and Alternaria leaf spot severity were important selection indices. Though the correlation analysis showed that 100-seed weight and volume weight were important, the path analysis indicated that these traits were less important. [ABSTRACT FROM AUTHOR]

Copyright of Anadolu (1300-0225) is the property of Anadolu Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study the impact of parent-inbred lines on the heterosis expression of the agronomic characteristics in sunflower hybrids, 24 sunflower hybrids along with the parent lines were evaluated for their agronomic characteristics as a randomised complete block design with three replications in the 2018-2019 growing seasons in Karaj, Iran. According to the results, the hybrids R29 × A346, R19 × A346, R29 × A40 had the highest achene yield (4 159, 4 143 and 4 108 kg/ha, respectively), but the highest heterosis was observed in R29 × A212 and R19 × A212 (182 and 181%, respectively) suggesting that the incidence of heterosis is related to the relative performance of both the parents and hybrids. The results confirmed the heterosis expression for most of the agronomic traits. The heterosis for the days to flowering and maturity were negative. All the mid-parent heterosis (MPH) for the plant height, head diameter, stem diameter and achene number were positive, while only the plant height was positive for the best parent heterosis (BPH). Almost all the MPH and BPH of the crosses for the achene and oil yield were positive, which indicates a considerable heterosis for the achene and oil yield. The results showed that the relative impact of the restorer (R)-lines was higher than the cytoplasmic mail sterile (CMS)-lines on the heterosis expression for the days to maturity, stem diameter, achene number per head and achene and oil yield. The CMS-lines had more of an impact on the heterosis expression for the plant height and the relative impact of the R-lines and CMS-lines were almost similar for the days to flowering, head diameter, achene weight and oil content. Due to the higher relative impact of the paternal lines on the heterosis expression for half of the studied characteristics in this study, choosing suitable parental lines will have a crucial role in breeding the sunflowers for a desired trait. [ABSTRACT FROM AUTHOR]

Copyright of Lucrari Stiintifice, Universitatea de Stiinte Agricole Si Medicina Veterinara Ion Ionescu de la Brad Iasi, Seria Horticultura is the property of University of Agricultural Sciences and Veterinary Medicine (Editura Ion Ionescu de la Brad) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Inbred line Mh174B with the yellow coloration of the sunflower plant top was produced by hybridization of annual wild species with cultivated sunflower. The aim research was to evaluate genetic control of yellow coloration of the sunflower plant top in combination with other morphological traits (branchiness, pollen fertility restoration and ray flower coloration). A total of four F2 hybrid combinations of were created: Сх1010А × Mh174B, Сх1012А × Mh174B, Сх2111А × Mh174B, Мх845А × Mh174B. Yellow coloration of the sunflower plant top was shown to follow a monogenic mode of inheritance and, presumably, be controlled by the gene y. This trait is inherited independently from such traits as branchiness, pollen fertility restoration and ray flower coloration. The mainstreams of use of yellow coloration of the sunflower plant top in sunflower breeding and seed production are discussed. [ABSTRACT FROM AUTHOR]

Salt stress is known to negatively affect the fundamental processes in plants, reducing their growth and yield. The role of Silicon (Si) to protect the sorghum and sunflower plants against salinity stress was assessed. The objective of this study was to evaluate the effects of different forms of Si application on the uptake and use efficiency of macronutrients and micronutrients in sorghum and sunflower plants under salinity stress under greenhouse conditions. Two experiments were conducted using sorghum and sunflower under greenhouse conditions. Four Si levels were applied to plants: no Si application; foliar application of 28.6 mmol.L−1; root application of 2.0 mmol.L−1; and combined Si application with both via nutrient solution and foliar spraying. Each Si treatment was applied in the absence and presence of NaCl (100 mM). Thirty days after treatments, sodium (Na+) and Si accumulation, nutrient uptake and use efficiency, and the roots and total plant dry weight were measured. Salinity stress induced nutritional imbalance and decreased dry weight production in both plant species. Our results showed that Si application alleviated the salinity stress by decreased Na+ uptake and increased nutritional efficiency, thereby favoring the total plant dry weight in sorghum by 27% and sunflower by 41%. This occurred when Si was applied either via root or in combination via root and foliar application, respectively. Collectively, our findings indicate that Si application can attenuate the deleterious effects of salt stress and increase yield in sorghum and sunflower plants in a sustainable manner. Image 1 • We tested different Si treatments on sorghum and sunflower under salt stress. • Si increased uptake and use efficiencies of macronutrients and micronutrients. • Combining root and foliar supply of Si is beneficial in non-Si-accumulating sunflower. • Root application of Si was sufficient in Si-accumulating sorghum. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the heavy metals (cadmium, lead, zinc, copper, iron and manganese) pollution in three regions in Bulgaria characterized with different type of pollution sources and to compare their bioaccumulation in selected agricultural plant species - perennial (apple and pear) and annual (corn and sunflower). The bioaccumulative ability of different plant parts was also investigated. The bioaccumulation factors of the analyzed heavy metals were evaluated by comparison of the determined concentrations in the plant parts from polluted regions to corresponding metal concentrations in the same plant species collected from a background region. A strong dependence of the accumulation of the studied plants on the specific pollutant was established as well as decreased transfer factors at increased heavy metals concentrations in the soils. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) is the most important oil crop in Romania. Fertilization of sunflower crops has as a system a complex basic fertilization (NPK or NPK+S+Mg), used in preparing the seedbed and planting, who supports the normal coverage of the critical period of nutrition and laying the foundation of total yield. The aim of this research is to analyse the behaviour of sunflower under the influence of the degree of fertilization and also of the pedoclimatic conditions in the Oltenia Plain. Research was performed in the year 2018, in the southern part of Romania, within the Agricultural Research and Development Station Caracal (44° 06' N latitude and 24° 21' E longitude) in Olt County. For setting up the experience, the NEOMA hybrid was used in 6 test variants as follows: V1 - N0P0K0 (control); V2 - N90P0K0; V3 - N90P60K0; V4 - N90P60K60; V5 - N90P60K60 plus 1.5 liters/hectare of Fertigrain foliar fertilizer; V6 - N120P60K60. The doses used are in kg/ha of active substance. Plant population was 57.000 plants per hectare and the determinations were performed throughout the entire vegetation period of the plant, including the harvest period where the yield value was between 2.234 kg/hectare and 4.035 kg/hectare. Climatic conditions during the vegetation period were favorable, as the average temperatures have registered values between 16.3 and 24.3°C. The total rainfalls was 378.8 mm, those been sufficient for the favorable development of the sunflower crop. [ABSTRACT FROM AUTHOR]

Background and Aims The pathways whereby foliar-applied nutrients move across the leaf surface remain unclear. The aim of the present study was to examine the pathways by which foliar-applied Zn moves across the sunflower (Helianthus annuus) leaf surface, considering the potential importance of the cuticle, stomata and trichomes. Methods Using synchrotron-based X-ray florescence microscopy and nanoscale secondary ion mass spectrometry (NanoSIMS), the absorption of foliar-applied ZnSO4 and nano-ZnO were studied in sunflower. The speciation of Zn was also examined using synchrotron-based X-ray absorption spectroscopy. Key Results Non-glandular trichomes (NGTs) were particularly important for foliar Zn absorption, with Zn preferentially accumulating within trichomes in ≤15 min. The cuticle was also found to have a role, with Zn appearing to move across the cuticle before accumulating in the walls of the epidermal cells. After 6 h, the total Zn that accumulated in the NGTs was approx. 1.9 times higher than in the cuticular tissues. No marked accumulation of Zn was found within the stomatal cavity, probably indicating a limited contribution of the stomatal pathway. Once absorbed, the Zn accumulated in the walls of the epidermal and the vascular cells, and trichome bases of both leaf sides, with the bundle sheath extensions that connected to the trichomes seemingly facilitating this translocation. Finally, the absorption of nano-ZnO was substantially lower than for ZnSO4, with Zn probably moving across the leaf surface as soluble Zn rather than nanoparticles. Conclusions In sunflower, both the trichomes and cuticle appear to be important for foliar Zn absorption. [ABSTRACT FROM AUTHOR]

Sixteen sunflower hybrids obtained by crossing between four CMS and four restorer lines as tester were evaluated for combining abilities of agronomic traits under optimum and water limited conditions using line×tester mating design. There was considerable variability among genotypes for the traits in both normal and stressed experiments. The results indicated that the lines AGK344 and AGK148 with suitable GCA for early maturity and plant height respectively and AGK52 for oil content and seed and oil yield were desirable combiner under both optimum and stressed condition. In other hand, AGK344 expressed a significant GCA for plant height in suitable direction under stressed condition. Among the testers RGK26 and RGK56 had suitable GCA for days to maturity under both conditions. RGK56 and RGK26 were appropriate combiner for oil content under optimum and water stressed conditions respectively the later had desired GCA for seed and oil yield under water stressed condition too. According to the results, there was differentiate GCA of testers for days to flowering, seed weight and oil content in normal and stressed condition. Differential expressions of GCA in parent inbred lines indicated that selection of restorer lines for the agronomic traits would be more efficient than the selection of CMS lines. It is concluded that heritability of a trait determines the kind of SCA in response to different environments and the SCA effects are more stable for traits with higher heritability. [ABSTRACT FROM AUTHOR]

The xylem cavitation threshold water potential establishes a hydraulic limit on the ability of woody species to survive in water‐limiting environments, but herbs may be more plastic in terms of their ability to adapt to drying conditions. Here, we examined the capacity of sunflower (Helianthus annuus L.) leaves to adapt to reduced water availability by modifying the sensitivity of xylem and stomata to soil water deficit. We found that sunflower plants grown under water‐limited conditions significantly adjusted leaf osmotic potential, which was linked to a prolongation of stomatal opening as soil dried and a reduced sensitivity of photosynthesis to water‐stress‐induced damage. At the same time, the vulnerability of midrib xylem to water‐stress‐induced cavitation was observed to be highly responsive to growth conditions, with water‐limited plants producing conduits with thicker cell walls which were more resistant to xylem cavitation. Coordinated plasticity in osmotic potential and xylem vulnerability enabled water‐limited sunflowers to safely extract water from the soil, while protecting leaf xylem against embolism. High plasticity in sunflower xylem contrasts with data from woody plants and may suggest an alternative strategy in herbs. Plasticity in leaf osmotic potential is well known in plants, but little is known about the plasticity in the xylem sensitivity to cavitation‐induced damage. Using sunflowers grown under high and low water availability we find a close coupling between osmotic adjustment and a shift in the xylem cavitation sensitivity. Leaves in water‐limited plants could extract more water from the soil by shifting both the osmotic potential and xylem cavitation threshold in a coordinated fashion. [ABSTRACT FROM AUTHOR]

In Europe, the surface devoted to sunflower cultivation has expanded by ∼ 26% from 2006 to 2016. Theoretically, this implies an increasing demand for pollinators, while at the same time, scientific reports claim that pollinator communities worldwide are threatened by multiple stressors such as agrochemicals, the loss of suitable habitats and habitat fragmentation. However, the question that arises is whether insect pollination is still relevant for modern sunflower varieties that are often highly self-fertile. Following recent studies which demonstrate that surrounding land use composition may affect ecosystem service provisioning in cropped fields, this study aims at re-examining the pollination status of sunflower while disentangling the effects of local and landscape variables on sunflower seed set and oil content in Central Italy. Commercial cultivars, regardless of their degree of self-fertility, showed increased seed set and oil content when receiving adequate amounts of cross-pollination; oil composition, though, was not affected by cross-pollination events. Honey bees accounted for the vast majority of pollinators ensuring an overall adequate pollination. Sunflower seed set was higher in fields surrounded by landscapes containing a greater abundance of beehives, early flowering crops, urban areas and woody linear elements; conversely, seed set was lower where herbaceous semi-natural habitats dominated the surrounding landscape. This information is necessary for a science-based planning of agricultural policies and shows that, despite the adoption of self-fertile cultivars, sunflower still benefits from insect pollination and land use planning may affect crop productivity. [ABSTRACT FROM AUTHOR]

With climate change and an ever-increasing human population threatening food security, developing a better understanding of the genetic basis of crop performance under stressful conditions has become increasingly important. Here, we used genome-wide association studies to genetically dissect variation in seedling growth traits in cultivated sunflower (Helianthus annuus L.) under well-watered and water-limited (i.e., osmotic stress) conditions, with a particular focus on root morphology. Water limitation reduced seedling size and produced a shift toward deeper rooting. These effects varied across genotypes, and we identified 13 genomic regions that were associated with traits of interest across the two environments. These regions varied in size from a single marker to 186.2 Mbp and harbored numerous genes, some of which are known to be involved in the plant growth/development as well as the response to osmotic stress. In many cases, these associations corresponded to growth traits where the common allele outperformed the rare variant, suggesting that selection for increased vigor during the evolution of cultivated sunflower might be responsible for the relatively high frequency of these alleles. We also found evidence of pleiotropy across multiple traits, as well as numerous environmentally independent genetic effects. Overall, our results indicate the existence of genetic variation in root morphology and allocation and further suggest that the majority of alleles associated with these traits have consistent effects across environments. [ABSTRACT FROM AUTHOR]

Dr Chao-Chien Jan, Research Geneticist with the USDA-Agricultural Research Service (USDA-ARS), Red River Valley Agricultural Research Center, Northern Crop Science Laboratory, Sunflower and Plant Biology Research Unit, Fargo, ND retired January, 2017 after 35 years of dedicated service. He began his research career in 1974 after receiving his Ph.D. in genetics from the University of California, Davis, CA, working with wheat. He was a postdoctoral Research Biologist at the Cancer Research Institute, University of California, San Francisco in 1975. From 1976 to 1981 he was a postdoctoral Research Agronomist, Department of Agronomy and Range Science, UC, Davis, CA. working on wheat. In 1981, Dr Jan joined the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) as a Research Geneticist at the Rice and Oilseed Unit at Davis, CA with an emphasis on cytogenetics, working on sunflower (Helianthus annuus) crop wild relatives (CWR) for the improvement of the sunflower crop. The sunflower program at Davis, CA was closed in 1984, and he was transferred to the USDA-ARS Sunflower Unit in Fargo, ND where he spent the rest of his career working on sunflower CWR. Dr Jan’ research contributed significantly to the ability to utilize the genetic diversity of the 53 species of wild sunflowers, especially in the areas of germination, use of embryo culture and chromosome doubling to overcome embryo abortion and fertility problems. His pioneering research in interspecific hybridization, cytoplasmic male sterility and fertility restoration, cytogenetic stocks, disease resistance and mutation opened doors to genetic diversity never before available for utilization by the sunflower industry. This led to his global stature with invitations to serve as a visiting scientist and fellowships in Australia, Serbia, Spain, Romania, and China. He has hosted over 20 scientists from 15 countries, as well as countless students during his career. Due to his stature, he has been invited to present several invited plenary talks, both national and international, and in 2012 he was presented the prestigious Pustovoit Award, the highest award in the sunflower industry given by the International Sunflower Association for his contribution to sunflower science and technology. [ABSTRACT FROM AUTHOR]

Present work focuses on tissue and concentration-dependent effect of nitric oxide (NO) on the modulation of cytosolic peroxidase (POD; EC 1.11.1.7) activity in 2-day old etiolated sunflower (Helianthus annuus L.) seedlings. Exogenously supplied NO (in the form of sodium nitroprusside [SNP] or diethylenetriamine NONOate [DETA]; 125 to 500 μM) results in noteworthy enhancement in seedling growth in a concentration dependent manner irrespective of salt-stress and differentially affects POD activity in 2-day old seedling cotyledons. Elevated NO availability leads to an increase in the specific activity of POD in a concentration-dependent manner within 48 hrs as a rapid signaling response. Purification of POD protein using immunoprecipitation technique has shown that cotyledons derived from salt stressed seedlings exhibit a higher extent of tyrosine nitration of POD as compared to the control seedlings. Out of the four tyrosine residues found in the amino acid sequence of POD, the one at position 100 has been predicted to undergo nitration. Thus, a probable NO-POD crosstalk is evident in sunflower seedling cotyledons accompanying salt stress. [ABSTRACT FROM AUTHOR]

The physiological performance of some sunflower genotypes (S.28111, SF0049, Hysun-33, Hysun-39) under salt, drought stress separately and in combination was examined. Salt, drought and a combination of these stresses were applied to plants by gradual increments. The plants were exposed to stress for two weeks. Relative water content, osmotic potential, stomatal conductance, performance index, dark adapted quantum yield and chlorophyll contents were reduced upon salinity and drought stresses. However, when plants were subjected to a combination of these stresses, a greater reduction in all tested attributes was observed. Proline and carotenoid contents in drought stress were elevated compared to salt stress. Superoxide dismutase (SOD) and catalase (CAT) showed the highest activity in individual salt and drought stress with less accumulation of H2O2. Combined stress reduced the activity of antioxidant enzymes which ultimately decreased the physiological performance of sunflower plants. However, among the tested genotypes, S.28111 and SF0049 were found to be more tolerant to drought, salt and combined stress than both Hysun genotypes. The physiological performance of genotypes against salinity and drought individually and in combination is discussed in detail. [ABSTRACT FROM AUTHOR]

Plant movements in response to directional solar radiation, known as “heliotropism” are frequently observed in nature. Although there is a considerable amount of literature on these movements in vegetative organs, knowledge about heliotropic responses in flowers and inflorescences is relatively limited. Here we comprehensively review studies on this topic, profile the diversity of responses encompassed under the term “heliotropism” and propose a conceptual framework for their classification. In addition, we discuss the mechanisms underlying different types of heliotropism in two species commonly used as model systems: Arabidopsis and sunflower. Finally, the ecological consequences of floral heliotropism are elaborated with an emphasis on the effects on plant reproductive success, and the potential agricultural implications of manipulating heliotropic responses are addressed as well. We conclude that inflorescence heliotropism appears conserved in many plant species that depend on pollinators, and consists of an auxin dependent response to solar radiation. [ABSTRACT FROM AUTHOR]

Ecological benefits associated with plant growth-promoting rhizobacteria (PGPR) inoculants offer a promising integrated nutrient management option to counteract plant nitrogen (N) deficiency. We performed field experiments to evaluate the effect of integrated N fertilizer regime involving chemical N fertilizer (CNF) and N-enriched compost (NEC), either alone or combined with selected PGPR ( Pseudomonas aeruginosa) on sunflower seed quality, N use efficiency (NUE) and soil fertility during 2014-2015. We found that integrated N biofertilizer application resulted in significantly higher seed oil concentration, fatty acid composition, and harvest index in both cropping years. Greater effects on N yield efficiency (NYE), N use efficiency (NUE), N physiological efficiency (NPE), and photosynthetic N use efficiency (PNUE) were recorded in nitrogen-enriched compost+PGPR inoculant (NECPI) treatment followed by chemical N fertilizer+PGPR inoculant (CNFPI) treatment. Statistically significant differences were observed in linoleic and linolenic acid, NYE, and NUE for treatment × year interaction, thus, suggesting that the integrated N biofertilizer approach facilitates the efficient N use by sunflower for improving yield and seed quality. Moreover, we also found considerable enhancement of soil N fertility after two consecutive cropping years of sunflower. The enhancement of seed quality, N use efficiencies, and soil N fertility through integrated N biofertilizer application emphasizes the importance of balanced crop N nutrition, ensuring sufficient N supply to sunflower with adequate N balance in soil for the next crop. Overall, combination of PGPR with NEC amendment may optimize N uptake efficiency and reduce N fertilizer losses, which is necessarily required for the sustainable sunflower production. [ABSTRACT FROM AUTHOR]

Accounting for the interannual climatic variations is a well-known issue for simulation-based studies of environmental systems. It often requires intensive sampling (e.g., averaging the simulation outputs over many climatic series), which hinders many sequential processes, in particular optimization algorithms. We propose here an approach based on a subset selection in a large basis of climatic series, using an ad-hoc similarity function and clustering. A non-parametric reconstruction technique is introduced to estimate accurately the distribution of the output of interest using only the subset sampling. The proposed strategy is non-intrusive and generic (i.e. transposable to most models with climatic data inputs), and can be combined to most “off-the-shelf” optimization solvers. We apply our approach to sunflower ideotype design using the crop model SUNFLO. The underlying optimization problem is formulated as a multi-objective one to account for risk-aversion. Our approach achieves good performances even for limited computational budgets, outperforming significantly standard strategies. [ABSTRACT FROM AUTHOR]

Accumulation of metal contaminants in soil as a result of various industrial and anthropogenic activities has reduced soil fertility significantly. Phytoextraction of metal contaminants can improve soil fertility and provide inexpensive feedstock for biorefineries. We investigated the hyperaccumulation capacity of sunflower (Helianthus annuus) biomass by cultivating these plants in various concentrations of metal contaminants. Sunflowers were grown in soils contaminated with various levels of heavy metals (10–2,000 mg/kg dry soil). The degree of metal uptake by different parts of the biomass and the residual concentration in the soil were estimated through inductively coupled plasma mass spectrometry. An almost 2.5-fold hyperaccumulation of Zn2+ was observed in the leaf and flower biomass compared with the concentration in the soil. For the subsequent saccharification of biomass with hyperaccumulated contaminants, a fungal lignocellulosic consortium was used. The fungal consortium cocktail retained more than 95% filter paper activity with 100 mM Ni2+ ions even after 36 h. The highest saccharification yield (SY, 87.4%) was observed with Ni2+ as the contaminant (10 mg/kg dry wt), whereas Pb2+ (251.9 mg/kg dry wt) was the strongest inhibitor of biomass hydrolysis, resulting in only a 30% SY. Importantly, the enzyme cocktail produced by the fungal consortium resulted in almost the same SY (%) as that obtained from a combination of commercial cellulase and β-glucosidase. Significant sugar conversion (61.7%) from H. annuus biomass hydrolysate occurred, resulting in the production of 11.4 g/L of bioethanol. This is the first study to assess the suitability of phytoremediated sunflower biomass for bioethanol production. [ABSTRACT FROM AUTHOR]

Young sunflower plants track the Sun from east to west during the day and then reorient during the night to face east in anticipation of dawn. In contrast, mature plants cease movement with their flower heads facing east.We show that circadian regulation of directional growth pathways accounts for both phenomena and leads to increased vegetative biomass and enhanced pollinator visits to flowers. Solar tracking movements are driven by antiphasic patterns of elongation on the east and west sides of the stem. Genes implicated in control of phototropic growth, but not clock genes, are differentially expressed on the opposite sides of solar tracking stems. Thus, interactions between environmental response pathways and the internal circadian oscillator coordinate physiological processes with predictable changes in the environment to influence growth and reproduction. [ABSTRACT FROM AUTHOR]

BACKGROUND Field-scale changes in the water footprint during crop growth play an important role in formulating sustainable water utilisation strategies. This study aimed to explore field-scale variation in the water footprint of growing sunflowers in the western Jilin Province, China, during a 3-year field experiment. The goals of this study were to (1) determine the components of the 'blue' and 'green' water footprints for sunflowers sown with water, and (2) analyse variations in water footprints and soil water balance under different combinations of temperature and precipitation. Specific actions could be adopted to maintain sustainable agricultural water utilisation in the semi-arid region based on this study. RESULTS The green, blue, and grey water footprints accounted for 93.7-94.7%, 0.4-0.5%, and 4.9-5.8%, respectively, of the water footprint of growing sunflowers. The green water footprint for effective precipitation during the growing season accounted for 58.8% in a normal drought year but 48.2% in an extreme drought year. When the effective precipitation during the growing season could not meet the green water use, a moisture deficit arose. This increase in the moisture deficit can have a significant impact on soil water balance. CONCLUSION Green water was the primary water source for sunflower growth in the study area, where a scarcity of irrigation water during sunflower growth damaged the soil water balance, particularly in years with continuous drought. The combination of temperature and precipitation effected the growing environment, leading to differences in yield and water footprint. The field experiments in this area may benefit from further water footprint studies at the global, national and regional scale. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The aim of this research is to characterize wild annual sunflowers on the basis of achene micro-morphology. Plant material was grown up on an experimental field of the Institute of Field and Vegetable Crops in Novi Sad during 2015. Achene samples were hand-collected at the time of physiological maturity. Morphological measurements of achenes were performed using stereoscopic microscope Leica MZ16 with Leica DFC 320 Camera. The micro-morphological diversity of achenes was assessed using scanning electron microscopy (SEM). Obtained results indicated the presence of some quantitative and qualitative differences in achene characteristics among analyzed species, such as in their size, color, carpopodium and stylopodium shape, and distribution of trichomes on the achene surface. The carpopodium of examined species was asymmetrical at the maturity. Differences in the cuticle and wax ornamentation in different parts of the achenes, on the anticlinal walls of epidermal cells, were identified. The SEM analysis revealed the presence of non-glandular, multicellular bi-seriate trichomes (twin hairs) on the achene surface. This trichome type consisted of two elongated, parallel cells of different length. Considering the distribution of trichomes among the apical, median and basal regions of the fruit, most of the species demonstrated greater trichome density in the apical part. [ABSTRACT FROM AUTHOR]

In nature plants are often simultaneously challenged by different biotic and abiotic stresses. Although the mechanisms underlying plant responses against single stress have been studied considerably, plant tolerance mechanisms under combined stress is not understood. Also, the mechanism used to combat independently and sequentially occurring many number of biotic and abiotic stresses has also not systematically studied. From this context, in this study, we attempted to explore the shared response of sunflower plants to many independent stresses by using meta-analysis of publically available transcriptome data and transcript profiling by quantitative PCR. Further, we have also analyzed the possible role of the genes so identified in contributing to combined stress tolerance. Meta-analysis of transcriptomic data from many abiotic and biotic stresses indicated the common representation of oxidative stress responsive genes. Further, menadione-mediated oxidative stress in sunflower seedlings showed similar pattern of changes in the oxidative stress related genes. Based on this a large scale screening of 55 sunflower genotypes was performed under menadione stress and those contrasting in oxidative stress tolerance were identified. Further to confirm the role of genes identified in individual and combined stress tolerance the contrasting genotypes were individually and simultaneously challenged with few abiotic and biotic stresses. The tolerant hybrid showed reduced levels of stress damage both under combined stress and few independent stresses. Transcript profiling of the genes identified from meta-analysis in the tolerant hybrid also indicated that the selected genes were up-regulated under individual and combined stresses. Our results indicate that menadione-based screening can identify genotypes not only tolerant to multiple number of individual biotic and abiotic stresses, but also the combined stresses. [ABSTRACT FROM AUTHOR]

Electrochromic shift measurements confirmed that the Q-cycle operated in sunflower leaves. The slow temporarily increasing post-pulse phase was recorded, when ATP synthase was inactivated in the dark and plastoquinol (PQH 2 ) oxidation was initiated by a short pulse of far-red light (FRL). During illumination by red light, the Q-cycle-supported proton arrival at the lumen and departure via ATP synthase were simultaneous, precluding extreme build-up of the membrane potential. To investigate the kinetics of the Q-cycle, less than one PQH 2 per cytochrome b 6 f (Cyt b 6 f ) were reduced by illuminating the leaf with strong light pulses or single-turnover Xe flashes. The post-pulse rate of oxidation of these PQH 2 molecules was recorded via the rate of reduction of plastocyanin (PC + ) and P700 + , monitored at 810 and 950 nm. The PSII-reduced PQH 2 molecules were oxidized with multi-phase overall kinetics, τ d = 1, τ p = 5.6 and τ s = 16 ms (22 °C). We conclude that τ d characterizes PSII processes and diffusion, τ p is the bifurcated oxidation of the primary quinol and τ s is the Q-cycle—involving reduction of the secondary quinol at the n-site, its transport to the p-site, and bifurcated oxidation there. The extraordinary slow kinetics of the Q-cycle may be related to the still unsolved mechanism of the “photosynthetic control.” [ABSTRACT FROM AUTHOR]

Emilia coccinea complex is a widespread and morphologically variable species in tropical and subtropical Africa. Jeffrey's (Kew Bull 52:205-212, ) revision of the African Emilia species with large capitula resulted in a complex of eight species with E. coccinea sensu stricto restricted to eastern and southern tropical Africa and characterised by long-appendaged style branches and bright orange flowers. To evaluate the delimitations within this complex, a morphological phenetic study based on 134 herbarium specimens spanning the geographical range of the E. coccinea complex was undertaken using cluster analysis and ordination (principal coordinates analysis and non-metric multidimensional scaling). Five of the eight species ( E. emilioides, E. jeffreyana, E. praetermissa, E. subscaposa, and E. vanmeelii) formed distinct phenetic groups, whereas two species ( E. caespitosa and E. coccinea) were indistinguishable because of variability in some key characters (viz., cypsela indumentum and shape of cauline leaves) suggesting that they are possibly one heterogeneous species. Emilia lisowskiana is not supported as a distinct species as three E. coccinea specimens group with it in the cluster analysis. Emilia emilioides with mostly long, narrow cauline leaves, narrow capitula, and unappendaged style branches apices is the most distinct taxon in all analyses. Univariate analyses of ten selected characters revealed that the reproductive features are able to distinguish some species, as well as a few vegetative ones. The application of various species concepts to this species complex is discussed. A key to the species in this complex is provided. [ABSTRACT FROM AUTHOR]

Plant roots exude numerous metabolites into the soil that influence nutrient availability. Although root exudate composition is hypothesized to be under selection in low fertility soils, few studies have tested this hypothesis in a phylogenetic framework. In this study, we examined root exudates of three pairs of Helianthus species chosen as phylogenetically-independent contrasts with respect to native soil nutrient availability. Under controlled environmental conditions, seedlings were grown to the three-leaf-pair stage, then transferred to either high or low nutrient treatments. After five days of nutrient treatments, we used gas chromatography-mass spectrometry for analysis of root exudates, and detected 37 metabolites across species. When compared in the high nutrient treatment, species native to low nutrient soils exhibited overall higher exudation than their sister species native to high nutrient soils in all three species pairs, providing support for repeated evolutionary shifts in response to native soil fertility. Species native to low nutrient soils and those native to high nutrient soils responded similarly to low nutrient treatments with increased exudation of organic acids (fumaric, citric, malic acids) and glucose, potentially as a mechanism to enhance nutrition acquisition. However, species native to low nutrient soils also responded to low nutrient treatments with a larger decrease in exudation of amino acids than species native to high nutrient soils in all three species pairs. This indicates that species native to low nutrient soils have evolved a unique sensitivity to changes in nutrient availability for some, but not all, root exudates. Overall, these repeated evolutionary divergences between species native to low nutrient soils and those native to high nutrient soils provide evidence for the adaptive value of root exudation, and its plasticity, in contrasting soil environments. [ABSTRACT FROM AUTHOR]

Background One of the best-known plant movements, phototropic solar tracking in sunflower (Helianthus annuus), has not yet been fully characterized. Two questions are still a matter of debate. (1) Is the adaptive significance solely an optimization of photosynthesis via the exposure of the leaves to the sun? (2) Is shade avoidance involved in this process? In this study, these concepts are discussed from a historical perspective and novel insights are provided. Scope and Methods Results from the primary literature on heliotropic growth movements led to the conclusion that these responses cease before anthesis, so that the flowering heads point to the East. Based on observations on 10-week-old plants, the diurnal East-West oscillations of the upper fifth of the growing stem and leaves in relation to the position of the sun (inclusive of nocturnal re-orientation) were documented, and photon fluence rates on the leaf surfaces on clear, cloudy and rainy days were determined. In addition, the light-response curve of net CO2 assimilation was determined on the upper leaves of the same batch of plants, and evidence for the occurrence of shade-avoidance responses in growing sunflower plants is summarized. Conclusions. Only elongating, vegetative sunflower shoots and the upper leaves perform phototropic solar tracking. Photon fluence response and CO2 assimilation measurements cast doubt on the 'photosynthesis-optimization hypothesis' as the sole explanation for the evolution of these plant movements. We suggest that the shadeavoidance response, which maximizes light-driven CO2 assimilation, plays a major role in solar tracking populations of competing sunflower plants, and an integrative scheme of these growth movements is provided. [ABSTRACT FROM AUTHOR]

Agricultural productivity is severely affected by soil salinity. In this study, seedlings of sunflower (Helianthus annuus L.) cultivar Baikuiza 6 were treated with Na-based salts to induce salt stress or alkali stress. Salt had no effect on sunflower growth, while high concentrations of alkali significantly inhibited sunflower growth. The main characteristic for sunflower in response of salt or alkali stress was that it kept higher K+ concentration and lower Na+/K+ ratio, which is closely related to regulation of Na+ and K+ transport on cotyledon node zone (CNZ). The CNZ of sunflower restricted Na+ transport resulting in less Na+ in leaf than in root under both stresses, and it maintained relatively low Na+/K+ ratio in leaf and high selectivity for K+ vs. Na+. However, CNZ slightly restricted NO3- and H2PO4- transport under alkali stress compared with salt stress. This led to enhanced organic acid content to remedy the shortage of inorganic anions, and energy consumption is greater than for salt stress, which might be one cause of reductions of relative growth rate (RGR) under alkali stress. [ABSTRACT FROM AUTHOR]

Salinity is one of the major environmental constraints for limiting crop production at the global level. Exogenous application of triacontanol has the ability to ameliorate the adverse effects of abiotic stresses including salinity stress by modulating a number of physio-biochemical processes in different plants. A wire house study was conducted to explore the prospective role of foliar-applied triacontanol (TRIA) in two sunflower (Helianthus annuus L.) cultivars (SMH-907 and SMH-917) at various growth stages under saline conditions. Both sunflower cultivars were grown-up in sand medium endowed with Hoagland's nutrient solution (full strength) under control (0 mM NaCl) and salt stress (150 mM NaCl) conditions. Foliar spray of three TRIA levels [0 (water spray), 50 and 100 μM] were pertained at three growth stages i.e. vegetative, flowering and vegetative + flowering stages. Imposition of salinity decreased shoot and root dry weights, while increased the accumulation of free proline, glycinebetaine (GB) and activity of glutathione reductase (GR) enzyme. However, a significant salt-induced suppression was observed in the activities of peroxidase (POD) and superoxide dismutase (SOD) enzymes. Foliar-applied TRIA improved the activities of POD, SOD and GR enzymes along with substantial increase in the free proline and glycinebetaine contents while activity of catalase (CAT) enzyme and total soluble protein contents remained unchanged under saline stress at all growth stages in both sunflower cultivars. Overall, foliar-applied TRIA was effective in ameliorating the salt-induced adverse effects on plant growth in terms of shoot and root dry weights of both sunflower cultivars particularly at vegetative growth stage by upregulating the activities of antioxidant enzymes and level of osmoprotectants. © 2015 Friends Science Publishers [ABSTRACT FROM AUTHOR]

Sunflower rust, caused by Puccinia helianthi Schw., is a widespread disease of sunflower ( Helianthus annuus L.) in China. To study physiological races, sunflower field surveys were undertaken in major sunflower growing areas of China in 2010. Forty-four rust-infected sunflower leaf samples were collected from 25 geographical locations. Freshly produced spores were used to study physiological race differentiation on a set of nine differentials. Race 300 was the most prevalent race observed over all locations with a 59% frequency followed by races 735, 310, 500, 724 and 737. To evaluate hybrids and varieties for resistance screening, spores of race 300 were used to inoculate 65 hybrids, and five open-pollinated varieties selected from breeding programmes and from the seed market. None of the confection hybrids and open-pollinated varieties was immune to race 300. Conversely, among oilseed hybrids, 3% of them showed immunity, 12% highly resistant, 59% resistant and 26% showed susceptible reactions. Open-pollinated varieties were the most susceptible to race 300 followed by confection and oilseed sunflower hybrids. Results from this study are projected to assist breeders in selection of hybrids and varieties against prevalent race as our results showed a diversity of resistance levels to race 300. [ABSTRACT FROM AUTHOR]

The effect of foliar fertilizers on young sunflower (Helianthus annuus L. cv. Biser) and corn (Zea mays L., cv. Knezha 613) plants under nitrogen deficiency was studied. The experiments were conducted in controlled conditions as sand culture. The plants were grown for 3 weeks separated in 2 groups -- control with complete Knop nutrient solution and plants under nitrogen deficiency with Knop without nitrogen. After that period the stressed plants were recovered with foliar fertilizers trade mark Aveikan and Poly-plant in concentrations of 0,3%. Three weeks later the biometrical and physiological parameters were analyzed. On the ground of the obtained results the foliar fertilizers Aveikan and Ploly-plant were suggested as a reliable tool which improves the growth of sunflower and corn plants under nitrogen deficiency. [ABSTRACT FROM AUTHOR]

• Premise of the study: Evolutionary changes in how flowering time responds to photoperiod cues have been instrumental in expanding the geographic range of agricultural production for many crop species. Locally adaptive natural variation in photoperiod response present in wild relatives of crop plants could be leveraged to further improve the present and future climatic ranges of cultivation or to increase region-specific yields. Previous work has demonstrated ample variability in photoperiod response among wild populations of the common sunflower, Helianthus annuus. Here, we characterize patterns of photoperiod response variation throughout the genus and examine the genetic architecture of intraspecific divergence. • Methods: The requirement of short day lengths for floral induction was characterized for a phylogenetically dispersed sample of Helianthus species. In addition, flowering time was assessed under short days and long days for a population of F3 individuals derived from crosses between day-neutral and short-day, wild H. annuus parents. • Key results: An obligate requirement for short-day induced flowering has evolved repeatedly in Helianthus, and this character was correlated with geographic ranges restricted to the southern United States. Parental flowering times under long days were recovered in high proportion in the F3 generation. • Conclusions: Together, these findings (1) reveal that substantial variation in the nature of flowering time responses to photoperiod cues has arisen during the evolution of wild sunflowers and (2) suggest these transitions may be largely characterized by simple genetic architectures. Thus, introgression of wild alleles may be a tractable means of genetically tailoring sunflower cultivars for climate-specific production. [ABSTRACT FROM AUTHOR]

A high-resolution genetic map of sunflower was constructed by integrating SNP data from three F2 mapping populations (HA 89/RHA 464, B-line/RHA 464, and CR 29/RHA 468). The consensus map spanned a total length of 1443.84 cM, and consisted of 5,019 SNP markers derived from RAD tag sequencing and 118 publicly available SSR markers distributed in 17 linkage groups, corresponding to the haploid chromosome number of sunflower. The maximum interval between markers in the consensus map is 12.37 cM and the average distance is 0.28 cM between adjacent markers. Despite a few short-distance inversions in marker order, the consensus map showed high levels of collinearity among individual maps with an average Spearman's rank correlation coefficient of 0.972 across the genome. The order of the SSR markers on the consensus map was also in agreement with the order of the individual map and with previously published sunflower maps. Three individual and one consensus maps revealed the uneven distribution of markers across the genome. Additionally, we performed fine mapping and marker validation of the rust resistance gene R12, providing closely linked SNP markers for marker-assisted selection of this gene in sunflower breeding programs. This high resolution consensus map will serve as a valuable tool to the sunflower community for studying marker-trait association of important agronomic traits, marker assisted breeding, map-based gene cloning, and comparative mapping. [ABSTRACT FROM AUTHOR]

A high-resolution genetic map of sunflower was constructed by integrating SNP data from three F2 mapping populations (HA 89/RHA 464, B-line/RHA 464, and CR 29/RHA 468). The consensus map spanned a total length of 1443.84 cM, and consisted of 5,019 SNP markers derived from RAD tag sequencing and 118 publicly available SSR markers distributed in 17 linkage groups, corresponding to the haploid chromosome number of sunflower. The maximum interval between markers in the consensus map is 12.37 cM and the average distance is 0.28 cM between adjacent markers. Despite a few short-distance inversions in marker order, the consensus map showed high levels of collinearity among individual maps with an average Spearman's rank correlation coefficient of 0.972 across the genome. The order of the SSR markers on the consensus map was also in agreement with the order of the individual map and with previously published sunflower maps. Three individual and one consensus maps revealed the uneven distribution of markers across the genome. Additionally, we performed fine mapping and marker validation of the rust resistance gene R12, providing closely linked SNP markers for marker-assisted selection of this gene in sunflower breeding programs. This high resolution consensus map will serve as a valuable tool to the sunflower community for studying marker-trait association of important agronomic traits, marker assisted breeding, map-based gene cloning, and comparative mapping. [ABSTRACT FROM AUTHOR]

Our study investigated the accumulation of chromium, nickel, lead and cadmium by maize (Zea mays L.), sunflower (Helianthus annuus L.), willow (Salix x smithiana Willd.), and poplar (Populus nigra L. x P. maximowiczii), and the relationship between the contaminants in soil and in plants. The experiment was performed in contaminated soil (former waste incineration plant) at the Hradec Králové (Czech Republic) site. Plant and soil samples were collected from three plots with different risk element contents (higher amounts of Cd, Cu, Hg, Zn, Cr, Ni, and Pb). The total and available soil metal concentrations in soil were investigated. Only a low portion of risk elements were available for plants (6%Ni, 14% Cd, 1.3 % Pb, and less than 1% of Cr). Chromium, nickel, and lead showed a similar trend to element accumulation where the highest amount was found in plant roots, higher in herbs than in trees (6.83 mg Cr⋅kg-1, 5.04 mg Ni⋅kg-1, and 7.76 mg Pb⋅kg-1). The highest cadmium concentration was found in leaves of willow (1.87 mg Cd⋅kg-1) and roots of willow (3.05 mg Cd⋅kg-1). The correlation between the concentration of risk elements in soil and in plants was the highest in the case of lead reaching up to R= 0.89. Results also indicated that translocation of Cr, Ni, Cd, and Pb from roots to aboveground biomass of willow and poplar was low (89-98% of risk elements was retained in roots). The highest translocation from plant roots to aboveground biomass of maize and sunflower was found in the case of Cd and Pb (57 and 83% of Cd, 56 and 76% of Pb). The behaviour of these elements concerning soil and plants differed among fields with unknown history of contamination and type of contaminants. [ABSTRACT FROM AUTHOR]

Genus Helianthus comprises diploid and polyploid species. An autoallopolyploid origin has been proposed for hexaploid species but the genomic relationships remain unclear. Mitotic and meiotic studies in annual Helianthus annuus (2 n = 2 x = 34) and perennial Helianthus resinosus (2 n = 6 x = 102) as well as the F hybrids between both species were carried out. Chromosome counting confirmed the hybrid origin of the latter plants and their tetraploid condition. Bivalents in hybrids ranged from 12 to 28 ( $$ \bar{x} $$ = 20.8). Univalents, trivalents and quadrivalents were also observed. Meiotic products comprised dyads, triads and normal tetrads and pollen grains were heterogeneous in size. These observations suggest the occurrence of 2 n pollen in addition to the expected n. Genomic in situ hybridization (GISH) of total H. annuus DNA on H. resinosus chromosomes rendered weak but uniform signals; similar hybridization pattern was observed using three other annual species. Hybridization with H. annuus probe performed on root tip cells of F H. annuus × H. resinosus hybrids revealed 17 chromosomes with a strong hybridization signal. GISH in hybrid meiocytes distinguished chromosomes from parental species and revealed autosyndetic pairing of H. resinosus chromosomes, allosyndetic pairing in bivalents, trivalents and quadrivalents, and the presence of univalents derived from parents, H. annuus and H. resinosus. Results obtained from classical and molecular cytogenetics do not support H. annuus as a direct ancestor of H. resinosus. The occurrence of allosyndetic pairing and the relatively high fertility of the F hybrids point to the possibility that useful genes could be transferred from H. resinosus to cultivate sunflower, although the effective rate of recombination has not been evaluated. GISH method proved effective to recognize parental chromosomes in H. annuus × H. resinosus progeny. [ABSTRACT FROM AUTHOR]

Sunflower crop sowed with densities of distance between plants (25,30, 35,40 cm) for three varieties Mangarin, Azur and Locc carried out with the factorial experiment in Randomized Complete Block Design (RCBD) in the field of Agricultural Technical College Alrashidia - Mosul at autumn season 2011 to study it's effect on growth and yield. The results showed that the variety Azur had a good performance for plant height, individual plant seeds yield and total seeds yield characters, the distance 25cm between plants were which achieved an increase in plant height, stem diameter and total seeds yield, a decrease in the average of characteristics when increasing the distance between the plants was shown, The interaction between Locc variety and distance 25cm between plants was higher in total seeds yield . [ABSTRACT FROM AUTHOR]

The present investigation was carried out during 2010 and 2011 seasons to study the effects of inbreeding depression in sunflower. In 2010 season, Giza102 an open-pollinated cultivar of sunflower was planted at Shandaweel Agric. Res. Stn., ARC. 100 plants were selected and selfed. After harvest, 23 S1 lines which produced enough seed were chosen for evaluation in the next season. In 2011 season, 23 S1 lines and Giza102 were evaluated in Randomized Complete Block Design (RCBD) experiment with three replicates. Data were recorded on days to 50% flowering, days to maturity, plant height, stalk diameter, head diameter, 100-achene weight, achene yield/plant, achene yield/plot and oil content. Analy-sis of variance revealed highly significant differences among S1 lines for all stud-ied traits. Broad sense heritability showed high estimates for all the studied traits. Phenotypic coefficient of variability (P.C.V) for various traits were relatively higher than genotypic coefficient of variability (G.C.V) for the S1 per se. Oil con-tent was negatively and not significant correlated with head diameter, 100-achene weight, achene yield/plant and achene yield/plot. Achene yield/plot was posi-tively and significant correlated with head diameter, 100-achene weight and yield/plant. The reduction of yield/plot of the S1 lines was 2.68% of the base pop. Achene yield/plot of 10 S1 lines per se were significantly or highly significantly fewer than the base pop. Giza102, while 8 S1 lines per se exceeded significantly or highly significant than the base pop. Giza102. The decrease in oil content due to inbreeding was 2.25%. Most of the S1 lines were less than the base population. The best ten S1 lines per se were Nos.1, 7, 11, 14, 15, 16, 17, 18, 20 and 21, which gave the higher oil content and some other desirable character were selected and used as parents to produce the first cycle selection. [ABSTRACT FROM AUTHOR]

To locate the somatic embryogenesis genes and select their relevant markers for marker - assisted selection in sunflower, 31 recombinants inbred lines F8 (RILs) derived from the cross between PAC - 2 and RH A - 266 were investigated. Somatic embryogenesis was induced using the thin epidermal layers from seedling hypocotyls. 3 QTLs associated with number of epidermal embryogenesis per 100 epidermis cultured ( EE/EC % ) were located at linkage group 5,10,13. They could explain the phenotypic variation of 14. 61%,10. 04% and 14. 07% respectively. In addition, 9 QTLs associated with number of embryos per epidermal embryogenesis ( E / E E ) were located at linkage group 2, 8, 10, 11, 12 and 19. They could explain the phenotypic variation of 6. 64% to 16. 96% . Four QTLs of them were located at linkage group 10 and their distance were shortened from 34. 57 cM to 47. 10cM. They could explain the phenotypic variation of 40. 3 9 % . In order to verify the results obtained and to increase the density of markers in the mapping of the QTL regions for selecting their relevant markers, the parameter of EE/EC % was determined by the following test. Two F2 populations were obtained by cross between 2 RILs with one high somatic embryogenesis and one low each. AFLP and SSR markers were used to scan these two F2 populations. 24, 6 and 18 new markers were got on linkage group 5,10,13 respectively, and 6, 0 and 4 new markers correlated with the somatic embryogenesis were added to their QTL regions respectively. The intervals of these three linkage groups were shortened from 6. 80 - 11. 40cM to 5. 10 - 5 . 60cM. The genotypes of the F2 lines were compared to their parents and grand - parents in QTL regions of EE/EC % . Seven lines with a high somatic embryogenesis capability and 7 lines with a low capability were preselected. The induced somatic embryogenesis of F3 families verified the preselected results. Genes controlling E/EE were located mainly at linkage group 10. The genes controlling EE/EC% were located mainly at linkage group 5 and 13. Four markers (e32m50 - 1, e38m49 - 2, e40m49 - 1, e32m62 - 10) were the closest markers to the genes of somatic embryogenesis. They could be used in marker - assisted selection. [ABSTRACT FROM AUTHOR]

During the period 2010-2012, on the experimental field of the Field Crops Institute - Chirpan was carried out a field experiment with oil-bearing sunflower (Helianthus annuus). A total of 18 variants from the three technologies for oil-bearing sunflower growing were investigated - conventional (hybrid Arena), Clearfield (hybrid Alego) and ExpressSun (hybrid P64LE20). Vegetation-applied herbicides Goal, Raft and Pledge combined with the soil-applied herbicide Pelican provide good control of annual broadleaved weeds in conventional technology for sunflower growing. Combinations of herbicides Stomp, Wing with herbicide Pelican can be applied to mixed weeding from annual grassy and some broadleaved weeds, but with the absence of Xanthium strumarium, Cirsium arvense and Convolvulus arvensis. Herbicide combination Modown + Pelican should be used in secondary weeding primarily from annual broadleaved weeds, but with the absence of Xanthium strumarium. Herbicide tank mixtures Pulsar + Stomp by Clearfield technology and Express + Stratos ultra by ExpressSun technology completely destroyed all annual and perennial grassy and broadleaved weeds. Vegetation use of herbicides by conventional technology causes high phytotoxicity on sunflower. Phytotoxicity was the highest by herbicide Goal, followed by Pledge. Phytotoxicity is weaker by herbicides Stomp, Raft, Wing and Modown. Treatment of growth stimulator Amalgerol premium with herbicides Goal, Raft, Wing, Pledge and Modown as tank mixtures increases the selectivity of these herbicides. [ABSTRACT FROM AUTHOR]

Field margins are key landscape features sustaining biodiversity in farmland mosaics and through that, ecosystem services. However, agricultural intensification has encouraged fencerow removal to enlarge cropping areas, reducing farmland biodiversity and its associated ecosystems services. In the present work, we assess the role of field margins in retaining farmland biodiversity across the sunflower cropping area of Argentina. Flower-visiting insects and entomophilous plants were intensively sampled along the margins of sunflower fields, in eight locations across eastern Argentina. We recorded 149 species of flowering plants and 247 species of flower-visitors. Plants and arthropods were mostly natives. Most of the floral visi-tors captured provide ecosystem services to agriculture. Our results show that many species of beneficial insects and native plants occur in semi-natural linear features in the intensively managed farmland of Argentina. Field margins may constitute the last refugia of native plant species and their associated fauna in farmland mosaics. Conservation of field margins in Argentine farmland may therefore be essential for preserving biodiversity and associated ecosystem services. [ABSTRACT FROM AUTHOR]

Two well-known methods of root porosity measurement (i.e. buoyancy and cross-sectional) were used to evaluate the porosity of adventitious roots of 3-day hypoxia treated sunflower (Helianthus annus L.) cultivars to address the effect of hypoxia on root porosity as well as advantages and disadvantages of each method. In the first experiment, length of adventitious roots of two sunflower cultivars (CMS14 × R-864 and Hysun-33) was divided to three segments as apical, middle, and basal portions and porosity was measured via both methods. In buoyancy method, root porosities of Hysun-33 and CMS14 × R-864 cultivars were 5.12% and 6.47% in aerated and 11.58% and 15.71% in hypoxic condition, respectively. There is no statistically significant difference between cultivars in aerated condition. In contrast, more than twice additional aerenchyma formation was observed due to hypoxic condition in comparison to aerated condition. Results of cross-sectional method showed that middle portion of adventitious roots is the place that aerenchyma initiates to form, but well-developed aerenchyma was seen at about 80-90 mm behind the root apex (basal portion) under hypoxia. The results of root porosity of basal portion of adventitious roots of four sunflower cultivars (CMS14 × R-864, CMS51 × R-14, CMS19 × R-N1-118 and Hysun-33) showed higher amounts of root porosity in buoyancy method in comparison to cross-sectional method. [ABSTRACT FROM AUTHOR]