Sunflower Populations Research Articles

Clinal Variation in Short Tandem Repeats Linked to Gene Expression in Sunflower (Helianthus annuus L.).

Short tandem repeat (STR) variation is rarely explored as a contributor to adaptive evolution. An intriguing mechanism involving STRs suggests that STRs function as "tuning knobs" of adaptation whereby stepwise changes in STR allele length have stepwise effects on phenotypes. Previously, we tested the predictions of the "tuning knob" model at the gene expression level by conducting an RNA-Seq experiment on natural populations of common sunflower (Helianthus annuus L.) transecting a well-defined cline from Kansas to Oklahoma. We identified 479 STRs with significant allele length effects on gene expression (eSTRs). In this study, we expanded the range to populations further north and south of the focal populations and used a targeted approach to study the relationship between STR allele length and gene expression in five selected eSTRs. Seeds from 96 individuals from six natural populations of sunflower from Nebraska and Texas were grown in a common garden. The individuals were genotyped at the five eSTRs, and gene expression was quantified with qRT-PCR. Linear regression models identified that eSTR length in comp26672 was significantly correlated with gene expression. Further, the length of comp26672 eSTR was significantly correlated with latitude across the range from Nebraska to Texas. The eSTR locus comp26672 was located in the CHUP1 gene, a gene associated with chloroplast movement in response to light intensity, which suggests a potential adaptive role for the eSTR locus. Collectively, our results from this targeted study show a consistent relationship between allele length and gene expression in some eSTRs across a broad geographical range in sunflower and suggest that some eSTRs may contribute to adaptive traits in common sunflower.

Characterization of Argentinian wild Helianthus annuus populations in their responses to Plasmopara halstedii infection

The pathogen Plasmopara halstedii, causing downy mildew (DM), is a widespread sunflower disease which can be controlled by single dominant genes. Wild Helianthus annuus have been a valuable source of vertical resistance to control P. halstedii, but such resistance may eventually be overcome by new races of the pathogen. Alternatively, quantitative, or partial resistance, is more stable and may be combined with vertical resistance to prevent DM outbreaks. We assessed the responses of six populations of wild H. annuus naturalized in Argentina to race 710 of P. halstedii. We examined: 1) the aerial phenotype (including seedling death) using two damage scales and three disease indices, 2) the growth of the pathogen along the hypocotyls, and 3) the presence of the pathogen in the root system. We found that the evaluated sunflower wild populations had lower disease levels than the susceptible cultivated controls. A histologic analysis showed that the wild H. annuus seedlings showed cellular reactions (e.g. necrosis and the deposit of materials on the walls of invaded cells) to restrict the pathogen’s growth, allowing the identification of two possible types of resistance: type I, when the growth of the pathogen was limited to the base of the hypocotyls, and type II, when the pathogen managed to invade the entire length of the hypocotyls. The wild sunflower populations also showed differential responses to root infections. A quantitative or partial genetic resistance, rather than resistance based on major genes, seems to be operating in the sampled populations. The individuals found to be resistant in each population represent promising germplasm for sunflower breeding.

Importance of pollinator diversity for sunflower seed production

The sunflower (Helianthus annuus Linnaeus) is one of the most important food crops in the world. In modern agroecology, this pivotal plant is deeply intertwined with diverse pollination mechanisms. This study elucidates the multifaceted contributions of various pollinator taxa, delving into their respective efficiencies and behaviors vis-à-vis sunflower reproductive success. The honeybee (Apis mellifera Linnaeus, 1758) plays a central role in sunflower pollination, transferring pollen over large distances, thereby bolstering the genetic diversity of sunflower populations. While sunflowers derive immense benefits from honeybee pollination, they reciprocally offer their pollen as vital nutrition for bee larvae. However, this symbiotic relationship is nuanced, with honeybees occasionally exhibiting selectivity based on sunflower cultivar. While honeybees are paramount, the richness of the ecosystem is further accentuated by the presence of other pollinators, each contributing uniquely to the sunflower’s lifecycle. The foraging fidelity of solitary bees, such as the leafcutter bee (Megachile spp.) and mason bee (Osmia spp.), underscores their indispensable role in cross-pollination. Bumblebees (Bombus spp.) introduce a fascinating "buzz pollination" mechanism, leveraging vibrations to optimize pollen release. Simultaneously, wasps provide functions beyond pollination, serving as biocontrol agents by preying on detrimental pests. Surprisingly, mosquitoes appeared to also be contributors to pollination, especially when traditional pollinators are scarce, with their nocturnal tendencies augmenting pollination continuity. Hoverflies render dual benefits: they aid in pollination and their larvae predate on pests. While butterflies are primarily nectar-oriented, they inadvertently partake in pollen transfer. Moths, through their nocturnal activities, complement pollination. Beetles, often overlooked, act as secondary pollinators. Regrettably, contemporary agricultural practices often disrupt this ecological equilibrium. Pervasive pesticide use and habitat fragmentation imperil these pollinators, underscoring the urgent need for pollinator-friendly approaches. As climate conditions fluctuate, understanding these pollinator dynamics becomes increasingly critical. This comprehensive examination advocates for holistic conservation strategies, targeting sustained sunflower yields and broader ecosystem resilience.

Genetic variability and association studies in BC3F1 population of sunflower (Helianthus annuus L.)

Genetic variability and association studies in BC3F1 population of sunflower (Helianthus annuus L.)

Fifty years of collecting wild Helianthus species for cultivated sunflower improvement

Abstract Wild Helianthus species have been undeniably beneficial in sustaining the sunflower crop by providing plant breeders with a diverse genetic pool of potentially useful traits. Exploration to collect populations of wild sunflowers is one of the more difficult and challenging activities in the conservation and utilization of these valuable genetic resources. The logistics of collecting requires careful planning, locating the target species, obtaining permission to access and collect, and timing the exploration to ensure the availability of mature seed. The US Department of Agriculture, Agricultural Research Service (USDA-ARS) established the wild Helianthus seed collection in 1976 at Bushland, Texas with the goal of collecting and conserving the broadest representative genetic diversity possible and serving as a central repository of germplasm and related information. In 1985 this collection was transferred to UDSA-ARS, North Central Regional Plant Introduction Station, Ames, Iowa. Over the last half century, 37 explorations were undertaken covering 175,000 km to collect the 53 Helianthus species from their distributional ranges in the forty-eight conterminous states in the US, three Canadian Providences (Manitoba, Saskatchewan, and Alberta), Argentina and Australia. The many explorations have created a global crop wild relatives (CWR) genebank collection. The current wild CWR sunflower genebank contains 2562 accessions of 53 species with 1065 wild Helianthus annuus accessions (42 %), 617 accessions representing populations of the 13 other wild annual species (24 %), and 880 accessions representing 39 perennial species (34 %). This collection is the largest and most genetically diverse ex situ sunflower collection in the world and is vital to the conservation of wild sunflower species for the global sunflower community.

First Report of Powdery Mildew Caused by Golovinomyces latisporus on Helianthus annuus in the Arizona.

Helianthus annuus, known as the common sunflower, is an annual plant indigenous to the United States. The crop is grown for its edible oil, seeds, and as an ornamental. In November 2021, powdery mildew-like signs and symptoms were observed on sunflower in a house garden located at Fortuna Foothills, Yuma County, AZ (32.6725°N, 114.4329°W). Signs of powdery mildew included white blotches of amphigenous and caulicolous mycelia. Initially, signs appeared as circular spots that expanded over the entire leaf and were also observed later on petioles and stems. Fungal hyphae were branched, septate, and with nipple-shaped appressoria. Foot cells of conidiophores were erect, cylindrical, and followed by one to three short cells bearing conidia. The conidiophores were hyaline, straight, cylindrical and produced short chains of up to four immature conidia. Conidia were ovoid to ellipsoid, seldom cylindrical, without-fibrosin bodies and measured 25 to 40 μm in length (mean= 34 μm) and 16 to 24 μm in width (mean= 18.6 μm) (n = 10), with an average length: width ratio of 1.8. The germination of conidia was Euoidium type with short germ tube. Chasmothecium formation was not detected. As the disease progressed, the infected leaves became wilted and senesced. The morphological characteristics of this fungus were in accordance with those described for G. latisporus (Braun and Cook, 2012; Qiu et al., 2020). For molecular identification, genomic DNA was isolated from fungal colonies using the DNeasy Plant kit (Qiagen). The internal transcribed spacer (ITS), large ribosomal subunit (28S), intergenic spacer (IGS), beta- tubulin (TUB2) and chitin synthase 1 (CHS1) regions were amplified using the primer sets, ITS5/ITS4 (White et al., 1990), LSU1/LSU2 (Scholin et al., 1994), IGS-12a/NS1R (Carbone and Kohn, 1999), TubF1/TubR1 and gCS1a1/gCS1b (Qiu et al., 2020). Sequences were submitted in the GenBank under accession numbers OP160535 (ITS), OP153874 (28S rDNA), OP160534 (IGS), OP168959 (TUB2) and OP168960 (CHS1). A BLAST search revealed 98.7 to 100-% identity to G. latisporus sequences (MK452603, NG_068877, MK452520, MK452476, and MK452428). Phylogenetic analysis based on the combined sequence datasets of ITS+28S rDNA+IGS+TUB2+CHS1 also grouped Yuma isolate in a monophyletic clade with G. latisporus accessions from Qiu et al. (2020). A pathogenicity test was carried out by inoculating four sunflower varieties (Velvet queen, Evening sun, Skyscraper and Mammoth). Conidia from infected leaves were dusted on the leaves of 10 individually potted, five-week-old seedlings of each variety. Four seedlings of each variety were not inoculated and served as controls. The inoculated and control plants were then kept in two separate greenhouses at 25-28°C at the Yuma Agricultural Center, Yuma, AZ. Inoculated plants started showing symptoms of powdery mildew within 7 days of inoculation, while the control plants stayed healthy and disease-free. The morphological characteristics of powdery mildew fungus on the inoculated plants were identical to the isolate collected from the garden, with the same sequence following PCR as above, thus fulfilling Koch's postulates. G. latisporus has been previously reported on common sunflower from Washington and California states (Qiu et al., 2020), however, this is a first report from Arizona. Although sunflower is not a major crop in Arizona, the wild sunflower population could serve as reservoir for the spread of the disease.

Gene regulatory network inference methodology for genomic and transcriptomic data acquired in genetically related heterozygote individuals.

Inferring gene regulatory networks in non-independent genetically related panels is a methodological challenge. This hampers evolutionary and biological studies using heterozygote individuals such as in wild sunflower populations or cultivated hybrids. First, we simulated 100 datasets of gene expressions and polymorphisms, displaying the same gene expression distributions, heterozygosities and heritabilities as in our dataset including 173 genes and 353 genotypes measured in sunflower hybrids. Secondly, we performed a meta-analysis based on six inference methods [least absolute shrinkage and selection operator (Lasso), Random Forests, Bayesian Networks, Markov Random Fields, Ordinary Least Square and fast inference of networks from directed regulation (Findr)] and selected the minimal density networks for better accuracy with 64 edges connecting 79 genes and 0.35 area under precision and recall (AUPR) score on average. We identified that triangles and mutual edges are prone to errors in the inferred networks. Applied on classical datasets without heterozygotes, our strategy produced a 0.65 AUPR score for one dataset of the DREAM5 Systems Genetics Challenge. Finally, we applied our method to an experimental dataset from sunflower hybrids. We successfully inferred a network composed of 105 genes connected by 106 putative regulations with a major connected component. Our inference methodology dedicated to genomic and transcriptomic data is available at https://forgemia.inra.fr/sunrise/inference_methods. Supplementary data are available at Bioinformatics online.

A comparative study of population genetic structure reveals patterns consistent with selection at functional microsatellites in common sunflower.

Microsatellites, also known as short tandem repeats (STRs), have long been considered non-functional, neutrally evolving regions of the genome. Recent findings suggest that they can function as drivers of rapid adaptive evolution. Previous work on the common sunflower identified 479 transcribed microsatellites where allele length significantly correlates with gene expression (eSTRs) in a stepwise manner. Here, a population genetic approach is used to test whether eSTR allele length variation is under selection. Genotypic variation among and within populations at 13 eSTRs was compared with that at 19 anonymous microsatellites in 672 individuals from 17 natural populations of sunflower from across a cline running from Saskatchewan to Oklahoma (distance of approximately 1600km). Expected heterozygosity, allelic richness, and allelic diversity were significantly lower at eSTRs, a pattern consistent with higher relative rates of purifying selection. Further, an analysis of variation in microsatellite allele lengths (lnRV), and heterozygosities (lnRH), indicate recent selective sweeps at the eSTRs. Mean microsatellite allele lengths at four eSTRs within populations are significantly correlated with latitude consistent with the predictions of the tuning-knob model which predicts stepwise relationships between microsatellite allele length and phenotypes. This finding suggests that shorter or longer alleles at eSTRs may be favored in climatic extremes. Collectively, our results imply that eSTRs are likely under selection and that they may be playing a role in facilitating local adaptation across a well-defined cline in the common sunflower.

Mutation Load in Sunflower Inversions Is Negatively Correlated with Inversion Heterozygosity.

Recombination is critical both for accelerating adaptation and purging deleterious mutations. Chromosomal inversions can act as recombination modifiers that suppress local recombination in heterozygotes and thus, under some conditions, are predicted to accumulate such mutations. In this study, we investigated patterns of recombination, transposable element abundance, and coding sequence evolution across the genomes of 1,445 individuals from three sunflower species, as well as within nine inversions segregating within species. We also analyzed the effects of inversion genotypes on 87 phenotypic traits to test for overdominance. We found significant negative correlations of long terminal repeat retrotransposon abundance and deleterious mutations with recombination rates across the genome in all three species. However, we failed to detect an increase in these features in the inversions, except for a modest increase in the proportion of stop codon mutations in several very large or rare inversions. Consistent with this finding, there was little evidence of overdominance of inversions in phenotypes that may relate to fitness. On the other hand, significantly greater load was observed for inversions in populations polymorphic for a given inversion compared to populations monomorphic for one of the arrangements, suggesting that the local state of inversion polymorphism affects deleterious load. These seemingly contradictory results can be explained by the low frequency of inversion heterozygotes in wild sunflower populations, apparently due to divergent selection and associated geographic structure. Inversions contributing to local adaptation represent ideal recombination modifiers, acting to facilitate adaptive divergence with gene flow, while largely escaping the accumulation of deleterious mutations.

Total and chloroplast proteins of the leaves of cultivated, population and wild sunflower varieties cultivated under thermic stress

Sunflower (Helianthus annus L) cultivation is affected by periods of severe drought that affect the growth and yield of sunflower crops. Wild sunflower species have brought many agronomically important traits to cultivated sunflower by quickly allowing them to undergo biotic and abiotic changes in their environment. Plants have developed several mechanisms that would enable them to tolerate high temperatures related to thermotolerance at the biochemical and metabolic levels. The present study aimed to highlight the variability of total and chloroplast proteins extracted from the wild and populations of sunflower leaves grown under different thermal stresses. The total proteins extracted from controlled and thermic stress leaves, characterized by SDS page were similar except polypeptides of molecular weight (MW) 42 kDa, 35 kDa, 31 kDa and 13.5 kDa which showed variability of sunflower varieties studied. Under thermic stress, the MW of chloroplast proteins was similar in the H petiolaris fallax and H praecox runyonni varieties. The protein markers of wild sunflower species revealed in response to thermal stresses contribute to the improvement of sunflowers in the face of environmental challenges.

Rapid Evolution of Seed Dormancy During Sunflower De-Domestication.

Hybridization between crops and their wild relatives may promote the evolution of de-domesticated (feral) weeds. Wild sunflower (Helianthus annuus L.) is typically found in ruderal environments, but crop-wild hybridization may facilitate the evolution of weedy populations. Using 1 crop-specific mitochondrial marker (CMS-PET1) and 14 nuclear SSR markers, we studied the origin and genetic diversity of a recently discovered weedy population of sunflower (named BRW). Then, using a resurrection approach, we tested for rapid evolution of weedy traits (seed dormancy, herbicide resistance, and competitive ability) by sampling weedy and wild populations 10 years apart (2007 and 2017). All the weedy plants present the CMS-PET1 cytotype, confirming their feral origin. At the nuclear markers, BRW showed higher genetic diversity than the cultivated lines and low differentiation with one wild population, suggesting that wild hybridization increased their genetic diversity. We found support for rapid evolution towards higher seed dormancy, but not for higher competitive ability or herbicide resistance. Our results highlight the importance of seed dormancy during the earliest stages of adaptation and show that crop-wild hybrids can evolve quickly in agricultural environments.

Genetic basis and dual adaptive role of floral pigmentation in sunflowers.

Variation in floral displays, both between and within species, has been long known to be shaped by the mutualistic interactions that plants establish with their pollinators. However, increasing evidence suggests that abiotic selection pressures influence floral diversity as well. Here, we analyse the genetic and environmental factors that underlie patterns of floral pigmentation in wild sunflowers. While sunflower inflorescences appear invariably yellow to the human eye, they display extreme diversity for patterns of ultraviolet pigmentation, which are visible to most pollinators. We show that this diversity is largely controlled by cis-regulatory variation affecting a single MYB transcription factor, HaMYB111, through accumulation of ultraviolet (UV)-absorbing flavonol glycosides in ligules (the 'petals' of sunflower inflorescences). Different patterns of ultraviolet pigments in flowers are strongly correlated with pollinator preferences. Furthermore, variation for floral ultraviolet patterns is associated with environmental variables, especially relative humidity, across populations of wild sunflowers. Ligules with larger ultraviolet patterns, which are found in drier environments, show increased resistance to desiccation, suggesting a role in reducing water loss. The dual role of floral UV patterns in pollinator attraction and abiotic response reveals the complex adaptive balance underlying the evolution of floral traits.

Reakcija populacija Xanthium strumarium L. i Helianthus annuus L. na nikosulfuron

Weedy sunflower, Helianthus annuus L. is an economically very important, invasive species widely distributed in many regions of the world, especially in the areas where sunflower hybrids tolerant to some als-inhibiting herbicides are intensively cultivated. The discovery and development of a new technology in cultivated sunflower increased the emergence of resistant biotypes due to high selection pressure and spontaneous hybridisation (transfer of genes responsible for tolerance from crop to wild species). This study examined the responses of two populations of weedy sunflower (HELAN 1 and HELAN 2) to nicosulfuron and imazamox in bioassay under greenhouse conditions. The experiment included five treatments with different application rates of imazamox (12, 24, 48, 96 and 192 g ha-1) and nicosulfuron (10, 20, 40, 80 and 160 g ha-1) that were applied over plants at their growth stage of 2-3 pairs of developed leaves. In addition to the visual assessment of plant damage, which was performed 7, 14, 21 and 28 days after the herbicide application, the following parameters were also measured: fresh and dry weight. The obtained results indicate changes in the sensitivity of the examined weedy sunflower populations to als inhibitors. Reduced sensitivity of the HELAN 1 to imazamox and HELAN 2 to nicosulfuron suggests a possible development of resistant populations of weedy sunflower in the Surčin area.

Отбор на устойчивость к заразихе расы G из популяции кондитерского подсолнечника

The purpose of the work was to develop forms of confectionary sunflower resistant to broomrape race G on artificial infection background both in fields and greenhouses and artificial climate chambers. The researches were conducted in V.S. Pustovoit All-Russian Research Institute of Oil Crops, Krasnodar, Russia, in 2019–2021. A line RG (Or7) was used as a donor of gen of resistance to broomrape race G. The confectionary sunflower variety SPK plus was a recipient. Using methods of hybridization, back-crosses and group interpollination, on severe infection background, a sunflower population resistant to the aggressive broomrape race was develop for the further breeding of confectionary sunflower varieties. These methods allowed increasing resistance step-by-step while maintaining high polymorphism that makes it possible to continue breeding of confectionary sunflower varieties for the further rise of productivity.

Shattercane (Sorghum bicolor (L.) Moench Subsp. Drummondii) and Weedy Sunflower (Helianthus annuus L.)—Crop Wild Relatives (CWRs) as Weeds in Agriculture

Shattercane (Sorghum bicolor (L.) Moench subsp. drummondii) and weedy sunflower (Helianthus annuus L.) are two examples of crop wild relatives (CWRs) that have become troublesome weeds in agriculture. Shattercane is a race belonging to a different subspecies than domesticated sorghum (Sorghum bicolor (L.) Moench subsp. bicolor). Weedy sunflower populations are natural hybrids between wild and domesticated sunflower (Helianthus annuus L.). Both species have key weedy characteristics, such as early seed shattering and seed dormancy, which play an important role in their success as agricultural weeds. They are widely reported as important agricultural weeds in the United States and have invaded various agricultural areas in Europe. Shattercane is very competitive to sorghum, maize (Zea mays L.), and soybean (Glycine max (L.) Merr.). Weedy sunflower causes severe yield losses in sunflower, maize, soybean, pulse crops, and industrial crops. Herbicide resistance was confirmed in populations of both species. The simultaneous presence of crops and their wild relatives in the field leads to crop–wild gene flow. Hybrids are fertile and competitive. Hybridization between herbicide-tolerant crops and wild populations creates herbicide-resistant hybrid populations. Crop rotation, false seedbed, cover crops, and competitive crop genotypes can suppress shattercane and weedy sunflower. Preventative measures are essential to avoid their spread on new agricultural lands. The development of effective weed management strategies is also essential to prevent hybridization between sorghum, sunflower, and their wild relatives and to mitigate its consequences.

Manipulation of sunflower population density and herbicide rate for economical and sustainable weed management

Field study tested weed control efficacy, crop yield and economic return using various weed management strategies in sunflower growing with different population density. Treatments included four rates of PRE emergence application of S-metolachlor + fluchloridon and one POST emergence application of flumioxazin + quizalofop-pethyl. PRE-em application (1.4 + 2.4 and 1.2 + 2.0) provided at the higher crop densities (70 000) best weed control. However, PRE- em treatments with lower doses (0.8 + 1.6 and 1.0 + 1.8) and POST- em application did not maintain acceptable control of dominant weeds. Grain yield increased with the crop density, but did not statistically differ between applied herbicide treatments. Finally, the implication of this study demonstrated that sole application of tested herbicide treatments at higher crop sowing density (60 000 and 70 000) was found to be economically the best alternative strategy for reducing weed infestation and achieving a better yield.

On-field phenotypic evaluation of sunflower populations for broad-spectrum resistance to Verticillium leaf mottle and wilt

Sunflower Verticillium Wilt and Leaf Mottle (SVW), caused by Verticillium dahliae (Kleb.; Vd), is a soil-borne disease affecting sunflower worldwide. A single dominant locus, known as V1, was formerly effective in controlling North-American Vd races, whereas races from Argentina, Europe and an emerging race from USA overcome its resistance. This emphasizes the need for identifying broad-spectrum genetic resistance (BSR) sources. Here we characterize two sunflower mapping populations (MPs) for SVW resistance: a biparental MP and the association MP from the National Institute of Agricultural Technology (INTA), under field growing conditions. Nine field-trials (FTs) were conducted in highly infested fields in the most SVW-affected region of Argentina. Several disease descriptors (DDs), including incidence and severity, were scored across four phenological stages. Generalized linear models were fitted according to the nature of each variable, adjusting mean phenotypes for inbred lines across and within FTs. Comparison of these responses allowed the identification of novel BSR sources. Furthermore, we present the first report of SVW resistance heritability, with estimates ranging from 35 to 45% for DDs related to disease incidence and severity, respectively. This study constitutes the largest SVW resistance characterization reported to date in sunflower, identifying valuable genetic resources for BSR-breeding to cope with a pathogen of increasing importance worldwide.

A TILLING by sequencing approach to identify induced mutations in sunflower genes

The Targeting Induced Local Lesions in Genomes (TILLING) technology is a reverse genetic strategy broadly applicable to every kind of genome and represents an attractive tool for functional genomic and agronomic applications. It consists of chemical random mutagenesis followed by high-throughput screening of point mutations in targeted genomic regions. Although multiple methods for mutation discovery in amplicons have been described, next-generation sequencing (NGS) is the tool of choice for mutation detection because it quickly allows for the analysis of a large number of amplicons. The aim of the present work was to screen a previously generated sunflower TILLING population and identify alterations in genes involved in several important and complex physiological processes. Twenty-one candidate sunflower genes were chosen as targets for the screening. The TILLING by sequencing strategy allowed us to identify multiple mutations in selected genes and we subsequently validated 16 mutations in 11 different genes through Sanger sequencing. In addition to addressing challenges posed by outcrossing, our detection and validation of mutations in multiple regulatory loci highlights the importance of this sunflower population as a genetic resource.

The Effect Of The Harvest Stages And Additives On The Silage Value Of The Different Sunflower Populations

The research was carried out in the irrigated trial areas of Atatürk University Faculty of Agriculture in 2009 and 2010. 7 different local sunflower varieties (Edirne-black-seeded, Edirne-white-seeded, Erzurum-black-seeded, Erzurum-white-seeded, Kırklareli-black-seeded, Kırklareliwhite-seeded and Tekirdağ) from 3 different harvest times (table formation, full flowering and seed filling) were examined for silage. In the study, silage was carried out using 5 different additives (additive-control, 10% barley, 10% straw, 5% molasses, 1% salt). Dry matter ratio, crude protein ratio, ADF ratio, NDF ratio, relative feed value and pH values ​​were determined in silage. The results showed that local varieties, form times and additives have important effects on silage quality of sunflower. Using barley and molasses as additives significantly improves silage quality. Although the delay in form time decreased the crude protein ratio and increased the ADF and NDF ratios, it improved the dry matter ratio and silage pH.

Bazı Yerel Çerezlik Ayçiçeği (Helianthus annuus L.) Populasyonlarında Verim ve Verim Öğelerinin Belirlenmesi

Bu çalışmada, Türkiye’nin farklı bölgelerinden toplanan bazı yerel çerezlik ayçiçeği popülasyonların Tokat ekolojik koşullarında verim ve verim unsurlarının belirlenmesi amaçlanmıştır. Araştırma Tokat-Kazova ekolojik koşullarında dikdörtgen latis deneme desenine” göre, 3 tekerrürlü olarak, 2 yıl süre ile yürütülmüştür. Araştırmada bitki boyu, tabla çapı, tane eni, tane boyu, 1000 tane ağırlığı ve tohum verimi incelenmiştir. Projede materyal olarak ülkemizin farklı bölgelerinden toplanmış, 20 adet çerezlik ayçiçeği yerel populasyonu ile standart olarak iki adet tescilli çeşit kullanılmıştır. İki yılın ortalama sonuçlarına göre; bitki boyu değerleri 154.3-265.4 cm arasında, tabla çapı 17.0-22.2 cm, tane eni 7.9-9.6 mm, tane boyu 20.4-25.9 mm, 1000 tane ağırlığı 122.2-167.1 g ve tohum verimi 180.4-474.0 kg/da arasında değişmiştir. Araştırmada incelenen özellikler birlikte değerlendirildiğinde 16, 3, 10, 13 ve 14 no’lu populasyonların ön plana çıktığı görülmüştür.