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 175000 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.

Downy mildew is one of the most important diseases of sunflower crop around the world caused by Plasmopara halstedii (Farl.) Berl.et de Toni. The aim of our study is the sunflower hybrid development with the durable resistance to downy mildew combining one parental line with the most effective for the specific location major gene ( Pl 15 for example) and the second parental line – with a high horizontal resistance to downy mildew. Experiments were conducted at All-Russia Research Institute of Oil Crops in 2016–2021. Experimental design was randomized blocks with three replications. CMS-lines with the highest level of horizontal resistance (VK 678 VA 732 VK 680 VK 934 VK 900 and new line SL 0516) were used as mother parents. Lines with Pl 15 resistant to all the downy mildew races were used as pollinators to create sunflower hybrids with durable resistance to downy mildew. A number of high-productive sunflower hybrids with durable resistance to DM (VK 732А × L 642-15 VK 732А × L 634-15 VK 680А × L 642-15 VK 680А × L 634-15 VK 934А × L 642-15 and VK 678А × L 634-15) were developed and tested.

The foliar fungal disease Septoria leaf spot is economically important for sunflowers. It develops most intensively during the wet and warm season. However the genetic nature of sunflower resistance to Septoria leaf spot is still not clear. The purpose of our work was to identify some inheritance patterns of sunflower resistance to this disease based on the assessment of lines and hybrids of the first and second generations. The studied material was sown in 2020 and 2021 and subsequently grown on a stationary artificial infectious plot enriched with Septoria helianthi pathogen. The frequency of infection and the severity of infection of each sample were taken into account. The two-factor variance analysis revealed a significant influence of genotype on the frequency of infection in six sunflower lines and confirmed the effect of individuality of the response of individual genotypes to disease damage. It was shown that about 65 % of the total variation of the trait is due to the genetic nature of the line and only a little more than 20 % and about 11 % – to the influence of the environment and the “genotype × environment” interaction respectively. Based on disease damage data in 2020 and 2021 the lines were classified as susceptible moderately susceptible moderately resistant and resistant. Differentiation of lines according to sensitivity to Septoria leaf spot made it possible to obtain hybrids with different manifestations of the trait in their parents. The nature of inheritance of infection frequency in F 1 sunflower hybrids was determined by the degree of dominance. As a result it was revealed intermediate inheritance as well as positive and negative overdominance of the trait. The severity of infection by S. helianthi pathogen in F 1 hybrids was inherited according to the type of parental form with greater resistance to the disease. F 2 populations were found to inherit infection frequency from the more resistant parent showing a proportion of infected plants similar to that of the more resistant line from a given cross combination. It has been shown that the frequency of infection of the F 2 population with Septoria leaf spot can be affected by the severity of infection of F 1 plant with the pathogen S. helianthi.

A field trail was performed to study the impacts of soil tillage system and some organic and inorganic fertilizers treatments on sunflower performance and soil characteristics in the semi-arid region across 2015–2016 growing season. The tillage systems were (T1) conventional tillage and (T2) reduced tillage while the fertilizer treatments were (F1) control (F2) 20 t ha −1 farmyard manure (F3) 40 t ha −1 farmyard manure (F4) 20 t ha −1 farmyard manure plus 50:25:25 kg ha −1 NPK (F5) 100:50:50 kg ha −1 NPK. The two-way entry (treatment) by tester (trait) biplot tool described 84 % of the observed variability (68 % and 16 % by the first two principal components respectively). The which-wins-where pattern showed six vertex treatment (tillage system × fertilizer type) as: T1-F1 which had the highest values for bulk density; T1-F3 which had the highest values for days to maturity organic matter and root depth; T1-F5 which had the highest values for soil phosphorus and harvest index; T2-F1 which had the highest values for mean emergence time; T2-F3 which had the highest values for soil potassium and achene yield; and T2-F4 which had the highest values for soil nitrogen. The ideal treatment pattern indicated that T2-F4 was the best treatment combination. We found that the best performance for sunflower achene yield was obtained with using reduced tillage system plus F3 or F4 fertilizer treatments. Finally application no fertilizer or using only chemical fertilizers could not improve sunflower performance in both tillage systems.

Compatible solutes control cell osmotic balance and compatible the cells’ metabolism whereas nano-particles have been introduced to increase crop production with inadequate knowledge. This investigation is done to evaluate the effects of application of salicylic acid glycine betaine and nano titanium dioxide on sunflower. Measured traits were plant height (PH) leaf length (LL) chlorophyll content (CHL) number of seeds per head (NSH) 1000-seed weight (TSW) day to maturity (DM) husk percentage (HP) kernel weight (KW) percentage of empty achenes (PEA) head number per plant (HNP) grain yield (GY) and oil percent (OIL). Results indicated that the first two principal components accounted 92% of total variation of the treatment by trait (T × T) interaction and were used to generate a T × T biplot. All treatments were identified as the vertex treatments in polygon of TT biplot and the nano titanium dioxide treatment had high values for all traits expect PEA HP and TSW. The nano titanium dioxide was identified as ideal treatment and GY and HNP were identified as ideal traits. The positive correlations between HNP and GY and between OIL and KW; and near zero correlations between TSW and HP and between TSW with DM as showed. Application of compatible organic solutes (glycine betaine and salicylic acid) had not any considerable improvement on traits while application of nano-titanium dioxide indicated considerably enhanced the yield and most traits of sunflower.

The main non-microbial cause of quality deterioration in lipid-containing food is lipid oxidation the process in which simplifying unsaturated fatty acids react with molecular oxygen via a free radical mechanism. The use of substances with antioxidant properties during the manufacturing process can minimize the extent of lipid oxidation. This research aimed to determine the effect of selected essential oils on the quality and oxidative stability of sunflower oils. Sunflower oils were obtained by refining and cold-pressing and their quality and oxidative stability were studied during the different storage conditions: 20 °C and 5 °C at dark and with light exposure. Obtained results suggested that the antimicrobial and antioxidant properties of essential oils can positively affect the oxidative stability and consequently the quality of sunflower oils during storage and implicate with further application of essential oils in the edible vegetable oil industry.

In order to study the genetic control of sunflower fatty acids under optimum and water limited conditions a set of 12 sunflower hybrids were evaluated as randomized complete block design with three replications in two separate experiments during two years (2019 and 2020) in Karaj Iran. The hybrids were obtained by crossing of four male sterile lines and three restorer lines as testers. Water limitation was imposed by water withholding during reproductive stage. Palmitic acid content was governed by both additive and non-additive effects and linoleic acid content by non-additive gene action under optimum and water limited conditions. Stearic acid content was controlled by both additive and non-additive effects in optimum but by additive effects under water limited condition. Oleic acid content was governed by non-additive factors in optimum while by both additive and non-additive effects in water limited condition. Oil content and leaf temperature were inherited by additive and seed yield by additive and non-additive effects in both conditions. Relative water content and chlorophyll content were controlled by both additive and non-additive effects under optimum but by non-additive effects in water limited condition. According to these results hybrid breeding is suggested for improvement of main sunflower fatty acids under optimum and water limited condition except that selection-based methods for improvement of stearic acid content.