Sunflower pollination has been a subject of research for more than 40 years at the Institute of Field and Vegetable Crops in Novi Sad, Serbia. Since the first experiments in 1970s, the importance of ...climatic conditions was acknowledged and analyzed as a key factor for the performance of plants and pollinators. Climatic conditions, disease and pest problems changed significantly during this period, but sunflower production technology and breeding also advanced making seed production more stable. Nonetheless, the quality of agronomic practices still varies which also reflects on the plant and pollinator performance. Sunflower breeding led to improved germplasm which still maintains high degree of variability for nectar content and pollinator attractivity. Pollinators are essential in crosses involving cytoplasmic male sterile lines, but are also beneficial in hybrid sunflower seed production. Pollinator attractivity is thus an important trait for both breeders and producers and worth to be considered as a quality trait in sunflower breeding programs.
A sunflower testing network that included 25 commercial hybrids and 26 sites in Serbia was analyzed by the sites regression biplot based on grain yield data in 2006 and 2007. The scientific aims of ...our study were to determine the representativeness and discriminating ability of the test sites and to identify good test sites for selecting generally and specifically adapted sunflower hybrids. Correlations among test sites, revealed by biplot and with Spearman's nonparametric rank correlation coefficients for each pair of test sites, were compared. Discriminating but nonrepresentative test sites in our study were represented by Aleksa Santic (18.8 °C average temperature, 72.0 mm precipitation, and 269.2 h of sunshine) and Rimski Sancevi (18.4 °C average temperature, 79.2 mm precipitation, and 252.1 h of sunshine), based on a biplot analysis of the 2006 testing network. Sombor (20.1 °C average temperature, 52.5 mm precipitation, and 304.7 h of sunshine) was also a discriminating but nonrepresentative test site, based on a biplot analysis of the 2007 testing network. A test site that was both discriminating and representative was Kikinda (20.2 °C average temperature, 63.3 mm precipitation, and 313.7 h of sunshine), based on a 2007 biplot analysis. Sombor and Kikinda could be suitable test sites for selecting specifically and generally adapted hybrids of sunflower, respectively, for dry and hot areas and seasons, since 2007 had less precipitation and a higher mean temperature in comparison to 2006. The presence of close association between test sites Rimski Sancevi and Kikinda, based on the 2006, 2007, and combined data, and on biplot and Spearman's correlations, suggested that the same information about the genotypes could be obtained from either of these 2 test sites, and consequently testing costs could be reduced. The relationships among test sites revealed by biplot did not always coincide with Spearman's rank correlation coefficients for site pairs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Although flower pollinator interactions are known to be mediated by floral traits, not enough attention has been paid to the research of secretory tissues and volatile components of sunflower disc ...florets as potentially important parameters in breeding programs. (1) To our knowledge, this is the first integrated study aimed at better understanding the attractiveness of sunflower capitula to insects. In the study, we have made a very detailed comparative analysis of secretory tissues and the characterization of the volatile components (VOCs) of disc florets in 10 wild perennial
species. (2) For anatomical analyses, cross-sections were obtained from the nectary zone of disc florets using a cryotechnique procedure. Micromorphological observation and morphological and anatomical analysis of disc florets were performed using light and scanning electron microscopy. For VOCs, we applied headspace, GC-FID, and GC/MS analyses. (3) The obtained results indicate that there is a difference between the analyzed traits among studied species.
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had high disc diameter values, a high cross-section area and disc floret corolla length, as well as the largest cross-section area and thickness of the disc florets nectary. In the analyzed VOCs, 30 different compounds were detected. The highest yield and quantity of α-Pinene was observed in
. (4) Inflorescence features, such as receptacle diameter, corolla and secretory tissue properties, and floret VOCs production and characterization, provided valuable information that can be used as guidelines in sunflower breeding programs to maximize pollinator attractiveness and increase seed yield.
Climate change projections for the 21st century pose great threats to semi-arid regions, impacting seed production and the quality of sunflowers. Crop yields are negatively affected by climate ...variability, especially in the event of droughts during the crucial growth stages. Understanding the relationships between agrometeorological, genetic, and agronomic factors is crucial for maintaining crop sustainability. Optimal sowing dates are an essential condition for maximizing crop genetic potential, but challenges come from annual weather variations. This study analyzes how sunflower genotypes respond to different sowing dates under climate change and focuses on the conditions for obtaining maximum seed yields and favorable agronomic traits. From 2020 to 2022, the experiment featured six genotypes sown across four different dates at two-week intervals, simulating seed sunflower production. The results obtained by ANOVA indicated that the seed yield and oil yield were significantly affected by the sowing date, the genotype, and their interaction, with coefficients of variation ranging from 7.6% for oil yield to 41.1% for seed yield. Besides seed yield and oil yield, LDA biplot and Discriminant Functions confirmed that seed germination energy also played a significant role in separating genotypes into clusters. A Visual Mixed Model showed that shifting the optimal sowing date (mid-April) to early May allows a reduction in the number of days the plants spend in critical growth stages, thereby escaping stressful conditions during pollination and seed filling. The findings resulted, on average, in increased yields and improved seed quality, which are the primary goals of seed production, but not in increased 1000-seed weight. Notably, high temperatures during the critical sunflower growth stages negatively affected the measured parameters of seed production. The increased precipitation during seed filling boosted the 1000-seed mass and seed yield. Extended flowering reduced the growth rate and seed germination, but longer seed filling increased the 1000-seed mass and seed yield. Our future breeding goals will be to create genotypes with a shorter flowering period and an extended seed-filling period to better respond to climate change.
Sunflower seeds are regularly infested by Plodia interpunctella during storage. Although this pest prefers damaged seeds, in practice it can infest undamaged seeds as well. This research assessed the ...influence of the sunflower seed type (oil, protein for human consumption and bird-feed) and the initial seed damage during post-harvest processing (dehulled kernels, 10, 20, 30% of damaged seeds and undamaged seeds) on development of P. interpunctella (larval mortality, larval development, mean developmental duration, adult emergence and fecundity). Biochemical analysis of seeds, kernels and hulls detected the highest content of phenols in the seed and hull and tocopherols in the kernel of the oil type hybrid. The antioxidative activity was the highest in the seed, kernel and hull of the protein type for bird feed. The shortest development (39.5 days) and the highest fecundity (91.3) were on the oil type seeds, while the longest development (42.1 days) and the lowest fecundity (68.1) were on the seeds of the protein type for bird feed. The highest mortality of larvae was on the undamaged seeds of the protein type for bird feed and human consumption (21.3% and 14.0%, respectively). The type of sunflower and the level of initial damage affected larval mortality, developmental duration and fecundity. The mean developmental duration and the number of emerged adults were dependent only on the initial seed damage. Principal component analysis detected strong positive correlation between mortality and development with the tocopherol content on the undamaged seeds while fecundity was associated with the state of kernel and the amount of tannins, proteins and oil content in the seed. The undamaged seeds of the protein type for the bird feed were the least suitable for the development of this pest, while the oil type kernels were the most suitable.
•Level of seed damage had the strongest influence on P. interpunctella development.•Oil type seeds were the most suitable and undamaged seeds were the least suitable.•Development was positively correlated with tocopherol and negatively with oil content.•Fecundity was negatively correlated with tocopherol content.
Summary
As plant breeding is a very complex and sophisticated process, it is of paramount importance to understand the nature and magnitude of interdependence between specific plant features. Using ...PCA and correlation analysis, this study examined the variability in features of two types of inbred sunflower lines and determined its connection with their seed yields. The experiment was conducted as a randomized complete block design with four replications in Rimski Šančevi (the experimental field of the Institute of Field and Vegetable Crops in Novi Sad) in 2018 and 2019. It examined a total of nine inbred sunflower lines created at the Institute of Field and Vegetable Crops in Novi Sad. The results obtained suggest a high degree of variability in the examined traits of inbred sunflower lines considered, whereas the significance indicated by the F test was confirmed by the Duncan test performed. A high degree of variability was also found between the different types of inbred lines considered. A positive correlation was found between all four traits observed in the inbred sunflower lines considered, with different levels of significance. A statistically significant positive increase in the head diameter was followed by an increase in the weight of 1000 seeds, which generated a higher seed yield per unit area. According to the arrangement of different types of inbred lines considered on the PCA biplot, it can be concluded that the linoleic inbred lines G7
L
and G8
L
had the highest average values of the 1000-seed weight, head diameter and seed yield throughout the course of both experimental years. The useful data obtained by PCA analysis can facilitate successful selection programs aimed at developing sunflower genotypes that possess high stability and seed yields.
Sunflower seed treatments are inevitable measure that ensures protection from soil-dwelling insects and pathogens at the first stages of plant development. Due to the ban of neonicotinoid based ...insecticides for the sunflower seed treatments, new registered preparations are put to test. The aim of this work was to assess the efficacy of currently registered insecticides against the wireworms (observed in field emergence and percent of damaged plants) and their effect on yield traits (yield, oil content and 1,000-seed weight) of the sunflower hybrids (Sumo 2 OR, Oliva and Novak) in comparison to previously used neonicotinoids. Seeds were treated with different pesticidal combinations: metalaxyl-m, metalaxyl-m + bifenthrine, metalaxyl-m + thiacloprid, metalaxyl-m + thiametoxam, and metalaxyl-m + imidacloprid. Twoway ANOVA and Duncan’s multiple range tests were performed. Field emergence was not influenced by the treatment. Sumo 2 OR and Oliva emergence did not differ significantly among the treatments (78.3-88.3%; 83.0-91.3%, respectively), but for Novak it was significantly lower (79.3%) when treated with metalaxyl-m. The lowest percent of damaged plants was in the treatment with metalaxyl-m + thiametoxam (1.1-2.4%). However, it did not differ significantly among other treatments (2.4-3.9%), regardless on the hybrid. Novak had the highest average yield (3,938.1 kg/ha), followed by Sumo 2 OR (3,566.1 kg/ha), and Oliva (3,199.8 kg/ha), regardless on the applied seed treatments. The highest 1,000-seed weight was measured for Oliva. Given indicates that currently registered insecticides for the seed treatment of sunflower, such as Sonido and Semafor, can be adequate substitute to the banned neonicotinoids like Cruiser and Gaucho.
Although flower pollinator interactions are known to be mediated by floral traits, not enough attention has been paid to the research of secretory tissues and volatile components of sunflower disc ...florets as potentially important parameters in breeding programs. (1) To our knowledge, this is the first integrated study aimed at better understanding the attractiveness of sunflower capitula to insects. In the study, we have made a very detailed comparative analysis of secretory tissues and the characterization of the volatile components (VOCs) of disc florets in 10 wild perennial Helianthus species. (2) For anatomical analyses, cross-sections were obtained from the nectary zone of disc florets using a cryotechnique procedure. Micromorphological observation and morphological and anatomical analysis of disc florets were performed using light and scanning electron microscopy. For VOCs, we applied headspace, GC-FID, and GC/MS analyses. (3) The obtained results indicate that there is a difference between the analyzed traits among studied species. H. eggertii, H. hirsutus, H. mollis, H. resinosus, and H. tuberosus had high disc diameter values, a high cross-section area and disc floret corolla length, as well as the largest cross-section area and thickness of the disc florets nectary. In the analyzed VOCs, 30 different compounds were detected. The highest yield and quantity of α-Pinene was observed in H. mollis. (4) Inflorescence features, such as receptacle diameter, corolla and secretory tissue properties, and floret VOCs production and characterization, provided valuable information that can be used as guidelines in sunflower breeding programs to maximize pollinator attractiveness and increase seed yield.
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