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.
,
,
,
, and
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.
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 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.
The objective was to assess the effect of chemical desiccation on seed germination and storability in three sunflower female inbred lines and to point at possible indicators for optimal performance ...time. Desiccation was performed with Diquat (2 l ha-1) applied at 7-day intervals from the end of flowering to harvest maturity. There were 6 treatments and control (untreated). Germination was tested 2 and 21 months after harvest. The highest germination was recorded when the desiccation was performed 35 days after flowering. Results showed that optimal moment for applying chemical desiccation when there is no negative effect on the seed germination is specific for each sunflower genotype. Seeds with a high level of germination (>90%) can be stored for 19 months without significant loss in germination, namely, it was not negatively affected by chemical desiccation. Seed moisture and growing degree-days can be used as reliable indicators for optimal desiccation time.
For the production of high-yielding sunflower hybrids, it is necessary to cross inbred lines, the parent components of hybrids, which differ in a number of traits. The aim of this paper was to ...examine the variability of sunflower inbred line for agronomically important traits and to classify them based on similarities. 110 inbred lines from the collection of the Institute of Field and Vegetable Crops in Novi Sad were used in this paper. Nine important agronomic traits were examined: plant height, head diameter, number of days from germination to flowering, number of days from germination to maturity, seed yield, oil percentage, oleic acid content, 1000 seed mass and hull percentage. Inbred lines showed high variability for tested traits. The largest coefficient of variations was for seed yield (CV = 42.51%), and the smallest was for days from germination to flowering (CV = 8.86%) and days from germination to ripening (CV = 8.27%). Based on the principal components analysis (PCA analysis), inbred lines were grouped by similarity: (I) inbred lines with high seed and oil yields, (II) inbred lines with a short period from germination to flowering and (III) inbred lines with a high percentage shells, for special use. Seed yield and oil percentage as the most important agronomic traits were positively correlated, and they were positively correlated with the largest number of examined trais. The data obtained in this paper will be taken into account when crossing the inbred line in order to create sunflower hybrids.
Summary
A useful approach for improving seed germination and seedling growth is a seed priming technique. Application of the priming technique enhances water absorption, causing activation of ...metabolic activities in the seed. The objective of this study was to evaluate the effect of seed priming on germination parameters of safflower and to compare different priming techniques: priming by soaking and priming on filter paper. The priming treatments included hydropriming (distilled water) and osmopriming with 0.1% and 0.5% solutions of KNO
3
for 8 and 16 hours. The experiment revealed significant difference between the priming treatments and the control. The highest germination (89.50%) was recorded within the priming treatments by soaking in the solution of 0.1% KNO
3
and priming on filter paper moistened with 0.5% KNO
3
for 8 hours. Considering germination index, mean germination time and time to 50% germination, the best results were obtained within hydropriming on filter paper for 16 hours. This study has shown that the priming techniques significantly improved germination parameters of safflower. Although priming on filter paper showed better results, the soaking technique – due to its simplicity, low cost and easiness of application – can be successfully used to improve germination parameters of safflower and increase the number of plants per unit of area and thus increase the seed yield per acreage.
Increasing yield of seed and oil in sunflower is certainly one of the most important imperatives in modern sunflower breeding. The aim of this experiment was to cross the sunflower genotypes in order ...to create a new genetic variation that will contribute in order to increase seed and oil yield. The material for this research included 6 sunflower genotypes selected on the basis of their agronomic and production characteristics. The crossing was done by incomplete dialel method in early morning hours by manual emasculation. The analysis of variance revealed the existence of a statistically significant difference between the genotypes used in crossing, which confirms that the selected parents differ in the examined properties. Comparing parents the highest average value of seed yield per plant was achieved by parent R1 (98.29 g), while the lowest seed yield per plant was achieved with parent R3 (46.52 g). The highest average value of seed yield per plant in the F2 generation was achieved with the combination R5 x R6 (79.75 g), while the lowest value was achieved with the combination R1 x R6 (49.85 g). In terms of oil yield, the highest aver-age value was measured at parent R1 (43.59 g), while in the F2 generation the highest oil yield was achieved by the combination R5 x R6 (38.66 g). Of the total of 15 F2 populations, higher average yield of seed and oil per plant compared to parents were achieved in 4 cross combinations. This result leads to the conclusion that the obtained F2 generations can represent an important source of new genetic variability to be used in the breeding program in order to obtain more productive sunflower hybrids. Calculated coefficient of inheritance, heritability, indicated that depending on the crossing combination, genetic material, non-hereditary factors had a greater or lesser impact on the expression of investigated traits.
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.
PDF
