Differentiation of valuable for breeding sunflower lines by resistance to Phoma rot

The purpose of the research is differentiation of valuable for breeding sunflower lines by resistance to Phoma rot. The promising constant sunflower lines were estimated by their resistance to Phoma rot using methods of artificial inoculation in the greenhouse and laboratory conditions. In greenhouse conditions, there were used two methods of artificial inoculation with a fungus Plenodomus lindquistii in the bottom of leaf petiole of a sunflower plant at a stage of the first true leaf pair. Application of the pieces of agar nutrient medium with mycelium, pycnidia and picnospores (unbroken) allowed to identify resistant and mid-resistant sunflower lines (VK 900, L 86 and L 107, L 132). At inoculation with 0.2 ml of a fungus spore suspension (concentration of 1 × 106 spores/ml), five susceptible and one very susceptible sunflower lines (L 2385, L 103, L 136, L 131, L 128, and L 82) were determined. In laboratory conditions, the quick test for estimation of susceptibility to Phoma rot (dose of infection – 12 g) allowed to reveal more than 50 % of plants with healthy root system and two constant sunflower lines L 116 and L 136 with the affection degree of one point. Estimation of susceptibility to Phoma rot infection of the different organs (stem and root system) at artificial inoculation showed a possibility to differentiate sunflower lines by resistance of roots and stems and to select the most promising for the further work in breeding.

Phyllody in sunflowers; 44 years to explain the appearance of aberrant flowers

Phyllody in sunflowers (Helianthus annuus L.) is characterized by the appearance of bracts and ray flowers in the centre of the heads. It has been discussed for decades among the sunflower plant breeders and experts without a clear “unique” explanation for it. The erratic appearance of the phenomena has led to consider it either a disease or hybrid defect and the plants with Phyllody as off-types, raising several farmers claims to seed producers. However, the auxins gradient, in the growing Asteraceae heads, determines the differentiation pathway of the undifferentiated cells. i.e., bracts and ray flowers at the border and disk flowers in the centre of the head. Disruption of the natural auxin gradient alters the cell differentiation in the growing heads and causes bracts and ray flowers to grow where only disk flowers should grow. The disruption of the natural head bottom auxin gradients may be caused by small injures in the fast-growing head receptacle. The most common causes of Phyllody are hormonal herbicide damage and Boron (B) deficiency, even temporary. Plants growing with B deficiency have brittle cell wall and membranes while a plant with high B levels produces plastic or elastic cell wall and membranes. Brittle cell walls are susceptible to breaks during growth. Sunflowers genotypes may react to crack or small damages in the sunflower bud in two ways. Some tend to repair the damages by regrowing new organs such as ligules or bracts and forming Phyllody. Others do not regrow and only heal the wound creating the funnel hole head shape.

Examination of the effect of pelleted poultry manure products on a sunflower test plant in a laboratory model experiment

Sunflower (Helianthus annuus L.) is one of the most important oil plants in Hungary, with a sown area of more than 627.000 ha in 2019. Sunflower cultivation is primarily important for use in the oil industry, but its role in feed and beekeeping cannot be neglected either. Sunflower adapts well to different production areas in terms of soil demand, yet, as important fact, it must be grown on soils with poorer conditions with intensive nutrient replenishment. From the agri-environmental point of view, in addition to the use of pelleted poultry manure products, which are also new to the consumer market, is of paramount importance. Their advantages include a wide range of nutrients as well as a soil structure improving effect. In our research, we investigated the starter effect of pelleted poultry manure products applied at different doses (200 kg ha-1 and 400 kg ha-1) on sandy soil with humus using a sunflower plant. The aim of our research to investigate the effect of using pelleted fertilizer products as starter fertilizers on sunflower plant germination, and investigate the effect of poultry manure products on soils. Based on our results, it can be stated that the pigment content (chlorophyll and carotenoid content) was positively influenced by the higher dose treatments (400 kg ha-1), thus increasing the photosynthetically active leaf area. Compared to the control, the carotenoid content in the test plants of the treatments increased, and the differences of this treatment proved to be significant (p<0.05). Our experiments supported the beneficial effect of pelleted poultry manure-based products in the soil-plant system.

Sunflower Helianthus annuus for Phytoremediation of Zinc in Hydroponic System

It has been noted that zinc contamination is hazardous which induces researchers seek new means to overcome it. One of the methods is to employ sunflower plant to eliminate zinc in soil. However, there is insufficient information about zinc phytoremediation by sunflower Helianthus annuus in hydroponic system. Hence in this study, a 15-day experiment was conducted using zinc concentrations of 0, 10, 20, and 30 mg/L in a hydroponic system. The effects of zinc concentration on the plant growth (length of root, length of stem and number of leaf), zinc uptake and zinc translocation were evaluated. The findings showed that the plant growth was inhibited, where the zinc concentrations had affected the growth of the sunflower root, length and stem, and the zinc uptake significantly (p<0.05). It was also found that there was a significant variation of root length and zinc uptake in leaves within certain phases statistically (p<0.05). Then the translocation factor was found significant different for the time parameter but not the zinc concentrations (p<0.05). Therefore, this experiment concluded that the sunflower plant was highly tolerant to zinc and able to extract the zinc from contaminated environments. Lastly, this study showed that the sunflower is potential to phytoremediate zinc in a hydroponic system.