Shuttle breeding in sunflower lines development

Shuttle breeding is a breeding system where generations undergo sequential evaluations at different locations, developed by N. Borlaug. Our study aims to demonstrate an opportunity of application shuttle breeding method in sunflower lines development and also to show its advantages and disadvantages. Experiments were mainly conducted at the Central Station (Krasnodar) of All-Russia Research Institute of Oil Crops (VNIIMK). Krasnodar region is situated in the Southern part of Russia near the Black Sea. Part of our work was made at Seed and Plant Improvement Institute (Karaj, Iran) and Experimental Station near Borozdjan (Busher Province of Iran). Released and experimental sunflower hybrids and lines of VNIIMK breeding were used as a material. The experimental design was randomized blocks with three replications. Each replication had four rows and two central rows were analyzed only to exclude the border effect. It is shown that the application of the shuttle breeding technique to sunflower was highly successful and results in elite line development.

Efficiency of selection–biotechnological system of selection for creation of breeding source material of sunflower resistant to herbicides and broomrape

The sunflower is a strategically important oil crop. Every year the area under this crop grows, and the rapid returning of sunflowers back to the fields provokes the formation of new more aggressive races of broomrape (Orobanche cumana Wallr.). Broomrape is a parasite that interferes with the normal development of sunflower and can lead to significant crop losses. For creating a sunflower hybrid (F1) it is needed to cross the parental components, which have a complex of important traits, among which there is a resistance to the herbicides and a broomrape. Considering that the creation of each of the components of the hybrid involves many years of painstaking work in the breeding process, modern approaches and methods are used to accelerate the creation of a new source material. Thus, using the technology of cultivating immature embryos in vitro culture, it is possible to reduce the time to create lines resistant to herbicides, for example. And during selection for resistance to pathogenic organisms, testing is most often used against an artificial infectious background, both in the field and in laboratory conditions, in order to differentiate the material on this basis. The aim of this work was to establish the effectiveness system when creating an initial breeding material resistant to herbicides and broomrape. As a result of testing the lines on an artificial infectious background, was identified plants which have high resistance to the G-race broomrape and were isolated from hybrid combinations resistant to tribenuron-methyl and imidazolinones. Thus, among the analyzed plants which are resistant to tribenuron‐methyl, four lines were isolated, which are highly resistant to the G-race broomrape from a hybrid combinations BH0118/SURES–2 (101/1, 101/4, 101/6, 101/7), and BH0318/SURES–2 (101/21, 101/24, 101/28, 101/30), and five lines (101/11, 101/12, 101/16, 101/17, 101/18) from a hybrid combination BH0218/SURES–2. Among imidazolinone-resistant sunflower lines – line 3 was isolated as highly resistant to the G-race broomrape.

New races of rust pathogen on sunflower in Russia

Over the past two decades, there was observed a widespread of rust on sunflower in some regions of Russia. The identification of the racial structure of Puccinia helianthi populations in Russia has not been done since the early 80s of the last century. At that time, races 100 and 300 were identified. In our recent study, in addition to these races, new biotypes: 700, 710, 722, 772 were identified for the first time. The purpose of this study is to determine the racial identity of 160 P. helianthi isolates collected from 2018 to 2020 in the Rostov, Saratov, and Krasnodar regions. We used eight standard differentiating lines of sunflower: SM-90, SM 29, R-386, HАR-1, HАR-2, HAR-3, HAR-4, HAR-5. Sunflower variety VNIIMK 8883 was used as a differentiator susceptible to all races of the pathogen. In addition to the six races mentioned above, we identified 11 more new races for the first time: 304, 351, 352, 364, 704, 736, 740, 741, 745, 760, 762. Race 700 prevailed among the isolates collected in the Rostov region in 2020; we also identified single specimens of races 760, 762. Thus, 17 races of P. helianthi were found on sunflower in three regions of the Russian Federation. Other races may be also present here, so further research is required.

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.

Effect of different dosage of EMS on germination, survivability and morpho-physiological characteristics of sunflower seedling

To find out the effect of EMS dosage on sunflower variety BARI Surjamukhi-2, different EMS concentrations were compared at the molecular biology laboratory (MBL), Oilseed Research Centre (ORC), Bangladesh Agricultural Research Institute (BARI), Gazipur. A total of 10 seeds were treated with each treatment and % germination, % survival and early seedling growth was investigated. Decreased % germination was found with the increasing dose of EMS for all the treatment compared to the control, except for T 4 (0.6% EMS) treatment where a 100% seed was found to be germinated. With an exception of treatment T 4, a decreasing trend of % survivability with the increasing dose of EMS was observed. The gradual reduction with the increasing dose of EMS were observed for most of the studied characters such as leaf area, number of internodes, internode length, fresh and dry weight of leaf, dry weight of shoot, and fresh and dry weight of root in comparison to non-treated control seedlings. However, stimulatory effect with lower dosage of EMS was observed for shoot length in T 2 (0.2% EMS), root length in T 3 (0.4% EMS), and stem fresh weight in T 2 over control. Based on a quadratic regression analysis, using % survivability data, LD50 was calculated and optimum EMS dose was found 0.5%. Hence, the optimized EMS dose of 0.5% may be used to develop large scale desirable mutant of sunflower variety BARI Surjamukhi-2.

The state of soil microbiotes during sunflower growing with an herbicide of imidazolinone group

The effects of various concentrations of herbicide Euro-Lightning Plus on the state of microbiota in the root zone of sunflower have been studied. Soil of plant rhizosphere and interrow soil after treatment with the herbicide at the doses of 1.2 and 2.5 l/ha were taken for the analysis at the end of sunflower growing season. Rhizosphere soil without herbicide application was used as a control. The herbicide was applied at the stage of 2–4 true leaves. The total number of bacteria in the rhizosphere of control plants was 12.82 million CFU/g of soil while in the rhizosphere and in the interrow soil after herbicide treatment with a dose of 2.5 l/ha it decreased by 1.4–1.5 times. A general trend of decline in number of the basic ecological and trophic groups of bacterial microorganisms with the increase in a dose of herbicide was established. Microbiological coefficients that reflect the functional activity of the microflora indicate changes in its biological activity under the influence of the herbicide Euro-Lightning Plus, which leads to deterioration in the agroecological state of the studied soils. It was also found that herbicide application resulted in a rearrangement of micromycete complexes in the root zone of sunflower which led to a two-fold reduction, compared to the control, of mycobiota species diversity and the formation of a specific species composition of mycocenoses. A greater genus and species diversity of fungi of the microflora in the rhizosphere of control plants, in comparison with the herbicide-treated soil, was revealed. A reduction in species diversity of the genus Penicillium from six species in the control to 1–2 species in the rhizosphere of experimental sunflower plants as well as the absence of rare saprophytic fungi species from the genera Acremonium, Verticillium, Trichoderma and Paecilomyces were noted.

Effect of different types of soil tillage for sunflower on some soil physical characteristics. Part I: soil moisture

The investigation was carried out during 2014–2016 in the land of General Toshevo town in the South Dobrudzha region on slightly leached chernozem soil type. The effect of the types of soil tillage for sunflower given bellow was followed: ploughing at 24–26 cm, chisel-plough at 24–26 cm, disking with disk harrow at 10–12 cm and direct sowing (no-tillage) on the soil moisture content. Based on bulk density, wilting point and the determined soil moisture content the plant-available water was calculated. The additional soil tilths of the areas subjected to ploughing, chisel-ploughing and disking with disc harrow included double spring pre-sowing cultivation with harrowing. To destroy the emerging weeds in the variant with direct sowing, a total herbicide was applied. The soil moisture content was evaluated during three main stages of sunflower development: emergence, flowering and technical maturity. The investigated parameter was determined for each of the studied layers – 0–10, 10–20, 20–30, 30–40 and 40–60 cm. In years with normal amounts of rainfalls, no significant differences in the soil moisture under the different ways of soil tillage were observed. Conventional ploughing and tillage without turning of the soil layer contributed to accumulation of more moisture and to higher moisture storage down the soil profile under heavy and intensive rainfalls. Tillage without turning of the soil layer, minimal and no tillage maintained more and better soil moisture in years with limited precipitation and in periods of drought.

Foliar fertilization of organic sunflower, enhanced yield components and seed yield in the humid tropics

In a two year experiment carried out on the organic research plots of the Institute of Food Security, Environmental Resources and Agricultural Research, Nigeria. Two liquid organic fertilizers (ARATI NAWOZ {2.01% N} and ARATI BAJA {1.01% N}) and control were applied to four sunflower varieties (SAMSUN 1, SAMSUN 2, SAMSUN 3 and SAMSUN 4) during the late cropping season (July – Nov.) of 2016 and 2017 to evaluate their agronomic response. The experiment was laid out in a randomized complete block design using a 4 × 3 factorial arrangement in three replicates. Data were collected on plant height at maturity, head diameter and weight, weight and number of seeds per head, 100 seed weight and seed yield. The varietal effect was significant (P < 0.05) on head diameter and weight, and number and weight of seeds per head, and seed yield in 2016. However, during the markedly dry 2017, the varietal effect was not significant for any trait measured. Foliar application of ARATI NAWOZ significantly (P < 0.05) increased height at maturity, the weight of seeds and head per plant and seed yield relative to the control in both years. Significant Variety × Fertilizer interaction effect was also recorded on the height at maturity, head diameter and weight, and seed yield in 2016. SAMSUN 4 (975.6 kg/ha) produced significantly (P < 0.05) higher seed yield than SAMSUN 1 (789.82 kg/ha) and SAMSUN 2 (778.54 kg/ha) in 2016. The efficacy of the application of both fertilizers was on par for most traits in both years. On average, the application of organic fertilizers resulted in a 15.76 and 69.02% increase in seed yield relative to the control in 2016 and 2017, respectively. ARATI NAWOZ and ARATI BAJA appeared promising for sunflower production in the humid tropics.