Sunflower Lines Research Articles

Validation of microsatellite markers to identify Pl6, Pl8 and Plarg genes that control resistance to Plasmopara halstedii in sunflower

Downy mildew caused by the oomycete Plasmopara halstedii (Farl.) Berl. et de Toni is one of the most harmful sunflower diseases. Among the various measures to control it, the most economical is the development of resistant genotypes. At present, Pl6, Pl8, and Plarg loci are promising for use in breeding, providing resistance to all known P. halstedii races. Microsatellite markers (SSR) help to control the transfer of genes that control resistance in breeding material. However, validation of the marker is needed to prove its reliability in gene detection. There was studied the polymorphism of 9 microsatellite loci in 196 sunflower lines with different resistance to downy mildew. The ORS328 microsatellite locus was chosen as a marker of the Pl6 gene. Amplified fragment with 271 bp allows identifying genotypes resistant to the race 330. The lines that are the sources of the Pl8 gene did not differ from the others in the allelic composition of the ORS781 locus. Among the analyzed breeding samples, no polymorphism was revealed at this locus. To identify the Plarg gene, SSR markers ORS662 and ORS509 were selected. The analysis of 12 samples of the F2 generation from RHA-419 × I3BC2 (VK585 × VK195) crossing at these loci showed that both markers are inherited codominantly. The studied DNA markers can be used in marker-assisted selection (MAS) of sunflower for resistance to downy mildew pathogen.

Genotypic and environmental variability of the total content of tocopherols in the seeds of inbred sunflower lines

Breeding for high total content of tocopherols (vitamin E) in sunflower seed oil involves studying the genetics of this trait. Twenty-nine inbred lines of sunflower with different total tocopherol content (TTC) were selected from 60 samples of the original material and studied at VNIIMK, Krasnodar, in 2016-2019. TTC was determined in an average sample from a head of shelled seeds by direct hexane extraction and further measurement of the optical density of the colored solution on a spectrophotometer. Both the genotype and the growing conditions influence the TTC in the seeds. The average range of variation over four years was from 302 to 605 mg kg-1. The largest differences, 2.6 times, between genotypes were found in 2018 with a range of variability from 258 to 667 mg kg-1. Significant differences were found between the average values of 360 mg kg-1 in 2017 and 432 mg kg-1 in 2019. The genotype and the year of growing have the greatest influence on the TTC, measured as 65% and 8%, respectively, and the genotype-year interaction accounts for 14% of the effect. The TTC correlation coefficient in the parent-offspring series was 0.65–0.85, and the heritability coefficient in the studied lines was 42–72%. The data on the valuable genetic control of TTC in seeds can help predict the effectiveness of breeding to improve this trait.

Plant growth regulator effects on sunflower parents and F1 hybrids

The need for augmented sunflower production requires finding new meth­ods and improving existing cultivation technologies to increase performance and resistance to stresses. The low performance of breeding and seed production lines is among obstacles to the rapid introduction of new and modern sunflower hybrids into production. The study purpose was to evaluate the individual responses of self-pollinating sunflower lines intended for breeding and seed production and of F1 hybrids, which were developed by crossing these lines, to plant growth regulators. It was found that the CMS-based lines had better yield elements and oil content in response to growth regulators compared to the lines based on normal cytoplasm. The plant growth regulators increased the heterosis effect in the experimental hybrids. The best response was observed in the threeline hybrid Skh808A/Kh1002B × Kh785V for all the studied parameters. The growth regulators strengthened a correlation between the 1000-seed weight and yield (r = 0.51–0.97). The oil content in seeds of F1 hybrids depended on the genotype and could be comparable both with the parent with a low content of oil and with the high-oil parent. Variations in the oil content in seeds depended on the type of growth regulator and soil/climatic conditions during the seed filling.

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

Abstract 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.

Breeding of sunflower lines resistant to race G of Broomrape

Relevance. Over the past decades, new and extremely virulent races have appeared in the southern regions of the Russian Federation, which overcame the resistance of domestic and foreign sunflower range of varieties. The most effective, long-term, and biologically safe way to protect sunflower from broomrape is to develop varieties and hybrids resistant to new races.Methods. We identified broomrape seeds of race G using internationally accepted differentiator lines: Record 1-3 (C), S-1358 (D), P-1380 (E), LC1093 and P96 (F). We used sunflower lines and hybrids of the breeding of V.S. Pustovoit All-Russian Research Institute of Oil Crops as a parent material. We carried out the evaluation of broomrape resistance by the method of A.Ya. Panchenko. To develop an infectious background, we introduced seeds of broomrape race G into boxes with a soil and sand mixture at the rate of 200 mg per 1 kg of the mixture, distributing them evenly. We grew sunflower plants at a temperature of 25-27 °С and a 16-hour photoperiod. In 25-30 days after the emergence if seedlings, we dug up plants and counted the broomrape specimens on their roots by a scale.Results. We developed sunflower lines resistant to races of broomrape from A to G. All of them are of branched form, with different lengths of the period from germination to flowering, they differ in height and oil content. The line L 82 is distinguished by a high content of oleic acid in oil — 91%. The lines have a high combinability. We obtained experimental hybrid combinations using these lines.

New races of rust pathogen on sunflower in Russia

Abstract 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.

Identification of proteins in sensitive and tolerant lines of sunflower (Helianthus annus L.) under water deficit

The importance of examining environmental stresses and their role in predicting and evaluating the growth and yield of crops is very evident. Environmental stresses are the most important factor in reducing agricultural yields worldwide. In order to evaluate the environmental impact of water loss on the amount of proteins affected in sunflower, an experiment was conducted in randomized complete block design with three replications at Karaj Oil Seeds Research Institute. In order to study the response of susceptible line (BGK221) and tolerant line (RGK46) under drought stress conditions, extraction of protein by acetone deposition method was performed in 8 leaves and of 3 seedlings in each replication. The amount of extracted protein was determined by Bradford method using two-dimensional electrophoresis and existence of significant difference between the bands in sensitive and tolerant lines was investigated. A total of 467 repeatable bands were found in the tolerant line and 417 repeatable bands appeared in the sensitive line. Among these proteins, 6 bands in tolerant line (No 503, 1901, 904, 3301, 7011, 9005) and 6 bands in sensitive line (No 704, 811, 3205, 4108, 7307, and 9207) were significantly affected by drought stress. In both sensitive and tolerate lines the main consequence is increase in amount of protein. The results showed that the most important factor of tolerant line adaptive for environmental stress conditions is maintaining normal cell metabolism, keeping moisture in the cell, strengthening cellular structure and antioxidant defense. The study also showed that drought stress had the greatest effect on cytoplasmic and nucleus proteins, metabolism and energy of proteins

Genotyping and lipid profiling of 601 cultivated sunflower lines reveals novel genetic determinants of oil fatty acid content

BackgroundSunflower is an important oilseed crop domesticated in North America approximately 4000 years ago. During the last century, oil content in sunflower was under strong selection. Further improvement of oil properties achieved by modulating its fatty acid composition is one of the main directions in modern oilseed crop breeding.ResultsWe searched for the genetic basis of fatty acid content variation by genotyping 601 inbred sunflower lines and assessing their lipid and fatty acid composition. Our genome-wide association analysis based on the genotypes for 15,483 SNPs and the concentrations of 23 fatty acids, including minor fatty acids, revealed significant genetic associations for eleven of them.Identified genomic regions included the loci involved in rare fatty acids variation on chromosomes 3 and 14, explaining up to 34.5% of the total variation of docosanoic acid (22:0) in sunflower oil.ConclusionsThis is the first large scale implementation of high-throughput lipidomic profiling to sunflower germplasm characterization. This study contributes to the genetic characterization of Russian sunflower collections, which made a substantial contribution to the development of sunflower as the oilseed crop worldwide, and provides new insights into the genetic control of oil composition that can be implemented in future studies.

Proteome Changes in Stem Tissues of Sunflower Lines Inoculated with Culture Filtrate of Sclerotinia sclerotiorum.

Background: Sclerotinia sclerotiorum (Lib.) de Bary cause a deleterious disease on sunflower plants. Oxalic acid is the main pathogenicity factor of S. sclerotiorum. Two dimensional gel electrophoresis and mass spectrometry have been used in several studies to investigate molecular changes that occur in the plants in response to S. sclerotiorum infection. Comparing responses of resistant and susceptible lines upon pathogen infection provided novel information regarding defense mechanisms against this necrotrophic pathogen.Objectives: The present study reports proteome changes of partially resistant and susceptible sunflower lines under pathogen’s culture filtrate treatment, resulting in the characterization of up- and down- regulated proteins.Material and Methods: Sunflower partially resistant and susceptible lines with two true leaves were exposed to fungus culture filtrate. The stems of treated and untreated plants were sampled at 24, 48 and 72 hours after treatment for two-dimensional electrophoresis. Twenty spots showed more than 1.5-fold change in abundance were subjected to MALDI/TOF-TOF MS for further analysis.Results: The identified proteins were categorized into several classes including carbohydrate and energy metabolism (25%), cellular metabolic process (15%), stress response (15%), plant cell wall biogenesis (10%), photosynthesis (10%), protein metabolism (10%), unknown function (10%) and redox homeostasis (5%).Conclusions: Our proteomic investigation demonstrates an increase in the expression of proteins only in partially resistant line, such as proteins involved in carbohydrate metabolism and plant defense responses (malate dehydrogenase and peroxidase), metabolic process (adenosine kinase), regulating cell redox homeostasis (disulfide isomerase) and lignin biosynthetic process (laccase). Moreover, the expression of pyrroline-5-carboxylate reductase, involved in proline biosynthesis, was significantly changed in both sunflower lines in response to pathogen culture filtrate. Proteins which were only up-regulated in the partially resistant lines might have a significant role in mediating the defense against Sclerotinia and could be considered for enhancing resistance against this devastating pathogen.

Исследование качества ДНК для полимеразной цепной реакции, экстрагированной разными способами из подсолнечника

Studying of plants DNA with PCR method plays an important role in the agrarian activity. Preceding stage of DNA studying is its extraction from plant material. We studied quality of DNA extracted by the different methods from seeds, seedlings, and green leaves of sunflower. We used an inbred sunflower line as a research object. For analysis we used embryos, dry and presoaked during 24 h seeds, roots, 7-day seedlings, green leaves. DNA was extracted using five methods: 1 – a standard method of extraction (1% CTAB), 2 – a modified method (2% CTAB), 3–4 – extraction with sets (Diamond DNA Plant Kit D, Russia; Lumiprobe, Germany), 5 – extraction from green leaves (2% CTAB with absorbent carbon). Amplification was conducted in thermocycler S1000тм (BioRad, USA). Spectrophotometery was done at scanning spectrophotometer LEKI SS2110UV (Russia). Analyzing all used methods we concluded they allow extracting of DNA from dry seeds, seedlings and green leaves of sunflower with sufficient reliability and repeatability, it is proved by PCR results. We couldn’t extract DNA from roots and presoaked seeds with the modified method (2% CTAB). The most economically profitable is first method (1% CTAB). Due to the results of spectrophotometery, the highest level of DNA clearance can be reached with method 3 – extraction by a set Diamond DNA Plant Kit D from seedlings and method 5 – extraction by 2% СТАВ with absorbent carbon from green leaves. The method 3 is more preferable by time necessary for DNA extraction.

Productivity and elements of the formation of the structure of the yield of sunflower genotypes when treated with plant growth regulators

Formulation of the problem. Among the main opportunities for improving seed production and the technology of growing sunflower in general is the use of plant growth regulators (further – PGRs). The main problem of PGRs is their strong dependence on weather conditions during the processing of plants. In addition, with the rapid increase in the number of PGRs in the State Register of Pesticides and Agrochemicals, their effect on various types of genotypes and their functionality under uncontrolled weather conditions remains poorly understood. Relevance of the topic. One of the most cost-effective and proven effective is the use of plant growth regulators. To date, a whole series of synthetic growth regulators, which in its composition has the active substances of humic origin, mineral compounds and extracts with different plants. But today the reaction of each genotype of sunflower separately from each other under the action of PGRs with different active substances remains little studied. Purpose. Study of the response of various genotypes of lines, hybrids and varieties of sunflower to the use of plant growth regulators. Material and methods. The studies were carried out in the period from 2018–2020., on the experimental field of the Department of Genetics, Breeding and Seed Production of KhNAU named after V.V. Dokuchaev. Lines, experimental hybrids and varieties of sunflower were used as the studied genotypes. Plant growth regulators Fulvital Plus, EcoStim, QuadroStim and applied by spraying during the growing season in the phase of 2–5 true leaves, and again in the phase of the sprocket. Conclusions. On average, over the years of research, the productivity of sterile lines increased from 0.7 to 38.1 %, depending on the PGRs and genotype. It is noted that lines SKh808A and SKh1002A have a greater potential to increase the structural indicators of the yield. One of the factors is their high adaptive capacity to the environment. The average rate of increase in line productivity according to PGRs from 5.1 g formed in the SKh1002A line and in SKh808A by 7.1 g. The weight of 1000 seeds increased from 0.3 to 24.7 % depending on PGRs, natural seeds and was within from -3.7 to 17.3 % depending on the drug and the line. The influence of PGRs on fertile lines of sunflower was weaker in comparison with sterile lines. By factor B, an increase in productivity was noted in the Kh785V line by 15.8 % and in the Kh1012B line by 27.7%, respectively. The main influence of PGRs in these lines under study was an increase in the mass of 1000 seeds. Thus, this indicator was 44.4 g for the Kh1012B line, which is 30.3 % more than the control and in the Kh06135V line – 53.1 g, an increase of 15.3 % to the control. The low performance of fertile lines compared to sterile lines is a consequence of the energy consumption of plants, since fertile lines produce pollen during the growing season, while fertile lines spend only energy on seed formation. The use of PGRs turned out to be quite effective in experimental hybrids. An increase in the genetic set occurs precisely during the creation of hybrids, the manifestation of heterosis increases the productive and adaptive capabilities of plants. The increase in the productivity of the hybrids was in the range of 0.3–19.6 %, the mass of 1000 seeds was in the range of 3.4–16.7 %. The productive characteristics of sunflower varieties had a low response to the use of PGRs Fulvital Plus, EcoStim and QuadroStim during the research period 2018–2020. Keywords. seed production, breeding, lines, sunflower, plant growth regulators, yield, hybrids, variety.

Evaluation of staygreen sunflower lines and their hybrids for yield under drought conditions

Abstract The experimental material for the present study comprised of 28 inbred lines (including two checks) which were developed by mutation and hybridization among the lines from AICRP trials MARS, UAS, Dharwad and on the basis of SPAD readings and stay green nature, they were considered as drought tolerant lines. These lines were used for the present experiment and were evaluated under both normal and moisture stress condition in rain out shelter to study their root characteristics. Among 28 inbreds evaluated, eight inbred lines i.e. DSR-13, DSR-19, DSR-23, DSR-24, DSR-37, DSR-66, DSR-107 and DSR-132 were identified as drought tolerant nature which exhibited least reduction in their yield under moisture stress condition. Simultaneously hybridization programme was also initiated during summer 2018 using these 28 inbred lines as testers (males) and 5 CMS lines as female lines in Line × Tester fashion. Among 140 hybrids developed, only 40 F1 hybrid combinations were further analyzed for heterosis and combining ability studies along with four checks RHA 6D-1, RHA 95C-1, KBSH-53 and Cauvery Champ. Most of the hybrid combinations showed significant negative heterosis for flowering indicating earliness, and also all the combinations showed a positive heterosis for plant height indicating tallness dominant over dwarf checks. The combinations CMS 7-1-1 A × DSR-37 (624 kg/ha), CMS-853A × DSR-19 (624 kg/ha), and CMS-853A × DSR-23 (619 kg/ha) exhibited significant maximum heterosis for seed yield (kg ha−1) over the checks KBSH-53 (496.50 kg/ha) and Cauvery Champ (486.50 kg/ha) showing maximum seed yield per hectare.

Environmental plasticity of sunflower lines for valuable economic traits

Our aim was to study the environmental plasticity of female sunflower lines for valuable economic traits, to select lines for heterosis breeding - sources of valuable economic traits with different categories of environmental plasticity. Results and Discussion. Expression of economically valuable traits and their environmental plasticity were studied in female maternal sunflower lines, including lines bred at NAAS institutions. Analyses of variance and regression showed that the lines were ranked according to the genotypic effect and the regression coefficient of these traits. Sunflower lines, which give relatively high yields and demonstrate optimal responses to the year conditions, are recommended to use in breeding for adaptability: short-season line Skh 1006 A (1.48 t/ha), early ripening line Skh 503 A (1.56 t/ha) and mid-early line Od 1042 A (1.60 t/ha). Early ripening line Skh 1002 A (50.4%) and mid-early line Od 1024 A (50.1%) are recommended to use in breeding programs as sources of high oil content and optimal expression of this trait across the years. Line Skh 51 A with a consistently high 1000-achene weight is a valuable source of large seeds. Mid-early line Od 1024 A is noticeable for a stable 1000-achene weight across the years and can serve as a valuable source in breeding programs to achieve a desirable level of this trait. A stable diameter of head was noted in early ripening lines Skh 1010 A and Skh 503 A and in mid-early line Skh 1012 A, which can be used as sources of this trait. Conclusions. The levels and environmental plasticity of the valuable economic traits were evaluated in the female sunflower lines. The lines were grouped in ranks according to the genotypic effect and the regression coefficient of the traits. Short-season, early ripening and mid-early sunflower lines have been identified as sources of valuable traits with different categories of response to the year conditions. The sunflower lines combining relatively high yield, oil content, 1000-achene weight and head diameter with an optimal response to the year conditions are recommended to use in breeding for adaptability.

Leaf metabolomic data of eight sunflower lines and their sixteen hybrids under water deficit

This article describes how metabolomic data were produced on sunflower plants subjected to water deficit. Twenty-four sunflower (Helianthus annuus L.) genotypes were selected to represent genetic diversity within cultivated sunflower and included both inbred lines and their hybrids. Drought stress was applied at the vegetative stage to plants cultivated in pots using the high-throughput phenotyping facility Heliaphen. Here, we provide untargeted and targeted metabolomic data of sunflower leaves. These compositional data differentiate both plant water status and different genotype groups. They constitute a valuable resource for the community to study the adaptation of crops to drought and the metabolic bases of heterosis.

Evaluation of horizontal resistance of sunflower (Helianthus annuus L.) to downy mildew (Plasmopara halstedii)

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 was to evaluate the horizontal resistance of elite and prospective lines to downy mildew in field conditions. Experiments were conducted at All-Russia Research Institute of Oil Crops (VNIIMK) in 2016–2020. Released and prospective sunflower lines bred at VNIIMK were studied, divided into four groups on the base of their race-specific resistance in laboratory tests. Experimental design was randomized blocks with two replications. Evaluation was made by recording all the recognizable symptoms of downy mildew from emergence till flowering. The results obtained allowed us to identify the lines with the highest race non-specific resistance to downy mildew: VK 678 (5.3%), VK 653 (7.3%), VA 760 (3.3%), VA 93 (2.0%) and VK 732 (6.3%). The final aim is the development of sunflower hybrids with the most durable resistance to downy mildew, combining one parental line with the major gene (Pl15) most effective for the specific location and the second parental line with a high level of horizontal resistance to downy mildew.

High stearic sunflower oil: Latest advances and applications

Regular sunflower oil is rich in linoleic acid. To improve its properties for different applications several genotypes with modified fatty acid compositions have been developed. Amongst them, the most remarkable have been high oleic and high stearic types. High stearic sunflower lines reported to date have been produced by traditional methods of breeding and mutagenesis. The mutations affected the expression of enzymes responsible for stearate desaturation in developing seeds. This trait has been combined with standard and high oleic backgrounds, giving high stearic lines with high contents of linoleic or oleic acids and thus different physical properties, increasing their functionality and potential applications. Nevertheless, for applications requiring plastic or confectionery fats, the oils have to be fractionated to obtain derived fats and butters with higher levels of solids. In the present review we present recent advances for the above mentioned topics related to high stearic sunflower oils.

An overview of innovative developments from the scientific provision of plant selection to resistance to diseases and pests

The Institute of Plant Protection of NAAS developed methods of plant selection for resistance to major pathogens and assessment methodology the resistance of winter wheat, potatoes, clover and alfalfa to pests to create complex resistant varieties. Donors of potato resistance to cancer, Alternaria, Phomosis and cyst-forming nematodes were identified. Methods for determining the resistance of cereals to high and low temperatures were developed. A collection of the Aegilops biuncialis L. wild wheat samples as sources of new resistance genes to plant diseases and pests was compiled. The soft winter wheat resistance genes to diseases by DNA markers were identified at the Institute of Plant Production named after V. Ya. Yuriev. The V. M. Remeslo Myronivka Institute of Wheat formed a set of winter wheat cultivars with group and complex resistance to diseases and pests. The Institute of Oilseed Crops of NAAS established physiological and biochemical mechanisms of resistance of sunflower, soybean, crown flax to pathogens. Collections of sunflower lines based on complex resistance to sunflower broomrape, dry rot, downy mildew and soybean lines based on complex resistance to white rot and Anthracnose were also created. In the National Scientific Center "Institute of Agriculture of NAAS", the fodder lupine resistance to the most important pathogens was investi-gated. The Institute of Agriculture in the Carpathian Region of NAAS revealed the spring barley, oat, rape, fiber flax varieties and selection numbers resistant to basic diseases; and the Institute of Rice of NAAS – rice cultivars resistant to diseases and pest pathogens. The resistance to main phytophagous insects of the modern genotypes of hemp, fiber flax and crown flax was assessed by the Institute of Agriculture of the North-East of NAAS. The assessment method of breeding value for the initial material of the main vegetables on the basis of disease resistance was developed by the Institute of Vegetables and Melons Growing of NAAS. Scientists of the Institute of Agroecology and Environmental Management of NAAS and V. M. RemesloMyronivka Institute of Wheat of NAAS revealed the cucumber and barley resistance to viral diseases. Key words: crops, pests, pathogens, resistance, resistance gene, resistance source.

Assessment of phenotypic variability among EEA INTA Pergamino sunflower lines: Its relationship with the grain yield and oil content

The aims of the present study were to assess the phenotypic diversity among 221 sunflower accessions of INTA Pergamino Sunflower Breeding Program, to obtain discriminant functions that allow the classification of new accessions in similar groups and to evaluate the relationship between genetic distance pairwise accessions and hybrid performance for grain yield and oil content. We used 19 quantitative descriptors to evaluate phenotypic and morphological variability. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were used to evaluate simultaneously all the variables and to describe phenotypic variation patterns of the germplasm. The distribution of germplasm in the dendrogram did not follow a clear pattern with regard to the predefined groups. This study revealed the variability observed among the lines that form the INTA Pergamino breeding program despite the highly selective forces applied to obtain inbred lines that produce superior hybrids for the Argentinean sunflower area. This work demonstrates the need for more in-depth study of genetic variability to be used as a predictor of heterosis in sunflower.

Differentiation of sunflower lines by cold tolerance

Purpose. The study purpose was to differentiate sunflower lines by cold tolerance and economically valuable traits for breeding hybrids with an increased adaptability to environmental stressors at the initial ontogenetic stages.Material and methods. Lines from a working collection of the Laboratory of Sunflower Breeding and Genetics of Plant Production Institute Industry named after V.Ya. Yuriev of NAAS (sterility fixers and fertility restorers) were taken as the test material. The field experiments were carried out in the scientific crop rotation fields of the Institute (township Elitne, Kharkivska Oblast, Kharkivskyi Raion). The field experiments were planned and conducted in accordance with conventional methods, with due account for the zonal features of sunflower cultivation.In the laboratory, the breeding material was assessed for tolerance to low temperatures by cold germination of sunflower seeds, with due account for the temperature mode peculiarities (5°C) and the germination length of sunflower line and hybrid seeds in a refrigerated thermostat (10 days). Cold tolerance was determined by germinability of sunflower seeds at 5оС related to the control (25оС). The resistance of breeding material to the causative agent of downy mildew was assessed in the laboratory by the method developed by YeM Dolgova et al. The oil content in seeds was determined by nuclear magnetic resonance. Data were statistically processed using Excel software.Results and discussion. Using cold germination of seeds harvested in 2016-2018, we differentiated sunflower lines by tolerance to low temperatures at the initial ontogenetic stages.The low temperature tolerance of lines – sterility fixers (sterile analogues) was found to range 4.7% to 88.8%. A high cold tolerance was noted in lines Skh 93 A (88.8%), Skh 1006 A (79.3%), and Skh 777 A (76.4%). The cold tolerance of sunflower lines – fertility restorers was revealed to vary in the range of 11.3–93.6%. A high tolerance to low temperatures was noted in lines Kh 720 V (93.6%), Kh 4913 V (77.9%), and Kh 15146 V (62.0%).The field results characterized the lines - sterility fixers (sterile analogues) and fertility restorers by breeding characteristics and their year-to-year variability. The valuable economic features, morphological traits and resistance to the downy mildew pathogen are described for lines – sources of cold tolerance.Conclusions. By the laboratory method of cold germination, the sunflower lines were differentiated by tolerance to low temperatures at the initial ontogenetic stages. Five lines with a high cold tolerance - Skh 93 A (88.8%), Skh 1006 A (79.3%), Skh 777 A (76.4%), Kh 720 V (93.6%), and Kh 4913 V (77.9%) - were identified as sources of this trait. The genotypic diversity of the sunflower lines was evaluated by breeding characteristics and their year-to-year variability. The lines – sources of cold tolerance were characterized by valuable economic features, morphological traits and resistance to the causative agent of downy mildew

Влияние морфометрических признаков растений самоопыленных линий подсолнечника на его полегаемость

We carried out the research in 2018-2019 at the experimental station of V.S. Pustovoit All-Russian Research Institute of Oil Crops. The aim of the research is to study the effect of certain morphometric characteristics of the overground part of plants and the architectonics of the root system on the sunflower lodging. We found significant differences in the architectonics of root systems in 17 maternal lines of sunflower: we identified three morphotypes, differing in the number and thickness of lateral roots of the first and subsequent orders, located in the top soil. We identified the sunflower lines that have a root system with a well-developed main root and many lateral roots of various orders (type A), lines with a normally developed main root and a small number of lateral roots (type B), and lines with a poorly developed main root and few lateral roots in top soil (type C). We identified the presence of both low and high lodging in sunflower lines with different types of root systems. At the same time, there is a tendency towards higher lodging in lines with root system types B and C. The line SL12 3660 showed the maximum lodging resistance during two years of observations. It may be of interest for further work as a possible source of a lodging resistance trait.