Pollen Fertility Restoration Research Articles

Mutations in nuclear genes encoding mitochondrial ribosome proteins restore pollen fertility in S male-sterile maize.

The interaction of plant mitochondrial and nuclear genetic systems is exemplified by mitochondria-encoded cytoplasmic male sterility (CMS) under the control of nuclear restorer-of-fertility genes. The S type of CMS in maize is characterized by a pollen collapse phenotype and a unique paradigm for fertility restoration in which numerous nuclear restorer-of-fertility lethal mutations rescue pollen function but condition homozygous-lethal seed phenotypes. Two nonallelic restorer mutations recovered from Mutator transposon-active lines were investigated to determine the mechanisms of pollen fertility restoration and seed lethality. Mu Illumina sequencing of transposon-flanking regions identified insertion alleles of nuclear genes encoding mitochondrial ribosomal proteins RPL6 and RPL14 as candidate restorer-of-fertility lethal mutations. Both candidates were associated with lowered abundance of mitochondria-encoded proteins in developing maize pollen, and the rpl14 mutant candidate was confirmed by independent insertion alleles. While the restored pollen functioned despite reduced accumulation of mitochondrial respiratory proteins, normal-cytoplasm plants heterozygous for the mutant alleles showed a significant pollen transmission bias in favor of the nonmutant Rpl6 and Rpl14 alleles. CMS-S fertility restoration affords a unique forward genetic approach to investigate the mitochondrial requirements for, and contributions to, pollen and seed development.

The trait-specific collection of large-seeded sunflower at VIR: ba source for breeding cultivars and hybrids

Background. In recent years, an increase has been observed in the share of sunflower seeds in the confectionery and food industries. There are 30 cultivars and only 3 hybrids for confectionery use among 839 zoned sunflower cultivars and hybrids listed in the State Register for Selection Achievements Admitted for Usage in 2023. Thus, the development of source material for breeding large-seeded cultivars and hybrids remains a relevant task.Materials and methods. The studied material included 90 accessions selected for their large seed size from VIR’s sunflower collection. The following characters were assessed: 1000 seed weight, days from sprouting to maturation, plant height, head diameter, cypsela color and size, and resistance to downy mildew. DNA markers were used to identify accessions with the Rf1 gene and CMS.Results. Accessions k-2818 (Primorsky Territory), k-3633, k-3748, k-3782 (China), and k-3578 (Ukraine) were the best in 1000 seed weight. Russian cvs. ‘Alekseyevsky Krupnoplodny 2’ (k-3552), ‘Gyar-Gyar’ (k-1589), ‘SPK’ (k-3426), and ‘Lakomka’ (k-3526) confirmed their large seed size. The sterile type of cytoplasm was identified in 12 accessions. Fourteen accessions with fertile cytoplasm had diagnostic markers of the nuclear Rf1 gene.Conclusion. The large-seeded cultivars developed at VNIIMK, ‘SPK’, ‘Lakomka’, and k-3782 from China were the best not only in their large seed size but also in downy mildew resistance. As a result of long-term studies, a trait-specific collection was established for the large seed size trait. It included 90 accessions that can be used in the development of confectionery cultivars. Large-seeded sunflower accessions carrying the Rf1 gene were identified. Some of them became the ancestors of donor lines for both pollen fertility restoration genes and large seed size.

Evaluation of Cytoplasmic Male Sterile Lines and Restorer Lines in Moricandia System for Heterosis Breeding in Indian Mustard [Brassica juncea (L.) Czern & Coss.

This study was undertaken with the objectives of Cytoplasmic Male Sterility (CMS) assessment and study of pollen fertility restoration using five Mori based Cytoplasmic Male Sterile lines viz., Mori ‘A’ SKM 109, Mori ‘A’ SKM 125, Mori ‘A’ SKM 201, Mori ‘A’ SKM 219, Mori ‘A’ SKM 303 and eight diverse Mori based fertility restorer lines viz., Mori ‘R’ GM 2, Mori ‘R’ GM 3, Mori ‘R’ SKM 9033, Mori ‘R’ SKM 301, Mori ‘R’ Pusa Bahar, Mori ‘R’ Vardan, Mori ‘R’ Bio 902, Mori ‘R’ 1-14 to identify good fertility restorer line and stain ability of pollen grains of sterile and fertile lines to Moricandia arvensis, cytoplasmic background of converted cytoplasmic male sterile lines of Indian Mustard [Brassica juncea (L.) Czern & Coss.] by repeated backcrossing at the Main Castor-Mustard Research station, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar-385506 Banaskantha. The pollen stain ability, plant fertility status and percentage siliquae set per plant was recorded for the morphological characterization and to confirm stability of true Cytoplasmic Male Sterile (CMS) line. The experimental material comprised of fifty-four genotypes consisting of five diverse CMS lines and eight Fertility Restorer lines were crossed in line X tester mating design and resultant forty hybrids along with their thirteen parents and standard check variety (Kranti) were evaluated in randomized block experimental design. The morphological characters were studied viz., pollen fertility, Number of siliquae set per plant, per cent siliquae set per plant in field as well as laboratory tests were conducted with 2 % Aceto-carmine to confirm pollen stain ability and purity of CMS (A-lines) for male sterility and pollen fertility restorability of R-lines. There were visual differences observed for the parents (male sterile lines and fertility restorer lines), all the F1 crosses and standard check parent for pollen fertility. The male sterile lines exhibited (100%) pollen sterility and the pollen fertility restorer lines varied from 80.05 % (Mori ‘R’ Pusa Bahar) to 97.97 %(Mori ‘R’ SKM 9033).

A Recombination Suppressed Region of Sunflower (<i>Helianthus annuus</i> L.) Linkage Group 13 Covers Restoration of Fertility (<i>Rf1</i>) and Downy Mildew Resistance (<i>Pl</i>) Gene Clusters

A number of genes that control valuable for breeding traits introgressed from wild relatives, i.e. pollen fertility restoration, resistance to fungal diseases (downy mildew and rust), are mapped on linkage group 13 of the cultivated sunflower Helianthus annuus L. genome. In sunflower and other plants, the recombination in the chromosome regions containing resistance genes can be suppressed that is favourable for marker assisted selection with applying molecular markers linked to these loci. The joint inheritance of the loci Rf1 (the phenotypic marker is fertility restoration trait) and Pl5/Pl8 conferring resistance to many races of Plasmopara halstedii (Farl) Berl. De Toni (the STS marker Ha-P1) was studied in the F2 generation of hybrids between a sterile line VIR 116A lines and pollen fertility restorers from sunflower VIR collection. In the crossing VIR 116А × VIR 740, the frequency of recombination between the loci Pl5Pl8 and Rf1 constituted 8.61 whereas in the crosses VIR 116А × VIR 195 and VIR 116А × VIR 80 turned out to be twice as high. In all examined F2 populations the absence of phenotypic class of sterile plants possessing paternal Нa-Р1 marker variant was mentioned. It has been shown by the cytological analysis that pollen fertility indices are most probably determined by the plant genotype rather than the male gametophyte allelic constitution. A deficiency of a recombinant F2 class was proposed to be associated with embryonic lethality, i.e. the collapse of zygotes carrying the recessive allele of fertility restoration gene and a specific allele of the resistance (susceptibility) gene obtained from the male parent.

Assessment of Cytomorphological Differences in Sorghum Fertility Restoration

Sorghum (Sorghum bicolor L. Moench) is ranked fifth as a cereal crop after maize, rice, wheat, and barley based on global cultivation area. However, heat and drought stresses cause improper fertility restoration and inefficient pollination, severely affecting sorghum productivity. The discovery of cytoplasmic male sterility (CMS) is a milestone for commercializing hybrids. This study assessed the pollen fertility and in vitro pollen germination percentage of male and female lines and F1 hybrids of sorghum using two years of pooled data with multivariate analysis. The principal component analysis (PCA) of female and male lines showed that PC1 represented 82.8% of the variation, whereas PCA of hybrids revealed a significant genetic divergence of 97.1%. Agglomerative hierarchical clustering marked that cluster II genotypes have a high pollen fertility contribution, which can generate superior and high-yielding hybrids. Three male-sterile lines exhibited 100% pollen sterility, with morphological attributes, viz., pinpointed, flattened, low anther extrusion, and starch-digested pollens. Pollen fertility restoration behavior revealed that nine hybrids were fully fertile, eighteen were partially fertile, and three were completely sterile amongst thirty hybrids. The findings of this study will facilitate the identification of potential restorers for the exploitation of high-yielding hybrids in sorghum breeding programs.

Comparative Transcriptome Analysis Reveals a Potential Regulatory Network for Ogura Cytoplasmic Male Sterility in Cabbage (Brassica oleracea L.)

Ogura cytoplasmic male sterility (CMS) lines are widely used breeding materials in cruciferous crops and play important roles in heterosis utilization; however, the sterility mechanism remains unclear. To investigate the microspore development process and gene expression changes after the introduction of orf138 and Rfo, cytological observation and transcriptome analysis were performed using a maintainer line, an Ogura CMS line, and a restorer line. Semithin sections of microspores at different developmental stages showed that the degradation of tapetal cells began at the tetrad stage in the Ogura CMS line, while it occurred at the bicellular microspore stage to the tricellular microspore stage in the maintainer and restorer lines. Therefore, early degradation of tapetal cells may be the cause of pollen abortion. Transcriptome analysis results showed that a total of 1287 DEGs had consistent expression trends in the maintainer line and restorer line, but were significantly up- or down-regulated in the Ogura CMS line, indicating that they may be closely related to pollen abortion. Functional annotation showed that the 1287 core DEGs included a large number of genes related to pollen development, oxidative phosphorylation, carbohydrate, lipid, and protein metabolism. In addition, further verification elucidated that down-regulated expression of genes related to energy metabolism led to decreased ATP content and excessive ROS accumulation in the anthers of Ogura CMS. Based on these results, we propose a transcriptome-mediated induction and regulatory network for cabbage Ogura CMS. Our research provides new insights into the mechanism of pollen abortion and fertility restoration in Ogura CMS.

The results of studying the productivity indicators of three-line sunflower hybrids and their parental forms under the influence of weather conditions

Topicality. At the present stage, the basis of the Ukrainian economy is agricultural production. Agriculture is the only sphere that is as dependent on weather fluctuations as any other. And it constantly has to adapt to the ongoing climate change. Climate changes, which cause an increase in temperatures, changes in the amount of precipitation and its distribution during the growth season, unstable weather conditions, the spread of pests and diseases, threaten the production of sunflower hybrids. The question about the influence of weather factors on the formation of productive traits of both hybrids and their parental forms, the dependence of agricultural crops on weather factors (temperature and precipitation, both for the entire growth season and for several months) is relevant. Purpose. To study of the influence of weather conditions on the formation of productive traits of hybrids and their parental components. Materials and Methods. The triple hybrids of sunflower (Helianthus annuus L.) Ahent, Ahronomicnyi, Kameniar, Marshal, Zaporizkyi 28, their parental components – single-cross sterile hybrids ZL(22х102)A, ZL(42х46)A, ZL(42х58)A and the restorers of fertility ZL512Rf, ZL678Rf and ZL7034Rf were studied. Results. Over the years of research, yield fluctuations reached to 0.90 t/ha for Ahent hybrid, 1.66 t/ha – Agronomichnyi, 0.13 t/ha – Marshal, 0.96 t/ha – Kameniar and 0.58 t/ha – Zaporizkyi 28. The highest yields and oil yield per unit area were in 2018. According to the results of three-year trials on hybrids and their parental forms, the Marshal hybrid had the highest yield – 2.64 t/ha with seed oil content of 50.78 % in 2016. Also in 2016, all pollen fertility restorers had the highest yields and oil yields. In 2018, four out of five hybrids showed the highest yields and oil yield per unit area. In 2017, the lowest oil content in the seeds of the tested hybrids was in the range of 45.16–48.49 % for Ahent and Zaporizkyi 28, respectively. Conclusions. It was established that Marshal is the most productive hybrid for sunflower cultivation in the southern Steppe of Ukraine, its average yield was 2.56 t/ha that exceeded by 0.27–0.48 t/ha this indicator in other hybrids. Key words: sunflower, hybrid, yield, oil content, 1000 seeds weight, oil yield, weather conditions, precipitation, temperature, sum of active temperatures, correlation coefficient

DNA marker-assisted identification of promising exotic advanced breeding lines as pollen fertility restorers and their validation based on field and laboratory assayable traits in chilli (Capsicum annuum L.)

DNA marker-assisted identification of promising exotic advanced breeding lines as pollen fertility restorers and their validation based on field and laboratory assayable traits in chilli (Capsicum annuum L.)

Population structure and genetic diversity of a germplasm for hybrid breeding in rye (Secale cereale L.) using high-density DArTseq-based silicoDArT and SNP markers

Investigating genetic structure and diversity is crucial for the rye hybrid breeding strategy, leading to improved plant productivity and adaptation. The present study elucidated the population structure and genetic diversity of 188 rye accessions, comprising 94 pollen fertility restoration lines (RF) and 94 cytoplasmic male-sterile (CMS) lines with Pampa sterilizing cytoplasm using SNP and silicoDArT markers from the diversity array technology (DArT)-based sequencing platform (DArTseq). Expected heterozygosity (He) and Shanon’s diversity (I) indexes varied slightly between marker systems and groups of germplasms (He = 0.34, I = 0.51 for RF and CMS lines genotyped using SNPs; He = 0.31, I = 0.48, and He = 0.35, I = 0.53 for RF and CMS using silicoDArTs, respectively). ANOVA indicated moderate variation (7%) between RF and CMS breeding materials. The same parameter varied when chromosome-assigned markers were used and ranged from 5.8% for 5R to 7.4% for 4R. However, when silicoDArT markers were applied, the respective values varied from 6.4% (1R) to 8.2% (3R and 4R). The model-based (Bayesian) population structure analysis based on the total marker pool identified two major subpopulations for the studied rye germplasm. The first one (P1) encompasses 93 RF accessions, and the second one (P2) encompasses 94 CMS and one RF accession. However, a similar analysis related to markers assigned to selected chromosomes failed to put plant materials into any of the populations in the same way as the total marker pool. Furthermore, the differences in grouping depended on marker types used for analysis.

A cytosolic pentatricopeptide repeat protein is essential for tapetal plastid development by regulating OsGLK1 transcript levels in rice.

Most plant pentatricopeptide repeat (PPR) proteins localize to and function inside plastids and mitochondria. However, the function of PPRs that only localize to the cytoplasm remains unknown. Here, we demonstrated that the rice (Oryza sativa) PPR protein CYTOPLASM-LOCALIZED PPR1 (OsCPPR1) contributes to pollen development and localizes to the cytoplasm. Knocking down OsCPPR1 led to abnormal plastid development in tapetal cells, prolonged tapetal programmed cell death (PCD) and tapetum degradation, and significantly reduced pollen fertility. Transcriptome analysis revealed that the transcript level of OsGOLDEN-LIKE1 (OsGLK1), which encodes a transcription factor that regulates plastid development and maintenance, was significantly higher in the OsCPPR1 knockdown plants compared to wild-type plants. We further determined that OsCPPR1 downregulates OsGLK1 transcription by directly binding to the single-stranded regions of OsGLK1 mRNAs. Overexpression of OsGLK1 resulted in abnormal tapetum and plastid development, similar to that seen in OsCPPR1 knockdown plants, and suppression of OsGLK1 partially restored pollen fertility in the OsCPPR1 knockdown plants. We therefore conclude that OsCPPR1 suppresses OsGLK1 in the regulation of plastid development and PCD in the tapetum. Our work revealed novel functions for a cytosolic PPR, demonstrating the diverse roles of PPRs in plants and identifying a new regulatory mechanism for regulating pollen development in rice.

Identification and expression analysis of phospholipase C family genes between different male fertility accessions in pepper.

Phospholipase C (PLC) is one of the major lipid-hydrolyzing enzymes, involved in lipid-mediating signal pathway. PLCs have been found to play a significant role in the growth and development of plants. In this study, the genome-wide identification and characteristic analysis of CaPLC family genes in pepper were conducted and the expression of two CaPLC genes were investigated. The results showed that a total of 11 CaPLC family genes were systematically identified, which were distributed on five chromosomes and divided into two groups based on their evolutionary relevance. Some cis-elements responding to different hormones and stresses were screened in the promoters of CaPLC genes. Quantitative real-time PCR indicated that the expression of CaPIPLC1 and CaPIPLC5 in flowers were dozens of times higher than in other tissues. In addition, with the development of flower buds, the relative expressions of CaPIPLC1 and CaPIPLC5 gradually increased in fertile materials R1 and F1. However, no expression of CaPIPLC1 and CaPIPLC5 were detected at all developmental stages of cytoplasmic male sterile lines (CMS) compared with fertile accessions. The study revealed the number and characteristics of the CaPLC family genes, which supplied a basic and systematic understanding of CaPLC family. In addition, these findings provided new insights into the role of CaPLC genes in pollen development and fertility restoration in pepper.

Selection of nuclear genotypes associated with the thermo-sensitivity of Owen-type cytoplasmic male sterility in sugar beet (Beta vulgaris L.).

Cytoplasmic male sterility in sugar beet becomes thermo-sensitive when combined with specific genotypes, potentially offering a means to environmentally control pollination by this trait. The stability of cytoplasmic male sterility expression in several genetic backgrounds was investigated in sugar beet (Beta vulgaris L.). Nine genetically heterogenous plants from open-pollinated varieties were crossed with a cytoplasmic male sterile line to obtain 266 F1 plants. Based on marker analysis using a multiallelic DNA marker linked to restorer-of-fertility 1 (Rf1), we divided the F1 plants into 15 genotypes. We evaluated the phenotypes of the F1 plants under two environmental conditions: greenhouse rooms with or without daytime heating during the flowering season. Three phenotypic groups appeared: those consistently expressing male sterility, those consistently having restored pollen fertility, and those expressing male sterility in a thermo-sensitive manner. All plants in the consistently malesterile group inherited a specific Rf1 marker type named p4. We tested the potential for thermo-sensitive male sterile plants to serve as seed parents for hybrid seed production, and three genotypes were selected. Open pollination by a pollen parental line with a dominant trait of red-pigmented hypocotyls and leaf veins resulted in seed setting on thermo-sensitive male sterile plants, indicating that their female organs were functional. More than 99.9% of the progeny expressed the red pigmentation trait; hence, highly pure hybrids were obtained. We determined the nucleotide sequences of Rf1 from the three genotypes: One had a novel allele and two had known alleles, of which one was reported to have been selected previously as a non-restoring allele at a single U.S. breeding station but not at other stations in the U.S., or in Europe or Japan, suggesting environmental sensitivity.

DNA Marker Assisted Identification of Promising Exotic Lines as Pollen Fertility Restorers and Validation Based on Restorer Related Traits Chilli (Capsicum Annuum L.) Test Cross Progenies

DNA Marker Assisted Identification of Promising Exotic Lines as Pollen Fertility Restorers and Validation Based on Restorer Related Traits Chilli (Capsicum Annuum L.) Test Cross Progenies

Resistance of sunflower lines and hybrids to major pathogenes in the Northern Steppe of Ukraine

The purpose was to establish the manifestation peculiarities of sunflower diseases and their combination with valuable economic traits depending on the genotype, as well as to select the best lines and hybrids for further use in production. To complete this purpose, the following objectives were achieved: to create a stationary infectious background for sunflower; to investigate the manifestation of major diseases of sunflower depending on the year conditions; to assess lines and hybrids for valuable economic characteristics and resistance to several pathogens; to select the best lines and hybrids.
 Materials and methods. The phytopathological studies were conducted on a long-term (2005–2020) sunflower monocrop, against artificial field infectious backgrounds, for the creation of which we used parts of naturally infected plants and laboratory infectious material. We studied resistance of sunflower lines and hybrids to pathogens widespread in the Northern Steppe of Ukraine: downy mildew (Plasmopara helianthi Novot.), dry head rot (Rhizopus nigricans Ehrend) and embellisia blotch (Embellisia helianthi (Hansf.) Pidolp). The infectious background level was determined by calculating the percentage of sunflower plants affected by pathogens related to the total number of sown achenes of an accession. The valuable economic characteristics of the genotypes were determined in accordance with the competitive trial methods. A total of 60 accessions, sunflower lines and hybrids bred by IOC NAAS and PPP nd a V.Ya. Yuriev NAAS, were studied.
 results and discussion. The infectious background level, defined as the percentage of infected plants, fluctuated over the study years. The variability ranges were as follows: for downy mildew in 2005–2020 – 7.2–27.3%; for dry head rot in 2012–2020 – 47.1–82.2%; for embellisia blotch in 2012–2020 – 11.0–88.8%. A line – sterile analogue (ZL70A), a line – pollen fertility restorer (Kh 114 V) and hybrids (Khazar, Koliada, Pervistok and Pryz) with high (score 7 points) or very high (score 9 points) resistance to the three studied pathogens have been identified. High resistance to downy mildew and dry head rot was recorded in line Kh 720 V and simple sterile hybrid KhZ 1701 A. Lines Skh 1008 A, ZL72A, ZL42A, and ZL260V as well as hybrid Haichur were distinguished due to their high resistance to downy mildew.
 During the years of studying valuable economic characteristics (2017–2020), high levels of the infectious backgrounds of the major pathogens of sunflower were observed, which made it possible to identify the best accessions combining high resistance (resistance score 7 and 9 points) with high yield, high 1000-seed weight (up to 58.6 g), high oil content in seeds (up to 52.12%) and low huskness (£ 24.6%). The ‘germination – physiological ripeness’ period in the best resistant hybrids was 95–105 days and, in the lines, it lasted 85–105 days. Hybrid Koliada jointly bred by PPI nd a V.Ya. Yuriev NAAS and IOC NAAS was the best in terms of yield (3.61 t/ha). Since 2020, Koliada has been the State Register of Plant Varieties Suitable for Dissemination in Ukraine.
 Conclusions. A possibility of identifying genotypes (lines and hybrids) with group resistance to the major sunflower pathogens, which are common in the Northern Steppe of Ukraine, has been proven. Lines and their hybrids combining high resistance to the major pathogens with high levels of economic characteristics have been identified.

Integrated system of selection of sunflower lines with economically valuable traits and adaptability of their F1 hybrids

Purpose. Determine the ecological plasticity and productivity of F1 sunflower hybrids created on the basis of maternal and parental lines, selected according to an accelerated selection system of lines resistant to herbicides (imidazoline and sulfonylurea groups) and broomrape (Orobanche cumana Wallr.). Methods. Statistical analysis of F1 sunflower hybrids was carried out using the methods of variation statistics, regression and analysis of variance using the Microsoft Office Excel 2016 application package. Molecular biological, biotechnological and classical selection methods were used for the accelerated system of line selection. Thus, for the purpose of targeted selection of sunflower sterility fixers, we used HRG01 molecular SCAR marker to identify the gene for the restoration of pollen fertility (Rf1). To accelerate the creation of parental lines resistant to tribenuron-methyl, we used a culture of immature embryos in vitro. Results. The results of testing of F1 sunflower hybrids at Kyiv, Chernihiv, Cherkasy (Uman and Shpolianskyi districts), Khmelnytskyi, Kharkiv, Kherson and Odesa regions. The hybrids were created on the basis of selected lines, chosen according to an accelerated selection system for herbicide-resistant lines (imidazoline (IMI-hybrids) and sulfonylurea (SU-hybrids) groups) and broomrape (Orobanche cumana Wall). The standards for comparison with hybrids were: for IMI hybrids – hybrids ‘NK Neoma’ (Syngenta) and ‘ES Genesis’ (Euralis), and for SU-hybrids – ‘SY Sumiko’ (Syngenta) and ‘P64LE25’ (Pioneer). As a result, it was found that among SU-hybrids, UA 2/106 had a 3.9% higher yield when compared to the standards (‘SY Sumiko’ and ‘P64LE25’). And for IMI-hybrids it was found that hybrids UA 1/67, UA 1/66, UA 1/84 have the same yield of 2.76 t/ha as the ‘NK Neoma’ standard. IMI hybrids UA 1/92, UA 1/102 have the same yield of 2.91 t/ha as ‘ES Genesis’. Conclusions. F1 hybrids were created on the basis of the original breeding material selected due to the accelerated system of sunflower lines selection. The hybrids were analyzed according to the yield indicator. The most productive among the tested SU-hybrids was UA 2/106 hybrid, among the IMI hybrids – UA 1/67, UA 1/66, UA 1/84, UA 1/92 and UA 1/102.

Development and validation of CAPS-marker associated with the <i>Rf2</i> gene in sorghum (<i>Sorghum bicolor</i> (L.) Moench)

Background. The development of heterotic hybrids based on cytoplasmic male sterility (CMS) is the leading strategy in breeding sorghum (Sorghum bicolor (L.) Moench). The trait of pollen fertility restoration in forms with CMS A1 (milo), predominantly used in sorghum breeding, is determined by at least two dominant complementary genes Rf1 and Rf2, and also gene Rf5. The development of accessible molecular markers of sorghum Rf genes is highly relevant for hybrid breeding, since they can significantly accelerate the process of creating female sterile forms (A lines), sterility maintainers (B lines) and pollen fertility restorers (R lines).Material and methods. The studied material included 36 sorghum accessions from the VIR collection, which differed by the ability to restore pollen fertility in forms with A1-type CMS. The nucleotide polymorphism of 935 bp fragments of the PPR genes Sobic.002G057050, Sobic.002G054100, and Sobic.002G054200 located at the chromosome 2 was studied.Results. The fragments obtained with the use of a pair of 2459403fw and 2459403 primers were 935 bp long and included parts of three genes: Sobic.002G057050, Sobic.002G054100, Sobic.002G054200. For identifying the sequence variant Sobic.002G057050-1090 associated with the Rf2 gene, Tru9 I restrictase was chosen, which allows obtaining a 572 bp fragment unique for all the studied R lines. Such a marker was found in 10 sorghum lines from West China and Kyrgyzstan, which are widely used in breeding as fertility restorers. The fragment was found neither in three lines with sterile cytoplasm and their fertile analogues, nor in 7 accessions of kafir sorghum, which lacked functional alleles of Rf genes.Conclusions. It has been demonstrated that the marker can be used for selection and checking purity of R and B/A lines. It is also applicable for verifying hybridity of F1 seeds and analyzing hybrid populations from crosses of R lines 924-4, 928-1, 929-3, 931-1, 933-1/6, 1237-3, 1243-2, 1251, 1150-1, F10BC2 with A lines Nizkorosloe 81s, А-83 and А-10598. It may be suggested that the ability to restore pollen fertility in R lines, which lack the marker CAPS- 572, is determined by another Rf gene. The studied 935 bp fragment of Sobic.002G057050 harbours 22 SNP, therefore the development of CAPS-markers for their identification and differentiation can be promising.

Diagnostic value of <i>Rf1</i> gene molecular markers in sunflower

Background. Modern production of sunflower seeds is currently based on the cultivation of high-yielding heterotic F1 hybrids from crossbreeding of lines with cytoplasmic male sterility (CMS) of PET1-type and fertility restorer lines. The paternal parent serves as a donor of the nuclear Rf1 gene functional allele, which is responsible for pollen fertility restoration in F1 plants. The detection of carriers of the Rf1 locus recessive and dominant alleles using diagnostic molecular markers accelerates breeding of female and male parental lines for creating hybrids.Materials and methods. The material for the study included 75 lines of various origins from the VIR sunflower genetic collection as well as hybrids from crosses of VIR 116A sterile line with fertile lines differing in the type of cytoplasm (fertile or sterile) and the presence of molecular markers, most of which were linked to the Rf1 locus. For marker validation, two different approaches were used: either by analyzing associations between the ability of a line to restore pollen fertility and the presence of molecular markers in its genotype, or by estimating recombination frequency between the Rf1 locus and marker loci in four segregating hybrid populations.Results. According to the obtained results, no markers demonstrated 100% efficiency in the analysis of the sample of genotypes. The ORS511 marker was most frequently observed among the lines presumably carrying the dominant allele Rf1. Pollen fertility of F1 hybrids from interline crossings was 89-99%. The segregation for fertility/sterility in F2 fitted the theoretical ratio of 3:1 expected in case of the monogenic control of the trait. The markers HRG01, HRG02 and ORS511 were linked to the fertility restoration trait, with recombination rates between Rf1 locus and markers varying in different cross combinations. The analysis of VIR 116А × VIR 740 and VIR 116А × RIL 130 hybrids showed that among the marker loci studied, the ORS511 was closest to the Rf1 locus Rf1 (recombination frequency of 2.2 and 3.3%, respectively). The recombination rate between the Rf1 and ORS511 loci equaled 7.5% in the cross VIR 116А × VIR 210 and 8.9% in VIR 116 × VIR 195.Conclusion. The markers ORS511, HRG01 and HRG02 are the most efficient for the identification of alleles of the Rf1 gene and for the marker assisted selection in hybrid populations produced involving sunflower lines from the VIR collection.

Study of the possibilities of using sunflower lines with different colours of seeds to create poultry feed

Abstract Sunflower is used for the production of oil, confectionery and animal feed. Birds are very fond of sunflowers and can be pests of sunflower crops, and are consumers of seeds. Sunflower poultry feed is an emerging market that determines the direction of breeding. Its development is based on the determination of bird preferences and the available variety of sunflower lines. This is what our research is devoted to. Experimental feeding of chickens with a mixture of sunflower seeds of different colours was carried out. Chickens have been found to prefer contrasting striped seeds with white and dark stripes more than others. The white colour of the seeds was eaten less than others. Studies of the genetics of sunflower colour allow us to distinguish two groups of lines by seed colour. The first has white seeds with the EwEwPP genotype, suitable for use in human confectionery and more protected from being eaten by wild birds in the fields. The second is striped seeds with the EstrEstrPP genotype, which can be fed whole seeds to birds. Donors of seed colour traits and other traits important for hybrid breeding were selected from the evaluated collection of sunflower lines. InK1039 line is a donor of small striped seeds and pollen fertility restoration. InK1587 line is a sterility fixer and donor of striped and early maturing seeds. To create hybrids with white seeds for human consumption and thus more resistant to ingestion by wild birds, white seed donors were isolated with KG9 to restore pollen fertility and I2K2218 in a pollen sterility fixer.

Variation of morphological indicators of three-line hybrids sunflower and their parental forms

The article presents the results of three-year (2016–2018) studies of five three-line hybrids of the IMC selection - Agent, Agronomichny, Marshal, Kamenyar, Zaporozhskij 28 and their parent components - simple unreduced hybrids - ZL22A/102B, ZL42A/46B, ZL42A/58B and pollen fertility restorers – ZL512V, ZL678V and ZL7034V. It was found that individual indicators do not change synchronously. The Agent, Marshal and Kamenyar hybrids had the highest plant height in 2016, one each in 2017 – Agronomichny and in 2018 – Zaporozhskij 28. At the same time, three hybrids (Agent, Agronomical, Marshal) had the largest basket diameter in 2018 and two (Zaporozhskij 28, Kamenyar) in 2017. The shortest growing season hybrids Marshal, Zaporozhskij 28 and Kamenyar had in 2016 (90, 105 and 105 days), and two – Agent and Agronomichny in 2018 – 100 and 103 days, respectively. Among the simple unrecovered hybrids, two – ZL42A/46B and ZL42A/58B had high indicators of plant height, basket diameter and duration of the growing season in 2016. In the ZL22A/102B hybrid, the diameter of the basket was also the largest in 2016 (18.5 cm), the average plant height in 2016 – 124.5 cm was slightly lower than in 2018 (125.4 cm), also in these years in it almost coincided with the duration of the growing season – 97 days in 2016 and 96 in 2018 Fertility restorers had the highest indicators of plant height and basket diameter in 2017, also this year they had the shortest growing season, in 2016, on the contrary, they had the lowest height and the diameter of the basket, and the long growing season. The size of the baskets in the Marshal and Kamenyar hybrids correlates with the moisture supply of plants and the hydrothermal coefficient – the correlation coefficients are 0.997, 0.902 and 0.990, 0.973, respectively. The phases of organogenesis of plants of hybrids Kamenyar and Zaporozhskij 28 are greatly influenced by temperature, the correlation coefficient of this indicator with plant height and with the duration of the growing season is 0.996 for Kamenyar and 0.946 for Zaporozhskij 28, and with a hydrothermal coefficient – 0.939 and 0.753. In the Agent hybrid, the temperatures in June have the greatest influence on plant growth - the correlation coefficient is 0.997 and precipitation in May is 0.968, and the temperatures in May - 0.999 and June - 0.998 on the size of the basket. For the height of plants and the duration of the growing season at Agronomichny, moisture availability at the beginning of the growing season is very important, the correlation coefficients are 0.918 and 0.994, and in August during the filling of seeds 0.996 and 0.927, as well as July precipitation is 0.995. Of the simple unrecovered hybrids, the most demanding for heat is ZL22A/102B - the correlation coefficients are 0.941 with plant height and vegetation duration, 0.843 with the basket size. For ZL42A/58B, the most important are the May precipitation, their correlation with the vegetation duration of 1,000 and the basket diameter of 0.987, and the July temperatures - 0.999 and 0.993, respectively. Among the pollen fertility restorers, the line ZL512V turned out to be the most demanding to weather conditions. For plant growth, the temperatures of April (0.906), May (0.995) and June (1.000) are very important, for the duration of the growing season respectively – 0.958, 0.971 and 0.991, and for the size of the basket, precipitation in May (0.956) and July temperatures (0.943). The correlation coefficient with the sum of active temperatures is – 0.829 for plant height – 0.851 for basket diameter – 0.902 for the growing season.

A comprehensive approach to modern aspects in sunflower selection

According to scientists of the NAAS network, the genetic potential of sunflower hybrids of Ukrainian selection is used in production by no more than 30%. Due to the reduction of the rotation period in crop rotation, crop losses from diseases increased from 10-15% to 35%, and in some favorable years for the development of diseases, losses only from rot are 70% or more. Phytopathological studies were performed on a stationary artificial infectious background of the Institute of Oilseeds NAAS during 2017-2020. We studied the biological resistance to major fungal diseases of new promising lines and hybrids of sunflower breeding institutions of NAAS (Institute of Plant Breeding Yur`eva). Synthetic artificial infectious background was formed during 16 years with forced introduction of infection during sowing of selection genotypes of sunflower. To assess the resistance of sunflower varieties to dry rot and embelization, the infectious background began to be created in 2012. Infectious material was developed in the immunity laboratory of the Institute of Oilseeds of NAAS by increasing pure cultures by the method of V.Y. White Assessment of resistance of sunflower to a number of diseases in the field was carried out according to the method of VP Mistletoe. Sowing was carried out with a seeding rate of 55 thousand / ha. According to the results of field and laboratory studies, sunflower lines and hybrids were identified, which were characterized by the duration of the growing season of the phase "seedlings-physiological maturity" in hybrids 95-110 days, in lines 85-105 days. The selected linear samples had a yield higher than the linear standard (ZL42 with a yield of 0.97 t/ha), and the studied sterile lines had a yield from 1.76 (+0.79) to 1.96 (+0.99) t/ha. Pollen fertility restorer lines had a yield at the level of 0.36 (-0.05) - 0.55 (+0.14) t/ha, when forming the yield of the control line ZL260V - 0.41 t / ha. Created hybrids based on these lines (parental components) formed a yield: Firstborn 3.34 t / ha, Tour - 3.80 t / ha, which is higher than the control hybrid Darius from 0.4 to 0.86 t / ha, respectively. The weight of 1000 seeds of sterile analogues varied in the range of 55.2 g - 56.4 g. In the lines of pollen fertility restorers in the range of 29.4-35.0 g. In the presented hybrids, the average weight of 1000 seeds was in the range of 57.0-60,1 g, while the standard Darius formed a mass of 1000 seeds within 49.0 g. The selected samples had a high percentage of fat accumulation in the seeds. This figure ranged from 49.76 (ZL96A) to 51.12% (ZL72A) among sterile analogues, while the standard sample ZL42A had an oil content of 49.26%. New selected sunflower hybrids were marked by fat content in seeds at the level of 51.88 (Prize) and 52.12% (Firstborn), while the hybrid - standard Darius also had a fairly high level of oil content, namely 48.13%. The presented lines and their hybrid combinations for the study period (2017-2020) combined relatively high resistance to powdery mildew, dry rot, embelisation and high economic performance. According to the results of a comprehensive assessment, a number of hybrids were identified. Among them are Tour, Prize and Firstborn. With such indicators, the presented hybrids are able to compete with dignity in the sunflower seed market.