F1 Hybrids Research Articles

Insular environment-dependent introgression from an arid-grassland orchid to a wetland orchid on an oceanic island

Abstract Adaptive introgression plays a vital role in allowing recipient species to adapt and colonize new environments. However, our understanding of such environment-dependent introgressions is primarily limited to specific plant taxa in particular settings. In Japan, two related orchid species, the autonomously self-pollinating Pogonia minor and the outcrossing Pogonia japonica, typically inhabit dry grasslands and wetlands, respectively. Intriguingly, an island ecotype of P. japonica exists in arid, wind-swept, open sites on volcanic mountain slopes on Kozu Island, in the oceanic Izu Islands. To investigate potential introgression and its implications between P. japonica and P. minor on Kozu Island, we applied a comprehensive approach that included examining morphological traits, genome-wide SNP data, and plastid DNA sequences. We also examined the breeding systems of these species on Kozu Island through artificial pollination experiments to determine if introgression from P. minor has endowed the P. japonica ecotype with selfing capabilities. Extensive sampling on Kozu Island revealed that all P. japonica specimens exhibit signs of introgression from P. minor, suggesting the absence of pure P. japonica populations on the island. Furthermore, the chloroplast haplotypes of the insular P. japonica ecotype consistently match those of P. minor, indicating a predominantly asymmetrical initial hybridization with P. minor acting mainly as the maternal parent in the formation of F1 hybrids. Despite the advantages of self-fertilization in isolated environments, the insular P. japonica does not exhibit autogamy. Consequently, the scarcity of moist habitats, rather than selection pressure for selfing, likely contributes to the observed widespread introgression. Our study strongly suggests that the arid-environment-adapted P. minor has introgressed into the insular ecotype of P. japonica, enabling its successful colonization of arid volcanic mountain slopes of the oceanic island.

Historical and contemporary processes driving the origin and structure of an admixed population within a contact zone between subspecies of a north temperate diadromous fish.

Hybridization between divergent lineages can result in losses of distinct evolutionary taxa. Alternatively, hybridization can lead to increased genetic variability that may fuel local adaptation and the generation of novel traits and/or taxa. Here, we examined single-nucleotide polymorphisms generated using genotyping-by-sequencing in a population of Dolly Varden char (Pisces: Salmonidae) that is highly admixed within a contact zone between two subspecies (Salvelinus malma malma, Northern Dolly Varden [NDV] and S. m. lordi, Southern Dolly Varden [SDV]) in southwestern Alaska to assess the spatial distribution of hybrids and to test hypotheses on the origin of the admixed population. Ancestry analysis revealed that this admixed population is composed of advanced generation hybrids between NDV and SDV or advanced backcrosses to SDV; no F1 hybrids were detected. Coalescent-based demographic modelling supported the origin of this population about 55,000 years ago by secondary contact between NDV and SDV with low levels of contemporary gene flow. Ancestry in NDV and SDV varies within the watershed and ancestry in NDV was positively associated with distance upstream from the sea, contingent on habitat-type sampled, and negatively associated with the number of migrations that individual fish made to the sea. Our results suggest that divergence between subspecies over hundreds of thousands of years may not be associated with significant reproductive isolation, but that elevated diversity owing to hybridization may have contributed to adaptive divergence in habitat use and life history.

REPRODUCTIVE AND GROWTH PERFORMANCE OF FOUR GENOTYPES OF RABBITS FED WITH TOASTED CHRISTMAS BUSH FRUITS (Alchornea cordifolia) SEED MEAL

The body weight and reproductive performance of four genotypes of rabbits fed with toasted Alchornea cordifolia seed meal were examined in the study, as well as the body weight performance of their first filial generation and their reciprocal crosses. Toasted Alchornea cordifolia seed meal (TASM) inclusion was to know the (%) level that will perform better. The mating ratio of 1 sire to 9 dams in combinations of Dutch black buck and New Zealand does (DTB X NZW), New Zealand buck and Dutch black does (NZW X DTB), and then their reciprocal crosses resulted in a total of 127 kittens (NZW X DTB). The treatment diets were formulated at different levels to meet the rabbit’s nutritional requirements. Rabbits were kept in hutches inside rabbit’s pens, and feed and water were provided ad libitum. Reproductive and body weight were recorded. Preliminary and phytochemical analysis of the TASM revealed that it has values of 20.00%, 90.30%, 14.50%, 12.00%, 1.05%, and 65.2% for crude protein, dry matter, Ether extract, crude fiber, Ash, and Nitrogen-free extract, and phytochemical contains 6.50mg/g and 86.05mg/g for phytic acid and tannins. From the experiment, it is revealed that the rabbit fed on 15% TASM (NZW X DTB) significantly (p˂0.05) had a better body weight and reproductive performance than other groups. The findings of this study show that TASM can be incorporated into rabbits' diets up to 15% inclusion level for better weight gain and reproductive efficiency without having any negative impact on the animal.

Authenticity Identification of F1 Hybrid Offspring and Analysis of Genetic Diversity in Pineapple

Breeding is an effective method for the varietal development of pineapple. However, due to open pollination, it is necessary to conduct authentic identification of the hybrid offspring. In this study, we identified the authenticity of offspring and analyzed the genetic diversity within the offspring F1 hybrids resulting from crosses between ‘Josapine’ and ‘MD2’ by single nucleotide polymorphism (SNP) markers. From the resequencing data, 26 homozygous loci that differentiate between the parents have been identified. Then, genotyping was performed on both the parents and 36 offspring to select SNP markers that are suitable for authentic identification. The genotyping results revealed that 2 sets of SNP primers, namely SNP4010 and SNP22550, successfully identified 395 authentic hybrids out of 451 hybrid offspring. We randomly selected two true hybrids and four pseudohybrids for sequencing validation, and the results have shown that two true hybrids had double peaks with A/G, while pseudohybrids had single peaks with base A or G. Further study showed that the identification based on SNP molecular markers remained consistent with the morphological identification results in the field, with a true hybridization rate of 87.58%. K-means clustering and UPGMA tree analysis revealed that the hybrid offspring could be categorized into two groups. Among them, 68.5% of offspring aggregated with MD2, while 31.95% were grouped with Josapine. The successful application of SNP marker to identify pineapple F1 hybrid populations provides a theoretical foundation and practical reference for the future development of rapid SNP marker-based methods for pineapple hybrid authenticity and purity testing.

Breeding and genetic improvement of spelt wheat (Triticum spelta) by interspecific hybridization

Spelt wheat (Triticum spelta L.) is a high-value grain crop which is characterized by high protein, gluten and aminoacids content, high adaptive potential, resistance to diseases and high antioxidant activity. However, it is significantly inferior to soft wheat in terms of yield capacity. From crosses of spelt and soft wheat new promising genotypes can be obtained with improved quantitative traits due to introgression in the genome of spelt wheat of genetic material of soft wheat. In the research presented here based on hybridization of Triticum spelta L. × Triticum aestivum L. we obtained new forms of spelt which differ among themselves in terms of morphological characteristics, productivity and grain quality. As a result of the conducted research, a wide form-forming process in terms of plant height, ear morphology and grain threshing quality was recorded. The height of plants in F1 hybrids is inherited by the type of dominance of high stemness or intermediate inheritance was established. In the F2–F4 generations, the share of obtaining short-stemmed forms of spelt wheat was higher than with the use of short-stemmed varieties of common wheat as the maternal form. In F2 offspring, the inheritance of threshing quality by the type of dominant epistasis according to the 12 : 3 : 1 scheme was established. In F3–4 offspring, splitting according to ear morphology occurred with the appearance of not only typical forms of spelt wheat or common wheat, but also intermediate forms with different ratios of spike length and density. High-yielding (5.75–5.79 t/ha) short-stemmed (h = 78–89 cm) spelt wheat samples 1817 and 1559 with high grain quality indicators (weight of 1000 grains 64.4 g, protein content – 21.0%, gluten – 43.7%) were identified. Sample 13, which successfully combined high grain quality indicators in particular high protein content (26.2%), gluten content (55.8%), grain hardness (66.5 units), flour strength (340 alveograph units) was selected.

Interspecific Hardy Geranium Progenies: Morphological Characterization and Genetic Evaluation

Hardy geranium is a popular ornamental plant with a high market demand. As a result, there is a strong need for continuous innovation to improve its ornamental qualities. Interspecific hybridization is a widely used technique for introducing desirable traits and creating new cultivars with added value. To explore the possibilities of creating novelty within the Geranium genus, we conducted 2438 interspecific crosses over three flowering seasons, resulting in the successful harvest of 445 seeds and the final production of 82 seedlings. Using embryo rescue increased the germination rate of a seedling from 0.17% to 1.01%. To validate the paternal genetic contribution in the new seedlings, we used amplified fragment length polymorphism (AFLP) to assess the proportion of uniquely inherited paternal markers in all seedlings. AFLP analysis confirmed that 54 of the 82 seedlings were indeed true hybrids (65.8% hybridization success rate). A morphological evaluation of the flowers and leaves, including flower diameter (mm), style length (mm), number of flowers, flowering period (weeks), and color of both flowers and leaves, provided further confirmation of the F1 hybrid status of the seedlings. The results of our interspecific breeding demonstrated the efficiency of interspecific hybridization in hardy geraniums and its potential to create distinctive and novel cultivars for the ornamental market.

Combining Ability and Hybrid Breeding in Tunisian Melon (Cucumis melo L.) for Fruit Traits

A half-diallel cross study of seven melon inbred lines was carried out. The seven parents and their 21 F1 hybrids were evaluated for precocity of maturity, average weight per fruit, and fruit quality (fruit size, rind thickness, and soluble solids). The Diallel analysis was investigated for breeding values of these melon genotypes via general and specific combining ability, relationships between general and specific combining ability, and heterosis for the evaluated traits. The analysis of variance of the traits evaluated indicated highly significant differences among genotypes, suggesting the presence of adequate genetic variation for breeding. Additive genetic effects were most important with respect to fruit weight, while genetic dominance and epistasis effects mainly controlled fruit quality traits (fruit size, rind thickness, and TSS). Parent 1 (P1) and parent 3 (P3) had significant positive general combining ability effects for fruit weight. Also, P3 had positive general combining ability effects for fruit length and diameter, and cavity diameter. P3 was found to show maximum significant GCA in the desirable direction for all the traits except for TSS. Evaluation of heterosis (%) revealed that hybrid P1 × P3 can be considered as the best-performing hybrid for average fruit weight, TSS, and precocity, which also exhibited the highest positive and significant SCA effect for these traits. These results suggested that, among the melon genotypes studied, there is the potential to generate superior new varieties in hybrid production.

Distinct genetic origins of eumelanin levels and barring patterns in cichlid fishes.

Pigment patterns are incredibly diverse across vertebrates and are shaped by multiple selective pressures from predator avoidance to mate choice. A common pattern across fishes, but for which we know little about the underlying mechanisms, is repeated melanic vertical bars. To understand the genetic factors that modify the level or pattern of vertical barring, we generated a genetic cross of 322 F2 hybrids between two cichlid species with distinct barring patterns, Aulonocara koningsi and Metriaclima mbenjii. We identify 48 significant quantitative trait loci that underlie a series of seven phenotypes related to the relative pigmentation intensity, and four traits related to patterning of the vertical bars. We find that genomic regions that generate variation in the level of eumelanin produced are largely independent of those that control the spacing of vertical bars. Candidate genes within these intervals include novel genes and those newly-associated with vertical bars, which could affect melanophore survival, fate decisions, pigment biosynthesis, and pigment distribution. Together, this work provides insights into the regulation of pigment diversity, with direct implications for an animal's fitness and the speciation process.

Two-Sex Life Table Analysis for Optimizing Beauveria bassiana Application against Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae).

Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) is a highly dispersive, polyphagous insect pest that severely defoliates crops. Excessive reliance on synthetic insecticides leads to ecological pollution and resistance development, urging scientists to probe eco-friendly biopesticides. Here, we explore the virulence of an entomopathogenic fungus, Beauveria bassiana, against S. exigua, resulting in 88% larval mortality. Using an age-stage, two-sex life table, we evaluated the lethal and sublethal effects of B. bassiana on the demographic parameters of S. exigua, including survival, development, and reproduction. Sublethal (LC20) and lethal concentrations (LC50) of B. bassiana impacted the parental generation (F0), with these effects further influencing the demographic parameters of the first filial generation (F1). The infected F1 offsprings showed a reduced intrinsic rate of increase (r), mean generation time (T), and net reproduction rate (R0). Larval developmental duration varied significantly between the control (10.98 d) and treated groups (LC20: 10.42; LC50: 9.37 d). Adults in the treated groups had significantly reduced lifespans (M: 8.22; F: 7.32 d) than the control (M: 10.00; F: 8.22 d). Reduced fecundity was observed in the B. bassiana-infected groups (LC20: 313.45; LC50: 223.92 eggs/female) compared to the control (359.55 eggs/female). A biochemical assay revealed elevated levels of detoxification enzymes (esterases, glutathione S-transferases, and acetylcholinesterase) in the F0 generation after B. bassiana infection. However, the enzymatic activity remained non-significant in the F1 generation likely due to the lack of direct fungal exposure. Our findings highlight the enduring effects of B. bassiana on the biological parameters and population dynamics of S. exigua, stressing its use in eco-friendly management programs.

P-159 Single-cell high-throughput methylation and transcriptomic analysis indicates variations in sensitivity to Folate-mediated one-carbon metabolism in mouse preimplantation embryos

Abstract Study question Do Folate-mediated one-carbon metabolism (FOCM) supplements impose methylating conditions that influence methylation and transcriptomic profiles during preimplantation period of mouse embryos? Summary answer Subtle differences in embryo methylation profiles were induced by FOCM supplements, despite transcriptomic signatures remained stable and selective genes related to metabolism were activated. What is known already Previous human studies of populations affected by seasonal variations in diet including folate availability have shown methylation changes in specific loci known as metastable epialleles (MEs). MEs exhibit stability across tissues, indicating these could be potential biosensors for heightened sensitivity to external methylating influences in early embryonic stages. Despite significant progress in IVF embryo culture conditions, the sensitivity to the outer metabolic environment during the extensive genomic transformation of embryo reprogramming remains inadequately understood. Study design, size, duration This is a prospective experimental study conducted from January 2023 to December 2023. A total of 111 fresh mouse zygotes (F1 hybrid (B6/CBA)) were subjected embryo culture conditions with different FOCM supplies of 5-MTHF and betaine up to expanded blastocyst stage (105 hours). At different timepoints, individual embryos were collected and disaggregated in individual cells for downstream single-cell analysis. Participants/materials, setting, methods Mouse zygotes were collected from the oviduct, washed and culture in KSOM supplemented with 5-MTHF and betaine at respectively concentrations of 50μM and 50μg/mL (THF/bet(50)), 10μM and 10μg/mL (THF/bet(10)) and no supplement till blastocyst stage at 37 °C, 6%CO2 and 5%O2. Individual embryos were collected at 2 cells, 4 cells, 8 cells, Morula and Blastocyst stage and disaggregated into single cells for subsequent single-cell RNAseq (SmartSeq2) and single-cell methylome analysis through Splinted Ligation Adapter Tagging (scSPLAT). Main results and the role of chance The methylation analysis conducted though scSPLAT revealed a comprehensive reduction in global methylation levels throughout developmental stages. Notably, zygotes exhibited a maximal proportion of methylated cytosines at CpG sites, while blastocysts displayed minimal methylation levels, with sporadic increases in isolated cells. Quantitative profiling indicated lower methylation intensities in treated embryos from zygote to 4 cells, followed by a reversal trend from 8 cells to blastocyst, suggestive of an enhanced assimilation of one-carbon metabolism (FOCM) supplements. Transcriptomic profiles obtained through scRNAseq exhibited correlation with developmental trajectories from zygote to blastocyst. However, no discernible variations were attributed to the combined exposure of Betaine and 5-MTHF. Gene enrichment analysis of differentially expressed genes at various timepoints highlighted specific metabolic responses, including mitochondrial oxidative stress and variations in glutathione metabolism. This suggests that the folate forms utilized in this study may possess a protective role as antioxidants, contributing to the observed effects on gene expression during embryonic development. Limitations, reasons for caution The methylation analysis shown in this study was a pilot carried out with low coverage of sequencing deepness, further analysis are ongoing to increase reads coverage. Wider implications of the findings Exposure of mouse embryos to FOCM enhanced global methylation during cell division from 8 cells to blastocyst, indicating heightened assimilation during DNA synthesis. While the transcriptomic signature remained stable, increased expression of genes linked to mitochondrial oxidative stress and glutathione metabolism suggests FOCM’s potential antioxidant role. Trial registration number not applicable

P-200 Vitrification induces a deviation in cleavage morphokinetic patterns and transcriptomic signatures along mouse embryo development

Abstract Study question Are there cellular, molecular and/or epigenetic risks associated with cryopreservation that may affect embryo development and compromise the health of future newborns? Summary answer Cryopreservation significantly impacted mice pre-implantation embryo morphokinetics, altered transcriptomic profiles, and cell lineage distribution. However, global DNA methylation remained unaffected by cryopreservation. What is known already Cryopreservation is currently widely used in assisted reproduction. However, epidemiological studies suggest a negative impact in the long-term health of children born after frozen-embryo transfer (FET). Recent population-based register studies have reported: 1) an increased risk of infant mortality from birth up to 1 year of life in singletons conceived using cryopreserved embryos vs natural conceptions; 2) high birth weights for gestational age associated with FET; 3) an increased risk of obstetrical complications in singletons conceived using cryopreserved embryos; 4) a higher incidence of childhood cancer and imprinting disorders associated with FET. Study design, size, duration F1 hybrid (B6/CBA) mice zygotes were collected following uterus dissection (n = 200 embryos/collection), and half of those were vitrified for comparison. Each embryo’s morphokinetics was assessed through time-lapse imaging using GERI, at 37 °C, 6% CO2, 5% O2, up to 105 hours. Extended culture beyond blastocyst stage was also performed. Fresh and cryopreserved blastocysts at E5.0 were cultured up to E9.0-E10 in static conditions (IVC1 and IVC2 medium). Participants/materials, setting, methods Fresh and cryopreserved embryos at several developmental stages were used for: 1) immunofluorescence staining, 2) gene expression analysis through RT-qPCR and 3) single-cell RNAseq. Global methylation activity, cell lineage distribution and single-cell transcriptome were assessed using one of the previously described methodologies. Main results and the role of chance The morphokinetics of preimplantation embryos were examined by tracking the time required to reach 4-cell, 8-cell, compactation, morula, full blastocyst, and expanded blastocyst stage. A comprehensive analysis revealed notable delays in the developmental rhythm of cryopreserved embryos compared to fresh embryos (p < 0.01). Applying single-cell RNA sequencing (scRNAseq), transcriptomic profiles were generated for fresh and cryopreserved embryos, covering the zygote to blastocyst stages. Notably, distinct transcriptomic signatures for fresh and frozen embryos emerged within separate clusters at different developmental stages. These findings suggest a potential functional impact of cryopreservation on embryo development. To complement this, gene expression analysis of DNA methyltransferases and MAT enzymes was conducted through RT-qPCR at 8-cell and blastocyst stages. No significant differences were detected between fresh and cryopreserved conditions. Furthermore, immunofluorescence staining of nuclear 5mC and DNMT1 in 8-cell embryos and blastocysts demonstrated similar levels between fresh and cryopreserved embryos. Additionally, differential staining of embryonic and extraembryonic cells (OCT4, GATA6 and GATA3) in extended embryos (E9 and E10) revealed distinct cell distribution patterns between fresh and cryopreserved conditions. Limitations, reasons for caution Our research, conducted using a mouse experimental model, has limited applicability to humans due to considerable species differences in embryonic development. Additional research is needed to validate our findings and establish their relevance to human embryos, facilitating translational approaches. Wider implications of the findings Our study highlights a noticeable functional impact of vitrification on mouse embryos. Given the global incorporation of this method in fertility clinics and its potential association with increased disease risks, our findings emphasize the need for increased research to reduce uncertainties regarding the health of children born from cryopreservation methods. Trial registration number Not applicable

Specific anti-SVCV antibodies in hybrids of common carp (Cyprinus carpio) and gibel carp (Carassius gibelio) reflect heterosis advantage and genetic breakdown

Spring viraemia of carp virus (SVCV) is a disease with a serious economic impact on the farming of cyprinid fish. High susceptibility to SVCV has been documented mostly in common carp (Cyprinus carpio), whilst gibel carp (Carassius gibelio) is a weakly susceptible species. Specific anti-SVCV antibodies were analyzed in pure lines of common carp and gibel carp, and various generations of F1 and post-F1 hybrids. Specifically, we focused on anti-SVCV antibodies in weakly susceptible F1 hybrids and highly infected backcross and F2 hybrids, hypothesizing that the level of anti-SVCV antibodies will reflect heterosis advantage in F1 generations and hybrid breakdown in post-F1 generations.Backcross generations with common carp exhibited the most frequently symptomatic infections, followed by pure common carp. The high capacity of susceptible common carp to produce anti-SVCV antibodies was reported, whilst gibel carp expressed almost undetectable levels of anti-SVCV antibodies. We found the very good capacity of F1 hybrids to produce anti-SVCV antibodies, suggesting heterosis advantage. In contrast, we revealed different patterns of anti-SVCV antibodies production between maternal backcrosses (having parents with the same mtDNA – here, gibel carp) and paternal backcrosses (having parents with different mtDNA, i.e., resulting from reciprocal crosses of F1 hybrids with gibel carp mtDNA and pure common carp). Whilst both maternal backcross generations and the F2 generation of hybrids tended to produce low anti-SVCV antibodies, both paternal backcross generations expressed levels of anti SVCV-antibodies similar to those of highly susceptible common carp. The low capacity to produce anti-SVCV antibodies in F2 hybrids may be interpreted as a potential consequence of genetic disruption. However, the different capacity to induce an adaptive response in paternal hybrids and maternal hybrids (with mtDNA C. gibelio) may be interpreted as potential compensation for the cyto-nuclear breakdown hypothesized for paternal hybrids when coping with viral infection. Alternatively, the genetic background of hybrid fish, i.e. a combination of the genes of highly susceptible common carp and of less susceptible gibel carp in the hybrid genome may be responsible for this pattern.

Cytogenetic analysis of meiotic behaviour and stability in a trigeneric hybrid (triticale x trigopiro).

Trigeneric hybrids in Triticeae may help to establish evolutionary relationships among different genomes present in the same cellular genetic background and to transfer different alien characters into cultivated wheat. In the present study, a trigeneric hybrid involving species of Triticum, Secale, and Thinopyrum was synthesized by crossing hexaploid triticale with hexaploid trigopiro. The meiotic behaviour of chromosomes belonging to different genomes was analyzed, using routine and in situ hybridization techniques in F1, F2, and F3 generations of the trigeneric hybrid. The purpose of this study was to determine the chromosome number and genomic constitution and to discuss the mechanisms involved in the stabilization of the artificial tricepiro hybrids. The chromosome number of the trigeneric F1 hybrid was 2n = 42. Between 12 and 16 bivalents were observed in the central zone of the equatorial meiotic plate and between 9 and 18 univalents were found in the periphery of the MI equatorial plate. Seven of these univalents showed hybridization signals with rye DNA. Lagging rye and non-rye chromosomes and separation of sister chromatids were found in anaphase I. Tetrads with a maximum of six micronuclei, with and without hybridization signals of rye DNA, were observed. After three generations, meiotic cells revealed the presence of 42 chromosomes and 21 bivalents in diakinesis cells. The presence of 14 rye (Secale cereale) chromosomes and the complete pairing of chromosomes in F3 hybrids suggest that rye chromosomes would be preferentially transmitted to the progeny and that an elimination mechanism would act on chromosomes of Thinopyrum and wheat D genome.

Differences in the structure of inflorescences of some winter and spring rapeseed (Brassica napus L.) F1 hybrids

Differences in the structure of inflorescences of some winter and spring rapeseed (Brassica napus L.) F1 hybrids

In-vitro test of five cacao (Theobroma cacao L.) F1 hybrids to Phytophthora palmivora

Abstract Phytophthora palmivora causes black pod diseases (BPD) in cacao pods and reduces up to 25% of cacao yield. Cacao plant breeding aims to produce superior plants resistant to BPD. This research intended to confirm the pathogen through morphological characteristics and molecular identification, as well as evaluate the resistance level of five cacao F1 hybrids against P. palmivora in-vitro. The morphology of colonies was observed visually and microscopically, while sequencing analysis was performed using primer-specific pairs YPh1F/2R, followed by phylogenetic analysis. Resistance studies were using five cacao F1 hybrids: 8-7 (1), 9-7 (1), 1-11 (1), 5-1 (2), 2-8 (3), and BL 50 as the comparison variety using leaf disc methods. The research findings were Phytophthora sp. colonies on carrot medium showed faster growth than on potato dextrose agar. The microscopic observation showed the presence of pear-shaped spores. Likewise, the phylogenetic analysis confirmed that this pathogen was P. palmivora, with a high similarity of 98.78%. In the in-vitro study, two clones categorized as resistant, with clones 2-8 (3) having the lowest severity score. Other clones, including comparison varieties, have moderately resistant levels. The results are important information in assembling superior cacao clones resistant to P. palmivora.

A 7×7 diallel cross for developing high-yielding and saline-tolerant barley (Hordeum vulgare L.)

In this experiment, F1s produced from a 7 × 7 half-diallel cross along with their parents were evaluated to develop high yielding and saline-tolerant barley lines. The investigation focused on the general combining ability (GCA) of parents, specific combining ability (SCA) of offspring, genetic action, and heterosis of eight quantitative variables. Genetic analysis and potence ratio suggested that different degrees of dominance controlling the inheritance of the studied traits. Significant GCA and SCA variances suggested the presence of both additive and non-additive gene actions controlling the traits. However, a GCA:SCA ratio lower than 1 indicated the preponderance of the non-additive gene action involved in the expression of the traits. The parents P5 and P6 possess the genetic potential favorable for early and short stature in their F1s. Conversely, P2 and P4 were more likely to produce short F1s with high yield potential. Based on the mean performance, SCA, and heterobeltiosis, crosses P2 × P3, P2 × P7, P3 × P4, P4 × P5, P5 × P6, and P6 × P7 were selected as promising F1s for earliness, short stature, and high yield potential. These crosses are recommended for further breeding to obtain early-maturing and high-yielding segregants. To identify saline-tolerant F1s, screening was conducted in saline media prepared in half-strength Hoagland solution. The salinity stress involved exposing F1s to 100 mM NaCl for first 10 days, and followed by an increase to 150 mM until maturity. Among the F1s, five crosses (P1 × P2, P2 × P3, P3 × P5, P4 × P6, and P4 × P7) exhibited promising signs of saline tolerance based on a comprehensive evaluation of healthy seed set, K+/Na+ ratio, root volume, generation of reactive oxygen species (O2•− and H2O2), and activities of key antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and glutathione reductase (GR). These crosses will undergo further evaluation in the next filial generation to confirm heritable saline tolerance.

Heterosis and combining ability for phenological yield and fiber traits of cotton (Gossypium hirsutum L.) genotypes

The seeds of 4 lines, 3 testers, and their 12 F1 hybrids were sown in a randomized complete block design (RCBD) with 3 replications at Botanical Garden, Department of Plant Breeding and Genetics, Sindh Agriculture University, Tandojam during Kharif 2019. F1 hybrids were raised for the estimation of heterotic effects, GCA and SCA for days to 1st squaring, days to 1st boll formation Bolls opened at 90 days after sowing, Sympodial branches plant-1, Bolls plant-1, Boll weight (g), Seed cotton yield plant-1 (g), 100-seed weight (g), Ginning outturn (%) and staple length (mm). Genotypes, parents, crosses, parent's v/s crosses, lines, testers and line × testers were significant for days to 1st squaring and days to 1st boll forming. Bolls unveiled their fissures precisely 90 days post-sowing, while parameters including sympodial branches per plant, bolls per plant, individual boll weight, seed cotton yield per plant, 100-seed weight, ginning outturn, and staple length underwent meticulous evaluation. The statistical scrutiny unveiled the insignificance of both lines and testers concerning the 90-day boll dehiscence. Similarly, the parental influence on boll weight, 100-seed weight, and staple length exhibited a lack of statistical significance. Line CRIS-134, Sindh, and tester FH-901 gave a higher mean performance for all the traits. Among the hybrids, Mehran × FH-901, Sindh-1 × CIM-602, CRIS-134 × CIM-602, CRIS-342 × Koonj, and CRIS-342 × CIM-602 gave a desirable mean performance and heterotic effect for all the traits. CRIS-342 × Koonj produced maximum SCA effects for bolls per plant. Mehran × FH-901 recorded higher SCA effects for seed cotton yield plant-1 and 100-seed weight, CRIS-342 × CIM-602 for lint percentage, and CRIS-342 × FH-901 for staple length. It is suggested that these lines and testers should be utilized in the breeding program to improve these traits.

Evaluation of Generational Implications of Metabolic Resistance Development in Malaria Mosquitoes against Permethrin Insecticides

Enzymes mediated resistance development and their activities are well documented in Anopheles gambiae vectors. However, biological consequences of such resistance development in malaria vectors are obscure. The present study aims to determine the implications of such response in An. gambiae (Kisumu) population following exposure to a concentration of Permethrin selection pressure across multiple generations. Adult Kisumu mosquitoes exposed to 0.2 µg/ CDC bottle over generations were compared with unexposed control populations by way of resistance status, cost of fitness, and correlating metabolic enzymes. Data obtained were analysed using SPSS. Analysis of Variance was employed to determine statistical differences at 95%. Fecundity rates of the mosquito population dropped progressively over generations. With increase in activity of metabolic enzymes, resistance status of the mosquito population progressed significantly (P< 0.05) over generations with 5.0 µg (18.00±0.00; 72%) at f4 generation. Mosquito resistance development is therefore a disadvantage to malaria vectors as it reduces ovipository capability, and increases longevity of immature stages (life cycle) with filial generations.

Создание во ВНИИМК несуществующей в природе озимой формы горчицы сарептской (обзор)

Breeding of a new winter form of mustard started at the V.S. Pustovoit All-Russian Research Institute of Oil Crops in 1959. This work was aimed on increasing of crop yield due to winter plant growth. Hybrids between winter rapeseed and spring mustard were used as initial material. These species cross easily and had fertile progenies. A breeding sample No. 7823 was selected in hybrid combinations; it withstands low temperatures – from minus 10 to minus 15 °C at autumn sowing. At favorable overwintering conditions, yield of this sample was 2.0–2.8 t/ha, oil content of seeds – 44–48%. During further works, the winter mustard samples No. 26205 and 25582 with yield of 3.65–4.06 t/ha were selected. However, in unfavora-ble winter conditions, the winter resistance of winter mustard was 30–40% low than of winter rapeseed. In 1968, another method to develop winter mustard was chosen: by resynthesis from the elementary species – winter turnip rape (genome AA) and black mustard (genome BB). Usage of grafting and gamma radia-tion of pollen allowed producing F1 hybrid seeds. As a result of long-term works (1971–1989), based on resynthesis hybrids, the first in the world practice variety of winter mustard Suzdalskaya was developed. It competed with winter rapeseed by seed yield and winter resistance, however, erucic acid content in seed oil was 35–37%. In 2002, the first erucic acid free (1.5%) variety of winter mustard Snezhinka was submitted for the State trial. In 2010, the absolutely erucic acid free variety of winter mustard Dzhuna was included into the State register of breeding achievements. In 2022, the variety Vyuzhanka was included into the State Register, it exceeds the variety Dzhuna by seed yield by 0.72 t/ha and has oil of high quality.

Использование молекулярно-генетических маркеров для идентификации генов чувствительности к фотопериоду в селекционном материале сои

Soybean is one of the important oil and forage crops. It contains large amounts of oil, protein, vitamins, and other valuable nutrients. Annually, sowing area under soybean in Russia enlarges towards central and Siberian regions. However, soybean is very sensitive to photoperiod that is a key factor in regulation of soybean growth and development. The identification of gens controlling a photoperiodic sensitivity in soybeans is important for breeding of new adaptive cultivars. DNA-markers are an effective instrument for the selection of valuable genotypes from breeding germplasm. In this work, we identified gens contributing the most of decrease in soybean sensitivity to a day length. There were estimated six cultivars, five lines F6–F7, and five hybrids F1 of soybean. We used six molecular markers. Due to results, the early maturing cultivars Elana and Barguzin had the largest amount of recessive alleles; the cultivar Mamont had the largest amount of dominant alleles that characterizes it as middle maturing. The rest samples had two or three recessive alleles and belong to maturity groups from early to middle early. The analysis of hybrid combinations showed that a molecular marker for a Е3-gen is inherited co-dominantly. This allowed using it to control transferring of desired gens at crosses in progeny. Thus, the usage of the molecular-genetic markers was effective in selection by a studied trait and can be used in the breeding process.