scholarly journals Shattercane X ALS-Tolerant Sorghum F1 Hybrid and Shattercane Interference in ALS-Tolerant Sorghum

2014 ◽  
Vol 6 (4) ◽  
pp. 159 ◽  
Author(s):  
Rodrigo Werle ◽  
Jared J. Schmidt ◽  
John Laborde ◽  
Angela Tran ◽  
Cody F. Creech ◽  
...  
Keyword(s):  
Gene Flow ◽  
Competitive Ability ◽  
Grain Sorghum ◽  
Alternative Methods ◽  
F1 Hybrids ◽  
Herbicide Application ◽  
Hybrid Fitness ◽  
F1 Hybrid ◽  
Greenhouse Study ◽  
Hybrid Plants

ALS-tolerant grain sorghum cultivars are expected to be available for farmers within the next few years. Knowing that: i) crosses between sorghum and shattercane are likely to occur resulting in crop-to-weed gene flow; ii) ALS-susceptible shattercane X ALS-tolerant grain sorghum F1 hybrids (hybrids) were ultimately resistant to ALS-herbicides under field conditions; and iii) hybrid fitness is equal to, or greater than, the wild parent, we conducted a greenhouse study to compare the competitive effect of shattercane and hybrid on sorghum, and whether or not herbicide application would influence the competitive ability of the hybrid plants. An additive design was used where weed densities varied while that of crop remained constant. The treatment design was a factorial with two weedy genotypes, shattercane and hybrid, with the hybrid being either exposed or not exposed to an ALS-herbicide application (nicosulfuron (26.25 g ai ha-1) + rimsulfuron (13.16 g ai ha-1)), and five weed densities (0, 1, 2, 3, and 4 plants pot-1). Sorghum density was kept at 1 plant pot-1. F-tests were performed to compare differences across treatment levels. Shattercane and hybrid produced similar amounts of total above ground biomass within each density, and herbicide exposure did not decrease hybrid biomass production. Moreover, shattercane and hybrid competed similarly with sorghum, and a herbicide application did not reduce the competitive ability of the hybrid. Sorghum wild relatives must be managed by alternative methods before and during the adoption of ALS-tolerant sorghum technology to avoid gene flow and crop yield loss due to competition.

Gene flow between introduced and native Eucalyptus species: crossability of native Tasmanian species with exotic E. nitens

2005 ◽  
Vol 53 (5) ◽  
pp. 465 ◽  
Author(s):  
R. C. Barbour ◽  
B. M. Potts ◽  
R. E. Vaillancourt
Keyword(s):  
Gene Flow ◽  
Native Species ◽  
Seed Set ◽  
Pollen Competition ◽  
F1 Hybrids ◽  
Eucalyptus Species ◽  
F1 Hybrid ◽  
Genetic Pollution ◽  
Morphometric Analyses ◽  
Natural Hybridisation

Eucalyptus nitens (Deane & Maiden) Maiden has been extensively introduced to the island of Tasmania for plantation purposes. Natural hybridisation with two native species has already been confirmed and this study aimed to determine which other Tasmanian native species could potentially hybridise with E. nitens. Controlled and supplementary pollinations with E. nitens pollen were undertaken on all Tasmanian native species that are potentially at risk of exotic gene flow and hence genetic pollution. Across the seven species tested by using controlled pollinations, seed set per flower, following E. nitens pollinations, was significantly less than for intraspecific outcross pollinations. No significant differences were evident in the percentage of seed that germinated or the percentage of germinants that grew into healthy seedlings in the glasshouse. Hybridity was verified by morphometric analyses and F1 hybrid seedlings were clearly differentiated from parental species and generally intermediate in morphology. Supplementary E. nitens pollination of open-pollinated native flowers was conducted to simulate natural pollination where pollen competition would occur. Seven of the fifteen species tested produced F1 hybrids in this case; however, further crossing is required to verify failed cross combinations. Although E. nitens can potentially hybridise with many native species, the results from both supplementary and controlled pollinations suggest the presence of post-pollination barriers of varying strength that need to be considered in assessing the risk of exotic gene flow from plantations.

scholarly journals Characterization of F1 interspecific hybrids between wild Helianthus annuus L. populations and cultivated sunflower

Genetika ◽  
2006 ◽  
Vol 38 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Sreten Terzic ◽  
Jovanka Atlagic ◽  
Dejana Pankovic
Keyword(s):  
Helianthus Annuus ◽  
Ssr Markers ◽  
Interspecific Cross ◽  
F1 Hybrids ◽  
Interspecific Crosses ◽  
Phenotypic Traits ◽  
F1 Hybrid ◽  
Helianthus Annuus L ◽  
Hybrid Plants ◽  
Pollen Vitality

Phenotype, chromosomes pairing and pollen vitality were compared between parental populations and F1 hybrids of interspecific cross between Helianthus annuus L. and cultivated sunflower. The investigation of the simple sequence repeats (SSR) polymorphism was also used to test the hybrid nature of F1 populations. The phenotypic traits of F1 hybrid plants were either closer to the wild species or intermediate. Irregular chromosome pairing was found in only 0 to 10% of meiocytes in the meiosis of F1 hybrid plants. Interspecific crosses were confirmed with SSR markers in all hybrid combinations. Alleles that were not present in parental DNA were frequently observed in F1 hybrids. That is additional evidence that those hybrid combinations were not produced by self-fertilization. The results suggest that SSR markers can be efficiently used for the F1 hybrid characterization in crosses between closely related species, in which, the changes of phenotype, meiosis and pollen vitality are not always significant.

Interspecific Hybridisation Between Trifolium repens and T. uniflorum

1987 ◽  
Vol 35 (2) ◽  
pp. 171 ◽  
Author(s):  
KK Pandey ◽  
JE Grant ◽  
EG Williams
Keyword(s):  
Pollen Fertility ◽  
Morphological Characteristics ◽  
F1 Hybrids ◽  
Interspecific Hybridisation ◽  
Parent Species ◽  
F1 Hybrid ◽  
Hybrid Plants ◽  
F2 Hybrids ◽  
Fertile Hybrids

Several partially fertile hybrids (2n = 32) were produced by embryo culture from crosses of the type T. repens (2n = 32) female × T. uniflorum (2n = 32) male . The reciprocal crosses, although giving better seed development in vivo, were less successful in producing viable hybrid plants. Backcrosses to both parent species and F2 hybrids were also produced. Hybrid materials were variable with respect to morphological characteristics but broadly within the expected intermediate range. Their root systems were generally coarser and deeper than that of T. repens, offering the prospect of improved resistance to beetle larvae and drought. One F1 hybrid proved to be highly self-compatible, although derived from self-incompatible parent species. Pollen fertility ranged from 0 to 58% for F1 hybrids, 0 to 13% for F2 hybrids, 0 to 84% for backcrosses to T. repens and 0 to 26% for backcrosses to T. uniflorum. Marked seasonal variations in pollen fertility were also observed. Up to two quadrivalent chromosome associations per pollen mother cell were observed at meiosis in F1 hybrids, indicating some intragenomic pairing of T. repens chromosomes. Quadrivalent associations were also observed in an F2 hybrid and three backcrosses to T. repens.

scholarly journals Identity of genes of resistance to broomrape race G in sunflower lines of different origin

2021 ◽  
Vol 187 (3) ◽  
pp. 3-9
Author(s):  
S.Z. Guchetl ◽  
◽  
T.A. Antonova ◽  
N.M. Araslanova ◽  
T.A. Chelyustnikova ◽  
...  
Keyword(s):  
Quantitative Resistance ◽  
Resistance Mechanisms ◽  
F1 Hybrids ◽  
Sources Of Resistance ◽  
F1 Hybrid ◽  
Oil Crops ◽  
Hybrid Plants ◽  
Russian Research Institute ◽  
New Strategies ◽  
Russian Research

Broomrape is an obligate parasite and one of the most significant biotic factors reducing sunflower yield. The main means of controlling broomrape is breeding for sunflower resistance to it. New strategies are required to develop parasite resistant breeding germplasm, such as a stacking of key genes or a combination of qualitative and quantitative resistance mechanisms. In this regard, it is necessary to keep searching for new sources of resistance and to combine existing genes in case they are not identical. Thus, it is necessary to determine whether the genes of resistance to race G of broomrape are identical in the sunflower lines bred at the V.S. Pustovoit All-Russian Research Institute of Oil Crops. The research material was the previously developed sunflower lines RG, RGP1, RGP2, RGВ, RGL1, RGL2, and RGM – donors of resistance to race G of broomrape. The F1 hybrids from pair crossbreeding of these lines were obtained in a greenhouse. The F2 hybrids were obtained in the field by self-pollination of F1 hybrid plants. Plants were tested in a greenhouse for resistance and susceptibility to broomrape using the method of early diagnosis. Mathematical processing was performed by using the χ 2 -test. 13 combinations of crossbreeding were received to complete the test for allelism. In each F1 combination 11–33 plants were evaluated for resistance to race G of broomrape. Among the tested combinations, there was no one resistant to broomrape. Despite the differences in the number of affected plants, the affection degree was small in all hybrid combinations – from 1.0 to 1.8. All F2 hybrid combinations were also affected by broomrape. For eight combinations of F2, two phenotypic classes were found. There was no segregation in three combinations. The number of plants of two combinations was too small to perform χ 2 -test. In general, the χ 2 values were higher than the acceptable ones with a probability of 0.05, which indicates that the genes of resistance to race G of broomrape in these lines are identical.

scholarly journals PRODUCTIVITY OF F1 HYBRID PLANTS OBTAINED BY CROSSING DWARF AND LOW-GROWING LINES AND HIGH-GROWING VARIETIES OF G. HIRSUTUM L.

2020 ◽  
Vol 6 (5(74)) ◽  
pp. 41-45
Author(s):  
M.Zh. Israilov ◽  
G.A. Muratov ◽  
S.G. Boboev ◽  
A. Muratov
Keyword(s):  
Plant Productivity ◽  
F1 Hybrids ◽  
Intermediate Type ◽  
F1 Hybrid ◽  
Hybrid Plants ◽  
Diallel Crossing ◽  
Recessive Genes ◽  
Constituent Elements ◽  
Dominant Genes

This article presents the results of an analysis of studies on the variability of the trait of plant productivity and its components in cotton F1 hybrids, obtained on the basis of complete diallel crossing of dwarf, low-growing lines with tall cotton varieties of the species G. hirsutum L. It was revealed that in F1hybrids according to the harvest of raw cotton and its constituent elements, it varies differently depending on the genotypes of the parent components and combinations of crosses. Moreover, in F1 hybrids, a sign of the productivity of plants and its components shows dominance and overdomination of the signs of better and worse parents, aswell as an intermediate type of inheritance. It has been established that the indicator of the number of bolls and the yield of raw cotton per plant in tall varieties is controlled mainly by dominant genes, and the raw mass of one box of these varieties is controlled mainly by recessive genes

Interspecific hybridisation and cytogenetic studies in ornamental sunflower breeding

2005 ◽  
Vol 45 (1) ◽  
pp. 93 ◽  
Author(s):  
J. Atlagic ◽  
V. Secerov-Fiser ◽  
R. Marinkovic
Keyword(s):  
Wild Species ◽  
Chromosome Structure ◽  
F1 Hybrids ◽  
Interspecific Hybridisation ◽  
F1 Hybrid ◽  
Dominant Phenotype ◽  
Hybrid Plants ◽  
Cytogenetic Studies ◽  
The Common ◽  
Chromosome Bridges

This study examined the possibility of using wild sunflower species as a source of desirable genes in breeding the common ornamental sunflower. Crossing 7 wild species with 6 inbred lines of common ornamental sunflower produced F1 hybrid plants only with Helianthus argophyllus and H. petiolaris. The F1’s exhibited the dominant phenotype of the wild species. Cytological analysis showed irregularities in meiosis and low pollen fertility in F1 hybrids. The most frequent configuration was 15 bivalents and 1 quadrivalent and 13 bivalents and 2 quadrivalents. The presence of quadrivalents at diakinesis indicated the occurrence of translocations. In a small percentage of anaphase I meiocytes, chromosome bridges were detected resulting from inversions. The occurrence of translocations and inversions showed the differences in chromosome structure among the crossed species. Helianthus argophyllus and H. petiolaris may be useful in ornamental sunflower breeding as valuable sources of desirable genes.

scholarly journals Using Reciprocal Transplants to Assess Local Adaptation, Genetic Rescue, and Sexual Selection in Newly Established Populations

Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 5
Author(s):  
Jacques Labonne ◽  
Aurélie Manicki ◽  
Louise Chevalier ◽  
Marin Tétillon ◽  
François Guéraud ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Sexual Selection ◽  
Gene Flow ◽  
Local Adaptation ◽  
Intraspecific Diversity ◽  
F1 Hybrids ◽  
Foreign Gene ◽  
Gene Pools ◽  
Genetic Rescue ◽  
F1 Hybrid

Small populations establishing on colonization fronts have to adapt to novel environments with limited genetic variation. The pace at which they can adapt, and the influence of genetic variation on their success, are key questions for understanding intraspecific diversity. To investigate these topics, we performed a reciprocal transplant experiment between two recently founded populations of brown trout in the sub-Antarctic Kerguelen Islands. Using individual tagging and genetic assignment methods, we tracked the fitness of local and foreign individuals, as well as the fitness of their offspring over two generations. In both populations, although not to the same extent, gene flow occurred between local and foreign gene pools. In both cases, however, we failed to detect obvious footprints of local adaptation (which should limit gene flow) and only weak support for genetic rescue (which should enhance gene flow). In the population where gene flow from foreign individuals was low, no clear differences were observed between the fitness of local, foreign, and F1 hybrid individuals. In the population where gene flow was high, foreign individuals were successful due to high mating success rather than high survival, and F1 hybrids had the same fitness as pure local offspring. These results suggest the importance of considering sexual selection, rather than just local adaptation and genetic rescue, when evaluating the determinants of success in small and recently founded populations.

scholarly journals Sequencing an F1 hybrid of Silurus asotus and S. meridionalis enabled the assembly of high-quality parental genomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weitao Chen ◽  
Ming Zou ◽  
Yuefei Li ◽  
Shuli Zhu ◽  
Xinhui Li ◽  
...  
Keyword(s):  
De Novo ◽  
Parental Species ◽  
F1 Hybrids ◽  
Pelteobagrus Fulvidraco ◽  
F1 Hybrid ◽  
Short Reads ◽  
Final Assembly ◽  
Genome Complexity ◽  
Hybrid Genome ◽  
Silurus Asotus

AbstractGenome complexity such as heterozygosity may heavily influence its de novo assembly. Sequencing somatic cells of the F1 hybrids harboring two sets of genetic materials from both of the paternal and maternal species may avoid alleles discrimination during assembly. However, the feasibility of this strategy needs further assessments. We sequenced and assembled the genome of an F1 hybrid between Silurus asotus and S. meridionalis using the SequelII platform and Hi-C scaffolding technologies. More than 300 Gb raw data were generated, and the final assembly obtained 2344 scaffolds composed of 3017 contigs. The N50 length of scaffolds and contigs was 28.55 Mb and 7.49 Mb, respectively. Based on the mapping results of short reads generated for the paternal and maternal species, each of the 29 chromosomes originating from S. asotus and S. meridionalis was recognized. We recovered nearly 94% and 96% of the total length of S. asotus and S. meridionalis. BUSCO assessments and mapping analyses suggested that both genomes had high completeness and accuracy. Further analyses demonstrated the high collinearity between S. asotus, S. meridionalis, and the related Pelteobagrus fulvidraco. Comparison of the two genomes with that assembled only using the short reads from non-hybrid parental species detected a small portion of sequences that may be incorrectly assigned to the different species. We supposed that at least part of these situations may have resulted from mitotic recombination. The strategy of sequencing the F1 hybrid genome can recover the vast majority of the parental genomes and may improve the assembly of complex genomes.

scholarly journals Fitness of F1 hybrids between 10 maternal wild soybean populations and transgenic soybean

2021 ◽  
Author(s):  
Jin Yue Liu ◽  
Ze Wen Sheng ◽  
Yu Qi Hu ◽  
Qi Liu ◽  
Sheng Qiang ◽  
...  
Keyword(s):  
Seed Weight ◽  
Wild Soybean ◽  
F1 Hybrids ◽  
Weed Competition ◽  
Transgenic Soybean ◽  
Wild Progenitor ◽  
F1 Hybrid ◽  
Dry Biomass ◽  
100 Seed Weight ◽  
Pod Number

AbstractThe releasing of transgenic soybeans (Glycine max (L.) Merr.) into farming systems raises concerns that transgenes might escape from the soybeans via pollen into their endemic wild relatives, the wild soybean (Glycine soja Sieb. et Zucc.). The fitness of F1 hybrids obtained from 10 wild soybean populations collected from China and transgenic glyphosate-resistant soybean was measured without weed competition, as well as one JLBC-1 F1 hybrid under weed competition. All crossed seeds emerged at a lower rate from 13.33–63.33%. Compared with those of their wild progenitors, most F1 hybrids were shorter, smaller, and with decreased aboveground dry biomass, pod number, and 100-seed weight. All F1 hybrids had lower pollen viability and filled seeds per plant. Finally, the composite fitness of nine F1 hybrids was significantly lower. One exceptional F1 hybrid was IMBT F1, in which the composite fitness was 1.28, which was similar to that of its wild progenitor due to the similarities in pod number, increased aboveground dry biomass, and 100-seed weight. Under weed competition, plant height, aboveground dry biomass, pod number per plant, filled seed number per plant, and 100-seed weight of JLBC-1 F1 were lower than those of the wild progenitor JLBC-1. JLBC-1 F1 hybrids produced 60 filled seeds per plant. Therefore, F1 hybrids could emerge and produce offspring. Thus, effective measures should be taken to prevent gene flow from transgenic soybean to wild soybean to avoid the production F1 hybrids when releasing transgenic soybean in fields in the future.

scholarly journals Ecological divergence in sympatry causes gene misregulation in hybrids

2019 ◽  
Author(s):  
Joseph A. McGirr ◽  
Christopher H. Martin
Keyword(s):  
Gene Expression ◽  
Reproductive Isolation ◽  
Differentially Expressed ◽  
F1 Hybrids ◽  
Adaptive Divergence ◽  
Lower Hybrid ◽  
Hybrid Fitness ◽  
Hybrid Gene ◽  
San Salvador ◽  
Ecological Selection

AbstractEcological speciation occurs when reproductive isolation evolves as a byproduct of adaptive divergence between populations. However, it is unknown whether divergent ecological selection on gene regulation can directly cause reproductive isolation. Selection favoring regulatory divergence between species could result in gene misregulation in F1 hybrids and ultimately lower hybrid fitness. We combined 58 resequenced genomes with 124 transcriptomes to test this hypothesis in a young, sympatric radiation of Cyprinodon pupfishes endemic to San Salvador Island, Bahamas, which consists of a dietary generalist and two novel trophic specialists – a molluscivore and a scale-eater. We found more differential gene expression between closely related sympatric specialists than between allopatric generalist populations separated by 1000 km. Intriguingly, 9.6% of genes that were differentially expressed between sympatric species were also misregulated in their F1 hybrids. Consistent with divergent ecological selection causing misregulation, a subset of these genes were in highly differentiated genomic regions and enriched for functions important for trophic specialization, including head, muscle, and brain development. These regions also included genes that showed evidence of hard selective sweeps and were significantly associated with oral jaw length – the most rapidly diversifying skeletal trait in this radiation. Our results indicate that divergent ecological selection in sympatry can cause hybrid gene misregulation which may act as a primary reproductive barrier between nascent species.SignificanceIt is unknown whether the same genes that regulate ecological traits can simultaneously contribute to reproductive barriers between species. We measured gene expression in two trophic specialist species of Cyprinodon pupfishes that rapidly diverged from a generalist ancestor. We found genes differentially expressed between species that also showed extreme expression levels in their hybrid offspring. Many of these genes showed signs of selection and have putative effects on the development of traits that are important for ecological specialization. This suggests that genetic variants contributing to adaptive trait divergence between parental species negatively interact to cause hybrid gene misregulation, potentially producing unfit hybrids. Such loci may be important barriers to gene flow during the early stages of speciation, even in sympatry.

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