scholarly journals Haploid Induction in Hull-less Seed Pumpkin through Parthenogenesis Induced by X-ray-irradiated Pollen

2013 ◽  
Vol 138 (4) ◽  
pp. 310-316 ◽  
Author(s):  
Kristina Košmrlj ◽  
Jana Murovec ◽  
Borut Bohanec
Keyword(s):  
Radiation Treatment ◽  
Chromosome Doubling ◽  
Significant Proportion ◽  
Pollen Grains ◽  
Female Parent ◽  
Haploid Induction ◽  
Ploidy Levels ◽  
X Ray ◽  
Pollen Donor ◽  
Spontaneous Chromosome

Production of hull-less seeds of styrian oil pumpkin (Cucurbita pepo ssp. pepo var. styriaca) is increasing as a result of demand for aromatic seed oil and for other uses. Hybrid cultivars have recently been released but a method for haploid induction has not been established. We focused on the development of a parthenogenetic haploid induction protocol based on pollination with pollen irradiated with X-ray radiation at 0, 50, 100, 150, 200, 300, and 350 Gy. Fruit set largely decreased at 200 Gy, whereas a decline in embryo formation was observed at 100 Gy. Various accessions were tested as the female parent or as the pollen donor and large differences were found. The best parthenogenetic response was found in ‘Turkey #2’ (10.0%), ‘Gleisdorfer Ölkürbis’ (4.4%), and ‘Naked Seed’ (3.9%), whereas ‘GL Opal’ and ‘White Acorn’ were efficient as pollen donors. The ploidy level of 3830 putative parthenogenetic embryos was determined using flow cytometry. Four ploidy levels (n, 2n, 3n, and 4n) were found with the majority being diploid. Interestingly, a significant proportion was determined to be tetraploid and this was clearly correlated with increased radiation delivered to pollen grains. Using selected simple sequence repeat markers on diploid embryos, no spontaneous chromosome doubling could be confirmed. In this study, haploid induction in styrian oil pumpkin was elaborated for the first time. We also showed that X-ray pollen irradiation provides an alternative to gamma radiation treatment, yielding a sufficient percentage of haploid plantlets.

scholarly journals Effect of Pepper Types on Obtaining Spontaneous Doubled Haploid Plants via Anther Culture

HortScience ◽  
2015 ◽  
Vol 50 (11) ◽  
pp. 1671-1676 ◽  
Author(s):  
Davut Keleş ◽  
Hasan Pınar ◽  
Atilla Ata ◽  
Hatıra Taşkın ◽  
Serhat Yıldız ◽  
...  
Keyword(s):  
Anther Culture ◽  
Chromosome Doubling ◽  
Haploid Plant ◽  
Naphthaleneacetic Acid ◽  
Green Pepper ◽  
Ploidy Levels ◽  
Doubled Haploidy ◽  
Spontaneous Chromosome ◽  
Future Work ◽  
Haploid Plants

The most successful technique used to obtain haploid plant in pepper is anther culture. The chromosome content of haploid plants can be doubled spontaneously or using colchicine. In this study, we compared the rate of spontaneous doubled haploidy of different pepper types. Seven charleston, six bell, eight capia, and seven green pepper genotypes were used as plant material. Murashige and Skoog (MS) nutrient medium with 4 mg·L−1 naphthaleneacetic acid (NAA), 0.5 mg·L−1 6-benzylaminopurine (BAP), 0.25% activated charcoal, 30 g·L−1 sucrose, and 15 mg·L−1 silver nitrate (AgNO3) was used. Ploidy levels of plants obtained through anther culture were detected using both flow cytometry and simple sequence repeats (SSR) markers. The results showed that different spontaneous doubled haploidy rates were obtained from different pepper types. The highest rate was observed in bell pepper type with 53.4% (mean of six genotypes) of haploid plants undergoing spontaneous chromosome doubling. This was followed by charleston and capia types with 31.9% and 30.4% doubling, respectively. Green pepper type gave the lowest spontaneous doubled haploidy rate with 22.2% doubling. The results obtained from this study will be useful both for future work on haploidy in pepper and for breeding programs.

scholarly journals Advances in Gene Editing of Haploid Tissues in Crops

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1410
Author(s):  
Pankaj Bhowmik ◽  
Andriy Bilichak
Keyword(s):  
Gene Editing ◽  
Chromosome Doubling ◽  
Rapid Development ◽  
Agricultural Practices ◽  
Haploid Induction ◽  
Genetic Mechanisms ◽  
Spontaneous Chromosome ◽  
Abiotic And Biotic Factors ◽  
Haploid Embryos ◽  
Short Time

Emerging threats of climate change require the rapid development of improved varieties with a higher tolerance to abiotic and biotic factors. Despite the success of traditional agricultural practices, novel techniques for precise manipulation of the crop’s genome are needed. Doubled haploid (DH) methods have been used for decades in major crops to fix desired alleles in elite backgrounds in a short time. DH plants are also widely used for mapping of the quantitative trait loci (QTLs), marker-assisted selection (MAS), genomic selection (GS), and hybrid production. Recent discoveries of genes responsible for haploid induction (HI) allowed engineering this trait through gene editing (GE) in non-inducer varieties of different crops. Direct editing of gametes or haploid embryos increases GE efficiency by generating null homozygous plants following chromosome doubling. Increased understanding of the underlying genetic mechanisms responsible for spontaneous chromosome doubling in haploid plants may allow transferring this trait to different elite varieties. Overall, further improvement in the efficiency of the DH technology combined with the optimized GE could accelerate breeding efforts of the major crops.

scholarly journals Hydrothermal Synthesis of Iridium-Substituted NaTaO3 Perovskites

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1537
Author(s):  
David L. Burnett ◽  
Christopher D. Vincent ◽  
Jasmine A. Clayton ◽  
Reza J. Kashtiban ◽  
Richard I. Walton
Keyword(s):  
Significant Proportion ◽  
Edge Length ◽  
Perovskite Oxide ◽  
Hydrogen Yield ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Profile Fitting ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
One Step

Iridium-containing NaTaO3 is produced using a one-step hydrothermal crystallisation from Ta2O5 and IrCl3 in an aqueous solution of 10 M NaOH in 40 vol% H2O2 heated at 240 °C. Although a nominal replacement of 50% of Ta by Ir was attempted, the amount of Ir included in the perovskite oxide was only up to 15 mol%. The materials are formed as crystalline powders comprising cube-shaped crystallites around 100 nm in edge length, as seen by scanning transmission electron microscopy. Energy dispersive X-ray mapping shows an even dispersion of Ir through the crystallites. Profile fitting of powder X-ray diffraction (XRD) shows expanded unit cell volumes (orthorhombic space group Pbnm) compared to the parent NaTaO3, while XANES spectroscopy at the Ir LIII-edge reveals that the highest Ir-content materials contain Ir4+. The inclusion of Ir4+ into the perovskite by replacement of Ta5+ implies the presence of charge-balancing defects and upon heat treatment the iridium is extruded from the perovskite at around 600 C in air, with the presence of metallic iridium seen by in situ powder XRD. The highest Ir-content material was loaded with Pt and examined for photocatalytic evolution of H2 from aqueous methanol. Compared to the parent NaTaO3, the Ir-substituted material shows a more than ten-fold enhancement of hydrogen yield with a significant proportion ascribed to visible light absorption.

scholarly journals Male meiosis and pollen morphology in diploid Indonesian wild bananas and cultivars

The Nucleus ◽  
2021 ◽  
Author(s):  
Fajarudin Ahmad ◽  
Yuyu S. Poerba ◽  
Gert H. J. Kema ◽  
Hans de Jong
Keyword(s):  
Hybrid Sterility ◽  
Pollen Grains ◽  
Chromosome Analysis ◽  
Male Meiosis ◽  
Enzyme Treatment ◽  
Unreduced Gamete ◽  
Ploidy Levels ◽  
Scientific Disciplines ◽  
Sterile Pollen ◽  
Mother Cells

AbstractBreeding of banana is hampered by its genetic complexity, structural chromosome rearrangements and different ploidy levels. Various scientific disciplines, including cytogenetics, linkage mapping, and bioinformatics, are helpful tools in characterising cultivars and wild relatives used in crossing programs. Chromosome analysis still plays a pivotal role in studying hybrid sterility and structural and numerical variants. In this study, we describe the optimisation of the chromosome spreading protocol of pollen mother cells focusing on the effects of standard fixation methods, duration of the pectolytic enzyme treatment and advantages of fluorescence microscopy of DAPI stained cell spreads. We demonstrate the benefits of this protocol on meiotic features of five wild diploid Musa acuminata bananas and a diploid (AA) cultivar banana “Rejang”, with particular attention on pairing configurations and chromosome transmission that may be indicative for translocations and inversions. Pollen slides demonstrate regular-shaped spores except “Rejang”, which shows fertile pollen grains of different size and sterile pollen grains, suggesting partial sterility and unreduced gamete formation that likely resulted from restitutional meiotic divisions.

scholarly journals VARIATION AMONG PERENNIAL RYEGRASS x TALL FESCUE PLANTS FROM TISSUE CULTURE

1988 ◽  
pp. 81-86
Author(s):  
A.G. Scott ◽  
D.W.R. White
Keyword(s):  
Tissue Culture ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Chromosome Doubling ◽  
Chromosome Elimination ◽  
Intergeneric Hybrids ◽  
Hybrid Plants ◽  
Spontaneous Chromosome

Tissue culture was used in an attempt to obtain a fertile perennial ryegrass x tall fescue hybrid. Regenerated hybrid plants were found to be morphologically variable and contain extensive chromosome rearrangements. Spontaneous chromosome doubling had occurred as well as chromosome elimination. though no fertile hybrid plants have been obtained to date. Keywords: somaclonal variation, Lolium perenne, Festuca arundinacea, intergeneric hybrids

scholarly journals Extension of thein vivohaploid induction system from maize to wheat

2019 ◽  
Author(s):  
Chenxu Liu ◽  
Yu Zhong ◽  
Xiaolong Qi ◽  
Ming Chen ◽  
Zongkai Liu ◽  
...  
Keyword(s):  
Pollen Viability ◽  
Haploid Induction ◽  
Male Sterile ◽  
Crop Breeding ◽  
Crop Species ◽  
Ploidy Levels ◽  
New Approach ◽  
Knock Out ◽  
Haploid Production

AbstractDoubled haploid breeding technology has been one of the most important techniques for accelerating crop breeding. In compare toin vivohaploid induction in maize, which is efficient and background independent, wheat haploid production by interspecific hybridization pollinated with maize is influenced by genetic background and requires rescue of young embryos. Here, we analyzed the homologues of maize haploid induction geneMTL/ZmPLA1/NLDin several crop species systematically, the homologues are highly conserved in sorghum, millet and wheat etc. Since wheat is a very important polyploidy crop, as a proof of concept, we demonstrated that thein vivohaploid induction method could be extended from diploid maize to hexaploid wheat by knocking out the wheat homologues (TaPLAs). Result showed that double knock-out mutation could trigger wheat haploid induction at ~ 2%-3%, accompanied by 30% - 60% seed setting rate. The performance of haploid wheat individual showed shorter plant, narrower leaves and male sterile. Our results also revealed that knockout ofTaPLA-A andTaPLA-D do not affect pollen viability. This study not only confirmed the function of the induction gene and explored a new approach for haploid production in wheat, but also provided an example that thein vivohaploid induction could be applied in more crop species with different ploidy levels. Furthermore, by combining with gene editing, it would be a fast and powerful platform for traits improvement in polyploidy crops breeding.

scholarly journals Doubled haploid technology for line development in maize: technical advances and prospects

2019 ◽  
Vol 132 (12) ◽  
pp. 3227-3243 ◽  
Author(s):  
Vijay Chaikam ◽  
Willem Molenaar ◽  
Albrecht E. Melchinger ◽  
Prasanna M. Boddupalli
Keyword(s):  
Doubled Haploid ◽  
Chromosome Doubling ◽  
Production Costs ◽  
Great Promise ◽  
Success Rates ◽  
Haploid Induction ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Line Production

Key Message Increased efficiencies achieved in different steps of DH line production offer greater benefits to maize breeding programs. Abstract Doubled haploid (DH) technology has become an integral part of many commercial maize breeding programs as DH lines offer several economic, logistic and genetic benefits over conventional inbred lines. Further, new advances in DH technology continue to improve the efficiency of DH line development and fuel its increased adoption in breeding programs worldwide. The established method for maize DH production covered in this review involves in vivo induction of maternal haploids by a male haploid inducer genotype, identification of haploids from diploids at the seed or seedling stage, chromosome doubling of haploid (D0) seedlings and finally, selfing of fertile D0 plants. Development of haploid inducers with high haploid induction rates and adaptation to different target environments have facilitated increased adoption of DH technology in the tropics. New marker systems for haploid identification, such as the red root marker and high oil marker, are being increasingly integrated into new haploid inducers and have the potential to make DH technology accessible in germplasm such as some Flint, landrace, or tropical material, where the standard R1-nj marker is inhibited. Automation holds great promise to further reduce the cost and time in haploid identification. Increasing success rates in chromosome doubling protocols and/or reducing environmental and human toxicity of chromosome doubling protocols, including research on genetic improvement in spontaneous chromosome doubling, have the potential to greatly reduce the production costs per DH line.

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