An efficient interspecific hybridisation protocol for Carica papaya L. × C. cauliflora Jacq.

1998 ◽  
Vol 38 (5) ◽  
pp. 523 ◽  
Author(s):  
P. M. Magdalita ◽  
R. A. Drew ◽  
I. D. Godwin ◽  
S. W. Adkins
Keyword(s):  
Interspecific Hybrid ◽  
Carica Papaya ◽  
Dichlorophenoxyacetic Acid ◽  
Gene Introgression ◽  
Interspecific Hybridisation ◽  
Papaya Ringspot Virus ◽  
Viable Pollen ◽  
Hybrid Plants ◽  
Mentor Pollen ◽  
2,4 Dichlorophenoxyacetic Acid

Summary. A protocol for interspecific hybridisation between Carica papaya and C. cauliflora is necessary for gene introgression between these 2 incompatible species. Carica papaya × C. cauliflora hybrids were successfully created using a new, efficient hybridisation protocol. This protocol includes the use of highly viable pollen of C. cauliflora produced during summer, autumn and/or spring, the use of an isolation time ranging from 90 to 120 days post-pollination of hybrid embryos, and the use of the most compatible C. papaya cultivar 2001 for crossing with C. cauliflora. Two types of interspecific hybrid embryos, namely single and multiple, were isolated in all resulting fruit. The application of gibberellic acid (0.6 or 0.8 mol/L) or 2,4- dichlorophenoxyacetic acid (1.5 or 2.0 mol/L) to freshly cross-pollinated flowers and pollination by mentor pollen did not promote either the rate of successful crosses or the production of hybrid embryos. Using this efficient protocol, hybridisation between C. papaya and C. cauliflora conducted in 3 locations in south-east Queensland produced 338 crosses which generated 43 736 seed. From these seed, 2100 hybrid embryos were recovered resulting in the production of 485 morphologically normal interspecific hybrid plants. Studies reported elsewhere show that these hybrids are resistant to papaya ringspot virus type P.

Inflorescence culture of Triticum aestivum × Secale cereale hybrids: production, characterization and cytogenetic analysis of regenerated plants

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 511-518 ◽  
Author(s):  
C. Doré ◽  
Y. Cauderon ◽  
M. C. Chueca
Keyword(s):  
Tissue Culture ◽  
In Vitro Culture ◽  
Chromosome Doubling ◽  
Dichlorophenoxyacetic Acid ◽  
Chromosome Counts ◽  
Hybrid Plants ◽  
Mother Plants ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Mother Cells

In vitro culture of immature inflorescences of F1 hybrid plants originating from the cross between the common wheat cultivar Roazon and two inbred lines of rye was carried out with 2,4-dichlorophenoxyacetic acid in the medium. After 3 or 8 weeks of culture as undifferentiated callus, 62 plants could be regenerated. Of these, 47 reached the adult stage; 46 of which were analysed for chromosome counts and chromosome pairing. For 44 of these, chromosome counts showed high stability and phenotypes were similar to those of the mother plants. In vitro culture of immature inflorescences could therefore be considered as a possible vegetative multiplication method to obtain numerous copies from one individual. The three other plants exhibited variations in phenotype and chromosome number: one was an amphiploid, and a chromosome was lost in each of the other two. All meristematic cells and pollen mother cells were involved in these numerical changes for each plant. The amphiploid plant (2n = 56) was nonchimeric and all the spikes were highly self-fertile. It could be an efficient method for chromosome doubling. This underscores the usefulness of inflorescence tissue culture for overcoming the sterility barrier in interspecific hybrids.Key words: wheat × rye hybrids, tissue culture, amphiploidization, aneuploidy, meiotic behaviour.

scholarly journals Anatomy of somatic embryogenesis in Carica papaya L.

2001 ◽  
Vol 44 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Juliana A. Fernando ◽  
Murilo Melo ◽  
Marli K. M. Soares ◽  
Beatriz Appezzato-da-Glória
Keyword(s):  
Somatic Embryogenesis ◽  
Somatic Embryos ◽  
Carica Papaya ◽  
Zygotic Embryos ◽  
Dichlorophenoxyacetic Acid ◽  
Internal Cell ◽  
Indirect Somatic Embryogenesis ◽  
Cell Layers ◽  
Morphological Differences ◽  
2,4 Dichlorophenoxyacetic Acid

Mature zygotic embryos of Carica papaya L. ‘Sunrise Solo’ were used as explants for embryogenesis induction. The explants were inoculated on Murashige and Skoog culture medium supplemented with 2 mg.L-1 2,4-dichlorophenoxyacetic acid and incubated in darkness at 25+2°C. Histological analysis of callogenesis and somatic embryogenesis indicated occurrence of direct and indirect somatic embryogenesis development. Direct somatic embryo formation was observed from hypocotyledonary epidermic cells only from explant 18 days after inoculation. Somatic embryos formed indirectly were originated from embryogenic superficial cells of pre-embryonic complexes located on peripherical and on internal cell layers of callus 49 days after inoculation. Diverse morphological differences including disformed embryos were observed among the somatic embryos.

In Vitro Shoot Regeneration from Callus Derived from Marubakaido Apple Rootstock under Different Aluminium Concentrations

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 460e-460 ◽  
Author(s):  
Marisa F. de Oliveira ◽  
Gerson R. de L. Fortes ◽  
João B. da Silva
Keyword(s):  
Shoot Regeneration ◽  
Dichlorophenoxyacetic Acid ◽  
Apple Rootstock ◽  
Under Five ◽  
Significant Difference ◽  
Previously Treated ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
In Vitro Shoot Regeneration

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.

Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483a-483
Author(s):  
Roy N. Keys ◽  
Dennis T. Ray ◽  
David A. Dierig
Keyword(s):  
Field Experiments ◽  
Reproductive Mode ◽  
Dichlorophenoxyacetic Acid ◽  
Initial Field ◽  
Breeding Lines ◽  
Reproductive Modes ◽  
Desert Southwest ◽  
2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

The role of a metabolic intermediate in the biodegradation of inhibitory substrates

1997 ◽  
Vol 36 (10) ◽  
pp. 27-36 ◽  
Author(s):  
P. Mungkarndee ◽  
S. M. Rao Bhamidimarri ◽  
A. J. Mawson ◽  
R. Chong
Keyword(s):  
The Other ◽  
Metabolic Product ◽  
Dichlorophenoxyacetic Acid ◽  
Mutual Inhibition ◽  
Metabolic Intermediate ◽  
Batch Cultures ◽  
Ortho Cresol ◽  
2,4 Dichlorophenoxyacetic Acid

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.

2,4-dichlorophenoxyacetic acid through lactation induces astrogliosis in rat brain

1997 ◽  
Vol 30 (3) ◽  
pp. 175-185 ◽  
Author(s):  
A. Brusco ◽  
J. Pecci Saavedra ◽  
G. García ◽  
P. Tagliaferro ◽  
A. M. Evangelista de Duffard ◽  
...  
Keyword(s):  
Rat Brain ◽  
Dichlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid

scholarly journals Improving Surface Imprinting Effect by Reducing Nonspecific Adsorption on Non-imprinted Polymer Films for 2,4-D Herbicide Sensors

Chemosensors ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 43
Author(s):  
Jin Chul Yang ◽  
Suck Won Hong ◽  
Jinyoung Park
Keyword(s):  
Morphological Changes ◽  
Unit Weight ◽  
Dichlorophenoxyacetic Acid ◽  
Surface Imprinting ◽  
Imprinted Polymer ◽  
Nonspecific Adsorption ◽  
Chemical Surface ◽  
Silane Modification ◽  
Silanized Silica ◽  
2,4 Dichlorophenoxyacetic Acid

Surface imprinting used for template recognition in nanocavities can be controlled and improved by surface morphological changes. Generally, the lithographic technique is used for surface patterning concerning sensing signal amplification in molecularly imprinted polymer (MIP) thin films. In this paper, we describe the effects of silanized silica molds on sensing the properties of MIP films. Porous imprinted poly(MAA–co–EGDMA) films were lithographically fabricated using silanized or non-treated normal silica replica molds to detect 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide as the standard template. The silanized mold MIP film (st-MIP) (Δf = −1021 Hz) exhibited a better sensing response than the non-treated normal MIP (n-MIP) (Δf = −978 Hz) because the imprinting effects, which occurred via functional groups on the silica surface, could be reduced through silane modification. Particularly, two non-imprinted (NIP) films (st-NIP and n-NIP) exhibited significantly different sensing responses. The st-NIP (Δfst-NIP = −332 Hz) films exhibited lower Δf values than the n-NIP film (Δfn-NIP = −610 Hz) owing to the remarkably reduced functionality against nonspecific adsorption. This phenomenon led to different imprinting factor (IF) values for the two MIP films (IFst-MIP = 3.38 and IFn-MIP = 1.86), which was calculated from the adsorbed 2,4-D mass per poly(MAA–co–EGDMA) unit weight (i.e., QMIP/QNIP). Moreover, it was found that the st-MIP film had better selectivity than the n-MIP film based on the sensing response of analogous herbicide solutions. As a result, it was revealed that the patterned molds’ chemical surface modification, which controls the surface functionality of imprinted films during photopolymerization, plays a role in fabricating enhanced sensing properties in patterned MIP films.

scholarly journals Exposures to 2,4-Dichlorophenoxyacetic acid with or without endotoxin upregulate small cell lung cancer pathway

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Geetika Kaur ◽  
B. V. Sunil Kumar ◽  
Baljit Singh ◽  
R. S. Sethi
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Lung Inflammation ◽  
Low Dose ◽  
Small Cell ◽  
Dichlorophenoxyacetic Acid ◽  
Small Cell Lung ◽  
Qrt Pcr ◽  
Histological Score ◽  
2,4 Dichlorophenoxyacetic Acid

Abstract Background Pesticide residues in food and environment along with airborne contaminants such as endotoxins pose health risk. Although herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) has been associated with increased risk of lung cancers such as small cell lung cancer (SCLC) among agricultural workers, there are no data on the SCLC signaling pathway upon 2,4-D exposure without LPS or in combination with endotoxin. Methods We exposed Swiss albino mice (N = 48) orally to high (9.58 mg kg− 1) and low (5.12 mg kg− 1) dosages of 2,4-D dissolved in corn oil for 90 days followed by E. coli lipopolysaccharide (LPS) or normal saline solution (80 μl/animal). Lung samples and broncho-alveolar fluid (BALF) were subjected to Total histological score (THS) and total leucocyte count (TLC) and differential leucocytes count (DLC) analyses, respectively. We used microarray and bioinformatics tools for transcriptomic analyses and differentially expressed genes were analyzed to predict the top canonical pathways followed by validation of selected genes by qRT-PCR and immunohistochemistry. Results Total histological score (THS) along with BALF analyses showed lung inflammation following long term dietary exposure to high or low doses of 2,4-D individually or in combination with LPS. Microarray analysis revealed exposure to high dose of 2,4-D without or with LPS upregulated 2178 and 2142 and downregulated 1965 and 1719 genes, respectively (p < 0.05; minimum cut off 1.5 log fold change). The low dose without or with LPS upregulated 2133 and 2054 and downregulated 1838 and 1625 genes, respectively. Bioinformatics analysis showed SCLC as topmost dysregulated pathway along with differential expression of Itgb1, NF-κB1, p53, Cdk6 and Apaf1. Immunohistological and quantitative real time PCR (qRT-PCR) analyses also supported the transcriptomic data. Conclusions Taken together, the data show exposures to high and low dose of 2,4-D with/without LPS induced lung inflammation and altered pulmonary transcriptome profile with the involvement of the SCLC pathway. The data from the study provide the insights of the potential damage on lungs caused by 2,4-D and help to better understand the mechanism of this complex relation.

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