scholarly journals The development of homozygous maize lines using an in vivo haploid induction in the Croatian germplasm

Poljoprivreda ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 19-25
Author(s):  
Maja Mazur ◽  
Sonja Vila ◽  
Ivan Brkić ◽  
Antun Jambrović ◽  
Domagoj Šimić

The in vivo haploid induction has been widely applied to the maize breeding in recent decades, but it has not been used in the breeding programs in the Republic of Croatia by now. This study's objectives were to examine the haploid induction rates in the Croatian germplasm and to evaluate the properties of the D0 haploids, which are essential for a successful implementation of this method in breeding. The in vivo haploid induction was performed on 11 single-cross hybrids using the Zarodyshevy Marker Krasnodarsky (ZMK) inducer, and colchicine was used as a chromosome doubling agent. Emergence, misclassification rate, colchicine treatment survival, chromosome doubling rate and self-pollination success were examined in the D0 generation. The haploid induction rates ranged from 6.9 to 15.8%, which is consistent with the average induction rates characteristic of the ZMK inducer and the other modern ones. Significant differences were found among the populations of D0 haploids for all tested properties, except for self-pollination success. On average, the misclassification rates were lower, and the seedling survival rates were higher than those reported in other studies, indicating a possibility of a successful application of the doubled haploid method in maize breeding.

2019 ◽  
Vol 132 (12) ◽  
pp. 3227-3243 ◽  
Author(s):  
Vijay Chaikam ◽  
Willem Molenaar ◽  
Albrecht E. Melchinger ◽  
Prasanna M. Boddupalli

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.


2020 ◽  
Vol 80 (03) ◽  
Author(s):  
R. K Khulbe ◽  
A. Pattanayak ◽  
Lakshmi Kant ◽  
G. S. Bisht ◽  
M. C. Pant ◽  
...  

The use of in vivo haploid induction system makes the doubled haploid (DH) technology easier to adopt for the conventional maize breeders. However, despite having played an important role in the initial developmental phases of DH technology, Indian maize research has yet to harvest its benefits. Haploid Inducer Lines (HILs) developed by CIMMYT are being widely used in maize breeding programmes in many countries including India. There, however, is no published information on the efficiency of DH line production using CIMMYT HILs in Indian maize breeding programmes. In the present study, the efficiency of DH production using CIMMYT’s tropically adapted inducer line TAILP1 was investigated with eight source populations including two of sweet corn. The average haploid induction rate (HIR) of TAILP1 was 5.48% with a range of 2.01 to 10.03%. Efficiency of DH production ranged from 0.14 to 1.87% for different source populations with an average of 1.07%. The information generated will be useful for maize breeders intending to use DH technology for accelerated development of completely homozygous lines.


Genetika ◽  
2021 ◽  
Vol 53 (1) ◽  
pp. 51-64
Author(s):  
Rahime Cengiz ◽  
Mesut Esmeray

In vivo doubled haploid technique has been widely used in advanced maize breeding programs due to cost, labor and time advantages and increase in efficiency. However, the number of available inducer lines in the world is sufficient. Six BC1 breeding populations including RWS and RWK-76 haploid inducer lines and late temperate ADK-451, ADK-737 and ADK-455 lines were developed by Sakarya Maize Research Institute (MRI) in Turkey. The RWS and RWK-76 haploid inducer lines were used as donors. Pedigree method was employed to develop the inducer lines. Anthocyanin coloration of plant, tassel length, branch number of tassel, plant height, days to flowering, embryo-endosperm colorfulness and haploid induction rate (HIR) were determined. The genotypes with the best characteristics were selected. The families from BC1F3 to BC1F7 were hybridized to liguleless line to determine the HIR and families with HIR over 8% were selected from BC1 populations. The HIR, plant height and days to tassel flowering values of in-1021 and in-1076 candidate haploid inducer lines were 10.5 and 12.3%, 195 and 200 cm, and 69 and 68 days, respectively. The HIR value of RWS donor haploid inducer ranged from 8.9 to 11.3% and for RWK-76 from 7.3 to 9.8%. Simple Sequence Repeats (SSRs) markers were used to identify genetic similarity between late temperate haploid inducer lines and donors. The similarity rates of in-1021 and in-1076 inducer lines to the RWS donor were 38 and 15%, and to the RWK-76 donor were 23 and 27%. The similarity rate between the two candidate inducer lines was 30%. The results indicated that the late temperate haploid inducer lines developed will increase the efficiency of maize breeding.


2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.


Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1742
Author(s):  
Melysa Fitriana ◽  
Wei-Lun Hwang ◽  
Pak-Yue Chan ◽  
Tai-Yuan Hsueh ◽  
Tsai-Tsen Liao

Head and neck squamous cell carcinomas (HNSCCs) are epithelial malignancies with 5-year overall survival rates of approximately 40–50%. Emerging evidence indicates that a small population of cells in HNSCC patients, named cancer stem cells (CSCs), play vital roles in the processes of tumor initiation, progression, metastasis, immune evasion, chemo-/radioresistance, and recurrence. The acquisition of stem-like properties of cancer cells further provides cellular plasticity for stress adaptation and contributes to therapeutic resistance, resulting in a worse clinical outcome. Thus, targeting cancer stemness is fundamental for cancer treatment. MicroRNAs (miRNAs) are known to regulate stem cell features in the development and tissue regeneration through a miRNA–target interactive network. In HNSCCs, miRNAs act as tumor suppressors and/or oncogenes to modulate cancer stemness and therapeutic efficacy by regulating the CSC-specific tumor microenvironment (TME) and signaling pathways, such as epithelial-to-mesenchymal transition (EMT), Wnt/β-catenin signaling, and epidermal growth factor receptor (EGFR) or insulin-like growth factor 1 receptor (IGF1R) signaling pathways. Owing to a deeper understanding of disease-relevant miRNAs and advances in in vivo delivery systems, the administration of miRNA-based therapeutics is feasible and safe in humans, with encouraging efficacy results in early-phase clinical trials. In this review, we summarize the present findings to better understand the mechanical actions of miRNAs in maintaining CSCs and acquiring the stem-like features of cancer cells during HNSCC pathogenesis.


2021 ◽  
Vol 22 (3) ◽  
pp. 1222
Author(s):  
Cristina Cuello ◽  
Cristina A. Martinez ◽  
Josep M. Cambra ◽  
Inmaculada Parrilla ◽  
Heriberto Rodriguez-Martinez ◽  
...  

This study was designed to investigate the impact of vitrification on the transcriptome profile of blastocysts using a porcine (Sus scrofa) model and a microarray approach. Blastocysts were collected from weaned sows (n = 13). A total of 60 blastocysts were vitrified (treatment group). After warming, vitrified embryos were cultured in vitro for 24 h. Non-vitrified blastocysts (n = 40) were used as controls. After the in vitro culture period, the embryo viability was morphologically assessed. A total of 30 viable embryos per group (three pools of 10 from 4 different donors each) were subjected to gene expression analysis. A fold change cut-off of ±1.5 and a restrictive threshold at p-value < 0.05 were used to distinguish differentially expressed genes (DEGs). The survival rates of vitrified/warmed blastocysts were similar to those of the control (nearly 100%, n.s.). A total of 205 (112 upregulated and 93 downregulated) were identified in the vitrified blastocysts compared to the control group. The vitrification/warming impact was moderate, and it was mainly related to the pathways of cell cycle, cellular senescence, gap junction, and signaling for TFGβ, p53, Fox, and MAPK. In conclusion, vitrification modified the transcriptome of in vivo-derived porcine blastocysts, resulting in minor gene expression changes.


2016 ◽  
Vol 62 (7) ◽  
pp. 543-549 ◽  
Author(s):  
Martin Beaudoin-Nadeau ◽  
André Gagné ◽  
Cyntia Bissonnette ◽  
Pier-Anne Bélanger ◽  
J. André Fortin ◽  
...  

Canadian oil sands tailings are predominately sodic residues contaminated by hydrocarbons such as naphthenic acids. These conditions are harsh for plant development. In this study, we evaluated the effect of inoculating roots of Alnus viridis ssp. crispa and Alnus incana ssp. rugosa with ectomycorrhizal fungi in the presence of tailings compounds. Seedlings were inoculated with 7 different strains of Paxillus involutus and Alpova diplophloeus and were grown under different treatments of NaCl, Na2SO4, and naphthenic acids in a growth chamber. Afterwards, seedling survival, height, dry biomass, leaf necrosis, and root mycorrhization rate were measured. Paxillus involutus Mai was the most successful strain in enhancing alder survival, health, and growth. Seedlings inoculated with this strain displayed a 25% increase in survival rate, 2-fold greater biomass, and 2-fold less leaf necrosis compared with controls. Contrary to our expectations, A. diplophloeus was not as effective as P. involutus in improving seedling fitness, likely because it did not form ectomycorrhizae on roots of either alder species. High intraspecific variation characterized strains of P. involutus in their ability to stimulate alder height and growth and to minimize leaf necrosis. We conclude that in vivo selection under bipartite symbiotic conditions is essential to select effective strains that will be of use for the revegetation and reclamation of derelict lands.


2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Vien T. M. Le ◽  
Hoan N. Le ◽  
Marcos Gabriel Pinheiro ◽  
Kenneth J. Hahn ◽  
Mary L. Dinh ◽  
...  

ABSTRACT The protective efficacy of tedizolid phosphate, a novel oxazolidinone that potently inhibits bacterial protein synthesis, was compared to those of linezolid, vancomycin, and saline in a rabbit model of Staphylococcus aureus necrotizing pneumonia. Tedizolid phosphate was administered to rabbits at 6 mg/kg of body weight intravenously twice daily, which yielded values of the 24-h area under the concentration-time curve approximating those found in humans. The overall survival rate was 83% for rabbits treated with 6 mg/kg tedizolid phosphate twice daily and 83% for those treated with 50 mg/kg linezolid thrice daily (P = 0.66 by the log-rank test versus the results obtained with tedizolid phosphate). These survival rates were significantly greater than the survival rates of 17% for rabbits treated with 30 mg/kg vancomycin twice daily (P = 0.003) and 17% for rabbits treated with saline (P = 0.002). The bacterial count in the lungs of rabbits treated with tedizolid phosphate was significantly decreased compared to that in the lungs of rabbits treated with saline, although it was not significantly different from that in the lungs of rabbits treated with vancomycin or linezolid. The in vivo bacterial production of alpha-toxin and Panton-Valentine leukocidin, two key S. aureus-secreted toxins that play critical roles in the pathogenesis of necrotizing pneumonia, in the lungs of rabbits treated with tedizolid phosphate and linezolid was significantly inhibited compared to that in the lungs of rabbits treated with vancomycin or saline. Taken together, these results indicate that tedizolid phosphate is superior to vancomycin for the treatment of S. aureus necrotizing pneumonia because it inhibits the bacterial production of lung-damaging toxins at the site of infection.


Crop Science ◽  
2016 ◽  
Vol 56 (3) ◽  
pp. 1127-1135 ◽  
Author(s):  
Albrecht E. Melchinger ◽  
Pedro Correa Brauner ◽  
Juliane Böhm ◽  
Wolfgang Schipprack
Keyword(s):  

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