A DMP-triggered in vivo maternal haploid induction system in the dicotyledonous Arabidopsis

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.

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Development of a photochemical thrombosis investigation system to obtain a rabbit ischemic stroke model

Scientific Reports ◽

10.1038/s41598-021-85348-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yoonhee Kim ◽

Yoon Bum Lee ◽

Seung Kuk Bae ◽

Sung Suk Oh ◽

Jong-ryul Choi

Keyword(s):

Ischemic Stroke ◽

Brain Damage ◽

Rabbit Model ◽

Specific Area ◽

Brain Atlas ◽

Rabbit Brain ◽

Stroke Model ◽

Triphenyltetrazolium Chloride ◽

Induction System

AbstractPhotochemical thrombosis is a method for the induction of ischemic stroke in the cerebral cortex. It can generate localized ischemic infarcts in the desired region; therefore, it has been actively employed in establishing an ischemic stroke animal model and in vivo assays of diagnostic and therapeutic techniques for stroke. To establish a rabbit ischemic stroke model and overcome the shortcoming of previous studies that were difficult to build a standardized photothrombotic rabbit model, we developed a photochemical thrombosis induction system that can produce consistent brain damage on a specific area. To verify the generation of photothrombotic brain damage using the system, longitudinal magnetic resonance imaging, 2,3,5-triphenyltetrazolium chloride staining, and histological staining were applied. These analytical methods have a high correlation for ischemic infarction and are appropriate for analyzing photothrombotic brain damage in the rabbit brain. The results indicated that the photothrombosis induction system has a main advantage of being accurately controlled a targeted region of photothrombosis and can produce cerebral hemisphere lesions on the target region of the rabbit brain. In conjugation with brain atlas, it can induce photochemical ischemic stroke locally in the part of the brain that is responsible for a particular brain function and the system can be used to develop animal models with degraded specific functions. Also, the photochemical thrombosis induction system and a standardized rabbit ischemic stroke model that uses this system have the potential to be used for verifications of biomedical techniques for ischemic stroke at a preclinical stage in parallel with further performance improvements.

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In Vivo Haploid Induction in Maize: Comparison of Different Testing Regimes for Measuring Haploid Induction Rates

Crop Science ◽

10.2135/cropsci2015.11.0668 ◽

2016 ◽

Vol 56 (3) ◽

pp. 1127-1135 ◽

Cited By ~ 10

Author(s):

Albrecht E. Melchinger ◽

Pedro Correa Brauner ◽

Juliane Böhm ◽

Wolfgang Schipprack

Keyword(s):

Haploid Induction

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Extension of thein vivohaploid induction system from maize to wheat

10.1101/609305 ◽

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.

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

Theoretical and Applied Genetics ◽

10.1007/s00122-019-03433-x ◽

2019 ◽

Vol 132 (12) ◽

pp. 3227-3243 ◽

Cited By ~ 14

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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