• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.40-40
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• 2003

DNA content of the sperm of tetraploid mud loach (Misgurnus mizolepis) males and the ploidy status of progenies generated by crossing tetraploid males with diploid females are described. Reproductive performance of the induced adult tetraploid males ranged from sterility to fertility. Of 48 tetraploid males tested, 12 were sterile but the other 36 produced functional sperm. Of these 36, 26 produced haploid sperm, which on fertilizing the haploid eggs, generated diploid progenies. Seven tetraploid males were mosaics in their sperm, as indicated by the production of diploid, aneuploid and/or triploid offspring. Only 3 males produced diploid sperm rendering the production of all-triploid progenies. The DNA content of sperm of a tested tetraploid male was consistent throughout the 3 progeny tests, i.e. the haploid sperm-producing 4n males persisted to produce the haploid sperm only likewise the diploid sperm producing4n males consistently produced the diploid sperm only, when progeny testing was extended to 3 successive but alternate years. Hence, a careful and direct examination of the DNA profile of sperm from tetraploid males is a pre-requisite for reproductive containment of genetically modified fish.

• Korean Journal of Plant Resources
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• v.22 no.6
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• pp.506-512
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• 2009

To study the effect of genotype of donor plants on anther culture, anthers of nine hybrid cultivars (Derby, Special, Bossanova, Minipaprika, Fiesta, Boogie, Phenlene, Kufrah, and Clarity) of sweet pepper (Capsicum annuum L.) were cultured in a petridish containing C medium (Sibi, Dumas De Vaulx medium) supplemented with 0.1 mg/L 2,4-D and 0.1 mg/L kinetin, 3% sucrose and 0.32% Phytagel. The cultures were incubated in the dark at $35^{\circ}C$ for seven days, and then cultured at $25^{\circ}C$ with a photoperiod of 16 hr. daylength for 40 days. Frequency of callus formation and plant regeneration was varied among cultivars. Callus formation was ranged from 6% in Phenlene to 69.8% in Kufrah. The highest percentage of regenerated plantlets was obtained in cv. Phenlene (2.67%) followed by Bossanova (2.41%). Result of ploidy analysis; chromosome number observation and flowcytometry analysis, showed that haploid plants could be developed from all of these hybrid cultivars except cv. Fiesta, where highest percentage of haploid plants were obtained in Minipaprika (40%) followed by cv. Bossanova (36.1%). Haploid plants derived from these hybrid cultivars contained single set of chromosome (12 in numbers), higher stomata density (numbers), and smaller sized stomata as compare to diploid plants. The mean length of stomata was 26.9 ${\mu}m$ in haploid plants and 35.7 ${\mu}m$ in diploids.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.237-241
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• 2006

This experiment was carried out comparison with haploid plants productivity by microspore culture among domestic cultivars of Brassica napus L. Isolated microspore from flower buds were cultured on NLN medium supplemented with 13% sucrose, $0.05mg/{\ell}$ BA and $0.5mg/{\ell}$ NAA. Genotype was important factor in haploid embryo productivity 'Tamlayuchae' showed the highest haploid embryo production frequency (176 embryos formed from 1 flower bud). But, 'Hallayuchae' and 'Youngsanyuchae' were not generated embryo even cell division. When suspension culture on NLN liquid medium at 100 rpm, embryos were developed multilobe abnormal embryo cluster. Multilobe abnormal embryos on MS medium basal solid medium were regenerated multiple shoots. Regenerated haploid plant with well developed shoots and roots on MS basal medium were successfully transferred to pots.

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.776-783
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• 2000

Various alcohol yeast strains have been isolated from main mashes of Korean traditional liquors, and their genetic diversities were previously reported [23]. In this study, the strain SHY111, showing the highest alcohol production, was tested for its fermentation and sporulation characteristics. Additionally, its haploid cells were isolated and tested for their growth and fermentation patterns. The strain was identified as Saccharomyces cerevisiae based on its morphological and physiological characteristics. The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA regions of S. cerevisiae SHY111 were found to be identical to those of S. cerevisiae that was obtained from through the yeast genome project. The maximum fermentation ratio obtained by the strain SHY111 (96.7%) was almost the same as that by S. cerevisiae Balyun No. 1 (96.5%) that was a little higher than that by S. cerevisiae KCCM11215(95.8%). The strain was induced for sporulation in a sporulation liquid medium using log phase cells grown in different types of pre-sporulation media, and its haploid cells were obtained by spore dissection using a micromanipulator. The majority of the spores formed a small colony on a YPD agar plate, and the haploid yeast cells derived from the strain SHY111 showed a variety of growth and alcohol fermentation patterns. It was proposed that the fermentation patterns were related to their growth phenotypes in the most haploid strains, but possible not in some strains.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.4
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• pp.90-102
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• 2024

Haploid/double haploid plants developed from isolated microspores can significantly accelerate plant breeding. Haploid plants can naturally double their chromosomes to create a pure homozygous line of diploid plants. We present a method for producing embryos from isolated microspores of hot peppers (Capsicum annuumL.). We analyzed the polyploidization levels of the regenerated plants. The donor plants produced the optimal stage of microspores following short-term growth under low-intensity light, which resulted in high rates of embryogenesis and cotyledonary embryogenesis. To find an efficient culture method, liquid, doubled-layer, and 2-step cultures were tested. Liquid culture yielded the highest number of embryos, whereas the highest efficiency for cotyledonary embryogenesis was afforded by the doubled-layer culture. When normal cotyledonary embryos were transplanted onto a regeneration medium, they developed into complete plants. From these, 208 plants were tested via flow cytometric analysis, and 35.6% and 72.7% of the chromosomes from the Milyang-jare and LV2319 genotypes, respectively, were found to be spontaneous double haploids. These results are the same as those obtained on analyzing horticultural characteristics, including the size of leaves and the size and shape of fruits. The present study provides information on the practical application of isolated microspore culture of hot peppers, factors that affect embryogenesis, and methods for polyploidy testing.

• Journal of Plant Biology
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• v.13 no.3
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• pp.17-19
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• 1970

Histological observation of micropore-originated haploid rice callus was reported previously. Present study was attempted to clarify the growth or development of the calli when they were transferred to differentiation media prepared exclusively for differentiation of plantlets. When the callus was transferred to differentiation medium, the cells and tissues became radially elongated. Meristematic tissues were present but few in number, and their structures were quite different from those grown in the propagaton medium. Differentiation of tracheid, chloroplast, and epidermis-like cell layer, and formation of gap in the callus tissue were more conspicuous in differentiation media. Approximately ten days after transfer of callus to differentiation medium, plantlet was formed.

• ALGAE
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• v.34 no.1
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• pp.35-43
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• 2019

Genetic study of haploid organisms offers the advantage that mutant phenotypes are directly displayed, but has the disadvantage that strains carrying lethal mutations are not readily maintained. We describe an approach for generating and performing genetic analysis of diploid strains of Chlamydomonas reinhardtii, which is normally haploid. First protocol utilizes self-mating diploid strains that will facilitate the genetic analysis of recessive lethal mutations by offering a convenient way to produce homozygous diploids in a single mating. Second protocol is designed to reduce the chance of contamination and the accumulation of spontaneous mutations for long-term storage of mutant strains. Third protocol for inducing the meiotic program is also included to produce haploid mutant strains following tetraploid genetic analysis. We discuss implication of self-fertile strains for the future of Chlamydomonas research.

• Journal of Aquaculture
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• v.19 no.3
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• pp.166-172
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• 2006

Induced androgenesis, a form of artificial parthenogenesis is an important tool for the generation and use of genetically isogenic or clonal fish strain. An optimized protocol for the genetic inactivation of mud loach (Misgurnus mizolepis) oocytes (i.e. production of androgenetic haploid) was developed using UV-irradiation. Various dose levels of UV significantly affected the fertilizing capacity of the eggs, hatchability of embryos and incidence of haploidy. Based on the extensive examinations of treatment conditions on embryo viability and haploid incidence, the optimum dose level of UV irradiation was turned out to be $10,800ergs/mm^2$ with 56.9% of hatching success and 94.6% of haploidy. The overall yield of putative androgen under optimized treatment condition was more than 50% out of total eggs inseminated. The success of androgenetic reproduction of haploid genome was verified by flow cytometry and PCR amplification of transgene that is exclusive to either one of parental sexes. However, a small portion $(8\sim11%)$ of presumed androgenetic haploid larvae was proven to contain residual DNA fragment(s) from maternal parent.

• Korean Journal of Breeding Science
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• v.43 no.1
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• pp.50-55
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• 2011

The introduction of doubled haploid (DH) approach into breeding programs has reduced the times and population sizes required for the production of pure lines. We carried out the experiment for development on effective method of producing haploid in wheat. Emasculated spikelets of wheat were pollinated with maize pollen and cultured in the solution containing 40 g/L sucrose and 2,4-D, NAA, 2,4,5-T and dicamba 24 h after pollination, and then incubated until embryo rescue. Fourteen to sixteen days after pollination, the embryos are excised and cultured in half-strength MS basal medium supplemented with 20 g/L sucrose and 1 mg/L NAA. The type of plant growth regulators was found to be most significant in production of haploid plants. The application of synthetic auxins to pollinated florets, stimulates haploid embryo development to a stage where the embryos can be rescued onto nutrient media. The percentage of seeded florets was significantly affected by 100 mg/L 2,4-D, 150 mg/L 2,4,5-T and 50 mg/L dicamba. The percentage of embryos formed was significantly increased by treatment with 2,4-D and 2,4,5-T at 100 mg/L, and dicamba at 50 mg/L, but the treatments with 150 mg/L 2,4-D inhibited embryo development and plant regeneration. The optimum application time of plant growth regulators was 24 hrs after pollination.

• Proceedings of the Korean Society of Crop Science Conference
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• 1997.05a
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• pp.24-25
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• 1997