• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.431-438
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• 2010

Anthers of sweet pepper $F_1$ cultivar 'Special' were cultured on Dumas De Vaulx (C medium), supplemented with $0.1mgL^{-1}$ 2, 4-D and $0.1mg{\cdot}L^{-1}$ kinetin with 3% sucrose, and 0.32% phytagel. The calluses obtained were further sub-cultured on Murashige and Skoog (MS) medium without growth regulators for regeneration. Regenerated plantlets were grown in plastic pots under plastic house and characterized their cytological and morphological characters in spring, 2008. Twenty percent plantlets were identified as haploid plants after chromosome and ploidy analysis. Haploid plants contained 12 chromosomes, high stomatal density with small stomatal length as compared to diploid plants. Stomatal length in haploids was 23.3% smaller than diploids. Haploid plants were characterized as small leaf and petiole size, poor vigor, thin stem and short plant height, short internodes and small flower buds, fruit size and fruit weight as compared to diploid plants and most of the haploid fruits were seedless. SP55, SP62, SP68, SP72 and SP77 are found high yielding double haploids with high total soluble content (8.6, 8.7, 9.2, 9.1 and $9.8^{\circ}Brix$, respectively) and desirable fruit shape, and recommended them to exploit as inbred lines for heterosis breeding.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.1
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• pp.21-26
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• 1988

Ten anther-derived doubled haploid (ADH) and 10 maternally-derived doubled haploid fines (MDH) from NC 2326 were evaluated in the field to compare their performance. Both anther-derived doubled haploid and maternally-derived doubled haploid lines were agronomically inferior to selfed parental variety for many parameters, but the degree of inferiority of the MDH lines were not significantly different from the selfed parental variety for any character investigated. The inferiority of the ADH lines were, however, significantly different from the selfed parental variety for yield, leaf length and width , and days to flower.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.39-45
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• 1999

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.531-536
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• 1993

Bulbosum method, which haploids are developed by pollinating with H. bulbosum have been productive to be recommended as an effective method for the production of genetically stable normal barley hybrids. The purpose of this study is to investigate several characters of H. bulbosum, seed set and embryo development rate pollinated with H. bulbosum in order to establish a method for improvement of embryo development and to find conditions favoring plant development from the embryos cultured in vitro. Three lines of H. bulbosum used as pollinators: GBC(2${\times}$), Spenish diploid(2${\times}$) and var. Jaaska (4${\times}$) were morphologically similar, having characteristically narrow leaves, narrow and long culms, long spikes and anthesis duration in comparison with H. vulgare. H. bulbosum, var. Jaaska(4${\times}$) on being pollinated to barley cultivars, increased embryo formation by 8% and plant development in vitro by three times compared to the other diploid lines. the plants developed were not normal barley hybrids but had some H. bulbosum chromosomes uneliminated, indicating that the line was unstable as a pollinator to induce barley haploids.

• Animal cells and systems
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• v.2 no.1
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• pp.123-131
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• 1998

The unc-29 region on the chromosome I of Caenorhabditis elegans has been mutagenized in order to obtain lethal mutations. In this screen, the uncoordinated phenotype of unc-29 (e193) mutant was used to identify any lethal mutations closely linked to the unc-29 gene, which encodes a subunit of nicotinic acetylcholine receptors. We have isolated six independent mutations (jh1 to jh6) out of approximately 5,200 ethyl methanesulfonate(EMS) treated haploids. Four of the six mutations demonstrated embryonic lethal phenotypes, while the other two showed embryonic and larval lethal phenotypes. Terminal phenotypes observed in two mutations (jh1 and jh2) indicated developmental defects specific to posterior part of embryos which appeared similar to the phenotypes observed in nob (no back end) mutants. Another mutation (jh4) resulted in an interesting phenotype of body-wall muscle degeneration at larval stage. These mutations were mapped by using three-factor crosses and deficiency mutants in this region. Here we report genetic analysis and characterization of these lethal mutations.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.56-60
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• 1999

Sexual reproduction is an essential process in the propagation of flowering plants. Recent advances in plant cell biology and biotechnology have brought new and powerful methodologies to investigate and manipulate the reproductive processes of angiosperms including agronomically important crop plants. Successful cryopreservation of maize, rye and triticale pollen and young embryos of microspore-and zygote-origine contributes to long term preservation of important plant germ-lines in gene banks. Discovering morphogenetic characteristics of the different developmental pathways taking place in wheat and maize androgenesis in vitro helps to influence the procedure to produce genetically and phenotipically stable homozygous doubled haploid plants for breeding purposes. Detailed ultrastructural and cell-biological studies on the developmental sequences of male and female gametophyte development in wheat, experimental protocols developed to isolate and micromanipulate egg cell protoplasts, make it possible to use plant gametes and the sexual route itself to produce genetically improved organisms. Plant gametes can become useful tools for crop improvement in the near future. Recent achievements by our laboratory in this field are reviewed in the present paper

• Journal of the Korean Society of Tobacco Science
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• v.6 no.2
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• pp.185-189
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• 1984

To classify the inheritance of resistance to potato virus Y, crosses between susceptible flue-cured tobacco variety NC 95 and resistant variety McNair 30 were conducted. The parents, $F_1$ plants, $F_2$ populations, and haploid plants derived from anthers of $F_1$ plants were screened for a resistance of two potato virus Y strains (PVY-VB and PVY-VN) isolated in Korea. The Chi-square values for the $F_3$ populations and haploids of $F_1$ fitted 1 :3 and 1 :1 ratios of resistant to susceptible for two strains, respectively. Therefore, it was found that the resistance of McNair 30 for the potato virus Y was controlled by a single recessive gene. Moreover the resistance to two strains screened was inherited dependently.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.93-96
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• 1985

This study was conducted to establish the maternal haploid method for the practical breeding of M tabacum using the interspeciflc hybridization between M tabacum and N. aflicana. The frequency of surviving seedling per seed capsule of interspecific hybridization was 4.15. Among them, the frequencies of maternal haploid and hybrid were 1.20 and 2.95, respectively. The chromosome numbers of n=24 for maternal haploid and 2n=47 for hybrid were identified in surviving seedling from interspecific hybridiztion. Except the chromosome number, distinguishable morphological differences of material haploid from hybrid were observed at seedling stage.

• Journal of Plant Biology
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• v.15 no.1
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• pp.28-32
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• 1972

Young haploid leaf derived from the anthers of tobacco plant was cultuerd and plantlets of various ploidies were obtained. When the leaf was put on the medium supplemented with kinetin as growth regulator, plantlets developed directly from the leaf, and the plants coming out in early stage of culture were all haploid. Plants developing in later stage were mostly haploids with some exception of diploid and aneuploid. Leaves were also cultured on the callus-inducing media supplemented with 2,4-D and kinetiion, and the calluses were sub-cultured for six months. Plants developed from these calluses were mostly aneuploids of various chromosome numbers. In view of the fact that the plants directly developed from the leaf were all haploid, the tissue of the original leaf explant was assumed to be uniform as far as chromosome number was concerned. On the other hand, it seemed that the occurrence of various ploidies in the plants derived from the calluses of same origin was the result of the influence of in vitro culture. Apical meristem tissues and various multicellular bodies were formed in the epidermal and inner mesophyll tissues as well as in the sub-epidermal cells.

• Journal of Plant Biology
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• v.36 no.2
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• pp.183-192
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• 1993

Efficient plant regeneration system was established through the culture of rice (Oryza sativa L.) microspores. Microspores released by anther shedding culture developed into proembryos and calluses in B5 medium within two weeks of culture. The optimal hormone and carbon sources were dependent on the genotypes used. Microspore's viability decreased rapidly in culture time, therefore less than 3% of the total microspores were viable at the 9th day when the first microspore division was observed. Of two types of microspores (pollen dimorphism) observed in culture, only the P-grain, larger microspores than normal one was able to divide. Using 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining, it was confirmed that the symmetrical division of uninucleate microspore was the first step leading to continuous microspore development. Microspore-derived proembryos and calluses were regenerated to plants in N6 medium containing 1 mg/L NAA and 5 mg/L kinetin, and 78.3% of the regenerated plants were haploids.