• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.193-197
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• 1994

This study was conducted to investigate optimal time for dissecting out embryos, effect of embryo size on plant generation, and kinds of media and environment in order to establish an effective bulbosum method. The optimum time for dissecting out the embryos for culture was found to be 17 days after pollination, when the size of embryos ranged from 0.8 to 1.0mm in length. Culture of embryos on B5 medium under continuous radiation was considered to be an efficient practice for production of barley hybrids. Haploid embryos, when compared to their counterpart diploid ones, were slower and fewer in plant development in culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.392-399
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• 1988

The experiments were conducted to establish the effective barley haploid production system using interspecific crosses. Three spring barley cultivars. Bruce. Klages and Rodeo were used for this experiment. 1, 687 florets of three barley cultivars were crossed with bulbosum pollens. 1, 079 seeds were harvested and obtained 834 embryos so that seed set rate and embryo production rate were 64% and 77%, respectively. IAA effect was superior to NAA for root development and 1 ppm concentration of IAA gave the best result among five concentrations; 0ppm, 1ppm., 5ppm, 10ppm and 30ppm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.757-767
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• 1995

This experiment was done to determine the optimum concentration of IAA for root development in plants regenerated from the callus culture of barley embryos. Two concentrations of 2,4-D, 3ppm and 5ppm selected as an optimum among five different concentrations in the previous experiment were used for callus induction and proliferation in this experiment. For callus induction, 3ppm of 2,4-D produced 35.6% in immature embryos and 4.4% in mature embryos, while 5ppm gave 33.8% in immature and 5.6% in mature embryos. Out of 320 immature embryos cultured, 111 embryos were induced to calli and 684 plants were produced from them, while only 16 embryos were induced to calli from 320 mature embryos and 92 plants were restored. The rates of callusing and plant regeneration were 34.7%, 214% in immature embryos and 5.0%, 28.7% in mature embryos, respectively. The average root lengths and root numbers of plants restored from callus at five different IAA concentrations of 0ppm, Ippm, 5ppm, l0ppm and 30ppm were 7.9mm, 3.6; 18.4mm, 5.2; 16.1mm, 3.9; 8.5mm, 3.5 and 6.4mm, 3.4, while plants directly obtained from mature embryos were 14.8mm, 4.9; 4.9mm, 3.6; 4.3mm, 3.1; 3.6mm, 2.6 and 3.2mm, 2.1, respectively. Therefore, 1ppm gave the best result for the root. promotion in callus, whle 0ppm, a control, gave the largest root developmemt in embryos. High concentration of lAA(30ppm) in callus and any exogeneous supplement of lAA in embryos negatively affected to the root lengths and root numbers. Genotypic effect was also observed in given four varieties, Bruce, Klages, Olbori and Albori. For chromosome doubling, when 0.1% colchicine was applied on 428 plants under three different conditions such as air circulation, temperatures and growth stages, 319 plants of doubled haploids were obtained so that the rate was 74.5%