• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.340-350
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• 1995

This study was conducted to obtain the basic information for the salt stress of Italian Ryegrass. Fourteen cultivars including 7 diploid and 7 tetraploid were subjected to eight levels of NaCl treatments during germination and early seedling stages. Germination percentage decreased remarkably over 300mM of NaCl concentration. The NaCl concentration that inhibited germination of 50% of the viable seeds in the cultivars was 344mM. The decreasing degree of germination percentage was higher in tetraploid type than in diploid type. The varietal difference of germination percentage was shown to be very conspicuous as the NaCl concentration increased. Top dry weight in 166 mM NaCl was decreased by 50% compared with that of control. Inhibition of NaCl appeared to be more in early seedling stage than in germination stage. Top dry weight of cultivars in NaCl stress was not related with germination capacity. Root dry weight in 148mM NaCl decreased by 50% compared with that of control. Root dry weight of cultivars was significantly correlated with top dry weight in NaCl treatment. Top dry weight and root dry weight was higher in diploid type than in tetraploid type at each 8 levels of NaCl concentration. Total chlorophyll content increased with the increase of NaCl concentration and the degree of increase in chlorophyll a was higher than that in chlorophyll b. Chlorophyll a was higher in tetraploid type than in diploid type. But chlorophyll b was higher in diploid type than in tetraploid type. There were significant correlation between chlorophyll a and top dry weight of cultivars over 150mM of NaCl concentration. Free proline content accumulated remarkably in NaCl treatment compared with control and was not difference between diploid type and tetraploid type. Free proline content of cultivars was not related with top dry weight in NaCl treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.575-580
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• 1986

Triploid rainbow trout (Salmo gairdneri) were produced on a large scale practice by the application of moderate heat treatment in 1986. Triploid treatment of the fertilized eggs was carried out with heat shock at $27^{\circ}C$ for 10 to 14 minutes starting 10 minutes after insemination at $10^{\circ}C$. Estimated triploidy ranged from $45\%\;to\;57\%$ ana the incidence of triploidy slightly increased with the treatment time. No significant differences of growth rate were observed between triploidy and diploidy at the early stage of growth. This observation was consistent with results of other fish species and other reports on this species. This heat shock technique, expecting further improvement, should be useful in the mass production of sterile triploid rainbow trout.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.810-817
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• 2010

We observed abnormal morphology of cotyledons occurring in seedlings derived from open-pollinated and cross-pollinated tetraploid grapes and selected aneuploids, especially hypo- and hyper-tetraploid in seedlings with abnormal morphology of cotyledons. Five types of morphologically abnormal cotyledons were observed. In open-pollination of four tetraploid grapes, the frequency of abnormal cotyledons was 1.6% (49 of 3029 seeds). Percentage of aneuploids in the seedlings of abnormal cotyledons was 20.4% (10 of 49 seedlings). Aneuploids in open-pollination consisted of three (4n = 4x-2), four (4n = 4x-1), and three (4n = 4x+1) seedlings. In cross-pollination of tetraploids, the frequency of abnormal cotyledons was 3.4% (59 of 1729 seeds). Percentage of aneuploids in the seedlings with abnormal cotyledons was 22.0% (13 of 59 seedlings). Aneuploids from cross-pollination of tetraploids consisted of two (4n = 4x-2), nine (4n = 4x-1), one (4n = 4x+1), and one (4n = 4x+3) seedlings. According to the results, although the abnormal cotyledon morphology of seedlings obtained from crossing between tetraploid grapes appeared at low rate (2.3%), aneuploid seedlings occurred at high rate (22.0%); therefore, it indicated that this selection strategy might be very efficient in the initial seedling stage.

• Journal of Aquaculture
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• v.9 no.2
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• pp.125-132
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• 1996

A study was carried out to test sex ratio of the progeny that were induced by the artificial fertilization between normal female and gynogenetic diploid eggs and sex-reversed gynogenetic diploid male sperm. Sex reversed gynogenetic diploid males were produced successfully in gynogenetic diploid female by immersion treatment with $17{\alpha}$-methyltestosterone at the concentration of 10 pub from $13.5{\pm}0.22$ mm to $57.6{\pm}5.1$ mm in total length. In $F_1$ progeny test, matings between normal females and sex-reversed gynogenetic males were not produced all female, but matings between gynogenetic diploid females and sex-reversed gynogenetic males were produced all female populations in six out of eight groups and two lots produced $96.9\%$ and $95\%$ female. These data showed that all-female populations were produced by crossing between gynogenetic diploid female and sex reversed gynogenetic diploid male.

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.70-71
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• 1990

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.10a
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• pp.34-35
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• 1990

• Horticultural Science & Technology
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• v.34 no.1
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• pp.163-171
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• 2016

We investigated the intensity and pattern of the scent produced by diploid and tetraploid Cymbidium flowers, using an electronic nose with 6 metal oxide sensors (MOS). The MOS responses were evaluated by principal component analysis, discriminant function analysis, and sensor data. These analyses revealed that tetraploid flowers had a stronger scent than diploid flowers in Cymbidium Golden Elf 'Sundust'. Furthermore, among the different flower parts-column, lip, and petals-the column produced the strongest scent. There was no significant difference between the flowering periods of diploid and tetraploid potted Cymbidium Golden Elf 'Sundust' and Cymbidium Elma 'Orient Toyo' grown in a greenhouse. Moreover, there were no significant differences between the number of flowers per flower stem and the length of flower stems on the diploid and tetraploid plants of these two Cymbidium cultivars. This study provides potentially useful information for the breeding of polyploidy Cymbidium in the floriculture industry.

• Journal of Life Science
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• v.23 no.9
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• pp.1079-1087
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• 2013

Speed germination success and robust vegetative growth of citrus rootstock through improved sowing methods and fertilizer inputs offer the usage of root system for the citrus. The current study evaluated the influence of seed coat removal and different fertilizer concentrations on plant germination and plant growth of spontaneous rootstock siblings. Decoated and coated seeds of diploid and tetraploid plants were sown in tubes. Commercial fertilizer concentrations of 0, 2, 4, 6, 8 and $10g{\cdot}l^{-1}$ were added. The experimental layout followed a randomized block $2{\times}6$ factorial design (seed coat removal ${\times}$ fertilizer concentration) for each rootstock. Fertilizer concentrations were 0, 10, 20 and $30g{\cdot}l^{-1}$ of the fertilizer for the resistance of the strength on the salt level. The germination rate of seeds without testa sown in vitro was improved (67-80%) compared to that of nontreated seeds. The eventual tree height of the seeds without testa in the diploid group was increased due to higher fertilization compared to that in the nontreated group. The removal of seed testa promoted the seed germination of both diploid and tetraploid trifoliate orange and resulted in greater height. Their vegetative development was also increased due to the increased fertilization of the rootstock. The Fv/Fm value for the diploid plants was 0.4 and 0.8 for the tetraploid ones under salt stress after 11 days of treatment. The removal of seed testa may improve the seed germination of trifoliate orange. Tetraploid trifoliate orange appears to possess resistance to salt stress compared to the diploid variety.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.900-910
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• 2015

This study aimed to investigate the efficiency of colchicine and oryzalin in inducing polyploidy in two Cymbidium hybrids [Showgirl 'Silky' and Mystery Island 'Silk Road' (Silk Road-4)]. Colchicine was used at concentrations ranging from 50 to $500mg{\cdot}L^{-1}$, with treatments lasting 1 to 3 weeks. Oryzalin was used at concentrations ranging from 3 to $20mg{\cdot}L^{-1}$, with treatments lasting 3 to 6 days or 1 to 3 weeks. The survival rate of PLBs was better in colchicine than in oryzalin solutions. The ploidy levels were screened using flow cytometry. In C. Showgirl 'Silky', the highest chromosome doubling efficiencies were obtained with the 1-week treatment in $50mg{\cdot}L^{-1}$ colchicine (60%) and the 2-week treatment in $5mg{\cdot}L^{-1}$ oryzalin (46.7%). In C. Mystery Island 'Silk Road' (Silk Road-4), the highest chromosome doubling efficiencies were obtained with the 1-week treatment in $50mg{\cdot}L^{-1}$ colchicine (16.7%) and the 3-day treatment in $10mg{\cdot}L^{-1}$ oryzalin (6.7%). Colchicine was more efficient than oryzalin in terms of polyploidy induction. Furthermore, pre-treatment, which entailed poking 10 times with forceps, improved the efficiency of chromosome doubling.

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.72-73
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• 1990