• Korean Journal of Microbiology
• /
• v.26 no.2
• /
• pp.82-87
• /
• 1988

The genetic analysis and characterization of protoplast fusion hybrids between complementary auxotrophic mutants of Candida pseudotropicalis were carried out. Nuclear fusion appeared to occur in fusion hybrids (e.g., F15 and F33), as strongly suggested by isolation of recombinants after mitotic segregation of parental genetic markers. This was confirmed by KNA content, nuclear staining and comparison of survival rate to UV light. After keeping fusion hybrids for approximately one year, the frequency of spontaneous mitotic segregation was $3.0\times 10^{-4}$ - $8.1\times 10^{-4}$ while that of induced mitotic segregation was $1.4\times 10^{-3}$- $1.7\times 10^{-3}$. These results suggested that they maintained stable karyogamy state. It was also found that the production of $\beta$-D-galactosidase from F15, F33 and F158 was somewhat increased when compared with that from either auxotrophic parents or wild type.

• Journal of Plant Biotechnology
• /
• v.31 no.2
• /
• pp.103-108
• /
• 2004

This study was carried out to develop the efficient methods for the subsequent progeny of intersectional hybrid between Oriental and Asiatic lily hybrids. The pollen fertility and germination ability of 3 different allotetraploids (OAOA) after somatic chromosome doubling was ranged from 0 to 80 percent on artificial pollen germination medium. The number of BC$_1$ progeny using allotetraploid of F$_1$ OA-hybrid as male and female parent was different. The efficiency of BC$_1$ progeny production was increased when F$_1$OA-hybrids was used as male rather than as female parent. And in back crosses of F$_1$ OA-hybrids with the Asiatic and Oriental hybrids, Asiatic hybrids showed higher efficiency on BC$_1$ progeny production. The ploidy level between 2x or 4x Asiatic hybrid and allotetraploid F$_1$ OA-hybrid was determined and showed higher progeny production in 2x-4x crosses rather than 4x-4x.

• Korean Journal of Plant Resources
• /
• v.22 no.3
• /
• pp.266-272
• /
• 2009

Morphological characteristics of leaves, trichomes and acorns were investigated in 6-year-old artificial hybrids of Q. aliena ${\times}$ Q. mongolica var. crispula and Q. serrata ${\times}$ Q. mongolica var. crispula. Leaf shapes of Q. aliena ${\times}$ Q. mongolica var. crispula $F_{1}$ were obovate and resembled to that of Q. aliena. But several characters including the size of leaf and petiole and the shape of leaf base resembled to those of Q. mongolica var. crispula. In F1 hybrids, small stellate hairs distributed sparsely on the abaxial surface and their lay length was intermediate between both parents. There were no big differences on characters of nuts and cupules between both parents and $F_{1}$ hybrids. Leaf shapes of Q. serrata ${\times}$ Q. mongolica var. crispula $F_{1}$ were obovate-elliptic, and the leaf shape and leaf base and the length of petiole resembled to those of Q. mongolica var. crispula, but leaf size and serration resembled to those of Q. serrata. The number of serration in a leaf was intermediate between both parents. Small stellate hairs distributed sparsely and large single hairs were mixed on the reverse side of leaves. there were no big differences on the number and size of stellate hairs between $F_{1}$ hybrid and Q. serrata. It is able to distinguish $F_{1}$ hybrids from both parents by the size leaf size and shapes, leaf base and serration, petiole length and trichome type in the leaf.

• Journal of Life Science
• /
• v.6 no.4
• /
• pp.227-233
• /
• 1996

The capsaicinoid content of F$_{1}$ hybrids between annuum L. 'California Wonder', four native Japanese cultivars, and three Korean F$_{1}$ cultivars were evaluated and the results compared with parental cultivars. The capsaicinoid content was higher in the placenta than in fruit flesh. The placenta of 'Yatsufusa', 'Taka no Tsume', 'Cheongyang', 'Sinhong', and Geoseong' were the most pungent cultivatrs, with capsaicinoid content of more than 1000mg/100g DW, while 'California Wonder', and 'Fushimi Amanaga' contained trace amounts. Capsaicinoid content in F$_{1}$ hybrids varied with reciprocal crossing. Capsaicinoid content also varied with fruit development, rapidly increasing in the fourth or fifth week after flowering, and thereafter slowly declined.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2003.10a
• /
• pp.37-37
• /
• 2003

Intraspecific hybrids have been proven to be a useful tool for increase growth rate in some freshwater fish species. However the effects of intraspecific hybrids in seawater fish species is little known. To assess whether intraspecific hybrids in red sea bream was associated with growth enhancement, growth performances of offspring from two inbred lines, selected Korean line (KORDI-F4) and cultured Japanese line (IPN) and two intraspecific hybrids lines (KORDI-F4♀×JPN♂ and JPN♀×KORDI-F4♂) of red sea bream were compared. There's no significant difference in body weight between offspring groups during seed production period (until 4 months old). At seven months old (after three months rearing trials on sea cages communally), the offspring from KORDI-F4 (41.0±11.1g) and JPN♀×KORDI-F4♂ (39.3±8.1g) showed significantly better performance in body weight than that of the offspring from KORDI-F4♀×JPN♂ (37.0±8.1g) and IPN (35.7±9.7g). At 15 months old, the offspring from JPN♀×KORDI-F4♂ showed best growth performances in body weight, weight gain, specific growth rate among four offspring groups. As the results, the intraspecific hybrids between cultured Japanese line and selected Korean line showed superior growth performances than their paternal and maternal inbred lines.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.18 no.1
• /
• pp.1-10
• /
• 1998

Eleven sorghun-sudangrass hybrids have been recommended as the government recommended forage cultivars, however, their forage performance and quality have mostly been tested at two regions, such as Suweon in the Middle Northwestern Coast Region and Sunghwan in the Middle Southwestern Coast Region. Therefore, the objective of this experiment was to retest the forage performance and quality of eleven government recommended sorghum-sudangrass hybrids(TE haygrazer, 988. TE haygrazer-R, SX-17, NC + 855, 855F, GW9110G, G83F, Sordan 79, Speed feed and Jumbo) at five regions, such as Icheon in the Middle Northern Inland, Suweon in the Middle Northwestern Coast, Sunghwan in the Middle Southwestern Coast, Keongsan in the Keongpook Inland and Kwangju in the Southern Inland, 1993 and 1995. Among the eleven hybrids tested, 'NC + 855' gave the highest forage yield at all regions when averaged over the two-year period, but others varied by region. 'NC + 855' was the highest yielding at Icheon, Keongsan and Kwangju, G83F was highest at Suweon and 855F was highest at Sunghwan. 'Jumbo' (headless type) was generally higher in forage quality than others, but at both Suweon and Icheon, 'NC + 855' and '855F' were higher quality than others. As the results of the experiment, 'TE haygrazer', 'NC + 855' , G83F and 'GW9110G1 at Icheon, 'G83F' and 'Sordan 79' at Suweon, 'NC + 855' and '855F' at Sunghwan, '988' and 'NC + 855' at Keongsan, and 'TE haygrazer-R' , 'NC + 855', 'GW9110G' and 'G83F' at Kwangju might be preferable to other hybrids because they have higher forage yield.

• Journal of the Korean Society of Tobacco Science
• /
• v.7 no.1
• /
• pp.33-38
• /
• 1985

In spite of their inferior quality, pale yellow flue-cured tobacco varieties (N. tabacum L.) are being cultivated as pre-crop of rice in paddy field because of its early leaf maturity. Fertile and male sterile Hicks as green variety , three pale yellow varieties and six single cross $F_1$ hybrids between green and pale yellow varieties, were evaluated. Fertile $F_1$ hybrids were similar to pale yellow varieties in early leaf maturity, curing characters and nicotine contents, where-as they were lower in total nitrogen, higher in reducing sugar comparing to those of the pale yellow varieties.

• Journal of Crop Science and Biotechnology
• /
• v.11 no.1
• /
• pp.75-82
• /
• 2008

Functional stay-green is a beneficial trait that may increase grain yield through the sustained photosynthetic competence during monocarpic senescence in cereal crops. The temporal changes of photosynthesis and related characteristics throughout the grain filling period of a stay-green japonica rice "SNU-SG1" was compared in growth chamber conditions with three high-yielding cultivars(HYVs) and their $F_1$ hybrids with SNU-SG1. SNU-SG1 exhibited a typical characteristic of functional stay-green in terms of chlorophyll degradation and photosynthetic competence during grain filling. According to the photosynthesis-light response curve measured at 10 and 35 d after heading for the flag leaf, SNU-SG1 exhibited higher initial light conversion efficiency and thus higher gross photosynthetic rate at light saturation compared to HYVs. Light saturation point was not different among genotypes, ranging from 1000 to 1500 ${\mu}mol$ photon $m^{-2}s^{-1}$. Net photosynthetic rate at light saturation($P_{max}$) of the upper four leaves in SNU-SG1 was much higher and sustained longer throughout grain-filling than HYVs and $F_1$ hybrids. The sustained high photosynthetic competence of SNU-SG1 during grain filling was ascribed to the longer maintenance of high mesophyll conductance that resulted from not only high chlorophyll content and its delayed degradation but also the slow degeneration of photosystem II(PS II) as judged by chlorophyll fluorescence($F_v/F_m$) of flag leaves. $F_1$ hybrids showed slow degeneration of photosystem II similar to the male parent SNU-SG1 while chlorophyll degradation pattern close to female parents, thus exhibiting a little higher $P_{max}$ than female parents. These results suggest that SNU-SG1 has a typical functional stay-green trait that can be utilized for increasing rice yield potential through the improved dry matter production during grain filling.

• Korean journal of applied entomology
• /
• v.32 no.2
• /
• pp.193-199
• /
• 1993

The morphological relationship between Drosophila melanogaster and D. simulans, and their hybrids were investigated using comparisons of internal reproductive organs. male sex comb tooth number and male genital discs. InterspecIfic hybrids of all crosses were completely sterile, and had rudImentary gonads. Dysgenic ovaries and testes were morphologically similar to those of gonadal dysgenesis stenlity associated with the PM system in D. melal1ogaster. The mean number of sex comb tooth in D. melrmogaster, D. simulans and their male hybrids were 10.73, 8.35 and 9.97, respectively. The general aspects of the genital disc of the malo hybrid were a mosaic-like structure between D. melanogaster and D. simulans.

• Korean Journal of Breeding Science
• /
• v.41 no.1
• /
• pp.1-8
• /
• 2009

This study was carried out to breed and develop high quality and functional nutrient tomato with multi disease resistance as well as a stable growing adaptation for fresh market usage under protected plastic houses cultivation. The materials were used 5 inbred lines and their 6 hybrids of large tomato group, which have been bred and developed from 1999 to 2007 in Division of Plant Resource Department of Chungnam National University. Fruit weight showed hybrid vigor effect that $F_1$ hybrids weighed more than their parent lines, fruit shape formed three type of oblate, deep oblate and globe shape, in firmness and pericarp thickness have got a high significant correlation, inbred DN611 line was measured the most firm fruit with 6.04 mm pericarp thickness. In fruit color at maturity, pink color crossed to red color appeared all red fruit color in the $F_1$ hybrids, it means red skin color is a dominant gene compared to pink skin color is a recessive gene in tomato, while between fruit skin color and shoulder part color showed no any co-relationship. The sugar content and titratable acid of $F_1$ hybrids inherited an intermediate data of their parent lines, the flavor of KP543 inbred line and the hybrid (JB535 x KP543) revealed the better taste with high brix and proper titratable acid content$^{*}$. In beta carotene content DN611 line showed 2~3 times higher than other materials so that its 3 hybrids contained an increased level of beta carotene, lycopene content was not so much difference among inbred lines and $F_1$ hybrids, of them MD508 contained higher of 8.72 mg and hybrid (JB535 x JA517) had 8.05 mg lycopene content per 100 g fruit, overall pink skin color and red skin color measured a higher lycopene content than yellow and orange skin color at ripe stage. In disease resistance test by PCR marker for Fusarium race2 (I2), Nematode (Mi1), ToMV ($Tm2^2$), Cladosporium (Cf9), (JB535 x JA517) hybrid have got multi-resistance with homozygote band in Nematode, ToMV, Cladosporium and heterozygote band in Fusarium race2. Through this breeding program we could select high quality and functional nutrient with multi resistant $F_1$ hybrids and inbred lines in tomato which are two best hybrids (JB535 x MD508), (JB535 x JA517), additionally developed high beta carotene inbred line DN611 and increased the level of lycopene inbred line MD508. These results will be very useful to make a high quality tomato variety continuously.