• Journal of Sericultural and Entomological Science
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• 제53권1호
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• pp.12-18
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• 2015

This study was conducted to consider practical use of F2 hybrid and intervariety crossing for the improvement of silkworm eggs export and silkworm eggs manufacture. Now Kumokjam and Baegokjam come into wide use to sericulture farmers but comparison test of F1, F2 hybrid and intervariety have not been done. We weighed against the productivity among economical character. While larval period of F2 among them is most long time, pupation percentage and cocoon yield per 10,000 3rd molted larvae are lower than intervariety. With comparing F2 and intervariety, single cocoon weight of F2 is lower 9 ~ 21% than intervariety, and cocoon shell weight of F2 was lower 10 ~ 18% than intervariety. By number of cocoons per liter, F2 hybrid was lower and more irregular size than intervariety. In coparison with number of egg laid, F2 hybrid Baegokjam was 655 ea (14%) and Kumokjam 625 ea (40%) more than F1 hybrid. Also, F2 hybrid for filament grade went down than F1 hybrid. The advantage of egg production in F2 hybrid can reduce costs because there is no necessity for sex discrimination and germination control. But besides increase of number of egg laid, the productivity including economical characters was greatly lowered. Except for being a lot of laying eggs, cocoon productivity of the F2 was greatly reduced by degeneration of practical traits. Therefore the further studies are needed in order to increase utilization value of the F2 hybrid silkworm.

• Horticultural Science & Technology
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• 제33권1호
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• pp.143-148
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• 2015

A new Dianthus cultivar 'URI 2010-6' was selected among F1 progenies from a cross between interspecific hybrid 'Evergreen Emerald' as the seed parent and D. chinensis ' Ruby' as the pollen parent. In 2007, the cross w as made, and the seedlings of $F_1$ progenies were obtained and investigated. After three rounds of characteristic evaluation from 2008 to 2010, a clone was selected and registered as 'URI 2010-6' at the Korea Seed and Variety Service (plant variety protection number: 4431) in 2011. The flower of 'URI 2010-6' is caryophyllaceous, single type, and mainly bright red (Red, N79C) with secondary white (White, N155C) on the edge or as spots on the petal. The flower has diameter of 2.7 cm and length of 0.8 cm. This cultivar blooms continuously about 150 d on average and may be used as evergreen plant during winter months.

• Journal of Korean Society of Forest Science
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• 제90권1호
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• pp.19-27
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• 2001

From two to five-year-old hybrids of Q. serrate ${\times}$ Q. dentate; Q. dentata ${\times}$ Q. serrata, Q. dentate ${\times}$ Q. mongolica var. crispula, and Q. dentata ${\times}$ Q. aliena, intermediate-size of stellate hairs or both types of their parents have been observed. Especially the hybrids between Q. serrate and Q. aliena and Q. aliena and Q. serrate had both types of their parents. The trichomes of the hybrids between Q. fabri and Q. serrate was the characteristics of Q. serrate. It was possible to identify two to five-year-old of interspecific hybrids based on trichome characteristics.

• Journal of Life Science
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• 제21권10호
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• pp.1452-1459
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• 2011

Citrus is a common term and genus (Citrus) of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar (Burma) and the Yunnan province of China. The taxonomy and systematics of the genus are complex and the precise number of natural species is unclear, as many of the named species are clonally propagated hybrids, and there is genetic evidence that even some wild, true-breeding species are of a hybrid origin. One of the most popular sequences for phylogenetic inference at the generic and infrageneric levels in plants is the chloroplast trnL-trnF region. We evaluated the seven taxa with the trnL-trnF region to estimate phenotypic relationships within the genera Citrus, Poncirus, and Fortunella in Korea. Alignment of the DNA sequences required the addition of numerous gaps. Sequence variation within Citrus was mostly due to insertion/deletion. Within the genus Citrus, C. lomonia and C. sinensis were relatives and sistered with C. aurantium in the four phylogenetic analyses (MP, ML, ME, and NJ). However, some external nodes were poorly supported.

• Korean Journal of Agricultural Science
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• 제20권2호
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• pp.125-132
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• 1993

This study was carried out to understand the relationship between sources and sinks in tillering maize hybrid. A non-tillering hybrid was included as check hybrid, The following treatments were imposed on the two hybrids at tasseling stages: 1) no leaves removed, 2) all leaves removed, 3) leaves above 1st ear node removed, 4) leaves below 1st ear node removed and 5) only 1st ear removed. The experiment was arranged in a split plot with hybrids as main plots and treatments as sub plots. Results obtained were summarized as follows: Plant heights in control were significantly higher in both hybrids than other treatments, No significant differences of plant height were observed among treatments of leaf removal in both hybrids. No significant differences of kernel weights of plant were found between locations of leaf removal, But seed weight of tillering hybrids was about 10 to 15% heavier than that of non-tillering hybrid. Stem weight showed the same tendency as the kernel weights. Leaf removal above the ear node lowered kernel weight significantly up to 60% compared with no leaf removal. The leaf removal below the ear node lowered the kernel weight about 40%. The effects of leaf removal on kernel weight was more serious in the non-tillering hybrid than in the tillering hybrid. Contribution of each part to the total dry matter varied with position of leaf removal. When no leaves were removed, contribution of each part to the total dry matter was great in the order of kernel weight, leaf weight and culm weight. When leaves above the ear node were removed, the contribution of each part to the total dry matter was in the order of culm weight, leaf weight and kernel weight. When leaves below the ear node were removed, the contribution of kernel weight was greater than the contribution of leaf and culm weights.

• Korean Journal of Plant Resources
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• 제14권2호
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• pp.163-168
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• 2001

This study was conducted to obtain basic information on cross breeding for developing bolting resistant variety of Angelica gigas NAKAI which has been subjected to severe yield reduction resulted from flower-stalk initiation during the growth. Compatibility of selfing and/or crossing pollination among 5 local cultivars were tested. Results obtained are summarized as follows. In case of three year old plant, all cultivars emerged March 14 and bolted from May 12 to May 13. Ponghwa cultivar was flowered 3 to 5 days earlier than other cultivars. Flower duration continued 41 to 43 days. Interval of flowering date from main stem to first primary branch, from first to second or second to third primary branch was 9 to 13 days. Emergency of stamen proceeded 4~8 days of pistil initiation demonstrating that Angelica gigas NAKAI is protandrous plant. Furthermore initiation of first pistil was 1~4days later than formation of last stamen in the same flower cluster. Percent pollination of Angelica gigas NAKAI was 52% under natural condition, so called open-pollination, but bagging by enveloping flowers was as low as 0.4~2.4%. In the result of compatibility test, all local cultivars tend to show both of self-and cross-compatibility. Inpollination, ‘Muju’$\times$‘Muju’combination showed highest fertility up to 40.8% whereases cross pollination, ‘Pyeongchang’$\times$‘Inje’combination, showed 67.0% fertility.

• Journal of The Korean Society of Grassland and Forage Science
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• 제19권2호
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• pp.147-154
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• 1999

A field experiment with 200, 400 and 600kg-N/ha/year application levels was carried out to study the nitrate nitrogen accumulation of sorghum sudangrass hybrids(Xtragraze II and Civa 1990) at Iksan College Farm in 1995. The nitrate nitrogen content of Xtragraze II and Civa 1990 was increased by the application of nitrogen and decreased as the plant matured, then the nitrate nitrogen content was below the toxic level of ruminant at the level of 200kg-N application during the whole growing period. The nitrate nitrogen content of Xtragraze II and Civa 1990 exceeded the safe level of ruminant at the level of 400kg-N application, and that in Xtragraze II decreased at the low level in the later stage of growth, but that in Civa 1990 was almost kept constantly at the same level. The nitrate nitrogen accumulation of Civa 1990 had a greater tendency than that of Xtragraze II. A sum exceeding 200kg-N does not necessarily result in increase the amount of nitrate nitrogen in sorghum sudangrass hybrids. It is suggested that 400kg-N application may results in toxic level of nitrate nitrogen, and special attention must be given in feeding them.

• Korean Journal of Breeding Science
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• 제42권1호
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• pp.100-108
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• 2010

This study was carried out to confirm the chromosome constitution and homoeologous recombination of progenies derived from various cross combination using tetraploid OA interspecific hybrid originated from mitotic chromosome doubling. Based on the chromosome analysis of progenies crossed reciprocally, there were only triploid progenies when crossed with diploid Asiatics as male or female parent. While only tetraploid progenies were produced when crossed tetraploid Asiatics or tetraploid OA hybrid with tetraploid OA hybrid, respectively. However, two types of progenies, that is, diploid and triploid plants, were produced from cross combinations between diploid Oriental hybrid and tetraploid OA hybrid. From the GISH analysis of OA hybrid, it was confirmed that diploid $F_1$ OA hybrid was consisted of 24 chromosomes (12 Oriental and 12 Asiatics) showing authentic OA hybrid. On the other hand, it was notified that triploid plants (3x=36) were consisted of 24 Asiatics lily chromosomes and 12 Oriental lily chromosomes by analysis of backcross progenies derived from either $A{\times}OA$ or $OA{\times}A$ crosses. In cross between tetraploid OA and OA, all the progenies were tetraploid with equal number of chromosomes without any homoeologous recombination, i.e. each 24 chromosomes of Oriental and Asiatics. In 2x-4x ($O{\times}OA$) cross combination, some progenies had 2x=24 chromosomes originated from only Oriental hybrid, and other progenies had 3x=36 chromosomes derived from 24 chromosomes of Oriental hybrid and 12 chromosomes of Asiatic hybrid. Only tetraploid Asiatics chromosomes without any Oriental one were produced in all the progenies from 4x-4x ($AA{\times}OA$) cross combination.

• Journal of Practical Agriculture & Fisheries Research
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• 제22권1호
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• pp.27-33
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• 2020

To date, various kiwifruit cultivars have been developed and released. Asexual propagation by grafting onto seedlings rootstock have been widely utilized commercially in fruit trees including kiwifruit (Actinidia spp.). Most of commercial kiwifruit cultivars belong to A. chinensis and A. deliciosa. Recently, several cultivars were developed by interspecific hybridization with different species including A. arguta. There is a possibility for graft-incompatibility due to interspecific hybridization and therefore, we investigated graft-compatibility of newly released yellow-fleshed kiwifruit cultivars and a hybrid cultivar with various rootstocks of different species. The yellow-fleshed cultivars grafted onto same species, A. chinensis 'Kuimi', showed good shoot elongation, about 1 m in length 50 days after grafting. In contrast, the shoot elongation of the yellow-fleshed kiwifruit grafted onto different species was retarded. The shoot length of a hybrid cultivar (A. arguta × A. deliciosa) 'Skinny Green' grafted onto four different species was about 1 m in length, showing good graft compatibility with other species. Nevertheless, long term studies for graft compatibility of hybrid cultivars are still needed since graft-incompatibility between different species can occur several years later.

• Journal of Plant Biotechnology
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• 제31권2호
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• pp.95-101
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• 2004

This study was undertaken to study the effect of interspecific pollination of L. longiflorum and L. ${\times}$formolongi as the female parent with Oriental, Martagon and Trumpet group as the male parent by cut-style pollination. In the interspecific pollination of L. longiflorum cv. Gelria and Lorina with Oriental group as the male parent, the corresponding fruits obtained immature embryo were 1, 8, and the mean number of embryo per fruit were 11.0, 3.0, respectively. In the interspecific pollination of L. ${\times}$formolongi cv. Raizan, the corresponding fruits obtained immature embryo were 17, and the mean number of embryo per fruit were 4.0. On the other hand, in the interspecific pollination between L. longiflorum and L. ${\times}$formolongi as the female parent and Martagon and Trumpet group as the male parent, the pollination of L. ${\times}$formolongi as the female parent and L. henryi of Trumpet group as the male parent were obtained only 2 fruits, however no embryo.