• 한국잠사곤충학회지
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• 제4권
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• pp.51-55
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• 1965

가잠의 교배별 잡종강세율의 비교를행한 결과. 1. 이계통간의 $F_1$($가_{육}$ $\times$$중_{백}$ )과 ($일_{백}$ $\times$$중_{백}$ )은 동계통간의 $F_1$보다 기잠체중의 V.R 및 타계량형질의 V.R에 있어서 높은 잡종강세율(V.R)를 나타냈다. 2. 이계통간의 $F_1$($가_{육}$ $\times$$중_{백}$ )과 ($일_{백}$ $\times$$중_{백}$)의 비교에서는 $가_{육}$ $\times$$중_{백}$ 교배형식이 전반적으로 우수한 잡종강세율(V.R)을 나타냈다. 3. 기잠체중의 잡종강세율(V.R)은 모체의 영향을 받아 의잠부터 용까지의 추이가 Smooth하게 나타나지 않고 계통간에 상당한 차이를 보였다.

• 한국잠사곤충학회지
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• 제10권
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• pp.67-72
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• 1969

In order to analyse the correlation between the parents and their hybrids in the silkworm, which were reared in spring, the author has surveyed the various quantitative characters which are significant in genetics, and the hybrid vigor rate. The duration of larvae life is shorter in F1 Value an in the mid parents value, cocoon size biffer, pupa rate, cocoon crop from ten thousand silkworms just molted in the fourth instar, total cocoon weight and cocoon layer weight increases in comparison with the mid parents value. Although cocoon layer ratio only shows increasing by 0.3％ or so, it is too little to admit the effect. F1 value is nearly equal to parent value and there is no correlation between F1 hybrids value and their mid parents value.

• 한국약용작물학회지
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• 제14권2호
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• pp.107-112
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• 2006

Two Atractylodes species, A. japonica Koidz. ex Kitam. (AJ) and A. macrocephala Koidz (AM) were used in this study. AJ population had higher amounts of Sesquiterpenoids and stronger tolerance to root rot but less vigor of root growth than AM population. Two populations (AJ and AM) were crossed to make interspecific hybrid population. A total of 98 lines propagated clonally were selected from a cross of AJ and AM, and evaluated for contents of sesquiterpenoids, atractylon (ATLN) and atractylenolide III (AT3) using high performance liquid chromatography (HPLC), and growth characters such as plant height, stem number and root weight. HPLC profiles of the hybrids were compared with those of parent plants, and it demonstrated the production of introgression hybrid by crossing between AJ and AM. Of 98 clonal lines,10 lines were selected by 10% level based on the growth vigor and tolerance to root rot, and AJM2102-51 line showed the heaviest root weight (117.1 g/plant) among them. A total of 98 hybrid lines contained on average $0.16\;{\pm}\;0.10\;mg/g$ of $AT3,\;2.00\;{\pm}\;1.37\;mg/g$ of ATLN, and $2.16\;{\pm}\;1.40\;mg/g$ of total sesquiterpenoids, showing high coefficients of variation (above 65%). Ten lines having high contents of sesquiterpenoids were selected, and AJM2101-15 had the highest amount (9.83 mg/g) of ATLN, and showed 40.8 g/plant of root weight similar to mean value (39.9 g/plant) of hybrid lines. The result showed that the introgression of both characters of vigorous growth from AM and high sesquiterpenoids content from AJ could be possible to make new hybrid lines by crossing between AJ and AM.

• 한국연초학회지
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• 제15권2호
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• pp.123-129
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• 1993

Mesophyll protoplasts derived from young leaves of Nicotiana rustica and N. tabacum cv Burley 21 were fused with the aid of polyethylene glycol(PEG). Cytological examination of protoplasts after PEG treatment revealed 12.8 % heterokaryocytes. After 7 weeks culture, the hybrid calli showing greenish white with a compact appearance were selected in contrast to parental type calli tinged with white or green color. The somatic hybrid plants were verified by morphological, biochemical and cyclological analysis. A heterosis effect for plant vigor and height was observed but the shape of leaves and flower characteristics were intermediate between N. tabacum and N. rutstica. The isozyme banding patterns for peroxidase of somatic hybrid lines were compared with the parent species. A number of isozyme bands derived from both parental species were found in the hybrids. Somatic hybrid plants have been successfully backcrossed to the parental N. tabacum particularly with somatic hybrid plants as female parents. These hybrid plants yielded small seeds, only few which were germinable.

• 식물조직배양학회지
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• 제24권4호
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• pp.239-256
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• 1997

Plants belonging to the category of 2n apomixis or agamospermy form embryos and seeds without the processes of normal meiosis and syngamy. Seeds produced in this way have identical genotype of their maternal parent. Three different types of agamospermy are recognized: diplospory, apospory, and adventitious (adventive) embryony. $F_1$ hybrid cultivars cannot be used as seed sources in the next ($F_2$) generation because this generation would be extremely variable as a result of genetic segregation. Hybrid vigor is also reduced in the $F_2$ generation. Therefore, parental stocks for hybrid seed production need to be maintained and cross must be continuously repeated. Agamospermic 2n apomixis would make it possible to fix the genotype of a superior variety so that clonal seeds faithfully representing that genotype could be continuously and cheaply produced independent of pollination. That is, $F_1$ hybrid seeds could be produced for many generations without loss of vigor or genotype alteration. Production of apomictic $F_1$ hybrid seed would be simplified because line isolation would not be necessary to produce seed or to maintain parental lines, and the use of male-sterile lines could be avoided. Overall, apomixis would enable a significant reduction in hybrid seed production costs. Additionally, the production of clonal seed is not only important for seed propagated crops, but also for the propagation of heterozygous fruit trees and timbers. Clonal seed would help avoid costly and time-consuming vegetative propagating methods that are currently used to ensure the large-scale production of these plants. Apomixis is scattered throughout the plant kingdom, but few important agricultural crops possess this trait Therefore, most research to date has centered on introgressing the trait of apomixis into agricultural crops such as wheat, maize, and some forage grasses from wild distant relatives by traditional cross breeding. The classical breeding approach, however is slow and often impeded by many breeding barriers. These problems could be surmounted by taking mutagenesis or molecular approach. Arabidopsis thaliana is a tiny sexually reproducing plant and is convenient in constructing and screening in molecular researches. Male-sterile mutants of Arabidopsis are particularly suitable genetic background for mutagenesis and screening for apomictic mutants. Molecular approaches towards isolating the genes controlling the apomictic process are feasible. Direct isolation of genes conferring apomixis development would greatly facilitate the transfer of this trait to wide variety of crops. Such studies are now in progress.

• 한국작물학회지
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• 제44권4호
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• pp.391-395
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• 1999

Barnyardgrass had relatively higher growth vigor at the earlier growth stage than inbred rice did, showing the 2 fold higher $\alpha$-amylase activity during the periods of germination and large leaf area Expansion with high net photosynthetic rate at the earlier autotrophic stage, but it performed weak growth at the late growth stage. However, the hlybrid rice Shanyou 63 had significantly higher $\alpha$-amylase activity and net photosynthetic rate than that of barnyardgrass, exhibiting heterosis for two physiologica1 traits during the germination (6~12 days) and autotrophic phase, respectively. Accordingly, hybrid rice, Shanyou 63, exhibited heterotic effect at the early growing stage when were presented with barnyardgrass. Shanyou 63 exhibited stronger tillering ability, faster leaf area expansion and higher net photosynthetic rate than those of barnyardgrass.

• 한국잠사곤충학회지
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• 제1권
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• pp.5-8
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• 1960

가잠에 있어 교잡제1대가 실용상 유리한것은 1841년 Robinert씨가 처음 실험한 보고가 있었고 일본에 있어서는 1906년 외출구태랑씨가 구주관후 귀국즉시 일대잡종이 경제상 유리한 점을 주장하면서 일방으로는 국립잠업시험장에서 우선 시험하여 장려해온 결과 1912 년경부터 점차보급되어 기후 1920년경에는 사견의 전부가 일대잡종으로 전환되었다. 1917년 일본잠업시험장 보고에 의하면(총괄적보고) 1. 일반으로 사육일수는 원종의 어느편보다 또는 기평균식보다 단축한다. (중략)

• 한국초지조사료학회지
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• 제14권4호
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• pp.288-294
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• 1994

Birdsfoot trefoil(MO-20)과 tetraploid narrowleaf trefoil(PI302921)및 이들 종간 잡종의 유식물 확력을 건물축적량 광합성율 생장분석 등을 통하여 비교검토하였다. 일반적으로 종간 잡종의 표현형은 그 들 부모의 중간 특성을 나타내었으며, 암호흡, 광합성 및 휴식물생육은 이 들 모계 계통인 MO-20 birdsfoot trefoil과 유사하였다. 중간잡종은 birdsfoot trefoil 보다 빨리 자랐으나 통계적인 유의성은 없었다. 또한 교잡종은 narrowleaf trefoil보다 유식물 활력이 더 우수하였는데 그것은 낮은 암호흡율과 높은 상대성장율에 기인되었다. 앞으로 birdsfoot trefoil의 유식물 활력의 유전적인 개량은 새로운 분야로서 개량의 여지가 많음을 보여 주었다.

• 한국자원식물학회지
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• 제20권5호
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• pp.442-445
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• 2007

해송$\times$소나무 인공교배 차대들의 침엽 및 생장특성을 조사하였다. 해송$\times$소나무 교잡종 3, 5, 8년생 수고생장은 조합간에 많은 차이가 있었다. 해송(충남 4)$\times$소나무(강원 29) 조합 3, 5, 8년생의 수고생장이 110, 172, 234cm로 전 조합 평균보다 8%, 9%, 11% 우수하였으며, 교배 모수인 해송 수형목 충남4호와 화분수인 소나무 수형목 경북 5호 보다도 각각 46%, 61% 우수한 생장을 하여 잡종강세 현상으로 생각된다. 해송$\times$소나무 침엽의 수지구지수는 $0.71{\sim}0.89$로서 교배모수인 해송을 더 많이 닮았다.

• 한국작물학회지
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• 제39권1호
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• pp.103-114
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• 1994

Pearl millet is a $C_4$ plant and summer crop originated from west Africa, and the sixth most important cereal in the world and the most widely cultivated millet in the semi-arid tropics as a major staple food crop. Its grain of higher quality protein is used to make unleavened bread chapatis and prepared as gruel, dumplings, couscous and beer. It is also used as animal feed and forage in both temperate and tropical regions because it has a capability to grow well not only in the fertile soil, but also in the poor and dry soil. Most of the current breeding procedures used in pearl millet are aimed at maximum exploitation of hybrid vigor for both grain and forage yields in Korea. Pearl millet is ideally suited for exploitation of heterosis using cytoplasmic male sterile lines as seed parent, and fertile inbred lines and open-pollinated cultivars as pollen parent. Pearl millet hybrids developed in Korea produced 3 to 7 tons of grain and 100 to 150 tons of green fodder per hectare.