• 한국자원식물학회지
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• 제22권3호
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• pp.209-214
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• 2009

To facilitate the introgression of F. esculentum into the traits of F. homotropicum, several accessions of the hybrids between these two species were pollinated with F. esculentum as the recurrent parent. The embryo in vitro rescue was performed to increase the recovery of backcross progenies. The $F_{2}$ generation was more amenable than $F_{1}$ hybrids to produce backcross progenies. The $F_{1}$ hybrids were backcrossed twice with common buckwheat (pin-type F. esculentum) (recurrent backcrossing). Also, alternate backcrosses with common buckwheat and F. homotropicum (congruity backcrossing) were carried out. Pollen tube growth of BC$F_{1}$ ${\times}$ F. esculentum (thrum) and F. homotropicum ${\times}$ BC$F_{1}$ was the disturbed penetration exceeded for all initial interspecific hybrids, and its requirement was proportionally lower when the common buckwheat was used as the recurrent parent and as the last parent of congruity hybrids. Effects of both common buckwheat and F. homotropicum on seed success rate for hybridization were observed. Growth of hybrid embryos before rescue, regeneration of mature hybrids all increased recurrent and congruity backcrosses and inter-crosses between $F_{1}$ plants and selected fertile plants of the second congruity backcrosses.

• 한국식물병리학회지
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• 제12권4호
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• pp.437-444
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• 1996

경북지역 재래종에 더뎅이병 저항성을 도입하기 위하여 작성한 칼미초$\times$PI271322, 수비초$\times$PI271322 조합의 BC\ulcornerF\ulcorner와 BC\ulcornerF\ulcorner세대로부터 BC\ulcornerF\ulcorner와 BC\ulcornerF\ulcorner세대까지 선발과 자식을 실시하였다. 이 결과 각 재래종의 원예적 특성에 PI271322에 들어있는 과민반응형 저항성 유전자 Bs\ulcorner와 비과민형의 일반저항성을 함께 가지는 계통이 육성되었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.41-46
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• 2004

A breeding programme was initiated by utilizing a robust bivoltine breed CSR$_{18}$ and a polyvoltine breed Cambodge with the main objective of developing robust polyvoltine silkworm breeds/hybrids. At F$_1$ and F$_2$, parthenogenetic development was induced following warm water treatment of eggs at 46$^{\circ}C$ for 18 min followed by two backcrosses with Bl$_{67}$, an evolved polyvoltine breed. The newly developed breed was subjected for hybrid study using eight hybrid combinations in the laboratory at F$_{8}$ generation. F$_1$ hybrids between newly developed breed Bl$_{67}$ (Pg) and promising bivoltine breeds exhibited their superiority by expressing significant hybrid vigour for several economic characters like cocoon yield/10,000 larvae, cocoon weight, cocoon shell weight, cocoon shell ratio and denier. Study on cocoon shape variability revealed that cocoons of all the F$_1$ hybrids except BL$_{67}$ (Pg)${\times}$NB$_4$D$_2$ were found comparatively uniform in shape.pe.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1378-1385
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• 2002

The importance of direct genetic, maternal, heterosis and epistatic effects were examined on post-weaning weight, height, length, girth, fat depth and muscle (ratio of stifle to hip width) with dry and wet season gains in these traits. The breeds used were two pure breeds (Jersey and Limousin), the Limousin${\times}$Jersey $F_1$, and two backcrosses ($F_1{\times}$Jersey dams and $F_1{\times}$Limousin dams). Direct genetic effects were large (p<0.001) for all traits except for length. Jersey maternal effects were large for weight, girth, fat depth and muscle in the post-weaning wet season gains which is an evidence of the impact of Jersey dam on progeny beyond weaning. There were large heterosis effects on fat depth and muscle relative to other traits. Epistatic effects were observed for post-weaning performance in weight, girth, fat depth and muscle. There are indications that there were different genetic effects for post-weaning compared to preweaning growth traits. Thus, it could be hypothesized from this study that different quantitative trait loci (QTL) affect early and late growth in Jersey and Limousin cross cattle breeds. The follow up work will examine the different chromosomal gene effects on pre- and post-weaning growth.

• Asian-Australasian Journal of Animal Sciences
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• 제15권9호
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• pp.1371-1377
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• 2002

During a 5-yr period, 1994-1998, pre-weaning and weaning data were collected on 591 calves produced by mating either straightbred Jersey, straightbred Limousin or $F_1$ (Limousin${\times}$Jersey) bulls to mature purebred Jersey or Limousin cows. Traits recorded included birth and weaning weight, height, length, girth, fat depth and a measure of muscle (ratio of stifle to hip width expressed as a percentage). All traits were analyzed assuming a model with sire and dam random effects that included effects of year and date of birth, sex, breed and year${\times}$sex interaction. Main effects were generally significant with few exceptions. Direct genetic effects were large for weight, height, girth and muscle with a breed trend from purebred Jersey (small) to purebred Limousin (large). At weaning, the maternal effect of the Jersey dam was positive for weight (10.9${\pm}$4.9 kg), girth (3.7${\pm}$1.0 cm) and muscle (6.0${\pm}$0.9%). Heterosis was highly significant and positive only for fat depth (1.5${\pm}$0.2 mm) with the $F_1$ progeny being the fattest, followed by the backcrosses, then purebred Jersey and purebred Limousin. Also, significant (p<0.001) but negative heterosis was observed for weight, girth and muscle. The change in ranking for fat depth relative to other traits is a reflection of the large heterotic effects relative to direct effects on fat depth. Epistatic effects were not significant on any trait at birth or weaning. This study has indicated the possibility of exploiting the positive heterotic and maternal effects for fat depth and muscularity to meet specific meat quality and quantity demand by consumers.

• Journal of Crop Science and Biotechnology
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• 제11권4호
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• pp.263-268
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• 2008

Bacterial leaf pustule (BLP) caused by Xanthomonas axonopodis pv. glycines is a serious disease to make pustule and chlorotic haloes in soybean [Glycine max (L). Merr.]. While inheritance mode and map positions of the BLP resistance gene, rxp are known, no sequence information of the gene was reported. In this study, we made five near isogenic lines (NILs) from separate backcrosses (BCs) of BLP-susceptible Hwangkeumkong $\times$ BLP-resistant SS2-2 (HS) and BLP-susceptible Taekwangkong$\times$ SS2-2 (TS) through foreground and background selection based on the four-stage selection strategy. First, 15 BC individuals were selected through foreground selection using the simple sequence repeat (SSR) markers Satt486 and Satt372 flanking the rxp gene. Among them, 11 BC plants showed the BLP-resistant response. The HS and TS lines chosen in foreground selection were again screened by background selection using 118 and 90 SSR markers across all chromosomes, respectively. Eventually, five individuals showing greater than 90% recurrent parent genome content were selected in both HS and TS lines. These NILs will be a unique biological material to characterize the rxp gene.

• 한국육종학회지
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• 제42권5호
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• pp.470-480
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• 2010

The objectives of this study were to identify QTLs for agronomic traits using introgression lines from a cross between a japonica weedy rice and a Tongil-type rice. A total of 75 introgression lines developed in the Tongil-type rice were characterized. A total of 368 introgressed segments including 285 homozygous and 83 heterozygous loci were detected on 12 chromosomes based on the genotypes of 136 SSR markers. Each of 75 introgression lines contained 0-9 homozygous and 0-8 heterozygous introgressed segments with an average of 5.8 segments per line. A total of 31 quantitative and 2 qualitative loci were identified for 14 agronomic traits and each QTL explained 4.1% to 76.6% of the phenotypic variance. Some QTLs were clustered in a few chromosomal regions. A first cluster was located near RM315 and RM472 on chromosome 1 with QTLs for 1,000 grain weight, culm length, grain width and thickness. Another cluster was detected with four QTLs for 1,000 grain weight, grain length, grain width and grain length/width ratio near the SSR marker RM249 on chromosome 5. Among the 31 QTLs, 9 (28.1%) Hapcheonaengmi3 alleles were beneficial in the Milyang23 background. ILs would be useful to confirm QTLs putatively detected in a primary mapping population for complex traits and serve as a starting point for map-based cloning of the QTLs. Additional backcrosses are being made to purify nearly isogenic lines (NILs) harboring a few favorable Hapcheonaengmi3 alleles in Milyang23 background.

• 한국육종학회지
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• 제42권4호
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• pp.357-364
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• 2010

In a previous study, we mapped 12 QTLs for 1,000 grain weight (TGW) in the 172 $BC_2F_2$ lines derived from a cross between Oryza sativa ssp. Japonica cv. Hwaseongbyeo and O. rufipogon. These QTLs explained 5.4 - 11.4% of the phenotypic variance for TGW. Marker-aided selection combined with backcrosses was employed to develop QTL-NILs for each QTL. $BC_2F_2$ lines with each target QTL were backcrossed to Hwaseongbyeo twice and then allowed to self to produce $BC_4F_5$ populations. SSR markers linked to TGW were employed to select QTL-NILs with the respective target QTL. Six QTL-NILs with the recurrent parent, Hwaseongbyeo were evaluated for nine traits for three years from 2007 and 2009. Differences were observed between each of the 6 QTL-NILs and Hwaseongbyeo in TGW. In addition to TGW, these QTL-NILs displayed differences in other agronomic traits possibly indicating a tight linkage of genes controlling these traits. The direction of the QTL for TGW in 6 QTL-NILs was consistent as in the $BC_2F_2$ lines from the same cross. Difference in TGW between each of the QTL-NILs and Hwaseongbyeo was associated with the difference in one or two grain shape traits; grain length, grain width, and grain thickness. SSR markers linked to the QTL for TGW will facilitate selection of the grain shape character in a breeding program to diversify grain shape and provide the foundation for map-based gene isolation. Also, the QTL-NILs developed in this report and the progenies from crosses between the QTL-NILs will be useful in clarifying epistatic interactions among QTLs for TGW.

• 한국작물학회지
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• 제29권1호
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• pp.1-10
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• 1984

통일형 찰벼를 매개체로 이용하는 육종 체계(wx-carrier technique)에서 맑은 쌀의 선발에 관한 효율성을 검토하기 위하여 기원이 다른 6개의 찰벼를 1회친으로 하고 2개의 통일형 계통 IR667과 IR1317을 반복친으로 하는 Backcross로 12개의 찰벼 계통을 육성해서 이들에다 맑은 쌀 모본 IR24, 수원287호 및 수원294호를 교배하여 그 F$_3$종자에 주당 평균 맑은 쌀의 분리 정도와 변이를 검토하였다. 그 결과를 요약하면 다음과 같다. 1. 찰벼 육성 계통들의 맑은 쌀 출현율은 주당 평균 3.7~78.9%까지로써 그 정도는 찰벼 계통 육성에 사용된 반복친별로 달라 IR677 조합에서보다 IR1317조합에서 높게 나타났다. 반복친의 맑은 쌀 비율은 IR667이 5.6%, IR1317이 47.6%이었으며. 맑은 쌀 메 모본들은 수원287호 83.7%, IR24 80.5% 그리고 수원294호가 73.5%이었다. 2. 메 회복 교배 조합 F$_3$종자에서 맑은 쌀의 분리는 IR24와의 조합에서는 16.7~73.9%, 수원294호와의 조합에서는 21.9~42.8% 그리고 수원287호와의 조합에서는 10.6~26.9%로 IR24 조합에서 가장 많이 분리되었다. 3. 동일한 찰벼 계통을 서로 다른 메벼 품종 수원287호 및 수원294호와 교배된 조합에 있어서의 맑은 쌀의 분리는 조합간에 유의한 정의 상관이 인정되었다. 4. 동일한 메 모본을 찰벼의 기원만 다르고 반복친이나 교배 회수는 동등한 찰벼 계통과 교배한 조합의 맑은 쌀의 분리에 있어서 조합간에 유의한 차이를 나타내었는데 IR1317이 반복친으로 쓰인 경우는 맑은 쌀의 분리가 많고, IR667이 반복친으로 쓰인 경우는 맑은 쌀의 분리가 적었다. 5. Homo메와 Hetero메의 맑은 쌀의 분리 비율은 개체간에 일정한 경향이 없었다. 6. 통일형 찰벼를 매개체로 하는 육종 체계에서는 적절한 모본을 선택함으로써 맑은 쌀의 선발 비율을 높일 수 있을 것으로 추론하였다.

• 한국응용곤충학회지
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• 제58권4호
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• pp.305-311
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• 2019

동소동속종인 팥나방(Matsumuraeses phaseoli)과 어리팥나방(M. falcana)(나비목: 잎말이나방과) 사이에 교잡 가능성을 알아보기 위해서 실험실에서 인위적으로 두 종을 교잡시켰다. 두 종의 암수를 교차하여 교미시켰을 때, F1 잡종세대가 발생하였다. 두 잡종세대 집단을 집단 내 및 집단 간 암수를 교차하여 교미시킨 경우들에서, 팥나방 암컷과 어리팥나방 수컷이 교잡되어 생성된 F1 잡종세대 집단(H집단)의 암컷이 같은 집단의 수컷 혹은 다른 집단의 수컷과 교미되었을 때, F2 후대를 거의 생성하지 못했다. 다른 집단으로 만들어진 F2 세대는 집단 내 교미에서 F3 세대를 생성시켰다. F1 잡종세대 집단 암수와 팥나방 혹은 어리팥나방 암수를 각각 교차하여 교미시킨 역교잡 8개 집단 중에서도 H집단의 암컷과 짝지어진 어미세대 수컷 집단 2개는 전혀 산란하지 못했다. 후대가 생성된 다른 6개 집단은 모두 집단 내 암수 교미에서 역교잡 F2 세대를 생성하였다. 이 결과는 팥나방 암컷과 어리팥나방 수컷이 교미하였을 경우 F1 후대잡종을 생성할 수 있으나, 이 F1 후대잡종 암컷은 불임이 되는 것을 나타냈다. 결과적으로 두 종 사이에 접합후 생식단계에서 부분적인 생식격리가 발생할 수 있는 것을 나타냈다.