• International Journal of Industrial Entomology and Biomaterials
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• v.19 no.1
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• pp.187-192
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• 2009

Silk filament progression study applying backcross breeding with recipient parent Jata and donor parent Daba ecoraces of tropical tasar silkworm, Antheraea mylitta Drury conducted during 2006 to 2008, revealed introgression of filament denier (10.2 d) superior to both parents at BC4 level. Also, the silk waste (0.35%) and filament breaks (2.6 nos) were reduced compared to both parents, while the filament length (973 m) and non break filament (296 m) improved over donor and could attain closer to recipient parent. The best performance of Jata $\times$ Daba at F1 level, with highest silk filament length (1646 m) of 12.5 d denier, denotes heterosis impact on silk trait with parental heterogenousity, an advantage to exploit silk filament yield. The progression of quality in terms of finer filament denier, less silk waste and least number of filament breaks over both parents and improvement in filament length and non break filament over donor parent except for a marginal shortage against recipient at BC4 level indicates the prospects of Jata and Daba ecoraces as source of breeding material for qualitative improvement of tasar silk filament. The study suggests that the commercially important finer denier of tasar silk filament can be attained with minor reduction in silk yield of wild Jata ecorace by adopting repeated backcrossing for four generations with semi domesticated Daba ecorace.

• Korean Journal of Plant Resources
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• v.22 no.3
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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.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.271.1-271
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• 2000

No Abstract, See Full Text

• Mycobiology
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• v.32 no.1
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• pp.11-16
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• 2004

Winter mushroom, Flammulina velutipes, needs low temperature during its cultivation. To save on farm costs, especially during summer, a strain adaptable to a higher or elevated-temperature must be developed. At the start of breeding program, parental strains which could endure high temperature were obtained. Seuenty four dikaryotic strains were collected and divided into four groups according to the nature of temperature. They also had different fruiting temperature. Finally we selected three brown strains ASI 4048, 4057 and 4072, and collected their spores. These selected strains can germinate even at a high temperature of $32^{\circ}C$, which were dramatically higher than the other strains. Based on these results, the new white strain adapted to mid-temperature by backcross mating was developed. Molecular markers were applied to select white fruitbody producing strains without cultivation. They showed a specific band which co-segregated with brown fruitbody forming strains in $BC_1F_1$ progenies. Selected white strains were tested under several elevated temperature conditions.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.8-12
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• 1999

New winter wheat winter barley hybrids were produced (Mv9 kr1 Igri, Mv9 kr1 Osnova, Asakazekomugi Manas). The wheat-barley hybrids showed entire male sterility and were multiplied in tissue culture. Chromosome configurations were studied with GISH in meiosis in the Mv9 krl x Igri hybrid and in its progenies multiplied in vitro. Chromosome pairing between wheat and barley has been observed in some cells in the hybrids multiplied in vitro. Backcross plants with 43 and 44 chromosomes were selected with the aim of developing new wheat-barley addition lines. Wheat-barley translocations were demonstrated with GISH in backcross progenies originating from in vitro regenerated wheat (Triticum aestivum L. cv. Chinese Spring) x barley (Hordeum vulgare L. cv. Betzes) hybrids. Five different translocations were observed. Sequential N-banding and GISH analyses were performed to further identify the translocations. The N-banding pattern of the Robertsonian translocation suggests that this chromosome consists of the short arm of barley chromosome 4H translocated to the long arm of 2B of wheat. Plants with four different homozygous translocations were selected from the following BC2F3 generation.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.7
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• pp.954-959
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• 2004

In a herd of 24 spring-born steers, plasma leptin and performance of selected purebred (n=5) and backcrossed Hereford (n=5) were compared in a year-round summer grazing and winter feedlot fattening. Bimonthly blood collection and body weight measurement were accomplished. The plasma samples were analyzed for leptin, insulin, total cholesterol, triglyceride, NEFA and glucose. The experimental design utilized one-way ANOVA with breed as the treatment. The purebred obtained higher plasma NEFA (p<0.001) compared to backcross, regardless of seasonal feeding systems (SFS). The backcross showed gradual increase and nonresponsiveness of plasma leptin to SFS. During summer grazing, attenuation of plasma leptin and sudden elevation when shifted to winter feedlot fattening were observed in purebred. Plasma leptin obtained linear relationship with body weight of purebred (r=0.53;p<0.001) and backcrossed Hereford (r=0.49; p<0.01). The purebred and backcrossed Hereford, when shifted to summer grazing, resulted to sustained and restricted daily gain, respectively. Therefore, cattle breeds of higher growth potential exhibit significant elevation of plasma leptin after 400 kg BW, when animal starts to deposit significant body fat.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.29-34
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• 1994

A leading sweet pepper cultivar, Keystone Resistant Giant #3, was crossed with a line with resistance to Phytophthora capsici, PI201232, for incorporation of the resistance and to study the inheritance of resistance to the disease. Seedlings of parents, $F_1$, $F_2$ and backcross populations of a cross between Keystone Resistant Giant #3 and PI201232 were inoculated with zoospore suspension of P. capsici at 36 days after seeding. Most of the $F_1$ seedlings survied the inoculation and this suggested that resistance is dominant over susceptibility. The number of survived plants in $F_2$ population was, however, much less than the killed. All the plants in a backcross to Keystone Resistant Giant #3 were killed. Therefore, the observed numbers did not fit the expected ratio for segregation of one or two dominant alleles as previously reported. The resistance to P. capsici appeared to be inherited in a quantitative mode in evaluation of root rot. Resistant individuals in $F_2$ population were selected and a breeding program for incorporation of the resistance to P. capsici by backcross method is continued.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.36-37
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• 2000

• Current Research on Agriculture and Life Sciences
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• v.10
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• pp.117-123
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• 1992

Twenty and 24 lines selected from Korean local cultivar, Kalmi and Punggak, respectively, were grown in the University experiment farm to select promising lines for recurrent parent in a backcross breeding program for incorporation of resistance to Phytophthora capsici and Xanthomonas campestris pv vesicatoria into the Korean local cultivars. All the selections of 'Kalmi' and 'Punggak' were relatively late in maturity and the range of the variation was wider in the selections of 'Kalmi' than in those of 'Punggak'. Many of the selections from 'Kalmi' were vigorous, high in sugar content, and tolerant to virus in the field. Many of the selections from 'Punggak' were bearing large fruits with thick pericarp and high milling percentage. Line 6, 9, 14, 18 of 'Kalmi' and line 14, 16, 18 of 'Punggak' were selected as promising lines for recurrent parent in the backcross program.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.265-265
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• 2017

This study was carried out to develop rice variety integrated with rice bacterial blight resistance gene and to know the information of major agronomic traits of developed variety. Advanced backcross Lines 21 having Xa3 and Xa21 gene cross from japonica cultivar Hwanggeumnuri and indica variety IRBB21. Days after seeding and culm length of ABLs21 were 108 days (Aug. 16) and 76 cm, respectively. Ripened grain rates was 87.4 %, which was similar to the parents. 1000 grain weight of brown rice of ABLs21 was 21.4g, which was lower than the donor parent. Milled rice yield of ABLs21 was 532 kg/10a, which was smaller than recurrent parent and higher than the donor parent. Grain length/width ratio of brown rice was form of japonica with short-ellipse and glossiness of cooked rice has japonica trait. Head rice rate showed a large difference compare to the donor parent and similar to the recurrent parent. ABLs21 would be useful genetic resources for resistance breeding program against bacterial blight.