• Horticultural Science & Technology
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• v.32 no.4
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• pp.535-543
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• 2014

Backcross breeding is the method most commonly used to introgress new traits into elite lines. Conventional backcross breeding requires at least 4-5 generations to recover the genomic background of the recurrent parent. Marker-assisted backcrossing (MABC) represents a new breeding approach that can substantially reduce breeding time and cost. For successful MABC, highly polymorphic markers with known positions in each chromosome are essential. Single nucleotide polymorphism (SNP) markers have many advantages over other marker systems for MABC due to their high abundance and amenability to genotyping automation. To facilitate MABC in hot pepper (Capsicum annuum), we utilized expressed sequence tags (ESTs) to develop SNP markers in this study. For SNP identification, we used Bukang $F_1$-hybrid pepper ESTs to prepare a reference sequence through de novo assembly. We performed large-scale transcriptome sequencing of eight accessions using the Illumina Genome Analyzer (IGA) IIx platform by Solexa, which generated small sequence fragments of about 90-100 bp. By aligning each contig to the reference sequence, 58,151 SNPs were identified. After filtering for polymorphism, segregation ratio, and lack of proximity to other SNPS or exon/intron boundaries, a total of 1,910 putative SNPs were chosen and positioned to a pepper linkage map. We further selected 412 SNPs evenly distributed on each chromosome and primers were designed for high throughput SNP assays and tested using a genetic diversity panel of 27 Capsicum accessions. The SNP markers clearly distinguished each accession. These results suggest that the SNP marker set developed in this study will be valuable for MABC, genetic mapping, and comparative genome analysis.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.875-888
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• 2018

Tulip (Tulipa L.) is one of the most important ornamental geophytes in the world. Analysis of molecular variability of tulips is of great importance in conservation and parental lines selection in breeding programs. Of the 70 genic microsatellites, 15 highly polymorphic and reproducible markers were used to assess the genetic diversity, structure, and relationships among 280 individuals of 36 wild and cultivated tulip accessions from two countries: Iran and the Netherlands. The mean values of gene diversity and polymorphism information content were 0.69 and 0.66, respectively, which indicated the high discriminatory power of markers. The calculated genetic diversity parameters were found to be the highest in wild T. systola Stapf (Derak region). Bayesian model-based STRU CTU RE analysis detected five gene pools for 36 germplasms which corresponded with morphological observations and traditional classifications. Based on analysis of molecular variance, to conserve wild genetic resources in some geographical locations, sampling should be performed from distant locations to achieve high diversity. The unweighted pair group method with arithmetic mean dendrogram and principal component analysis plot indicated that among wild tulips, T. systola and T. micheliana Hoog exhibited the closest relationships with cultivated tulips. Thus, it can be assumed that wild tulips from Iran and perhaps other Middle East countries played a role in the origin of T. gesneriana, which is likely a tulip species hybrid of unclear origin. In conclusion, due to the high genetic variability of wild tulips, they can be used in tulip breeding programs as a source of useful alleles related to resistance against stresses.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.17-22
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• 2015

A total of CNU 28 hybrids were developed at the CNU Corn Breeding Lab. were evaluated to identify new cultivars in botanical characteristics, fresh yield per 10a and taste qualities. Most of these hybrids were stable in environmental stresses such as lodging, disease and insects. Stem height ranged from 115.0 to 239.3 cm, and ear height ranged from 30.7 to 107.0 cm. The ear height to stem height ratio was showed low than 50% of standard as a stable plant type to lodging. The range of ear length was 14.2 cm to 23.0 cm. Especially, CNU 13H-73 was very longest ear as a 23 cm. The fresh yield per 10a was high in purple of CNU13H-79 hybrid than control hybrid Miheuckchal, and CNU13H-73 in white hybrid was similar Yeonnong check hybrid. The 100-kernel weights in CNU13H-3 and CNU13H-9 hybrids were higher than that of the control hybrid. CNU13H-98 among hybrids had a 100-kernel weight of 20.32 g, which was heavier than that of the control hybrid Daehackchal Gold 1. The average pericarp thickness was $41.4{\mu}m$, CNU13H-46 among hybrids had a very thin pericarp as a $35.5{\mu}m$. The mean sugar content of the used hybrids was 14.95 brix%; CNU13H-73 and CNU13H-55 had higher than Mibak2 as a control hybrid.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.503-506
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• 2011

A new hybrid, Phalaenopsis 'Pink Marble' was made by the National Institute of Horticultural and Herbal Science, Rural Development Administration, in 2005. This hybrid was selected from self-crossed progenies of P. '21-1' (collected number) in 1999. In 2001, one line was selected based on the aspects such as flower color, leaf shape, flower stalk, and vigorous growth. Trials were conducted from 2003 to 2005 for evaluation and selection of this cultivar. 'Pink Marble' had a medium flowering habit and a dark pink spot (RHS, RPN74B) on white petal and sepal when fully opened. The number of flowers on each peduncle was 7.5, and flower diameter was 52.3 cm. The general impression of petals and sepals is a plate shape. The thick sepal could extend the long flowering time. The average length of leaf and peduncle were 16.5 cm and 6.8 cm, respectively. It had a half-erect leaf form, and was a fast-growing cultivar. This hybrid is relatively easy to clone.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.134-138
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• 1994

Potato Virus Y(PVY), vein necrosis strain, in Korea causes severe symptoms on burley tobacco(Nicotiana tabacum L.). As the results, programs to incorporate PVY resistance into commercial cultivars were initiatEd. But the development of the homozygous fertile line resistant to PVY is time consumming. This study was conducted whether the Fl hybrid could be used to reduce the yield losses caused by PVY. Four F1 hybrids were made between male - sterile(ms) NC 107 and KB 107 as maternal parent, and TC 612 and TC 613 as Pollen donor, respectively, and were evaluated for their PVY resistance and negatively associated traits. (ms NC 107 X TC 612) F1, named as KB 109, Ivas applied to yield trial and compared with commercial cultivars for the level of disease resistance, agronomic characteristics, chemical contents and physical properties. All Fl hybrid could be used commercially as the PVY resistant cultivar. Especially KB 109 have the resistance against PVY, tobacco mosaic virus and black shank(Phytophthora parasitica var. nicotianae). It had wider leaves, flowered one day later, and yield of acceptable quality was higher than that of Burley 21, standard cultivar in Korea.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.109-112
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• 2006

The use of commercial silkworm hybrids resistant to important silkworm diseases is economical and better option particularly in tropical areas. This necessitated the evolution of productive bivoltine silkworm breeds non-susceptible to $BmDNV_1$. Non-susceptibility to $BmDNV_1$, infection was found to be controlled by a single recessive gene, nsd-l or a dominant gene, Nid-l. A major dominant/recessive gene confers resistance to $BmDNV_1$, from potent donor parents have been transferred to 10 productive but susceptible bivoltine silkworm strains through conventional breeding methods. By utilizing these breeds prepared 25 hybrids $(5{\times}5)$ and hybrid evaluation was carried out to identify most promising hybrids resistant to $BmDNV_1$. All these hybrids are inoculated with $BmDNV_1$ inoculum along with productive control hybrid $CSR2{\times}CSR4$ and reared under standard rearing procedure. Based on inoculated rearing and test reeling results, two most promising hybrids $(CSR18DR{\times}CSR29DR\;and\;CSR21DR{\times}CSR50DR)$ were selected for commercial exploitation. The selected hybrids have shown a survival rate of >85% with productive traits, where as control hybrid have shown 11.1% survival with inferior cocoon traits. The methodologies adopted were discussed.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.65-68
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• 2001

A new silkworm variety, Chunsujam, for spring rearing season is F$_1$ hybrid between Japanese race Jam145 bred by 8459/8711 and Chinese race Jam146 by 8544/M8626. Jam145, Japanese parent of the Chunsujam, showed high GCA in pupation rate and Jam146, Chinese parent, showed high GCA in pupation rate and single cocoon weight. In the local adaptability test performed at 8 local areas in spring of 1999, Chunsujam was 5% higher in larval weight, 3% in single cocoon weight, and 4% in cocoon yield from 10,000 of the 3rd molted larvae, respectively, than the check variety Baegokjam.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.77-81
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• 2002

A new non-cocooning silkworm variety, Hachojam, suitable for autumn rearing season is single cross Fl hybrid between Japanese race Jam 307 and Chinese race Jam 126. Jam 307, Japanese parent of the Hachojam, which is a source for non-cocooning process showed a high GCA (generation combining ability) in naked pupation rate and Jam 126, Chinese parent, showed a high GCA in pupation rate and single pupal weight. In the local adaptability test performed at 8 local areas in autumn of 1999 to 2000, the naked pupation rate and thin cocoon rate of Hachojam were 64.7% and 35.3% , respectively. The pupal weight calculated from 10,000 of the 3rd molted larvae was 24% heavier in Hachcjam than the cocoon-producing, check variety Daesungjam.

• Journal of Aquaculture
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• v.12 no.2
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• pp.163-165
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• 1999

A production method for scaled and scaleless strain of common carp (Cyprinus carpio) at a breeding trial is developed by test-cross technique. When the fish with scaleless (Israeli strain of common carp) were crossed with scaled strain (hybrid fish between oriental and Israeli strain of the species), we can easily obtain 2 types of common carp with or without scale. The frequency of scaleless fish in this experiment was about 40% in the population, however, their growth rate was slightly higher than scaled fish after 3 months of this experiment.

• Journal of Sericultural and Entomological Science
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• v.41 no.2
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• pp.94-101
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• 1999

Twelve pure silkworm lines identified based in higher G.C.A values from a line${\times}$Tecter crossing programme, were crossed with twelve breeds showing cocoon shell ratio>22% and hybrids prepared, evaluated in a Multiple index method. Seven hydrids showing average index value>50 in all the 10 economic characters were seclcted and evaluated in the laboratory. However, two hybrids viz., A3${\times}$935E and A3${\times}$916B were finally selected based on the superiority of the breeds in one day shorter larval duration and with and with higher reeling characters compared to control KA${\times}$NB4D2. The breeding procedure involed in evolution hybrids are discussed.