• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.99-105
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• 2007

The success of rearing with presently available conventional bivoltine is unpredictable in some seasons of the tropical regions due to highly fluctuating adverse climatic conditions. Thus, in order to popularize bivoltine breeds in tropical parts of India, it is very much essential to have a bivoltine breed(s), which can give stable cocoon crop under variable environments. With this objective a breeding programme was undertaken to improve the survival trait in bivoltine silkworm by introducing multivoltine genes into bivoltine through back crossing. Resultant bivoltine lines showed significantly higher survival in compared to the receptor (Bivoltine) parent and control bivoltine breed. Esterase isozyme analysis revealed similar banding pattern in the developed bivoltine and in the donor multivoltine, which predicts the introgression of multivoltine character into evolved bivoltine.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.99.3-99
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• 2000

No Abstract, See Full Text

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1566-1572
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• 2020

Objective: The extensive breeding of commercial chickens has led to a sharp decrease in the resources of many indigenous chickens, especially the indigenous chickens in the southeastern coastal region, which are on the verge of extinction, and the indigenous chickens in the northwestern region of China, which are also at risk. However, there are few reports on the evaluation of genetic diversity and conservation of genetic resources of indigenous chickens in remote areas in the Northwest of China. Methods: In the present study, the genetic diversity and phylogenetic relationship of six indigenous chickens from different regions were studied based on variation in mitochondrial DNA control region (D-loop), and the degree of introgression from commercial breeds into these chickens was determined by the amount of haplotype sharing between indigenous and commercial breeds. Results: Twenty-five polymorphic sites and 25 haplotypes were detected in 206 individuals. Principal component analysis showed that the Jingning chicken had the highest genetic diversity among the six indigenous chickens. According to the degree of introgression, the six indigenous breeds may be involved in haplotype sharing with commercial breeds, and the introgression from commercial chickens into the Haidong chicken is the most serious. Conclusion: The genetic uniqueness of indigenous chickens has been eroded, so it is necessary to consider the protection of their genetic resources. Phylogenetic analysis suggests that the six indigenous chickens have two major matrilineal origins: one from Yunnan or its surrounding areas in China and the other from the Indian subcontinent.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.269-269
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• 2022

Pre-harvest sprouting (PHS) on rice panicles is getting problematic in recent several years in Korea due to climate changes such as high temperature and more frequent typhoons during harvesting season. PHS negatively affects grain quality severely and also yield. Genetic improvement of Korean varieties (Oryza sativa ssp. japonica) through a marker assisted-backcross breeding (MAB) with the known PHS resistant genes must be one of ideal solutions. However, the final breeding products of MAB occasionally exhibit unwanted traits, especially the cross between genetically distant parents. This might be caused by linkage drag and/or presence of the gene-unlinked donor introgressions, resulting that the final products could not be released to the farmers. The major PHS resistance gene, Sdr4 (Seed dormancy 4) originated from an indica cultivar, Kasalath was selected as a donor gene. In order to avoid unexpected phenotypes in the breeding products, we performed a precision marker-based breeding (PMBB) consisting of foreground, recombinant, and background selections (FS, RS, and BS) which aim to develop 'single small introgression lines' (~100 kb introgression). Korean varieties (Ilpum and Gopum) were crossed with Kasalath. We developed Sdr4-allele specific markers for FS and a set of polymorphic flanking markers near the Sdr4 (-350kb and +420kb) for RS. To minimize linkage drag, the small introgression (< 125kb) containing Sdr4 was selected in Ilpum background (BC₂F₄) through 1^st RS with ~1,200 F₂ or BC₁F₂ plants (one side trimmed) and then 2^nd RS with ~1,000 progenies from the 1^st RS selected plants (another side trimmed). After RS, the selected lines were genotyped by using Infinium 7K SNP chip to detect other donor introgressions and the lines were backcrossed. Currently BS is on-going from the backcross-derived progenies with BS markers to remove residual introgressions. During the PMBB process, genetic effect of Sdr-4-Kasalath allele was confirmed in Ilpum and Gopum backgrounds by PHS phenotyping using the segregating BC₂F₃ or BC₁F₄ materials. The Sdr4 PMBB lines in Ilpum background (< 125kb introgression) will be valuable genetic resources to improve PHS resistance in modem popular temperate japonica varieties.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.10b
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• pp.132-133
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.10b
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• pp.330-331
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.10a
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• pp.94-95
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• 2004

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.108-109
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• 2004

• Korean Journal of Plant Taxonomy
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• v.31 no.4
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• pp.343-358
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• 2001

We have examined the pedicel pubescence and other major morphological characters of 11 putative hybrid populations of Aconitum subgn. Aconitum at Mt. Sobaek to understand their origin. These populations show very complicated patterns of variation in pedicel pubescence ; they contain individuals having pedicels (1) completely glabrous, (2) with few micropapillate curved hairs near the receptacle, (3) moderately pubescent with micropapillate curved hairs from middle to upper portion, (4) sparsely pubescent with a mixture of micropapillate curved hairs and smooth-surfaced spreading glandular hairs near the receptacle, and (5) moderately pubescent with both types of hairs but from middle to upper portion. All five types of individuals co-occur in most populations with varying proportions. These results, in conjunction with evidence from the analysis of other major morphological characters, suggest that the populations at Mt. Sobaek were derived from the multiple hybridization events involving A. kusnezoffii, A. japonicum subsup. napiforme, and A. jaluense subsp. jaluense. In addition, the absence of "typical" forms of these putative parental taxa in Mt. Sobaek area suggests that repeated introgression has probably occurred in these populations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.533-538
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• 2004

An introgression line, WH79006 was produced from a single plant from $BC_5F_3$ families from a cross between Hwaseongbyeo used as a recurrent parent and O. minuta (BBCC, Ace. No. 101154) as a donor parent, which was subsequently self-pollinated for three generations. WH79006 resembled the O. sativa parent, Hwaseongbyeo. However it differed from Hwaseongbyeo in several traits including days to heading, culm length, grain size, spikelets per panicle and fertility. These differences in the traits between WH79006 and Hwaseongbyeo can be attributed to the O. minuta introgressions. To detect the introgressions, 294 SSR markers of known chromosomal position have been used. At least, 28 introgressed chromosomal segments have been identified using SSR markers and they map to all chromosomes except chromosome 2. The size of the introgressed segments ranged from 4 to 35cM. A QTL related to culm length was detected using 75 $F_2$ plants from the Hwaseongbyeo/WH79006 cross. This QTL, cl6 located on chromosome 6 explained $9.6\%$ of the total phenotypic variation in the population. This QTL has not been detected in the previous QTL studies between Oryza sativa cultivars, indicating potentially novel alleles from O. minutan.