• Journal of Sericultural and Entomological Science
• /
• v.15 no.2
• /
• pp.15-20
• /
• 1973

This will be second publication regard with silkworm selection using anesthetic followed by previous report. This treatise investigated for nacorsis recovery concerned with silkworm health through more directions than the previous paper. After the author has found a possibility of silkworm seperation through nacorsis recovery, he has recommended to use Balance Health (BH) value system to evaluate or identify silkworm health and to produce better homogeneous silkworm eggs. Also, the author has continued the observation for the next generation how once nacortized parents affect to their family. The obtained results are summarized as followings. 1. Basic investigation a) Hybrid silkworm variety recovers from nacorsis earlyer than pure line because it is stronger. b) Strong pure line variety recovers from nacorsis earlyer than weak one because it is stronger. c) Male worm recovers from nacorsis earlyer than female worm because it is stronger. 2. Establishment of Balance Health(BH) value system. In order to identify each seperated group by nacorsis and their family, the following Balance Health (BH) value indicating system was established.(Table Omitted) 3. In order to select better silkworm during breeding service, the BH value indicating system is strongly recommended. That is, in case BH value is smaller than four, it would be strong group or in case BH value is larger than four, it would be weak group. 4. Once nacortized parents do not harm any nature for next generation regardless P$_1$ or F$_1$ production. 5. The seperation through nacorsis may delay retrograde phenomenon some years than other case, so, this system should be used for pure line production every year. 6. It is recommended to nacortize silkworm for five minutes on breeding purpose, but two and half minutes on pure lines reproduction at fifth instar. 7. This report has been discussed in relation to practical industry promotion aspects, but there are many subjects to be solved from academical aspect in future

• Korean Journal of Weed Science
• /
• v.30 no.4
• /
• pp.330-339
• /
• 2010

In order to suggest correct direction of researches on Miscanthus spp. which are promising bioenergy crop, authors had reviewed and summarized various literature about botanical taxonomy, morphology and present condition of breeding, cultivation and utilization of miscanthus. Among the genus of Miscanthus which are known 17 species, the most important species are M. sinensis and M. sacchariflorus which origin are East Asia including Korea, and M. x giganteus which is inter-specific hybrid of tetraploid M. sacchariflorus and diploid M. sinensis. Miscanthus is superior to other energy crops in resistance to poor environments including cold, saline and damp soil, nitrogen utilization efficiency, budget of input energy and carbon which are required for producing biomass and output which are stored in biomass. The major species for production of energy and industrial products including construction material in Europe, USA and Canada is M. x giganteus which was introduced from Japan in 1930s. In present, many breeding programs are conducted to supplement demerits of present varieties and to develop "Miscanes" which is hybrid of miscanthus and sugar cane. In Korea, the researches on breeding and cultivation of miscanthus were initiated in 2007 by collecting germplasms, and developed "Goedae-Uksae 1" which is high biomass yield and "mass propagation method of miscanthus" which can improve propagation efficiency in 2009. In order to develop "Korean miscanthus industry" in future, the superior varieties available not only domestic but also foreign market should be developed by new breeding method including molecular markers. Researches on production process of cellulosic bio-ethanol including pre-treatment and saccharification of miscanthus biomass also should be strengthen.

• Journal of Plant Biotechnology
• /
• v.29 no.3
• /
• pp.151-159
• /
• 2002

Genetic map and molecular marker have a great importance in improving and facilitating crop breeding program as well as in genome analysis and map-based cloning of genes representing desirable characters. This study aimed at developing RAPD markers and constructing a genetic linkage map using 82 BC$_1$F$_1$individuals originated from the cross between '835' and B$_2$in radish (Raphanus sativus L.). One of the parents for genetic linkage map construction, '835'(P$_1$) of egg type is susceptible to Fusarium wilt and have medium resistance to virus infection and the other parent, B$_2$(P$_2$) of round type, is susceptible to Fusarium wilt and virus, Screening of 394 RAPD primers in BC$_1$F$_1$) population resulted in selecting 128 polymorphic markers which displayed 1:1 segregation pattern. Two markers failed to display 1:1 segregation and showed the segregation ratio skewed to maternal genotype. Selected markers were categorized into 14 linkage group based on LOD score represented by MAPMAKER/EXP program. Five groups composed of single marker among them were excluded from the linkage map, and consequently, the remaining groups are well matched with the number of radish chromosome (n＝9). The linkage map constructed with 128 markers covers 1,688.3 cM and the average distance between markers was 13.8 cM. For developing STS marker, we determined the partial nucleotide sequence of OPE10 marker at both ends and designed a oligonucleotide primer pair based on this sequence. STS PCR using the primer pair displayed a single, clear band of which segregation is perfectly matched with that of OPE10 marker. This implies that RAPD markers could readily convert into clear and reliable STS markers.

• Korean Journal of Breeding Science
• /
• v.41 no.3
• /
• pp.349-353
• /
• 2009

We developed a new barley cultivar "Dami" (Hordeum vulgare L.) with the auricleless gene lig (al, li, aur-a). The characteristic of auricleless is a spontaneous mutant type which has known as a monogenic recessive gene. The plant with the gene has erect leaf blades because of no auricle. The cultivar was derived from a cross between 'BGS60' and 'Kangbori'. 'BGS60' has the auricleless gene (li), while 'Kangbori' showed a high biomass with winter hardiness and resistance to BaYMV (Barley Yellow Mosaic Virus). Subsequent generations were handled by the bulk method in a pedigree selection program. A promising line showed both high yield and lodging resistance in the yield trials at Iksan in 2003 to 2004, and designated as Iksan414. The line was subsequently evaluated for winter hardiness, earliness, and yield in the seven locations around Korea for three years from 2005 to 2007 and was designated as "Dami" and released. It has the growth habit of III, erect plant type, green leaf and stem similar to the check cultivar 'Sunwoo' Its heading date was April 30, and maturing date May 31 in paddy field conditions, which were similar to those of 'Sunwoo' respectively. The cultivar Dami was 97 cm in culm length, had 643 spikes per $m^2$ and higher leaf dry weight, and better adaptability to dense planting, winter hardiness, and resistance to BaYMV than the check cultivar did. The average forage yield of "Dami" was about 12 ton $ha^{-1}$ in dry matter (33 ton $ha^{-1}$ in fresh matter) in paddy field. "Dami" also showed 7.5% of crude protein content, 28.5% of ADF (Acid Detergent Fiber), 50.1% of NDF (Neutral Detergent Fiber), and 66.4% of TDN (Total Digestible Nutrients), including higher grade of silage quality for whole crop barley. This cultivar would be suitable for the area where the daily minimum temperature of January is above $-8^{\circ}C$ in Korean peninsula.

• Korean Journal of Breeding Science
• /
• v.43 no.3
• /
• pp.184-189
• /
• 2011

'Younghan' (Hordeum vulgare L.), a winter barley for forage use, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, Rural Development Administration in 2008. It was derived from a cross between $F_1$['YB3433-3B-5'/'YB3135-3B-2-3'] and 'YB3135-3B-2-3'. 'SB971305-B-B-B-4-4' line was selected for its earliness, resistance to disease and good agronomic characteristics. The promising line showed both high yield and lodging resistance in the yield trials in Iksan in 2004 to 2005, and designated as 'Iksan420'. The line was subsequently evaluated for winter hardiness, earliness, and yield at eight locations throughout Korea for two years from 2007 to 2008 and finally named as 'Younghan'. It has the growth habit of IV, erect plant type, green leaf and thick culm in diameter. Its heading date was April 24, and the maturing date was May 25 in paddy field conditions, which were one day earlier than those of the check cultivar 'Youngyang'. The cultivar 'Younghan' had better winter hardiness, and resistance to lodging and BaYMV than those of the check cultivar did. The average forage dry matter yield of 'Younghan' was approximately 12.0 MT/ha in adapted region. 'Younghan' also showed 8.5% of crude protein content, 27.2% of ADF, and 67.1% of TDN, including higher grade of silage quality for whole crop barley. This cultivar would be suitable for (area with daily minimum temperature in January) above $-8^{\circ}C$ in Korean peninsula.

• Korean Journal of Breeding Science
• /
• v.42 no.3
• /
• pp.307-312
• /
• 2010

'Cheonghaejinmi' is a new japonica rice variety developed from three-way cross between Samjiyeon/SR14694-57-4-2-1-3-2-2//Iri402 by the rice breeding team of National Institute of Crop Science, RDA. Heading date of this variety is August 18, 4 days later than that of 'Sobibyeo' in middle plain areas. It has culm length of 78 cm, 125 spikelets per panicle, 92.5% of ripened grain rate, and 23.9 g of 1000-brown rice weight. It showed 12 days of heading delay, and 63% spikelet fertility in cold-water irrigation stress. 'Cheonghaejinmi' is susceptible to blast disease, bacterial blight, virus diseases and plant hoppers. The nitrogen use efficiency of this variety is higher than that of Sobibyeo in low nitrogen application level. Milled rice of 'Cheonghaejinmi' exhibits translucent, clear non-glutinous endosperm and medium short grain. It has 5.9% protein content, 20.3% amylose content, and 0.28 palatability index of cooked rice compared to -0.11 of Hwaseongbyeo. The milled rice yield of 'Cheonghaejinmi' was about 5.31 MT/ha at low nitrogen application level of ordinary season culture. This variety had 98.8% whole grain in milled rice and 76% milling recovery of whole grain. 'Cheonghaejinmi' would be adaptable to middle plain areas and middle-western coastal areas in Korea.

• Korean Journal of Breeding Science
• /
• v.43 no.3
• /
• pp.190-195
• /
• 2011

'Youho' (Hordeum vulgare L.), a new ruminant-palatable forage barley cultivar, was developed by the breeding team at the Department of Rice and Winter Cereal Crop, National Institute of Crop Science, RDA in 2008. It was derived from the cross between 'Suwon339' and 'Suwon355'. Among the cross made in 1999, a promising line, SB992047-B-B-B-6-2, showed good characteristics in potential forage yield in the yield trial tested at Iksan from 2005 to 2006. In 2007, it was designated as 'Iksan431' and placed in regional yield trials at eight locations in Korea for two years from 2007 to 2008, and was released as the name of 'Youho'. It has the growth habit of group II, erect plant type, green leaf and hood spike. Its average heading and maturing dates were on Apr. 24 and May 26, respectively, which are similar to check cultivar 'Yuyeon'. 'Youho' also showed weaker winter hardiness, but better resistance to lodging, shattering and BaYMV than those of check cultivar. It showed higher crude protein content, grade of silage quality than those of check cultivar. The average forage dry matter yield in the regional yield trial was about 14.1, $10.9MT\;ha^{-1}$ in upland and paddy field, respectively, which were 1% to 4% lower than that of the check cultivar. This cultivar would be suitable for the area whose daily minimum temperature was above $-8^{\circ}C$ in January in Korean peninsula.

• Korean Journal of Breeding Science
• /
• v.51 no.4
• /
• pp.448-453
• /
• 2019

'Haedamssal' is an early maturing and rice stripe virus disease-resistant cultivar adaptable for early-transplanting cultivation that was developed by the rice breeding team of the Department of Southern Crop, NICS, RDA, in 2014. This cultivar was derived from the cross YR25869 (YR21247-B-B-B-49-1/Sasanishiki BL4//Koshihikari) and YR25868 (Unkwang//YR21247-B-B-B-49-1/Sasanishiki BL4) made in the 2005/2006 winter season and was advanced to the F₅ generation by a bulk breeding method using rapid generation advance. To incorporate rice stripe virus resistance, marker-assisted selection on the RSV gene was conducted in 3-way and 6-way cross F₁ generation using the tightly linked marker RM6897. From testing in the replicated yield trial in 2011, a promising line YR26258-B-B-B-33-3 was selected and it was designated as 'Milyang276'. A local adaptability test of 'Milyang276' was performed at three locations from 2012 to 2014 and it was named as 'Haedamssal', which was a good eating quality variety. The culm length was 67 cm in yield trials, which was 4 cm shorter than 'Jopyeong'. The number of spikelets per panicle was lower than 'Jopyeong', whereas the number of tillers per hill was higher. This variety was resistant to RSV disease, bacterial blight, and leaf blast disease. The milled rice yield of 'Haedamssal' was 5.48 MT per ha at the early transplanting in the local adaptability test. 'Haedamssal' is well adapted to early transplanting cultivation in the southern plain area (Registration No. 6811).

• Asian Journal of Turfgrass Science
• /
• v.22 no.1
• /
• pp.85-100
• /
• 2008

Gray leaf spot (GLS) is a serious fungal disease caused by Pyricularia oryzae Cavara, recently reported on the important turf and forage species, perennial ryegrass (Lolium perenneL.). This fungus also causes rice blast, which is usually controlled by host resistance, but durability of resistance is a problem. Few instances of GLS resistance have been reported in perennial ryegrass. However, two major QTL for GLS resistance have been detected on linkage groups 3 and 6 in an Italian x perennial ryegrass mapping population. To confirm that those QTL are still detectable in the next generation and can function in a different genetic background, a resistant segregant from this population has been crossed with an unrelated susceptible perennial clone, to form a new mapping population segregating for GLS resistance. QTL analysis has been performed in the new population, using two different ryegrass field isolates and RAPD, RFLP, and SSR marker-based linkage maps for each parent. Results indicate the previously identified QTL on linkage group 3 is still significant in the new population, with LOD and percent of phenotypic variance explained ranging from 2.0 to 3.5 and 5% to 10%, respectively. Also two QTL were detected in the susceptible parent, with similar LOD and phenotypic variance explained. Although the linkage group 6 QTL was not detected, the major QTL on linkage group 3 appears to beconfirmed. These results will add to our understanding of the genetic architecture of GLS resistance in ryegrass, which will facilitate its use in perennial ryegrass breeding programs.

• Journal of Life Science
• /
• v.30 no.9
• /
• pp.798-803
• /
• 2020

Late in the 1960s, South Korea established cultivation technology and began breeding new "Tongil" type rice cultivars by crossing indica and japonica. To date, this cultivation technique has been used to produce a wide variety of cultivars to meet consumer preferences and adapt to extreme weather conditions. Once major genetic traits are no longer segregated through advanced generations, varieties obtained from a cross between different crops may become a new variety. In this study, we confirmed the agronomic traits of F₄, F₅, and F₆ by advanced generation a population in which drought tolerance and brown planthopper (BPH) resistance were crossed. HV23, Ilmi/HV23, and Drimi2ho/HV23 were used. HV23 was drought-tolerant, and Drimi2ho was resistant to BPH. As a result, it was possible to consider that the agronomic traits were fixed because none of them showed a significant difference from the others. While it takes more than 10 years for the pedigree method of breeding, this study confirmed that the agronomic traits were fixed in 4-6 years. In the future, we will investigate the homology of the CaMsrB2 gene and the Bph1 gene, to confirm that both genes are closely related to each other, and analyze the stable inheritance of the introduced gene for multiple successive generations.