• The Journal of Fisheries Business Administration
• /
• v.41 no.1
• /
• pp.113-128
• /
• 2010

This study is aimed to analyze the economic feasibility of the selective breeding program on the Oliver flounder aquaculture. First of all, in order to evaluate this program, we review the concept and research trend on the selective breeding. The objective of this research is the selective breeding program on the Oliver flounder aquaculture in the Genetics and Breeding Research Center, NFRDI. It was conducted to investigated economic effects of three factors of the selective breeding program on the Oliver flounder aquaculture such as fast growth, disease resistance and increase exports. The results of economic analysis of the selective breeding program on the Oliver flounder aquaculture are as follows; First, there were the significant meaning of the economic effects on the technology of the selective breeding program by fast growth, disease resistance and increase exports. Second, we analyzed in the economic feasibility of the selective breeding program on the Oliver flounder aquaculture from 2004 to 2020, internal rate of return(IRR) was 419%, a benefit-cost ratio was shown to be 24.92, net present value(NPV) was 989,942,464 thousand won, which indicates the economic feasibility of the selective breeding program is very high. Finally, in order to improve the economic feasibility, there is need to be focused on the efficient the selective breeding program on the Oliver flounder aquaculture.

• Journal of Crop Science and Biotechnology
• /
• v.10 no.4
• /
• pp.277-280
• /
• 2007

Pepper fruit anthracnose, caused by Colletotrichum acutatum, results in serious yield loss and affects crop quality in many Asian countries, making it a disease of economic consequence. A source resistant to C. acutatum was identified by the AVRDC within the line Capsicum chinense Jacq. PBC932. The resistant breeding line C. annuum AR is the $BC_3F_6$ generation derived from C. chinense Jacq. PBC932. The inheritance of resistance to C. acutatum was analyzed in segregating populations derived from the two crosses HN 11$\times$AR and Daepoong-cho$\times$AR. Detached mature green fruits were inoculated using microinjection method. The disease response was evaluated as the disease incidence at 7 DAI. The segregation ratios of resistance and susceptibility to C. acutatum in the $F_2$ and $BC_R$ populations derived from the two crosses fit significantly to a 1:3 Mendelian model. This indicates that the resistance of AR to C. acutatum is controlled by a single recessive gene.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.13-13
• /
• 2017

By the progress of genome sequencing, infrastructures for marker-assisted breeding (MAB) of rice came to be established. Fine mapping and gene isolation have been conducted using the breeding materials derived from natural variations and artificial mutants. Such genetic analysis by the genome-wide dense markers provided us the knowledge about the many genes controlling important traits. We identified several genes or quantitative trait loci (QTL) for heading date, blast resistance, eating quality, high-temperature stress tolerance, and so on. NILs of each gene controlling heading date contribute to elongate the rice harvest period. Determination of precise gene location of blast resistance gene pi21, allowed us to overcome linkage drag, co-introduction of undesirable eating quality. We could also breed the first practical rice cultivar in Japan with a brown planthopper resistance gene bph11 in the genetic back-ground of an elite cultivar. Discovery of major and minor QTLs for good eating quality allowed us to fine-tune of eating quality according to the rice planting area or usage of rice grain. Many rice cultivars have bred efficiently by MAB for several traits, or by marker-assisted backcross breeding through chromosome segment substitution lines (CSSLs) using genetically diverse accessions. We are also systematically supporting the crop breeding of other sectors by MAB or by providing resources such as CSSLs. It is possible to pyramid many genes for important traits by using MAB, but is still difficult to improve the yielding ability. We are performing a Genomic Selection (GS) for improvement of rice biomass and grain yield. We are also trying to apply the genome editing technology for high yield rice breeding.

• The Plant Pathology Journal
• /
• v.37 no.2
• /
• pp.200-203
• /
• 2021

Rice blast caused by the filamentous fungus Magnaporthe oryzae, is arguably the most devastating rice disease worldwide. Development of a high-throughput and reliable field blast resistance evaluation system is essential for resistant germplasm screening, resistance genes identification and resistant varieties breeding. However, the occurrence of rice blast in paddy field is easily affected by various factors, particularly lack of sufficient inoculum, which always leads to the non-uniform occurrence and reduced disease severity. Here, we described a procedure for adequately inducing the occurrence of rice seedling blast in paddy field, which involves pretreatment of diseased straw, initiation of seedling blast for the first batch of spreader population, inducing the occurrence of the second batch of spreader population and test materials. This procedure enables uniform and consistent infection, which facilitates efficient and accurate assessment of seedling blast resistance for diverse rice materials.

• Korean journal of applied entomology
• /
• v.31 no.3
• /
• pp.256-275
• /
• 1992

Insects are among the most important abiotic and biotic constraints to rice production. National rice research programs are in various stages in the development and implementation of integrated pest management (IPM) stratagies for rice insect control. Among the various control tactics, insect resistant cultivars are sought as the major tactic in rice IPM. Through the activities of interdisciplinary teams of scientists significant progress has been made in the development and release of insect resistant cultivars to farmers. Because of its compatibility with other control tactics insect resistance has proven to fit well into the IPM approach to rice insect control agents and minimize the need for insecticide applications. The development of biotypes which overcome the resistance in rice plants has been a significant constraint in the breeding of rice for resistance to insects. Most notable examples in Asia are the green leafhopper, Nephotettix virescens, brown planthopper, Nilaparvata lygens and the Asian rice gall midge, Orseolia oryzae. The current breeding stratege is to develop rice cultivars with durable resistance on which virulent biotypes cannot adapt. In spite of the significant progress made in the breeding of insect resistant cultivars there are still numerous important rice insect species for which host plant resistance as a control tactic has not been fully utilized. Advances in biotechnology provide promise of solving some of the problems that have limited the use of host plant resistance as a major tactic in the integrated management of rice insect pests.

• Journal of Ginseng Research
• /
• v.14 no.1
• /
• pp.50-56
• /
• 1990

Root-rot of ginseng caused by Fusarium solani is one of the most obstacles to ginseng cultivation. We evaluated some inoculating techniques of ginseng with Fusarium solani, for selection of disease resistant breeding lines. The most effective inoculating techniques evaluated were inserting toothpicks colonized by F. solani into the seedling roots in laboratory test and dusting seedlings with vermiculite after dipping in conidial sllspension and then replanting method in field test. The resistance to diseased by F. solani was lines of 82022 and 82066 in laboratory test. 82920-1 and 78093 in field test.

• Current Research on Agriculture and Life Sciences
• /
• v.21
• /
• pp.11-16
• /
• 2003

Lines bred for resistance to Phytophthora capsici by incorporation of resistance to P. capsici in PI201234 or CM334 into 'Subi' and 'Chilseong', land races in Youngyang, and 'Punggak', a land race in Cheongdo in Gyeungbuk province, and lines bred for fortification of one of them above with resistance to viral complex, and tolerant selections from another landrace collection from Punggak (KC268) were evaluated for resistance to P. capsici by inoculation at seedling stage. Almost all the breeding lines showed high level of resistance to P. capsid and selections from KC268 showed tolerance or moderate resistance to P. capsid. The selected plants were grown in a net cage in an outdoor nursery for seed production. Utilization of the lines in breeding was discussed.

• The Plant Pathology Journal
• /
• v.31 no.1
• /
• pp.12-24
• /
• 2015

Rice Blast is the most devastating disease causing major yield losses in every year worldwide. It had been proved that using resistant rice varieties would be the most effective way to control this disease. Molecular screening and genetic diversities of major rice blast resistance genes were determined in 192 rice germplasm accessions using simple sequence repeat (SSR) markers. The genetic frequencies of the 10 major rice blast resistance genes varied from 19.79% to 54.69%. Seven accessions IC337593, IC346002, IC346004, IC346813, IC356117, IC356422 and IC383441 had maximum eight blast resistance gene, while FR13B, Hourakani, Kala Rata 1-24, Lemont, Brown Gora, IR87756-20-2-2-3, IC282418, IC356419, PKSLGR-1 and PKSLGR-39 had seven blast resistance genes. Twenty accessions possessed six genes, 36 accessions had five genes, 41 accessions had four genes, 38 accessions had three genes, 26 accessions had two genes, 13 accessions had single R gene and only one accession IC438644 does not possess any one blast resistant gene. Out of 192 accessions only 17 accessions harboured 7 to 8 blast resistance genes.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.3 no.2
• /
• pp.187-190
• /
• 2001

Inheritance pattern of resistance to Bombyx mori nuclear polyhedrosis virus (BmNPV) was studied in an Indian silkworm stock TX by single back-cross test method. The resistant parent ［TX］, susceptible parent ［HM］, their Fl, F2, and Fl progeny back-crossed to TX [BC(R)] and HM [BC(S)] were inoculated per os with a fixed concentration of BmNPV($0.5{\times}10^{th} PIB/ml$) on the first day of second stadium. The cumulative mortality was recorded until day $10^{\times}$ post-inoculation. The results show that the resistance to BmNPV in TX fellow mono Mendelian inheritance pattern. The resistance dominated over the susceptibility at Fl. At F2, the resistant and susceptible offspring segregated in 3:1 ratio whereas at BC(S), the resistant and susceptible offspring segregated in 1:1 ratio. The response of BC(R) was more or less like the resistant parent TX which confirms the involvement of a major dominant gene conferring resistance to BmNPV in TX. The possible mechanism of inheritance of resistance in TX is discussed.

• Korean Journal of Breeding Science
• /
• v.40 no.3
• /
• pp.215-222
• /
• 2008

Fifty-two Korean japonica rice cultivars were analyzed for leaf blast resistance and genotyped with 4 STS and 26 SSR markers flanking the specific chromosome sites linked with blast resistance genes. In our analysis of resistance genes in 52 japonica cultivars using STS markers tightly linked to Pib, Pita, Pi5(t) and Pi9(t), the blast nursery reaction of the cultivars possessing the each four major genes were not identical to that of the differential lines. Eight of the 26 SSR markers were associated with resistant phenotypes against the isolates of blast nursery as well as the specific Korean blast isolates, 90-008 (KI-1113), 03-177 (KJ-105). These markers were linked to Pit, Pish, Pib, Pi5(t), Piz, Pia, Pik, Pi18, Pita and Pi25(t) resistance gene loci. Three of the eight SSR markers, MRG5836, RM224 and RM7102 only showed significantly associated with the phenotypes of blast nursery test for two consecutive years. These three SSR markers also could distinguish between resistant and susceptible japonica cultivars. These results demonstrate the usefulness of marker-assisted selection and genotypic monitoring for blast resistance of rice in blast breeding programs.