• Title/Summary/Keyword: Linkage group

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QTL Analysis of Soybean Seed Weight Using RAPD and SSR Markers

  • Chung, Jong-Il;Ko, Mi-Suk;Kang, Jin-Ho
    • Plant Resources
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    • v.3 no.3
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    • pp.184-193
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    • 2000
  • Soybean [Glycine max (L.) Merr.] seed weight is a important trait in cultivar development. Objective of this study was to identify and confirm quantitative trait loci (QTLs) for seed weight variation in the F2 and F2:3 generations. QTLs for seed weight were identified in F2 and F2:3 generations using interval mapping (MapMaker/QTL) and single-factor analysis of variance (ANOVA). In the F2 plant generation (i.e., F3 seed), three markers, OPL9a, OPM7a, and OPAC12 were significantly (P<0.01) associated with seed weight QTLs. In the F2:3 plant row generation (i.e., F4 seed), five markers, OPA9a, OPG19, OPL9b, OPP11, and Sat_085 were significantly (P<0.01) associated with seed weight QTLs. Two markers, OPL9a and OPL9b were significantly (P<0.05) associated with seed weight QTLs in both generations. Two QTLs on USDA soybean linkage group C1 and R were identified in both F2 and F2:3 generations using interval mapping. The linkage group C1 QTL explained 16% of the variation in seed weight in both generations, and the linkage group R QTL explained 39% and 41% of the variation for F2 and F2:3 generation, respectively. The linkage group C2 QTL identified in F2:3 generation explained 14.9% of variation. Linkage groups C1, C2 and R had previously been identified as harbouring seed size QTLs. The consistency of QTLs across generations and populations indicates that marker-assisted selection is possible in a soybean breeding program.

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Predicting the Accuracy of Breeding Values Using High Density Genome Scans

  • Lee, Deuk-Hwan;Vasco, Daniel A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.2
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    • pp.162-172
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    • 2011
  • In this paper, simulation was used to determine accuracies of genomic breeding values for polygenic traits associated with many thousands of markers obtained from high density genome scans. The statistical approach was based upon stochastically simulating a pedigree with a specified base population and a specified set of population parameters including the effective and noneffective marker distances and generation time. For this population, marker and quantitative trait locus (QTL) genotypes were generated using either a single linkage group or multiple linkage group model. Single nucleotide polymorphism (SNP) was simulated for an entire bovine genome (except for the sex chromosome, n = 29) including linkage and recombination. Individuals drawn from the simulated population with specified marker and QTL genotypes were randomly mated to establish appropriate levels of linkage disequilibrium for ten generations. Phenotype and genomic SNP data sets were obtained from individuals starting after two generations. Genetic prediction was accomplished by statistically modeling the genomic relationship matrix and standard BLUP methods. The effect of the number of linkage groups was also investigated to determine its influence on the accuracy of breeding values for genomic selection. When using high density scan data (0.08 cM marker distance), accuracies of breeding values on juveniles were obtained of 0.60 and 0.82, for a low heritable trait (0.10) and high heritable trait (0.50), respectively, in the single linkage group model. Estimates of 0.38 and 0.60 were obtained for the same cases in the multiple linkage group models. Unexpectedly, use of BLUP regression methods across many chromosomes was found to give rise to reduced accuracy in breeding value determination. The reasons for this remain a target for further research, but the role of Mendelian sampling may play a fundamental role in producing this effect.

Gene Location for "Gamadiness" in Rice(Oryza sativa L.) (벼 "Gamadiness"특성의 유전분석)

  • Shrestha,, G.L.;M. H. Heu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.29 no.2
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    • pp.128-135
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    • 1984
  • Gamadi, a native rice cultivar from Nepal in which the panicle remains enclosed within its flag leaf sheath upto maturity, was crossed with different genetic marker testers of 12 linkage groups in order to analyze its linkage relationship. The results obtained from the experiment were summarized as follows: Normal segregations of all the genetic marker genes used in this experiment viz Cl, wx and Pla of linkage group I, Pn, Rd and Pub of linkage group III, and lg, g, Ps, gh, Hla, la, nl, bl, be and gl of linkage groups II, IV, V, VI, VII, VIII, IX, X, XI, and XII respectively confirmed the previous results, and also strongly indicated that the genetic constituent of the Gamadi and marker testers is same. 'Gamadiness' (the panicle enclosing character) was controlled by two complementary dominant genes with the segregation ratio of 9 Gamadi to 7 normal panicle-exserting types. These genes have been temporarily proposed as G-a and G-b for gamadiness. G-a gene was found to be linked with the neckleaf gene (nl) of linkage group Ⅸ with the crossover value of 0.3733$\pm$0.027. G-b gene appeared to be associated with the brittle culm gene (bc) of the linkage group XI with the crossover value of 0.2725$\pm$0.061.TEX>0.061.

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Linkage Group Analysis of Profenofos Resistance in the Housefly(Diptera: Mucsidae) (Profenofos에 대한 집파리(Musca domestica L.) 저항성 유전자의 연쇄군 해석)

  • 박정규;정야준부;안용준
    • Korean journal of applied entomology
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    • v.35 no.2
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    • pp.159-163
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    • 1996
  • The profenofos-resistant P-Pro strain of house fly (Muscn domestica L.) was derived from the pyraclofos-resistant strain by selecting with profenofos for 7 generations. The resistance was shown to be incompletely dominant by the reciprocal crosses between the resistant and susceptible strains. Linkage group analysis for the dominant factor responsible for this resistance was carried out by the F, male-backcross method, using susceptible multi-chromosomal marker strain. The major factors for profenofos resistance were located on the second and the fifth chromosome and the other chromosomes had a little effect on the development of this resistance. The male determining factor (M) was linked to the third chromosome in this strain.

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QTL analysis of agronomic traits in recombinant inbred lines of sunflower under partial irrigation

  • Haddadi, P.;Yazdi-Samadi, B.;Naghavi, M.R.;Kalantari, A.;Maury, P.;Sarrafi, A.
    • Plant Biotechnology Reports
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    • v.5 no.2
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    • pp.135-146
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    • 2011
  • The objective of the present research was to map QTLs associated with agronomic traits such as days from sowing to flowering, plant height, yield and leaf-related traits in a population of recombinant inbred lines (RILs) of sunflower (Helianthus annuus). Two field experiments were conducted with well-irrigated and partially irrigated conditions in randomized complete block design with three replications. A map with 304 AFLP and 191 SSR markers with a mean density of 1 marker per 3.7 cM was used to identify QTLs related to the studied traits. The difference among RILs was significant for all studied traits in both conditions. Three to seven QTLs were found for each studied trait in both conditions. The percentage of phenotypic variance ($R^2$) explained by QTLs ranged from 4 to 49%. Three to six QTLs were found for each yield-related trait in both conditions. The most important QTL for grain yield per plant on linkage group 13 (GYP-P-13-1) under partial-irrigated condition controls 49% of phenotypic variance ($R^2$). The most important QTL for 1,000-grain weight (TGW-P-11-1) was identified on linkage group 11. Favorable alleles for this QTL come from RHA266. The major QTL for days from sowing to flowering (DSF-P-14-1) were observed on linkage group 14 and explained 38% of the phenotypic variance. The positive alleles for this QTL come from RHA266. The major QTL for HD (HD-P-13-1) was also identified on linkage group 13 and explained 37% of the phenotypic variance. Both parents (PAC2 and RHA266) contributed to QTLs controlling leaf-related traits in both conditions. Common QTL for leaf area at flowering (LAF-P-12-1, LAF-W-12-1) was detected in linkage group 12. The results emphasise the importance of the role of linkage groups 2, 10 and 13 for studied traits. Genomic regions on the linkage groups 9 and 12 are specific for QTLs of leaf-related traits in sunflower.

Genetical Studies on the Non-molting Allele Mutation in Bombyx mori (새로운 돌연변이 불면잠의 유전학적 연구)

  • 노시갑;토정랑굉
    • Journal of Sericultural and Entomological Science
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    • v.33 no.2
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    • pp.72-74
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    • 1991
  • The recessive lethal mutation 'non-molting of Nho' (symbol, ㎚n) was founded on one preservation stocks. All dwarf larvae continued to eat a few mulberry leaves and very slightly increasing body-size over a 7 days, and then died without entering into molt. Linkage experiments showed that ㎚n was linked with Knob(K) on the 11th linkage group. Precise localization of the gene was performed by mating with ㎚ gene. This mutant was confirmed to be allelic with the ㎚ gene located on the same chromosome.

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Aspergillus niger에서 단백질분해효소 결함 돌연변이주의 제조 및 특성규명

  • Jeong, Heon Se;Chae, Suhn Kee;Park, Hee Moon;Maeng, Pil Jae;Kim, Jeong-Yoon
    • Microbiology and Biotechnology Letters
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    • v.25 no.4
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    • pp.379-385
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    • 1997
  • Several protease-deficient mutants of Aspergillus niger have been isolated by halo-screening on skim milk plate after UV irradiation of conidiospores. The extracellular proteolytic activities of the mutant strains grown in an optimized medium varied from 3% to 85% of that of the parental strain. Especially, two mutant strains named as ANPD-129 and ANPD-153, which had 3% and 49% of acid protease activity of the parental strain, respectively, were further characterized both physiologically and genetically. The growth rates of the mutants, ANPD-129 and ANPD-153, were similar to that of the parental strain, unlike other protease-deficient mutants. The diploid formed between the two mutants restored protease activity to a similar level of that of the parental strain. This result revealed that ANPD-129 and ANPD-153 had mutations at different loci. Using master strains with marked chromosomes these loci were assigned to linkage groups. The mutation locus (prt129) in ANPD-129 was assigned to linkage group VI and the locus (prt153) in ANPD-153 to linkage group III.

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QTL Mapping of Resistance to Gray Leaf Spot in Ryegrass: Consistency of QTL between Two Mapping Populations

  • Curley, J.;Chakraborty, N.;Chang, S.;Jung, G.
    • Asian Journal of Turfgrass Science
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    • v.22 no.1
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    • pp.85-100
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    • 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.

Cross Resistance of Cypermethrin-and Methomyl-Resistance and Linkage Group Analysis on Cypermethrin Resistance in House Fly(Musca domestica L.) (Cypermethrin과 Methomyl 저항성 집파리의 교처저항성과 Cypermethrin 저항성에 대한 연관군 분석)

  • Yoo, Ju;Park, Chung-Gyoo;Lee, Si-Woo;Choi, Byeong-Ryeol
    • Korean journal of applied entomology
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    • v.40 no.4
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    • pp.337-344
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    • 2001
  • The house fly (Musca domestica L.) strains were derived from the Yumenoshima III strain by selecting with cypermethrin and methomyl for 19 and 16 generations, respectively. The resulting strains, cypermethrin resistance strain (Cyp-R19) and methomyl resistance strain (Met-R16), showed high level of resistance by 12906 and 51 times, respectively, comparing with the susceptible SRS strain. The Cyp-R19 strain was resistant to synthetic pyrethroids such as deltamethrin, esfenvalerate, fenpropathrin, $\beta$-cyfluthrin, showing > 11000, 1231, 103, 292 times higher $LD_{50}$ values than the SRS strain, respectively. It was also resistant to 3 organophosphates and 2 carbamates such as fenitrothion, profenofos, pyridaphenthion, benfuracarb, methomyl, showing resistance ratios fo 51, 17, 49, 39 and 62 comparing to SRS strain. The Met-R16 strain was resistant to synthetic carbamate benfuracarb, showing 6 times higher $LD_{50}$ value than SRS strain. It was also resistant to 4 organophosphates such as acephate, fenitrothion, profenofos and pyridaphenthion, showing > 40, 103, 19, 60 times higher $LD_{50}$ value. It was also resistant to 5 pyrethroids and a pyrrole such as cypermethrin, deltamethrin, esfenvalerate, fenpropathrin, $\beta$-cyfluthrin and chlorfenapyr, showing 3030, 249, 4063, 34, 330 and 86 times higher $LD_{50}$ values than the SRS strain. Cyp-R14 strain which was selected for 14 generations by cypermethrin and developed 11014 times higher resistance to the SRS strain was used in the dominance and linkage group analysis. Cypermethrin resistance inheritance was incompletely dominant in house fly as judged by the reciprocal cross between the resistant and susceptible strains. The linkage group analysis for the major factors responsible for this resistance was carried out by the$ F_1$male-backcross method, using susceptible multi-chromosomal marker aabys strain. The major factors for cypermethrin resistance were located on the 1st, the 3rd and the 4th chromosomes, and the effect of the 3rd chromosome was most prominent.

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Identification of Quantitative Trait Loci for Resistance to Soybean Cyst Nematode Race 14 (콩시스트 선충 race14에 대한 저항성 유전자좌 구명)

  • Choi, In-Soo;Kim, Yong-Chul
    • Journal of Life Science
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    • v.13 no.4
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    • pp.375-382
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    • 2003
  • A direct and precise explanation of soybean resistance to soybean cyst nematode will be possible only when the individual gene(s) involved in the resistance are tagged. This study was conducted, (1) to identify and localize quantitative trait loci for resistance to soybean cyst nematode race 14 on RAPD map, (2) to identify the magnitude and mode of inheritance for each quantitative trait loci, and (3) to identify the best combinations of quantitative trait loci for resistance to soybean cyst nematode race 14. Thirty markers (29 RAPD and 1 RFLP) showed significant association with resistance to soybean cyst nematode race 14. From MAPMAKER/QTL analysis, we identified two regions (linkage group C-7 and linkage group C-9) for resistance to soybean cyst nematode .ace 14. The first quantitative trait loci that was localized at 6.0 cM from $H06^1$ on linkage group C-7 showed a dominant inheritance mode. However, we can not exclude the possibility of additive inheritance mode. The second quantitative trait loci that was localized between $B15^2$ and $E01^1$ on linkage group C-9 also showed a dominant mode of inheritance. One pair of flanking markers ($H06^1$ and $H06^2$) and B15$^2$ were used for multiple regression analysis. Marker combination that included 2 markers, $B15^2$ and $H06^1$, explained the highest total variance (22.9%) for resistance to soybean cyst nematode race 14. Further localization of genes for resistance to soybean cyst nematode race 14 and examination of interaction between quantitative trait loci will accelerate the exploitation of resistance to soybean cyst nematode.