• The Plant Pathology Journal
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• 제38권6호
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• pp.572-582
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• 2022

Sheath blight disease caused by the necrotrophic, soilborne pathogen Rhizoctonia solani Kuhn, is the global threat to rice production. Lack of reliable stable resistance sources in rice germplasm pool for sheath blight has made resistance breeding a very difficult task. In the current study, 101 rice landraces were screened against R. solani under artificial epiphytotics and identified six moderately resistant landraces, Jigguvaratiga, Honasu, Jeer Sali, Jeeraga-2, BiliKagga, and Medini Sannabatta with relative lesion height (RLH) range of 21-30%. Landrace Jigguvaratiga with consistent and better level of resistance (21% RLH) than resistant check Tetep (RLH 28%) was used to develop mapping population. DNA markers associated with ShB resistance were identified in F₂ mapping population developed from Jigguvaratiga × BPT5204 (susceptible variety) using bulk segregant analysis. Among 56 parental polymorphic markers, RM5556, RM6208, and RM7 were polymorphic between the bulks. Single marker analysis indicated the significant association of ShB with RM5556 and RM6208 with phenotypic variance (R²) of 28.29 and 20.06%, respectively. Co-segregation analysis confirmed the strong association of RM5556 and RM6208 located on chromosome 8 for ShB trait. This is the first report on association of RM6208 marker for ShB resistance. In silico analysis revealed that RM6208 loci resides the stearoyl ACP desaturases protein, which is involved in defense mechanism against plant pathogens. RM5556 loci resides a protein, with unknown function. The putative candidate genes or quantitative trait locus harbouring at the marker interval of RM5556 and RM6208 can be further used to develop ShB resistant varieties using molecular breeding approaches.

• 한국작물학회지
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• 제49권5호
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• pp.429-433
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• 2004

A single recessive gene, rxp, controls the bacterial leaf pustule (BLP) resistance in soybean and in our previous article, it has been mapped on linkage group (LG) D2 of molecular genetic map of soybean. A total of 130 recombinant inbred lines (RILs) from a cross between BLP-resistant SS2-2 and BLP-susceptible Jangyeobkong were used to identify molecular markers linked to rxp. Fifteen simple sequence repeat (SSR) markers on LG D2 were screened to construct a genetic map of rxp locus. Only four SSR markers, Satt135, Satt372, Satt448, and Satt486, showed parental polymorphisms. Using these markers, genetic scaffold map was constructed covering 26.2cM. Based on the single analysis of variance, Satt372 among these four SSR markers was the most significantly associated with the resistance to BLP. To develop new amplified fragment length polymorphism (AFLP) marker linked to the resistance gene, bulked segregant analysis (BSA) was employed. Resistance and susceptible bulks were made by pooling equal amount of genomic DNAs from ten of each in the segregating population. A total of 192 primer combinations were used to identify specific bands to the resistance, selecting three putative AFLP markers. These AFLP markers produced the fragment present in SS2-2 and the resistant bulk, and not in Jangyeobkong and the susceptible bulk. Linkage analysis revealed that McctEact97 $(P=0.0004,\;R^2=14.67\%)$ was more significant than Satt372, previously reported as the most closely linked marker.

• Plant Biotechnology Reports
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• 제4권1호
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• pp.95-99
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• 2010

Decamer RAPD primers were tested on dioeceious and hermaphrodite plants of Commiphora wightii to identify sex-specific molecular markers. Sixty different random decamer primers were screened out of which only three primers were found to be associated with sex expression. A ~1,280-bp fragment from the primer OPN06 was found to be present in all the female individuals. Another primer OPN 16 produced a unique ~400-bp amplification product in only hermaphrodite individuals. The third marker, OPA20 amplified a ~1,140-bp fragment from female and hermaphrodite DNAs, but failed to do so from the male plant DNAs.

• Molecules and Cells
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• 제25권2호
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• pp.205-210
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• 2008

To develop molecular markers linked to the $L^4$ locus conferring resistance to tobamovirus pathotypes in pepper plants, we performed AFLP with 512 primer combinations for susceptible (S pool) and resistant (R pool) DNA bulks against pathotype 1.2 of pepper mild mottle virus. Each bulk was made by pooling the DNA of five homozygous individuals from a T10 population, which was a near-isogenic $BC_4F_2$ generation for the $L^4$ locus. A total of 19 primer pairs produced scorable bands in the R pool. Further screening with these primer pairs was done on DNA bulks from T102, a $BC_{10}F_2$ derived from T10 by back crossing. Three AFLP markers were finally selected and designated L4-a, L4-b and L4-c. L4-a and L4-c each underwent one recombination event, whereas no recombination for L4-b was seen in 20 individuals of each DNA bulk. Linkage analysis of these markers in 112 $F_2$ T102 individuals showed that they were each within 2.5 cM of the $L^4$ locus. L4-b was successfully converted into a simple 340-bp SCAR marker, designated L4SC340, which mapped 1.8 cM from the $L^4$ locus in T102 and 0.9 cM in another $BC_{10}F_2$ population, T101. We believe that this newly characterized marker will improve selection of tobamovirus resistance in pepper plants by reducing breeding cost and time.

• 한국작물학회지
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• 제52권1호
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• pp.12-16
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• 2007

To facilitate breeding of lines with either the Ppd-D1a or ppd-d1a, we screened 342 $F_2$ progenies from a cross between Laura (photoperiod insensitive, Ppd-D1a) spring wheat and SWP5304 (photoperiod sensitive, ppd-d1a) for their time to heading under 10 hour day length, and with a set of 37 microsatellite primers previously mapped to chromosome 2D. Bulk segregant analysis was used to identify tow linked microsatellite loci. The Ppd-D1a locus was flanked by Xgwm484 with 13.7 cM distance and Xgwm455 with 27 cM. These markers may be useful in selection of the desired photoperiod sensitivity in segregating populations grown in Northern latitude.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.25-25
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• 2017

Inflorescence architecture mainly contributes to final grain yield in crops. Sorghum inflorescence is basically composed of one fertile sessile spikelet (SS) and two infertile pedicellate spikelets (PS). To identify regulatory factors involved in the inflorescence architecture, we screened an EMS mutagenesis population from the pedigreed sorghum mutant library. We found inflorescent architecture mutants, named as multi-seed mutants, msd, with gained fertile ability in PS and also an increased number of floral branches. In natural sorghum populations, it is not common that are fertile. A detailed dissection of developmental stages of wild type and msd1 mutant described that the PS in wild type do not have floral organs, including ovary, stigma, filament and anther, while the msd1 mutants generate intact floral organ in the sessile spikelet. We found MSD1 encoded a TCP transcription factor using bulk segregant analysis (BSA) of F2 population, and was a strongly enriched expression during inflorescence developmental stages. We proposed that MSD1 functions to suppress floral organ maintenance at PS during inflorescence development in Sorghum. To explore the regulatory network associated with PS fertility, whole genome expression profiling was performed at 4 different developmental stages in 6 various tissue types between wild type and msd1. Taken together, we demonstrated that MSD1 was involved in the plant hormone and maybe influenced program cell death in PS via the activation of plant hormonal pathway.

• 한국육종학회지
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• 제50권4호
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• pp.387-395
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• 2018

다산 등 15개의 통일형 벼 품종을 이용하여 mesotrione을 처리한 후 5일부터 다산 등 13개 품종들은 신엽에서 백화현상이 발생하였으나, 밀양154호와 수원382호는 백화현상이 발생하지 않아 저항성 품종으로 선발되었다. Mesotrione 처리 후 다산 등 13개 품종들의 초장 및 건물중 억제율은 밀양154호와 수원382호보다 더 높았으며 약량에 따른 억제율이 증가하였다. 한아름2호/밀양154호의 $F_2$ 집단을 이용한 유전분석 결과 저항성이 149개체, 감수성이 41개체로 이론적 분리비 3:1($X^2=1.19$, P=0.31)에 적합하여, mesotrione 저항성 관련 유전자는 1개의 우성유전자에 지배되는 것으로 나타났다. BSA방법을 이용하여 mesotrione 저항성 관련 유전자를 탐색한 결과, 2번 염색체의 10.2 Mb에 위치한 SSR marker RM1358과 RM3501을 선발하였다. Fine mapping을 위해 선발된 5개의 저항성 개체 중에서 $F_2-137$은 RM12921부터 RM3501까지 재조환이 일어났고, $F_2-76$은 RM324부터 RM5101까지 재조환이 일어났다. 따라서, mesotrione 저항성 관련 유전자는 RM3501과 RM324 사이인 10.2 Mb~11.4 Mb에 존재하며, RM3501과 RM324의 조환률이 각각 0.53%과 2.65%이므로, RM3501을 mesotrione저항성 유전자 DNA 연관 marker로 선발하였다. 다산 등 20개 통일형 품종 및 mesotrione에 저항성을 나타내는 자포니카 품종인 운광과 감수성인 통일형 한아름의 $BC_2F_2$ 집단을 이용하여 RM3501의 MAS 이용 가능성을 검토한 결과, mesotrione 저항성 선발 marker로 활용은 가능하나, 정확한 선발 maker로 활용하기 위해서는 추가적인 실험이 필요할 것으로 판단된다.