Molecular mapping of a new gene for resistance to frogeye leaf spot of soya bean in 'Peking'

Amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeat, SSR) techniques were used to map the _RGSp_eking gene, which is resistant to most isolates of Cercospora sojina in the soya bean cultivar ‘Peking’. The mapping was conducted using a defined F₂ population derived from the cross of ‘Peking’(resistant) בLee’(susceptible). Of 64 EcoRI and MseI primer combinations, 30 produced polymorphisms between the two parents. The F₂ population, consisting of 116 individuals, was screened with the 30 AFLP primer pairs and three mapped SSR markers to detect markers possibly linked to Rcs_Peking. One AFLP marker amplified by primer pair E‐AAC/M‐CTA and one SSR marker Satt244 were identified to be linked to Res_Peking. The gene was located within a 2.1‐cM interval between markers AACCTA178 and Satt244, 1.1 cM from Satt244 and 1.0 cM from AACCTA178. Since the SSR markers Satt244 and Satt431 have been mapped to molecular linkage group (LG) J of soya bean, the Res_Peking resistance gene was putatively located on the LG J. This will provide soya bean breeders an opportunity to use these markers for marker‐assisted selection for frogeye leaf spot resistance in soya bean.     

Molecular markers linked to rhizomania resistance in sugar beet, Beta vulgaris, from two different sources map to the same linkage group

Rhizomania, one of the most important diseases of sugar beet, is caused by beet necrotic yellow vein virus, a Furovirus vectored by the fungus Polymyxa betae Keskin. Reduction of the production losses caused by this disease can only be achieved by using tolerant cultivars. The objective of this study was the identification and mapping of random amplified polymorphic DNA (RAPD) markers linked to a rhizomania resistance gene. The RAPD markers were identified using bulked segregant analysis in a segregating population of 62 individuals derived by intercrossing plants of the resistant commercial hybrid GOLF, and the resistance locus was positioned in a molecular marker linkage map made with a different population of 50 GOLF plants. The resistance locus, Rr1, was mapped to linkage group III of our map of Beta vulgaris L. ssp. vulgaris, which consisted of 76 RAPDs, 20 restriction fragment length polymorphisms (RFLPs), three sequence characterized amplified regions (SCARs) and one sequence tagged site (STS). In total, 101 molecular markers were mapped over 14 linkage groups which spanned 688.4 cM with an average interval length of 8.0 cM. In the combined map, Rr1 proved to be flanked by the RAPD loci RA411₁₈₀₀ and AS7₁₁₀₀ at 9.5 and 18.5cM, respectively. Moreover, in our I₂ population, we found that a set of markers shown by Barzen et al. (1997) to be linked to the ‘Holly’ type resistance gene was also linked to the ‘GOLF’-type resistance gene. These results appeared to indicate that the rhizomania resistance gene present in the GOLF hybrid could be the same gene underlying resistance in ‘Holly’-based resistant genotypes. Two other explanations could be applied: first, that two different alleles at the same locus could have been selected; second, that two different genes at two different but clustered loci underwent the selection process.     

Mapping of Re,a gene conferring the red leaf trait in ornamental kale (Brassica oleracea L. var. acephala)

Variegated leaf colour is an important agronomic trait that affects the market value of ornamental kale (Brassica oleracea L. var. acephala). The red leaf phenotype in kale is due to anthocyanin accumulation. To investigate the pattern of inheritance of this trait, we constructed an F₂ population by crossing ‘Y005‐15’, a double haploid with red leaves, with a white‐leaved double haploid, ‘Y011‐13‐38’, followed by self‐pollination. An F₂ population consisting of 4284 individuals was used to study the inheritance of this trait, which showed that the character was controlled by a dominate gene. All of the 1050 white leaf trait plants in the F₂ were used for mapping and developing markers linked to Re gene. Results showed that Re was mapped to a locus on linkage group C09 of Brassica oleracea, and the locus was mapped between six SSR markers (C9Z1, C9Z16‐1, C9Z90, C9Z94, C9Z96 and C9Z99), with a genetic distance of 6.7, 1.0, 0.3, 2.0, 2.1 and 0.4 cM from Re gene, respectively. These results may facilitate marker‐assisted selection of the red leaf trait in kale breeding as well as map‐based cloning of the red leaf trait gene.     

Development of molecular linkage maps in sweet potato (Ipomoea batatas L.) using sequence‐related amplified polymorphism markers

Sweet potato is an important food crop with high starch content. It is a hexaploid species, for which the chromosomes have not yet been well characterized. In this study, we used 856 SRAP primer pairs to analyse the 240 individuals from a mapping population, which were derived from a hybrid F₁ generation of ‘Luoxushu 8’ (female) and ‘Zhengshu 20’ (male). Genetic linkage maps of the two parents were constructed. In the female parent (‘Luoxushu 8’), the linkage map consisted of 1391 markers, and the length of the linkage map was estimated to be 10,188.4 cM with an average distance of 7.17 cM between markers. In the male parent (‘Zhengshu 20’), the final linkage map consisted of 1,112 markers, and the estimated length of the map was 9,165.17 cM with an average distance of 8.40 cM between markers. Our results provide a basis for the detailed characterization of sweet potato chromosome sequences and the development of related molecular markers.     

Male and female genetic linkage map of hops, Humulus lupulus

A male and female linkage map of hop has been constructed using 224 DNA polymorphisms (106 amplified fragment length polymorphisms (AFLPs), three random amplified polymorphic DNAs (RAPDs), one RAPD‐sequence‐tagged‐site (STS), and three microsatellite (STSs) segregating in an F₁ population of the English cultivar ‘Wye Target’‐the German male breeding line ‘85/54/15’. Linkage between these loci was estimated using JOINMAP Version 2.0. The final map for the female parent consisted of 110 loci assigned to eight linkage groups covering a distance of 346.7 cM. For the male map, 57 loci could be mapped on nine linkage groups spanning over 227.4 cM. One of these male linkage groups (Gr09‐M) presumably represents the Y chromosome, since all markers assigned (10 AFLPs, three RAPDs and one STS) were closely linked to the male sex (M). Because of their sex‐specific segregation, 10 doubly heterozygous AFLPs spanning a distance of 18.7 cM could be identified as markers describing the X chromosome, which is part of the male and female map. Three STMSs, which had already proved useful in hop genotyping, could be integrated as codominant locus‐specific markers and thus allowed to produce reliable allelic bridges between the female and male counterparts.     

Genetic linkage map construction for white jute (Corchorus capsularis L.) using SRAP,ISSR and RAPD markers

White jute (Corchorus capsularis) and dark jute (Corchorus olitorius) are two important cultivated crops that are used for natural fibre production. Some genetic maps have been developed for dark jute, but the genetic map information for white jute (C. capsularis) is limited. In this study, a linkage map comprising 44 sequence‐related amplified polymorphisms (SRAPs), 57 intersimple sequence repeats (ISSRs) and 18 randomly amplified polymorphic DNA (RAPD) covering 2185.7 cM with a mean density of 18.7 cM per locus was constructed in an F₂ population consisting of 185 individuals derived from a cross between two diverse genotypes of ‘Xinxuan No. 1’ and ‘Qiongyueqing’ in white jute. These markers were evenly distributed in the linkage groups without any clustering. This genetic linkage map construction will facilitate the mapping of agronomic traits and marker‐assisted selection breeding in white jute.     

Investigation and genetic mapping of a Glomerella leaf spot resistance locus in apple

Apple Glomerella leaf spot (GLS) is a severe fungal disease that damages apple leaves during the summer in China. Breeding new apple varieties that are resistant to the disease is considered the best way of controlling GLS. Fine mapping and tightly linked marker are critically essential for the preselection of resistant seedlings. In this study, a population of 207 F₁ individuals derived from a cross between ‘Golden Delicious’ and ‘Fuji’ was used to construct a fine simple sequence repeat (SSR)‐based genetic linkage map. The position of R_gls, a locus responsible for resistance to GLS, was identified on apple linkage group (LG) 15 using SSR markers CH05g05 and CH01d08, which was adapted from a published set of 300 SSR markers that were developed using the bulked segregant analysis (BSA) method. These two SSR markers flanked the gene, and its recombination rate was 8.7% and 23.2%, respectively. A total of 276 newly developed SSR markers around the target region and designed from the genome apple assembly contig of LG15 were screened. Only nine of these were determined to be linked to the R_gls locus. Thus, a total of 11 SSR markers were in linkage with R_gls, and mapped at distances ranging from 0.5 to 33.8 cM. The closest marker to the R_gls locus was S0405127, which showed a genetic distance of approximately 0.5 cM. The first mapping of the gene R_gls was constructed, and the locations of the 11 effective primers in the ‘Golden Delicious’ apple genome sequence were anchored. This result facilitates better understanding of the molecular mechanisms underlying the trait of resistance to GLS and could be used in improving the breeding efficiency of GLS‐resistant apple varieties.     

‘新世纪梨’ב崇化大梨’F1代分子遗传连锁图谱的构建

研究目的在于为以后控制重要农艺性状的QTL定位、梨分子标记辅助育种及品种改良提供基础理论。利用‘新世纪梨’ב崇化大梨’杂交得到的210 株F1代实生苗为作图群体,对分离群体进行了ISSR、SRAP、SSR 标记的多态性检测,共得到154 条多态性条带,其中偏离孟德尔遗传比例的含21.4%(P＜0.01)。应用JoinMap 4.0 软件对154 个多态性条带进行遗传连锁分析,构建了一张包括9 个SSR标记,79个SRAP标记,8个ISSR标记,合计96个标记分属于14个连锁群的遗传图谱,图谱总长度为1530 cM,平均图距为16.1 cM,最大的连锁群含有64个标记,最小遗传距离小于0.1 cM。     

Quantitative trait loci mapping of seed colour,hairy leaf,seedling anthocyanin,leaf chlorosis and days to flowering in F2 population of Brassica rapa L.

A diversity arrays technology (DArT) map was constructed to identify quantitative trait loci (QTL) affecting seed colour, hairy leaf, seedling anthocyanin, leaf chlorosis and days to flowering in Brassica rapa using a F₂ population from a cross between two parents with contrasting traits. Two genes with dominant epistatic interaction were responsible for seed colour. One major dominant gene controls the hairy leaf trait. Seedling anthocyanin was controlled by a major single dominant gene. The parents did not exhibit leaf chlorosis; however, 32% F₂ plants showed leaf chlorosis in the population. A distorted segregation was observed for days to flowering in the F₂ population. A linkage map was constructed with 376 DArT markers distributed over 12 linkage groups covering 579.7 cM. The DArT markers were assigned on different chromosomes of B. rapa using B. rapa genome sequences and DArT consensus map of B. napus. Two QTL (RSC1‐2 and RSC12‐56) located on chromosome A8 and chromosome A9 were identified for seed colour, which explained 19.4% and 18.2% of the phenotypic variation, respectively. The seed colour marker located in the ortholog to Arabidopsis thaliana Transparent Testa2 (AtTT2). Two QTL RLH6‐0 and RLH9‐16 were identified for hairy leaf, which explained 31.6% and 20.7% phenotypic variation, respectively. A single QTL (RSAn‐12‐157) on chromosome A7, which explained 12.8% of phenotypic variation was detected for seedling anthocyanin. The seedling anthocyanin marker is found within the A. thaliana Transparent Testa12 (AtTT12) ortholog. A QTL (RLC6‐04) for leaf chlorosis was identified, which explained 55.3% of phenotypic variation. QTL for hairy leaf and leaf chlorosis were located 0–4 cM apart on the same chromosome A1. A single QTL (RDF‐10‐0) for days to flowering was identified, which explained 21.4% phenotypic variation.     

The first genetic linkage map of crape myrtle (Lagerstroemia) based on amplification fragment length polymorphisms and simple sequence repeats markers

Lagerstroemia (crape myrtle) are famous ornamental plants with large pyramidal racemes, long flower duration and diverse colours. Genetic maps provide an important genomic resource of basic and applied significance. A genetic linkage map was developed by genotyping 192 F₁ progeny from a cross between L. caudata (female) and L. indica (‘Xiang Xue Yun’) (male) with a combination of amplification fragment length polymorphisms (AFLP) and simple sequence repeats (SSR) markers in a double pseudo‐testcross mapping strategy. A total of 330 polymorphic loci consisting of 284 AFLPs and 46 SSRs showing Mendelian segregation were generated from 383 AFLP primer combinations and 150 SSR primers. The data were analysed using JoinMap 4.0 (evaluation version) to construct the linkage map. The map consisted of 20 linkage groups of 173 loci (160 AFLPs and 13 SSRs) covering 1162.1 cM with a mean distance of 10.69 cM between adjacent markers. The 20 linkage groups contained 2–49 loci and ranged in length from 7.38 to 163.57 cM. This map will serve as a framework for mapping QTLs and provide reference information for future molecular breeding work.     

Quantitative trait loci for leafhopper (Empoasca fabae and Empoasca kraemeri) resistance and seed weight in the common bean

A population of 108 common bean recombinant inbred lines (RILs) (F_5:6‐9), derived from a leafhopper (Empoasca fabae and E. kraemeri)‐susceptible cultivar (‘Berna’) and a leafhopper‐resistant line (EMP 419) was used to identify molecular markers genetically linked to leafhopper resistance and seed weight. Bulked segregant analysis and quantitative trait analysis identified eight markers that were associated with resistance to E. fabae, and four markers that were associated with E. kraemeri resistance. Three markers were associated with resistance to both species. A partial linkage map of the bean genome was constructed. Composite interval mapping identified quantitative trait loci (QTL) for resistance to both leaf hopper species on core‐map linkage groups B1, B3 and B7. QTL for seed weight were found close to the locus controlling testa colour and an α‐phaseolin gene.     

Construction of an integrated genetic map based on maternal and paternal lineages of tea (Camellia sinensis)

Genetic study on important traits of tea is difficult because of its self-incompatibility in nature. Moreover, development of a new variety usually needs more than 20 years, since it takes many years from seedling to matured plants for trait investigation. Genetic map is an essential tool for genetic study and breeding. In this study, we have developed an integrated genetic map of tea (Camellia sinensis) using a segregating F1 population derived from a cross between two commercial cultivars (‘TTES 19’ and ‘TTES 8’). A total of 574 polymorphic markers (including SSR, CAPS, STS, AFLP, ISSR and RAPD), 69 markers with highly significant levels of segregation distortion (P < 0.001) (12.0 %) were excluded from further analyses. Of the 505 mapped markers, there were 265 paternal markers (52.5 %), 163 maternal markers (32.3 %), 65 doubly heterozygous dominant markers (12.9 %), and 12 co-dominant markers (2.4 %). The co-dominant markers and doubly heterozygous dominant markers were used as bridge loci for the integration of the paternal and maternal maps. The integrated map comprised 367 linked markers, including 36 SSR, 3 CAPS, 1 STS, 250 AFLP, 13 ISSR and 64 RAPD that were assigned to 18 linkage groups. The linkage groups represented a total map length of 4482.9 cM with a map density of 12.2 cM. This genetic map has the highest genetic coverage so far, which could be applied to comparative mapping, QTL mapping and marker assisted selection in the future.     

A genetic linkage map of Spinacia oleracea and localization of a sex determination locus

A genetic map of Spinach (Spinacia oleracea) was constructed in a classical back cross population using 101 AFLP and 9 microsatellite markers. The map was divided into seven linkage groups with a total length of 585 cM and an average distance between the markers of 5.18 cM. The linkage map was constructed with LOD 3.5, but was quite stable with seven linkage groups remaining until LOD 7.0. Gender segregated 1 male to 1 female in the mapping population and was mapped to a small area of one linkage group with a distance of 1.9 cM to a microsatellite marker termed SO4. This small chromosomal region co-segregating with sex determination in the species is in contrast to previous reports on a heterologous XY chromosome system in spinach. Microsatellite markers used as anchors in the map construction were isolated from sequences of known nuclear encoded genes in spinach. This enabled simultaneous positioning on the map of these genes: Rubisco activase (Rca), Photosytem 1 subunit V (PsaG), Protein Kinase (Pk), Nitrate reductase (Nir), ferrodoxin:thioredoxin reductase (Ftr), Ribosomal protein L1 (Rps22), Choline monooxygenase (Cmo), Pseudogene for BZIP protein (Bzip), Glycerol-3-phosphate acyltransferase (Act1) and stromal ascorbate peroxidase, thylakoid-bound ascorbate peroxidase (Apx2). Spinach has a small genome, which makes it suitable for basic genomic studies and many physiologically important genes have been cloned from the species. The present map anchored with user friendly microsatellite markers will be useful for future studies of physiology and genetics of the species as well as studies of the nature of gender determination.     

An Extended Linkage Map of Sugar Beet (Beta vulgaris L.) Including Nine Putative Lethal Genes and the Restorer Gene X

An extended genetic map of sugar beet (Beta vulgaris L.) is presented encompassing 177 segregating markers (2 morphological traits, 7 isozymes, and 168 RFLP markers) on 9 linkage groups. The linkage map comprises 1057.3 cM equivalent to an average genetic spacing of 6.0 cM/marker. The length of individual linkage groups varies between 80.7 (group VIII) and 167.4 cM (group VIII). The number of markers per linkage group ranges between 13 and 24. No indication of duplicate regions was found, confirming the true diploid nature of B. vulgaris. Twenty-six markers (15 %) deviated significantly (a = 0.01) from the expected segregation ratio. This distorted segregation was probably caused by linkage with lethal genes. Four such genes (designated Let Ib, Let 5b, Let 6b, Let 8) could be located at discrete positions due to their absolute linkage to skewed RFLP markers. The restorer gene X has been located terminally on linkage group ÜI, 9.6 cM distant from RFLP marker pKP1238.     

A new citrus linkage map based on SRAP,SSR, ISSR,POGP, RGA and RAPD markers

Sequence-related amplified polymorphism (SRAP), simple sequence repeats (SSR), inter-simple sequence repeat (ISSR), peroxidase gene polymorphism (POGP), resistant gene analog (RGA), randomly amplified polymorphic DNA (RAPD), and a morphological marker, Alternaria brown spot resistance gene of citrus named as Cabsr caused by (Alternaria alternata f. sp. Citri) were used to establish genetic linkage map of citrus using a population of 164 F₁ individuals derived between ‘Clementine’ mandarin (Citrus reticulata Blanco ‘Clementine) and ‘Orlando’ tangelo’ (C. paradisi Macf. ‘Duncan’ × C. reticulata Blanco ‘Dancy’). A total of 609 markers, including 385 SRAP, 97 RAPD, 95 SSR, 18 ISSR, 12 POGP, and 2 RGA markers were used in linkage analysis. The ‘Clementine’ linkage map has 215 markers, comprising 144 testcross and 71 intercross markers placed in nine linkage groups. The ‘Clementine’ linkage map covered 858 cM with and average map distance of 3.5 cM between adjacent markers. The ‘Orlando’ linkage map has 189 markers, comprising 126 testcross and 61 intercross markers placed in nine linkage groups. The ‘Orlando’ linkage map covered 886 cM with an average map distance of 3.9 cM between adjacent markers. Segregation ratios for Cabsr were not significantly different from 1:1, suggesting that this trait is controlled by a single locus. This locus was placed in ‘Orlando’ linkage group 1. The new map has an improved distribution of markers along the linkage groups with fewer gaps. Combining different marker systems in linkage mapping studies may give better genome coverage due to their chromosomal target site differences, therefore fewer gaps in linkage groups.     

苦荞SSR分子遗传图谱的构建及分析

构建苦荞遗传连锁图谱,为今后有关苦荞基因组结构、重要农艺性状QTL定位、分子标记辅助育种和基因克隆等研究工作奠定基础。以栽培苦荞‘滇宁一号’和苦荞野生近缘种杂交产生的119份F4代分离材料为作图群体,利用SSR分子标记来构建苦荞的分子遗传连锁图谱。本研究构建的连锁图谱包含15个连锁群,由89个标记组成,其中偏分离的标记有22个,占24.7%,每条连锁群上的标记在2~16之间。连锁群长度在6.9~165.8 cM的范围,覆盖基因组860.2 cM,总平均长度9.7 cM。本研究构建了首张苦荞SSR遗传连锁图谱,为苦荞QTL定位、基因克隆、遗传选育等研究奠定了基础。     

Molecular mapping of two recessive genes controlling resistance to bacterial leaf pustule disease in soybean (Glycine max)

Bacterial leaf pustule (BLP) caused by Xanthomonas axonopodis pv. glycines (Xag) is a serious soybean disease. A BLP resistant genotype ‘TS-3’ was crossed with a BLP susceptible genotype ‘PK472’, and a segregating F₂ mapping population was developed for genetic analysis and mapping. The F₂ population segregation pattern in 15:1 susceptible/resistance ratio against Xag inoculum indicated that the resistance to BLP in ‘TS-3’ was governed by two recessive genes. A total of 12 SSR markers, five SSR markers located on chromosome 2 and seven SSR markers located on chromosome 6 were identified as linked to BLP resistance. One of the resistance loci (r1) was mapped with flanking SSR markers Sat_183 and BARCSOYSSR_02_1613 at a distance of 0.9 and 2.1 cM, respectively. Similarly, SSR markers BARCSOYSSR_06_0024 and BARCSOYSSR_06_0013 flanked the second locus (r2) at distances of 1.5 and 2.1 cM, respectively. The identified two recessive genes imparting resistance to BLP disease and the SSR markers tightly linked to these loci would serve as important genetic and molecular resources to develop BLP resistant genotypes in soybean.     

AFLP–SSR maps of maize × teosinte and maize × maize: comparison of map length and segregation distortion

Two genetic linkage maps of Zea mays were constructed: one population comprised 94 F₂ individuals of a dent ‘B64’ × teosinte (Z. mays ssp. huehuetenangensis) cross while the second consisted of 94 F₂ individuals of a ‘B64’ × Caribbean flint ‘Na4’ cross. The level of polymorphism was higher in the ‘B64’ × teosinte combination than the ‘B64’ × ‘Na4’ combination. In the ‘B64’ × teosinte cross, a total of 338 amplified fragment length polymorphism (AFLP) and 75 simple sequence repeat (SSR) markers were mapped to 10 chromosomes, which covered 1402.4 cM. In the ‘B64’ × ‘Na4’ cross, a total of 340 AFLP and 97 SSR markers were mapped to 10 chromosomes, covering 1662.8 cM. Segregation distortion regions were found on chromosomes 4, 5 and 8 in the ‘B64’ × teosinte cross and on chromosome 9 in the ‘B64’ × ‘Na4’ cross. Comparison of the two maps revealed that the maize × teosinte map was 11.5% shorter than the maize × maize map. The maps generated in this study may be useful to identify genes controlling flooding tolerance.     

Detection of linkage disequilibrium QTLs controlling low-temperature growth and metabolite accumulations in an admixed breeding population of <Emphasis Type="BoldItalic">Leymus</Emphasis> wildryes

Low-temperature soluble carbohydrate accumulations are commonly associated with anthocyanin coloration, attenuated growth, and cold adaptation of cool-season grasses. A total of 647 AFLP markers were tested for associations with anthocyanin coloration, tiller formation, leaf formation, cumulative leaf length, percent soluble carbohydrate, and dry matter regrowth among replicated clones of an admixed Leymus wildrye breeding population evaluated in low-temperature growth chambers. The admixed breeding population was derived from a heterogeneous population of L. cinereus × L. triticoides F₁ hybrids, with two additional generations of open pollination. Two AFLP linkage maps, constructed from two full-sib mapping populations derived from the same F₁ hybrid population, were integrated to produce a framework consensus map used to examine the distribution of marker-trait associations in the admixed F₁OP₂ population. Thirty-seven linkage blocks, spanning 258 cM (13.6%) of the 1895 cM consensus map, contained 119 (50%) of the 237 markers showing at least one possible trait association (P < 0.05). Moreover, 28 (68%) of the 41 most significant marker-trait associations (P < 0.005) were located in 15 QTL linkage blocks spanning 112.9 cM (6%) of the linkage map. The coincidence of these 28 significant marker-trait associations, and many less significant associations, in 15 relatively small linkage blocks (0.6 cM to 21.3 cM) provides evidence of admixture linkage disequilibrium QTLs (ALD QTLs) in this heterogeneous breeding population. At least four of the remaining 13 putative marker-trait associations (P < 0.005) were located in genetic map regions lacking other informative markers. The complexity of marker-trait associations results from heterogeneity within and substantial divergence among the parental accessions.     

Construction of a linkage map for quantitative trait loci associated with economically important traits in creeping bentgrass (Agrostis stolonifera L.)

Creeping bentgrass (Agrostis stolonifera L.) is the most widely cultivated and high-value turfgrass species. Genetic linkage maps of creeping bentgrass were constructed for quantitative trait loci (QTL) analysis of gray snow mold (Typhula incarnata) resistance, recovery and leaf width. A segregating population of 188 pseudo-F₂ progeny was developed by two-way pseudo-testcross mapping strategy. Amplified fragment length polymorphism, new developed Agrostis specific expressed sequence tag-single sequence repeat (SSR), random amplified polymorphic DNA and genomic SSR markers corresponding to DNA polymorphisms heterozygous in one parent and null in the other, were scored and placed on two separate genetic linkage maps, representing each parent. In the male parent map, 100 markers were mapped to 14 linkage groups covering a total length of 793?cM with an average interval of 8.2?cM. In the female parent map, 146 markers were clustered in another 14 linkage groups spanning 805?cM with an average distance of 5.9?cM between adjacent markers. We identified three putative QTL for leaf width and one QTL for snow mold disease resistance. The construction of a linkage map and QTL analysis are expected to facilitate the development of disease resistant creeping bentgrass cultivars by using molecular marker-assisted selection.