AFLP markers linked to resistance against Striga gesnerioides race 1 in cowpea (Vigna unguiculata)

Genome ◽  
2002 ◽  
Vol 45 (5) ◽  
pp. 787-793 ◽  
Author(s):  
Jeremy T Ouédraogo ◽  
Jean-Baptiste Tignegre ◽  
Michael P Timko ◽  
François J Belzile

Amplified fragment length polymorphism (AFLP) analysis was used in combination with bulked segregant analysis (BSA) to identify molecular markers linked to two cowpea (Vigna unguiculata (L.) Walp.) genes conferring resistance to Striga gesnerioides race 1. After AFLP analysis of an F2 population derived from a cross between the resistant cultivar Gorom and the susceptible cultivar Tvx 3236, seven AFLP markers were identified that are linked to Rsg3, the gene conferring race 1 resistance in 'Gorom'. The distances between these markers and Rsg3 ranged from 9.9 to 2.5 cM, with two markers, E-AGA/M-CTA460 and E-AGA/M-CAG300, flanking Rsg3 at 2.5 and 2.6 cM, respectively. Analysis of a second F2 population derived from the cross between 'Tvx 3236' and the resistant cultivar IT81D-994 identified five AFLP markers linked to the race 1 resistance gene 994-Rsg present in 'IT81D-994'. The two markers showing the tightest linkage to the994-Rsg locus were E-AAG/M-AAC450 and E-AAG/M-AAC150 at 2.1 and 2.0 cM, respectively. Two of the markers linked to 994-Rsg, E-AGA/M-CAG300 and E-AGA/M-CAG450, were also linked to Rsg3. The identification of molecular markers in common between the two sources of race 1 resistance suggests that either Striga resistance genes are clustered in these plants or that these loci are allelic. Mapping of the resistance loci within the cowpea genome revealed that three markers linked to Rsg3 and (or) 994-Rsg are located on linkage group 6.Key words: cowpea, AFLP markers, Striga resistance, bulked segregant analysis.

1997 ◽  
Vol 10 (9) ◽  
pp. 1035-1044 ◽  
Author(s):  
Takao Kasuga ◽  
Shanmukhaswami S. Salimath ◽  
Jinrui Shi ◽  
Mark Gijzen ◽  
Richard I. Buzzell ◽  
...  

The resistance of soybean to Phytophthora root and stem rot caused by Phytophthora sojae is conferred by a series of single-dominant Rps genes. We have applied random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) analyses to isolate molecular markers linked to Rps1-k. Five RAPD markers were identified and mapped closely to one side of Rps1-k. AFLP analysis was carried out with near isogenic lines and bulks obtained from F3 families. Twenty-seven markers were identified. Nineteen of these were specific to the resistant parent. Five AFLP markers were amplified from the susceptible parent. One of these markers, TC1, mapped at 0.07 centimorgans (cM) from the Rps1 locus. Three AFLP markers were co-dominant, and one of these, CG1, mapped at a distance of 0.06 cM from the Rps1 locus on the opposite side of the rest of the markers. Two RAPD, 17 AFLP, and 14 restriction fragment length polymorphism (RFLP) markers originating from duplicated sequences were mapped within a 3-cM map interval. These results suggest that Rps1-k is located at the end of an introgressed region. Physical mapping data indicate that the Rps1-k-flanking markers CG1 and TC1 may be located within a 125-kb chromosomal fragment.


2009 ◽  
Vol 7 (03) ◽  
pp. 244-251 ◽  
Author(s):  
Didiana Gálvez-López ◽  
Sanjuana Hernández-Delgado ◽  
Maurilio González-Paz ◽  
Enrique Noe Becerra-Leor ◽  
Miguel Salvador-Figueroa ◽  
...  

Genetic diversity and relationships among 112 mango (Mangifera indica) plants native to 16 states of Mexico and four controls [three mango cultivars (Ataulfo, Manila and Tommy Atkins) and one accession ofMangifera odorata] were evaluated based on amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) molecular markers. Mango germplasm shows broad dispersion through Mexico and genetically similar germplasm from different agroecological regions has previously been found by our group. Both AFLP and SSR analyses indicated high genetic similarity among mango populations that were clustered in two major groups: mangos from Gulf of Mexico coastline and mangos from Pacific Ocean coastline and locations far away from the sea. The highest genetic diversity was found within plants from each state, and significant genetic differentiation (FST = 0.1921, AFLPs and 0.1911, SSRs) was also observed among mango populations based on geographical origin and genetic status (cultivars versus landraces). Heterozygosity values ranged from low (0.38) to moderate (0.68), and no heterozygote deficits were found. The highest genetic variability was found in mango populations from Tabasco, Michoacán and Oaxaca. Data suggested that mangoes are subjected to natural or induced pollination, so segregation as well as genetic recombination plays major roles on genetic diversification of Mexican mangos. AFLP analysis was more robust than SSR for determining the genetic relationships among mango landraces from Mexico.


2001 ◽  
Vol 102 (6-7) ◽  
pp. 1029-1036 ◽  
Author(s):  
J. T. Ouédraogo ◽  
V. Maheshwari ◽  
D. K. Berner ◽  
C.-A. St-Pierre ◽  
F. Belzile ◽  
...  

2005 ◽  
Vol 30 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Renata Silva-Mann ◽  
Maria G. G. Carvalho Vieira ◽  
José C. Machado ◽  
José Roberto Bernardino Filho ◽  
Kalinka C. C. Salgado ◽  
...  

Fungal diseases in cotton (Gossypium hirsutum), such as anthracnose caused by Colletotrichum gossypii and ramulose caused by C. gossypii var. cephalosporioides, are responsible for large yield losses. These pathogens are seed borne and morphologically similar although they induce different symptoms, which can lead to misdiagnosis using the blotter testing method. The present study was carried out to assess the viability of using Amplified Fragment Length Polymorphism (AFLP) markers to differentiate these pathogens. Five isolates, for each pathogen, were classified according to pathogenicity on cotton plants, and mycelial growth morphology. Conidial suspensions were sprayed on 30-day-old cotton plants and the symptoms assessed ten and 40 days after inoculation. For growth morphology 200 cottonseeds were inoculated with seven-day-old pure cultures, and the mycelial traits observed under a stereoscopic microscope seven days after inoculation. The DNA for AFLP analysis was obtained from seven-day-old fungal mycelia grown in liquid medium, using the Dneasy Qiagen protocol. Using the AFLP technique 318 polymorphic bands were selected to estimate similarities using Dice's Coefficient. The results clearly distinguished between ramulose and anthracnose isolates, which agreed with morphological and pathogenicity testing.


HortScience ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 32-34 ◽  
Author(s):  
Joseph N. Wolukau ◽  
Xiaohui Zhou ◽  
JinFeng Chen

Gummy stem blight (GSB) caused by the ascomycete fungus Didymella bryoniae (Auersw.) Rehm is an important disease of melon. Molecular markers linked to resistance would be useful for melon breeding programs. The amplified fragment length polymorphism (AFLP) technique and bulk segregant analysis were used to identify molecular markers linked to the resistance of melon to Didymella bryoniae. Segregation analysis of F2 progeny from a cross of PI 420145, a resistant line, and PI 136170, a susceptible line, showed that resistance to GSB was controlled by a dominant gene. One AFLP marker, E-TG/M-CTC200, was identified that is tightly linked to GSB resistance gene at a distance of 2.0 cM. To our best knowledge, this is the first report of AFLP markers linked to GSB resistance in melon. The identification of AFLP markers provides a step toward the use of marker-assisted selection and the characterization of the gene encoding resistance to GSB in melon.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 500a-500 ◽  
Author(s):  
K.M. Haymes ◽  
S.C. Hokanson ◽  
K. Salazar ◽  
J. Maas

The commercial strawberry (Fragaria × ananassa Duch.) is susceptible to red stele root rot caused by the fungus Phytophthora fragariae Hickman var. fragariae. Characteristics of the disease are the reddened steles and “rat tail” appearance of the roots. Infected plants are dwarfed, exhibit wilting, and eventually die. Red stele resistance in strawberries and virulence of P. fragariae behave according to the gene-for-gene system. Resistance genes and their corresponding avirulence genes have been identified by screening plant roots for infection. The goal of this international research project with CPRO-DLO, The Netherlands, is to develop highly specific molecular markers for various Rpf resistance genes (Rpf1, Rpf2, Rpf3, and Rpf6) that confer resistance against P. fragariae. Bulked Segregant Analysis was used to identify RAPD and AFLP markers putatively linked to P. fragariae resistance genes. The bulked DNAs representing subsets of three F1 populations that segregated monogenically for either resistance or susceptibility to P. fragariae. The map of these Rpf loci was generated using JoinMap®. The RAPD markers linked to the resistance genes are being converted into SCAR markers, while the AFLP markers will be used as probes for the detection of P. fragariae. The application of the molecular markers linked to resistance genes will have direct applicability to strawberry breeding programs. Marker-facilitated selection of these resistance genes would allow an efficient means in the screening and selection of plant material containing these genes and help in the pyramiding for resistance to P. fragariae. Genetic improvement of the strawberry by the ability to pyramid resistance genes will contribute to the productivity of the strawberry industry worldwide.


2019 ◽  
Vol 47 (3) ◽  
pp. 970-979 ◽  
Author(s):  
Jie CAO ◽  
Zhongcheng ZHOU ◽  
Junfan TU ◽  
Shuiyuan CHENG ◽  
Jinglei YAO ◽  
...  

In this study, the technologies of simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers were used to analyze the genetic diversity of 30 sand pear (Pyrus pyrifolia) ‘Nakai’ varieties. Ten pairs of SSR polymorphic primers were selected to amplify P. pyrifolia ‘Nakai’ varieties. A total of 90 alleles were detected. The polymorphism information content index was between 0.5578 and 0.8423, with an average of 0.7585. The selected 10 pairs of AFLP primer combinations were used to amplify the analyzed pear varieties, and 1,046 polymorphic loci were detected. The average amplification results of each primer combination detected 105 bands with an average polymorphism percentage of 86.46%. The combined data of SSR and AFLP analysis showed that the analyzed P. pyrifolia ‘Nakai’ varieties were characterized by extremely rich genetic diversity and were highly representative. According to the results of SSR, AFLP, and SSR+AFLP cluster analysis, the analyzed P. pyrifolia ‘Nakai’ varieties can be categorized into three clusters. The results of genetic structure showed that the hybridization between these P. pyrifolia ‘Nakai’ varieties resulted in the heterozygosity of genotypes. In addition, we found that ‘Nijisseik’, ‘Ejima’, and ‘Fuli’ are good parent resources among the pear varieties through observing the genetic background of the analyzed pear varieties. This study reveals the genetic diversity levels of P. pyrifolia ‘Nakai’ varieties at the molecular level, which was important in molecular identification and protection of pear germplasm resources, as well as pear variety breeding and genetic improvement.


2002 ◽  
Vol 127 (4) ◽  
pp. 623-627 ◽  
Author(s):  
Margaret R. Pooler ◽  
Louise G.H. Riedel ◽  
S.E. Bentz ◽  
A.M. Townsend

Controlled pollinations were made between five hemlock (Tsuga) species from eastern North America and Asia, resulting in over 5700 germinating seedlings. A subset of putative hybrid seedlings from each cross was tested for authenticity by various DNA marker systems. The most reliable and useful system for verifying hybrids was amplified fragment-length polymorphism (AFLP) markers. Hybridizations between the eastern North American species, T. canadensis [L.] Carriere and T. caroliniana Engelm., and the Asian species, T. chinensis (Franch.) E. Pritz., were used as a model to test the inheritance, reliability, and ease of use of these markers. Using AFLP markers, we were able to verify 58 hybrids between T. caroliniana and T. chinensis, one hybrid between T. caroliniana and T. canadensis, but could find no definitive hybrids between T. canadensis and T. chinensis. Results using other marker systems, including RAPD, SCAR, ITS, and SSR, are also presented.


Genome ◽  
2004 ◽  
Vol 47 (3) ◽  
pp. 469-474 ◽  
Author(s):  
K Matsui ◽  
Y Kiryu ◽  
T Komatsuda ◽  
N Kurauchi ◽  
T Ohtani ◽  
...  

Shattering habit in buckwheat has two forms: brittle pedicel and weak pedicel. Brittle pedicel is observed in wild buckwheat, but not in cultivated buckwheat. Brittle pedicel in buckwheat is produced by two complementary, dominant genes, Sht1 and Sht2. The sht1 locus is linked to the S locus; almost all common buckwheat cultivars possess the allele sht1. To detect molecular makers linked to the sht1 locus, we used amplified fragment-length polymorphism (AFLP) analysis in combination with bulked segregant analysis of segregating progeny of a cross between a non-brittle common buckwheat and a brittle self-compatible buckwheat line. We screened 312 primer combinations and constructed a linkage map around the sht1 locus by using 102 F2 plants. Five AFLP markers were linked to the sht1 locus. Two of these, e54m58/610 and e55m46/320, cosegregated with the sht1 locus without recombination. The two AFLP markers were converted to STS markers according to the sequence of the AFLPs. The STS markers are useful for marker-assisted selection of non-brittle pedicel plants and provides a stepping-stone for map-based cloning and characterization of the gene encoding non-brittle pedicel.Key words: Fagopyrum esculentum, brittle pedicel, self-compatibility, bulked segregant analysis.


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