Assessing genetic variability among Brazilian strains of Xanthomonas axonopodis pv. manihotis through restriction fragment length polymorphism and amplified fragment length polymorphism analyses

1999 ◽  
Vol 45 (9) ◽  
pp. 754-763 ◽  
Author(s):  
S. Restrepo ◽  
T.L. Valle ◽  
M.C. Duque ◽  
V. Verdier
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Genetic Variability ◽  
Restriction Fragment ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Xanthomonas Axonopodis ◽  
Restriction Fragment Length

Assessing genetic variability among Brazilian strains ofXanthomonas axonopodispv.manihotisthrough restriction fragment length polymorphism and amplified fragment length polymorphism analyses

1999 ◽  
Vol 45 (9) ◽  
pp. 754-763 ◽  
Author(s):  
S Restrepo ◽  
T L Valle ◽  
M C Duque ◽  
V Verdier
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Restriction Fragment Length Polymorphism ◽  
Restriction Fragment ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Bacterial Blight ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Restriction Fragment Length

Xanthomonas axonopodis pv.manihotis (Xam) causes bacterial blight, a major disease of cassava, which is a starchy root crop that feeds about 500 million people throughout the world. To better select resistant cassava germplasm, we examined the population structure of Xam in Brazil, Latin America's largest producer of cassava, and a major center of diversity for the crop. The 79 strains collected between 1941 and 1996 from three edaphoclimatic zones were analyzed by restriction fragment length polymorphism (RFLP), using a probe linked to a Xam pathogenicity gene (pthB). Thirty-eight haplotypes were identified, and geographical differentiation for the Xam strains was demonstrated. Strains from subtropical zone (ECZ 6) showed high genetic diversity in most of the sites from which they were collected. They also showed migration from site to site. RFLP and amplified fragment length polymorphism (AFLP) analyses were carried out on 37 Xam strains and compared; the AFLP assays were performed using eight primer combinations. A multiple correspondence analysis, used to assess genetic relatedness among strains and estimate genetic diversity, indicated that the Brazilian Xam population showed high diversity. No correlation was found between AFLP and RFLP data, but the two techniques provided complementary information on the genetic diversity of Xam. Most strains were highly aggressive on a susceptible cultivar. The genetic analysis presented here contributes to a better understanding of the Xam population structure in Brazil and will help select strains of the pathogen for screening cassava germplasm resistant to the disease.Key words: cassava bacterial blight, resistance, genetic diversity, molecular characterization.

An integrated restriction fragment length polymorphism - amplified fragment length polymorphism linkage map for cultivated sunflower

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Melaku Ayele Gedil ◽  
Crispin Wye ◽  
Simon Berry ◽  
Bart Segers ◽  
Johan Peleman ◽  
...  
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Restriction Fragment ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Aflp Markers ◽  
Rflp Markers ◽  
Linkage Groups ◽  
Restriction Fragment Length

Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflower (Helianthus annuus L.) using three independent sets of RFLP probes. The aim of this research was to integrate RFLP markers from two sets with RFLP markers for resistance gene candidate (RGC) and amplified fragment length polymorphism (AFLP) markers. Genomic DNA samples of HA370 and HA372, the parents of the F2 population used to build the map, were screened for AFLPs using 42 primer combinations and RFLPs using 136 cDNA probes (RFLP analyses were performed on DNA digested with EcoRI, HindIII, EcoRV, or DraI). The AFLP primers produced 446 polymorphic and 1101 monomorphic bands between HA370 and HA372. The integrated map was built by genotyping 296 AFLP and 104 RFLP markers on 180 HA370 × HA372 F2 progeny (the AFLP marker assays were performed using 18 primer combinations). The HA370 × HA372 map comprised 17 linkage groups, presumably corresponding to the 17 haploid chromosomes of sunflower, had a mean density of 3.3 cM, and was 1326 cM long. Six RGC RFLP loci were polymorphic and mapped to three linkage groups (LG8, LG13, and LG15). AFLP markers were densely clustered on several linkage groups, and presumably reside in centromeric regions where recombination is reduced and the ratio of genetic to physical distance is low. Strategies for targeting markers to euchromatic DNA need to be tested in sunflower. The HA370 × HA372 map integrated 14 of 17 linkage groups from two independent RFLP maps. Three linkage groups were devoid of RFLP markers from one of the two maps.Key words: amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), Helianthus, sunflower, genetic map.

Sign in / Sign up

Export Citation Format

Share Document