ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

AFLP analysis of African cassava (Manihot esculenta Crantz) germplasm resistant to the cassava mosaic disease (CMD) (2000)

Fregene, M. ; Bernal, A. ; Duque, M. ; [et al.]

Springer

Theoretical and applied genetics 100 (2000), S. 678-685

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Cassava ; AFLP ; Genetic distances ; QTL

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Amplified fragment length polymophism was assessed in 20 land races and nine elite lines of cassava from Africa, resistant and susceptible to the cassava mosaic disease (CMD). Eleven accessions from a representative core collection from Latin America, previously studied by AFLPs, were included as a reference. AFLP data from all accessions was analyzed by both the unweighted pair group mean average (UPGMA) and multiple cluster analysis (MCA) methods of analysis. Genetic differentiation between clusters and the coefficient of genetic differentiation was also calculated. Results reveal a genetic divergence between African and Latin American accessions, although some overlap was found between them. African land races resistant to CMD, were also found to be genetically differentiated from susceptible land races and from resistant elite lines. AFLP analysis identified a considerable number of duplicates in the African accessions, suggesting a sizeable percentage of redundancy. A unique AFLP fragment, found in a relatively high frequency in African accessions, but absent in the Latin American accessions, was found to be associated with branching pattern by QTL mapping in an F1 progeny derived from African and Latin American parents. The likely source and the utility of the unique AFLP fragment in understanding the processes of genetic divergence in Africa is discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220051339

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

2

Electronic Resource

Genetic mapping of resistance to bacterial blight disease in cassava (Manihot esculenta Crantz) (2000)

Jorge, V. ; Fregene, M. A. ; Duque, M. C. ; [et al.]

Springer

Theoretical and applied genetics 101 (2000), S. 865-872

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Bacterial blight ; Cassava ; Disease resistance ; Mapping QTLs

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Cassava bacterial blight (CBB), caused by Xanthomonas axonopodis pv. manihotis (Xam), is a major disease of cassava (Manihot esculenta Crantz) in Africa and South America. Planting resistant varieties is the preferred method of disease control. Recent genetic mapping of an F1 cross (TMS 30572 × CM 2177–2) led to the construction of the first molecular genetic map of cassava. To better understand the genetics of resistance to CBB, we evaluated individuals of the F1 cross for CBB resistance by controlled greenhouse inoculations and visually assessed symptoms on days 7, 15, and 30 days after inoculation, using a scale where 0 = no disease and 5 = maximum susceptibility. Five Xam strains were used: CIO-84, CIO-1, CIO-136, CIO-295, and ORST X-27. Area under the disease progress curve (AUDPC) was used as a quantitative measure of resistance in QTL analysis by single-marker regression. Based on the AUDPC values, eight QTLs (quantitative trait loci), located on linkage groups B, D, L, N, and X of the female-derived framework map, were found to explain 9–20% of the phenotypic variance of the crop’s response to the five Xam strains. With the male-derived framework map, four QTLs on linkage groups G and C explained 10.7–27.1% of the variance. A scheme to confirm the usefulness of these markers in evaluating segregating populations for resistance to CBB is proposed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220051554

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

3

Electronic Resource

AFLP analysis of relationships among cassava and other Manihot species (1997)

Roa, A. C. ; Maya, M. M. ; Duque, M. C. ; [et al.]

Springer

Theoretical and applied genetics 95 (1997), S. 741-750

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Cassava ; Manihot genus ; AFLP ; Genetic diversity ; Wild relatives of cassava

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Despite the worldwide importance of cultivated cassava (M. esculenta Crantz) its origin and taxonomic relationships with other species in the genus have not been clearly established. We evaluated a representative sample of the crop’s diversity and six wild taxa with AFLPs to estimate genetic relationships within the genus. Groupings of accessions of each species by data analysis corresponded largely with their previous taxonomic classifications. A mixed group, consisting of Manihot esculenta subsp. flabellifolia and M. esculenta subsp. peruviana, was most similar to cassava, while M. aesculifolia, M. brachyloba, and M. carthaginensis were more distant. Species-specific markers, which may be useful in germ-plasm classification or introgression studies, were suggested by the unique presence of AFLP products in samples of each of the three wild species. Heterogeneity of similarities among individuals of certain species suggested the existence of intraspecific gene pools, a hypothesis that was supported by morphological or ecogeographic evidence with varying degrees of success. Quantitative assessment of genetic diversity revealed greater homogeneity among cassava accessions than among itsclosest wild relatives. The demonstration of unique genetic diversity in the two M. esculenta subspecies and their genetic similarity to the crop supports the hypothesis that these materials may be the ancestors of cassava.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050620

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

4

Electronic Resource

Variability of chloroplast DNA and nuclear ribosomal DNA in cassava (Manihot esculenta Crantz) and its wild relatives (1994)

Fregene, M. A. ; Vargas, J. ; Ikea, J. ; [et al.]

Springer

Theoretical and applied genetics 89 (1994), S. 719-727

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Cassava ; Wild Manihot species Chloroplast DNA ; Nuclear ribosomal DNA ; Phylogeny

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Chloroplast DNA (cp) and nuclear ribosomal DNA (rDNA) variation was investigated in 45 accessions of cultivated and wild Manihot species. Ten independent mutations, 8 point mutations and 2 length mutations were identified, using eight restriction enzymes and 12 heterologous cpDNA probes from mungbean. Restriction fragment length polymorphism analysis defined nine distinct chloroplast types, three of which were found among the cultivated accessions and six among the wild species. Cladistic analysis of the cpDNA data using parsimony yielded a hypothetical phylogeny of lineages among the cpDNAs of cassava and its wild relatives that is congruent with morphological evolutionary differentiation in the genus. The results of our survey of cpDNA, together with rDNA restriction site change at the intergenic spacer region and rDNA repeat unit length variation (using rDNA cloned fragments from taro as probe), suggest that cassava might have arisen from the domestication of wild tuberous accessions of some Manihot species, followed by intensive selection. M. esculenta subspp flabellifolia is probably a wild progenitor. Introgressive hybridization with wild forms and pressures to adapt to the widely varying climates and topography in which cassava is found might have enhanced the crop's present day variability.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00223711

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

5

Electronic Resource

A molecular genetic map of cassava (Manihot esculenta Crantz) (1997)

Fregene, M. ; Angel, F. ; Gomez, R. ; [et al.]

Springer

Theoretical and applied genetics 95 (1997), S. 431-441

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Cassava ; Molecular markers ; Genetic mapping ; Polyploidy

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract A genetic linkage map of cassava has been constructed with 132 RFLPs, 30 RAPDs, 3 microsatellites, and 3 isoenzyme markers segregating from the heterozygous female parent of an intraspecific cross. The F1 cross was made between ‘TMS 30572’ and ‘CM 2177-2’, elite cassava cultivars from Nigeria and Colombia, respectively. The map consists of 20 linkage groups spanning 931.6 cM or an estimated 60% of the cassava genome. Average marker density is 1 per 7.9 cM. Since the mapping population is an F1 cross between heterozygous parents, with unique alleles segregating from either parent, a second map was constructed from the segregation of 107 RFLPs, 50 RAPDs, 1 microsatellite, and 1 isoenzyme marker from the male parent. Comparison of intervals in the male-and female-derived maps, bounded by markers heterozygous in both parents, revealed significantly less meiotic recombination in the gametes of the female than in the male parent. Six pairs of duplicated loci were detected by low-copy genomic and cDNA sequences used as probes. Efforts are underway to saturate the cassava map with additional markers, to join the male- and female-derived maps, and to elucidate genome organization in cassava.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050580

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

6

Electronic Resource

Towards an integrated linkage map of common bean. 4. Development of a core linkage map and alignment of RFLP maps (1998)

Freyre, R. ; Skroch, P. W. ; Geffroy, V. ; [et al.]

Springer

Theoretical and applied genetics 97 (1998), S. 847-856

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Phaseolus vulgaris L. ; Core linkage map ; RFLPs ; RAPDs

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Three RFLP maps, as well as several RAPD maps have been developed in common bean (Phaseolus vulgaris L.). In order to align these maps, a core linkage map was established in the recombinant inbred population BAT93×Jalo EEP558 (BJ). This map has a total length of 1226 cM and comprises 563 markers, including some 120 RFLP and 430 RAPD markers, in addition to a few isozyme and phenotypic marker loci. Among the RFLPs mapped were markers from the University of California, Davis (established in the F2 of the BJ cross), University of Paris-Orsay, and University of Florida maps. These shared markers allowed us to establish a correspondence between the linkage groups of these three RFLP linkage maps. In total, the general map location (i.e., the linkage group membership and approximate location within linkage groups) has been determined for some 1070 markers. Approaches to align this core map with other current or future maps are discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050964

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

7

Electronic Resource

Microsatellites in Cassava (Manihot esculenta Crantz): discovery, inheritance and variability (1998)

Chavarriaga-Aguirre, P. P. ; Maya, M. M. ; Bonierbale, M. W. ; [et al.]

Springer

Theoretical and applied genetics 97 (1998), S. 493-501

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Cassava ; Microsatellites ; Fluorescence-based genotyping ; Heterozygosity ; Linkage

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Fourteen microsatellites containing GA-repeats were isolated and characterized in cassava (Manihot esculenta Crantz, Euphorbiaceae). Microsatellite heterozygosity (h) was estimated in 48 accessions using (32P)-end-labeled primers and in more than 500 accessions using fluorescence-based genotyping. Heterozygosity values ranged from 0.00 to 0.88 and the number of alleles detected varied from 1 to 15. The reproducibility of allele sizing was also assessed using fluorescence-based genotyping. The average inter-gel size difference was 1.03 nucleotides. Chi-square tests (χ2) were performed to analyse segregation distortion and the linkage between alleles segregating from either or both parents in an F1 mapping population. Most microsatellite loci segregated in the expected 1 : 1, 1 : 2 : 1 or 1 : 1 : 1 : 1 ratio. Linkage was detected between loci segregating from either parent, and segregation distortion from the male parent was detected for locus GA-131. Approximately 80% of the microsatellites detected one or two alleles per accession, suggesting a low degree of microsatellite locus duplication, an unexpected finding for a putative allopolyploid, highly heterozygous species. The high h values of most microsatellites, their amplification in other Manihot taxa and their suitability for high-throughput, fluorescence-based genotyping, make microsatellites the marker of choice for germplasm characterization and saturation of the cassava map.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050922

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

8

Electronic Resource

AFLP Fingerprinting of Phaseolus lunatus L. and Related Wild Species from South America (1999)

Caicedo, A. L. ; Gaitán, E. ; Duque, M. C. ; [et al.]

Springer

Crop science 39 (1999), S. 1497-1507

add to mindlist on the mindlist

Details

ISSN: 1435-0653

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Phaseolus lunatus L.) and related species (P. augusti Harms, P. bolivianus Piper, P. pachyrrhizoides Harms, and P. rosei Piper) from South America and to identify specific genetic reserves for conservation. These relationships were investigated by means of amplified restriction fragment length polymorphism (AFLPs) on total genomic DNA. The 122 accessions formed a cluster that was distant from common bean (P. vulgaris L.), confirming earlier morphology and hybridology data. Two gene pools of wild Lima beans were confirmed. One was widely distributed in neotropical lowlands, while the other was restricted to the western Andes, in Ecuador and northern Peru. The study also revealed the existence of a third group of wild Lima bean distributed in the Departments of Boyacá and Cundinamarca, Columbia. The three species P. augusti, P. bolivianus, and P. pachyrrhizoides differed very little, certainly not sufficiently to merit a separate taxonomic ranking at the species level. The accessions could be grouped instead according to four geographic origins: Ecuador and northern Peru; and Bolivia and northwestern Argentina. Results from this study should result in a better selection of parental materials in breeding programs and point to areas where germplasm collections and conservation are needed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

9

Electronic Resource

Structure of Genetic Diversity among Common Bean Landraces of Middle American Origin Based on Correspondence Analysis of RAPD (2000)

Beebe, S. ; Skroch, P.W. ; Tohme, J. ; [et al.]

Springer

Crop science 40 (2000), S. 264-272

add to mindlist on the mindlist

Details

ISSN: 1435-0653

Source: Springer Online Journal Archives 1860-2000

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Phaseolus vulgaris L.) by correspondence analysis of random amplified polymorphic DNA (RAPD) data to determine the genetic structure of the Middle American gene pool of cultivated bean. One hundred eighty landraces originating in Mexico, the remainder in Central America and secondary centers of diversity within the Americas, and two checks were studied. DNA was extracted, RAPD reactions carried out, and polymorphic bands were scored as present or absent on the basis of 39 primers. Groups were formed which in part corresponded to races defined previously by morphological and agroecological criteria. However, tropical small-seeded Race M was composed of two groups: one largely Mexican that included most small-seeded black beans of upright plant habit; and one Central American with landraces of various seed colors. Most non-black small-seeded germplasm of Race M phenotype from secondary centers grouped with the Central American landraces, except for cream-seeded and purple-seeded accessions from Brazil. Races D and J could be distinguished and within races D and J further divisions could be recognized which were related to geographic origin. The more commercial Race D landraces formed a genetic group that was predominant in the western part of the Mexican highland plateau. Another Race D group was concentrated at the eastern extreme of the neovolcanic axis and was differentiated morphologically as well. Guatemalan germplasm contained accessions of climbing bean that did not group with any of the previously defined races and should be considered a separate race. Thus, Middle American germplasm of common bean is more complex than previously thought, and contains diversity that remains to be explored for its practical value.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/

Permalink