排序方式: 共有4条查询结果,搜索用时 30 毫秒
1
1.
Microsatellites in Cassava (Manihot esculenta Crantz): discovery, inheritance and variability 总被引:2,自引:0,他引:2
P. P. Chavarriaga-Aguirre M. M. Maya M. W. Bonierbale S. Kresovich M. A. Fregene J. Tohme G. Kochert 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(3):493-501
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.
Received: 4 September 1997 / Accepted 16 March 1998 相似文献
2.
Chavarriaga-Aguirre Paul Maya María M. Tohme Joe Duque Myriam C. Iglesias Carlos Bonierbale Merideth W. Kresovich Steve Kochert Gary 《Molecular breeding : new strategies in plant improvement》1999,5(3):263-273
The cassava core collection was selected to represent, with minimum repetitiveness, the potential genetic diversity of the
crop. The core (630 accessions) was chosen from the base collection (over 5500 accessions) on the basis of diversity of origin
(country and geographic), morphology, isozyme patterns and specific agronomic criteria. To asses the genetic diversity of
the core, 521 accessions were typed with four microsatellite loci. Allele diversity and frequency, and size variance of dinucleotide
repeats (Rst statistic) were estimated. Microsatellite allele numbers and frequencies varied among countries: Colombia and
Brazil had the largest number of different alleles across all loci. Mexico also had a high number, ranking fifth after Peru,
Costa Rica and Venezuela (which tied). Unique alleles were present in accessions from Brazil, Colombia, Guatemala, Venezuela
and Paraguay. A small number (1.34%) of potential duplicates were identified through isozyme and AFLP profiles. Thus, the
present results indicated that traditional markers have been highly effective at selecting unique genotypes for the core.
Future selections of cassava germplasm sets can be aided by DNA-based markers to ensure genetically representative, non-redundant
samples.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
Roa AC Chavarriaga-Aguirre P Duque MC Maya MM Bonierbale MW Iglesias C Tohme J 《American journal of botany》2000,87(11):1647-1655
Microsatellite amplification was performed on cassava (Manihot esculenta) and six other different species (all wild) of the Manihot genus. We used ten pairs of microsatellite primers previously developed from cassava, detecting 124 alleles in a sample of 121 accessions of the seven species. The number of alleles per locus ranged from four to 21 alleles, and allelic diversity was greater in the wild species than in cassava. Seventy-nine alleles, including unique ones, were detected in the wild species but were not found in the crop. The lower level of heterozygosity in some wild species probably resulted from a combination of fine-scale differentiation within the species and the presence of null alleles. Overall, microsatellite primers worked across the genus, but, with increasing genetic distance, success in amplifying loci tended to decrease. No accession of M. aesculifolia, M. carthaginensis, and M. brachyloba presented a banding pattern at locus Ga-140; neither did one appear for M. aesculifolia at locus Ga-13. Previous work with amplified fragment length polymorphism (AFLP) markers and this microsatellite analysis show that these three wild taxa are the most distant relatives of the crop, whereas the wild forms M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana appear to be the closest. 相似文献
4.
1