排序方式: 共有37条查询结果,搜索用时 31 毫秒
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Nicolè S Erickson DL Ambrosi D Bellucci E Lucchin M Papa R Kress WJ Barcaccia G 《Génome》2011,54(7):529-545
The potential of DNA barcoding was tested as a system for studying genetic diversity and genetic traceability in bean germplasm. This technique was applied to several pure lines of Phaseolus vulgaris L. belonging to wild, domesticated, and cultivated common beans, along with some accessions of Phaseolus coccineus L., Phaseolus lunatus L., and Vigna unguiculata (L.) Walp. A multilocus approach was exploited using three chloroplast genic regions (rbcL, trnL, and matK), four intergenic spacers (rpoB-trnC, atpBrbcL, trnT-trnL, and psbA-trnH), and nuclear ITS1 and ITS2 rDNA sequences. Our main goals were to identify the markers and SNPs that show the best discriminant power at the variety level in common bean germplasm, to examine two methods (tree based versus character based) for biodiversity analysis and traceability assays, and to evaluate the overall utility of chloroplast DNA barcodes for reconstructing the origins of modern Italian varieties. Our results indicate that the neighbor-joining method is a powerful approach for comparing genetic diversity within plant species, but it is relatively uninformative for the genetic traceability of plant varieties. In contrast, the character-based method was able to identify several distinct haplotypes over all target regions corresponding to Mesoamerican or Andean accessions; Italian accessions originated from both gene pools. On the whole, our findings raise some concerns about the use of DNA barcoding for intraspecific genetic diversity studies in common beans and highlights its limitations for resolving genetic relationships between landraces and varieties. 相似文献
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Mapping the jp (jumbo pollen) gene and QTLs involved in multinucleate microspore formation in diploid alfalfa 总被引:2,自引:0,他引:2
S. Tavoletti P. Pesaresi G. Barcaccia E. Albertini F. Veronesi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(3):372-378
The objective of this research was to map the jumbo-pollen trait in diploid alfalfa. Homozygous recessive (jpjp) plants are characterized by the complete failure of post-meiotic cytokinesis during microsporogenesis resulting in 100%
4n-pollen formation. Three F1 segregating populations were produced and analyzed for pollen-grain production and the segregation of RFLP markers. The first
cross combination did not segregate for the jumbo-pollen trait, but showed a clear segregation for multinucleate (bi-, tri-
and tetra-nucleate)-microspore formation. Cytological analysis showed that few plants produced 100% normal (uninucleate) microspores,
whereas most of them produced multinucleate microspores at a variable frequency (0–75%). Plants with multinucleate microspores
always showed a prevalence of binucleated microspores, even though some plants showed a background presence of tri- and tetra-nucleate
microspores. QTL analysis based on ANOVA I and Stepwise Multiple Regression identified three QTLs with a highly significant
effect on multinucleate-microspore formation. Two cross combinations, subsequently executed, showed Mendelian segregation
for the jumbo-pollen trait and were effective in locating the jp gene on linkage group 6 close to the Vg1G1b RFLP locus. Interestingly, this RFLP locus was also linked to one QTL for multinucleate-microspore
formation. Genetic models are discussed concerning the presence in linkage group 6 of a cluster of genes involved in multinucleate-microspore
formation together with possible relationships between the jp gene and the Vg1G1b QTL.
Received: 28 January 1999 / Accepted: 16 December 1999 相似文献
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Inheritance and mapping of 2n-egg production in diploid alfalfa. 总被引:3,自引:0,他引:3
The production of eggs with the sporophytic chromosome number (2n eggs) in diploid alfalfa (Medicago spp.) is mainly associated with the absence of cytokinesis after restitutional meiosis. The formation of 2n eggs through diplosporic apomeiosis has also been documented in a diploid mutant of M. sativa subsp. falcata (L.) Arcang. (2n = 2x = 16), named PG-F9. Molecular tagging of 2n-egg formation appears to be an essential step towards marker-assisted breeding and map-based cloning strategies aimed at investigating and manipulating reproductive mutants of the M. sativa complex. We made controlled crosses between PG-F9 and three wild type plants of M. sativa subsp. coerulea (Less.) Schm. (2n = 2x = 16) and then hand-pollinated the F1 progenies with tetraploid plants of M. sativa subsp. sativa L. (2n = 4x = 32). As a triploid embryo block prevents the formation of 3x progenies in alfalfa because of endosperm imbalance, and owing to the negligible selfing rate, seed set in 2x-4x crosses was used to discriminate the genetic capacity for 2n-egg production. F1 plants that exhibited null or very low seed sets were classified as normal egg producers and plants with high seed sets as 2n-egg producers. A bulked segregant analysis (BSA) with RAPD (random amplified polymorphic DNA), ISSR (inter-simple sequence repeat), and AFLP (amplified fragment length polymorphism) markers was employed to identify a genetic linkage group related to the 2n-egg trait using one of the three F1 progenies. This approach enabled us to detect a paternal ISSR marker of 610 bp, generated by primer (CA)8-GC, located 9.8 cM from a putative gene (termed Tne1, two-n-eggs) that in its recessive form determines 2n eggs and a 30% recombination genomic window surrounding the target locus. Eight additional RAPD and AFLP markers, seven of maternal, and one of paternal origin, significantly co-segregated with the trait under investigation. The minimum number of quantitative trait loci (QTLs) controlling seed set in 2x-4x crosses was estimated by ANOVA and regression analysis. Four maternal and three paternal independent molecular markers significantly affected the trait. A paternal RAPD marker allele, mapped in the same linkage group of Tne1, explained 43% of the variation for seed set in 2x-4x crosses indicating the presence of a major QTL. A map of the PG-F9 chromosome regions carrying the minor genes that determine the expression level of 2n eggs was constructed using selected RAPD and AFLP markers. Two of these genes were linked to previously mapped RFLP loci belonging to groups 1 and 8. Molecular and genetic evidence support the involvement of at least five genes. 相似文献
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Apomixis is a mode of asexual reproduction through seed. Progeny produced by apomixis are clonal replicas of a mother plant. The essential feature of apomixis is that embryo sacs and embryos are produced in ovules without meiotic reduction or egg cell fertilisation. Thus, apomixis fixes successful gene combinations and propagates high fitness genotypes across generations. A more profound knowledge of the mechanisms that regulate reproductive events in plants would contribute fundamentally to understanding the evolution and genetic control of apomixis. Molecular markers were used to determine levels of genetic variation within and relationship among ecotypes of the facultative apomict Hypericum perforatum L. (2n = 4x = 32). All ecotypes were polyclonal, being not dominated by a single genotype, and characterised by different levels of differentiation among multilocus genotypes. Flow cytometric analysis of seeds indicated that all ecotypes were facultatively apomictic, with varying degrees of apomixis and sexuality. Seeds set by haploid parthenogenesis and/or by fertilisation of aposporic egg cells were detected in most populations. The occurrence of both dihaploids and hexaploids indicates that apospory and parthenogenesis may be developmentally uncoupled and supports two distinct genetic factors controlling apospory and parthenogenesis in this species. Cyto-embryological analysis showed that meiotic and aposporic processes do initiate within the same ovule: the aposporic initial often appeared evident at the time of megaspore mother cell differentiation. Our observations suggest that the egg cell exists in an active metabolic state before pollination, and that its parthenogenetic activation leading to embryo formation may occur before fertilisation and endosperm initiation. 相似文献
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One hundred and six landraces belonging to 7 species of the Triticeae tribe were collected in central Italy by DBVBA (Perugia University), DIBIAGA (Ancona University) and ARSSA (Abruzzo Region Agricultural Development Agency) in different individual and joint missions. A few accessions were supplied by private and other public organisations. Triticum dicoccum Schubler is the most widespread species, followed by T. aestivum L., T. monococcum L., T. spelta L., T. turgidum var. durum Desf., Secale cereale L. and Hordeum vulgare L. Besides the presence of landraces reproduced by farmers over generations, information related to on-farm management and to qualitative/organoleptic traits as well as information related to their local names, uses, traditions and social context was gathered during the missions. The majority of the accessions was characterised by morphological and phenological traits and molecular markers. This work shows the presence of morpho-phenologic and genetic differences among landraces and the importance of some species in the agricultural systems and food customs of the investigated area. Particularly for emmer three well distinct landraces are present, "Farro Italia Centrale", "Farro della Garfagnana" and "Farro Italia Meridionale". Other interesting and traditional landraces are the "Solina" common wheat in Abruzzo and the "Orzo mondo" naked barley in Marche. Most of the populations are still cultivated in marginal lands and under low input or organic agronomic conditions; nevertheless, in many cases, they are found near modern varieties in conventional agriculture systems. Moreover, the in situ (on-farm) conservation of Triticeae landraces in central Italy is strictly linked to elderly farmers. 相似文献
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G. Barcaccia A. Mazzucato E. Albertini J. Zethof A. Gerats M. Pezzotti M. Falcinelli 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):74-82
Gametophytic apomixis in Kentucky bluegrass (Poa pratensis L.) involves the parthenogenetic development of unreduced eggs from aposporic embryo sacs. Attempts to transfer the apomictic
trait beyond natural sexual barriers require further elucidation of its inheritance. Controlled crosses were made between
sexual clones and apomictic genotypes, and the parthenogenetic capacity of (poly)diploid hybrids was ascertained by the auxin
test. A bulked segregant analysis with RAPD and AFLP markers was then used to identify a genetic linkage group related to
the apomictic mode of reproduction. This approach enabled us to detect both an AFLP marker located 6.6 cM from the gene that
putatively controls parthenogenesis and a 15.4-cM genomic window surrounding the target locus. A map of the P. pratensis chromosome region carrying the gene of interest was constructed using additional RAPD and AFLP markers that co-segregated
with the parthenogenesis locus. Highly significant linkage between parthenogenesis and a number of AFLP markers that also
appeared to belong to a tight linkage block strengthens the hypothesis of monogenic inheritance of this trait. If a single
gene is assumed, apomictic polyploid types of P. pratensis would be simplex for a dominant allele that confers parthenogenesis, and this genetic model would be further supported by
the bimodal distribution of the degree of parthenogenesis exhibited in the (poly)diploid progenies from sexual x apomictic
matings. The molecular tagging of apomixis in P. pratensis is an essential step towards marker-assisted breeding and map-based cloning strategies aimed at investigating and manipulating
its mode of reproduction.
Received: 13 January 1998 / Accepted: 19 January 1998 相似文献
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Antonella Mencacci Christian Leli Angela Cardaccia Marta Meucci Amedeo Moretti Francesco D'Alò Senia Farinelli Rita Pagliochini Mariella Barcaccia Francesco Bistoni 《PloS one》2012,7(12)