Molecular diversity in pineapple assessed by RFLP markers

Pineapple, #Ananas comosus (L.) Merr, is the third most important tropical fruit cultivated in all tropical and subtropical countries. Pineapple germplasm includes all seven species of the genus #Pseudananas. A knowledge of its diversity structure is needed to develop new breeding programs. Restriction fragment length polymorphism (RFLP) was used to study molecular diversity in a set of 301 accessions, most of which were recently collected. This sample was analysed using 18 homologous genomic probes. Dissimilarities were calculated by a Dice index and submitted to Factorial Analysis. The same data were represented as a diversity tree constructed with the score method. #Pseudananas sagenarius$displayed a high polymorphism and shares 58.7$. Within #Ananas, variation appears continuous and was found mostly at the intraspecific level, particularly in the wild species #Ananas ananassoides and #Ananas parguazensis. As for the cultivated species, #Ananas comosus appears relatively homogeneous despite its wide morphological variation and #Ananas bracteatus, which is grown as a fence and for fruit, appears still much less variable. By contrast #Ananas lucidus cultivated by the Amerindians for fiber, displays a high polymorphism. This tree displayed a loose assemblage of numerous clusters separated by short distances. Most species were scattered in various clusters, a few of these being monospecific. Some accessions which had not been classified, as they shared morphological traits typical of different species, re-group with one or the other, and sometimes with both species in mixed clusters. No reproductive barrier exists in this germplasm and these data indicate the existence of gene flow, enhancing the role of effective sexual reproduction in a species with largely predominant vegetative multiplication. (Résumé d'auteur

A new aspect of genetic diversity of Indonesian oil palm (Elaeis guineensis Jacq.) revealed by isoenzyme and AFLP markers and its consequences for breeding

Oil palm (#Elaeis guineensis$ Jacq.) plays an important economic role in some countries of Southeast Asia like Indonesia, which is the world's second producer of palm and palm kernel oil. The quality improvement of planting material needs a better understanding of the genetic relationships between genotypes from differents populations used in the breeding programmes. In this study, 48 parents, representative of four populations used in Indonesia Oil Plam Research Institute (IOPRI) breeding programmes, were analysed with five selected AFLP primer pairs and four isoenzymatic systems. One hundred and fifty eight scorable band levels were generated of which 69 (61%) were polymorphic. AFLP allowed us to identify off-type descendants which were excluded from analysis. The use of unbiased Rogers distance clearly separated the four studied populations. The Neighbor-Joining method re-groups two African populations wich are known as originating from different regions. Nevertheless, the variability revealed is in accordance with oil palm breeders' knowledge. The results obtained with AFLP showed that the crosses among the African sub-population, which is excluded in oil palm reciprocal recurrent selection (RRS) breeding programmes, may be more interesting than the crosses between the African and the Deli populations. (Résumé d'auteur

Use of cpSSRs for the characterisation of yam phylogeny in Benin

Equipe SRG - UMR DAPInternational audienceThe Dioscorea cayenensis - Dioscorea rotundata species complex is the most widely cultivated yam in West Africa. This species complex has been described as deriving from wild yams belonging to the Enanthiophyllum section through domestication by African farmers. To study patterns of yam evolution and to establish phylogenetic relationships existing between wild and cultivated species sampled in Benin, we investigated changes in chloroplast DNA simple sequence repeats (cpSSR) in 148 yam accessions selected to cover the wider possible genetic diversity existing in the country. Dioscorea cayenensis and D. rotundata share the same haplotype. The morphotype "abyssinica" appeared to be subdivided into 2 haplotypes. One of these haplotypes shares the same haplotype with the Dioscorea cayenensis - Dioscorea rotundata species complex and with morphotypes praehensilis, suggesting that they might belong to the same species. Relationships among sections Lasiophyton, Macrocapaea, Opsophyton, and Enanthiophyllum were clarified, and some taxonomic changes within the Enanthiophyllum section were suggested. Dioscorea minutiflora, D. smilacifolia, and D. burkilliana might be considered as 1 single genetic group, and they are suspected of belonging to the same speciesLe complexe d'espèces Dioscorea cayenensis – Dioscorea rotundata est l'igname la plus cultivée de l'Afrique de l'ouest. Il a été décrit comme résultant de la domestication, par les paysans africains, de formes sauvages d'ignames appartenant à la section Enanthiophyllum. Dans le but de répondre à des interrogations concernant l'évolution de l'igname et d'essayer de compléter les connaissances sur les relations phylogéniques entre les espèces cultivées et les espèces sauvages au Bénin, nous avons étudié la variation du nombre de répétitions de motifs simples de l'ADN chloroplastique (cpSSR) dans 148 accessions d'igname élaborées pour couvrir la diversité génétique présente dans le pays. Dioscorea cayenensis et D. rotundata ont montré le même haplotype. Le morphotype « abyssinica » est subdivisé en 2 haplotypes. L'un des deux partage son haplotype avec le complexe d'espèces Dioscorea cayenensis – Dioscorea rotundata et les morphotypes praehensilis, suggérant qu'ils pourraient appartenir à la même espèce. Les relations entre les sections Lasiophyton, Macrocapaea, Opsophyton et Enanthiophyllum sont plus clarifiées et au sein de la section Enanthiophyllum des modifications taxonomiques sont proposées. Dioscorea minutiflora, D. smilacifolia et D. burkilliana pourraient être considérées comme appartenant au même groupe génétique et probablement à la même espèc

A new set of microsatellite markers for the peach palm (Bactris gasipaes Kunth): characterization and across-taxa utility within the tribe Cocoeae.

A (GA)n microsatellite-enriched library was constructed and a new set of 18 nuclear simple sequence repeat loci was isolated in Bactris gasipaes var. gasipaes. The loci were found to be highly variable in the target species and readily transferable to related Bactris species as well as to the Astrocaryum and Elaeis genera of the same Cocoeae tribe. These microsatellite resources are made available to study the genetic diversity and gene flow within the Bactris complex for a better understanding of the domestication process of the peach palm and for further Cocoeae genetic

Nuclear microsatellite markers for the date palm (Phoenix dactylifera L.): characterization and utility across the genus Phoenix and in other palm genera.

A (GA)n microsatellite-enriched library was constructed and 16 nuclear simple sequence repeat (SSR) loci were characterized in Phoenix dactylifera. Across-taxa amplification and genotyping tests showed the utility of most SSR markers in 11 other Phoenix species and the transferability of some of them in Elaeis guineensis, 11 species of Pritchardia, Pritchardiopsis jeanneneyi and six species of Astrocaryum. The first to be published for P. dactylifera, these new SSR resources are available for cultivar identification, pedigree analysis, germplasm diversity as well as genetic mapping studie

Genetic diversity of the greater yam (Dioscorea alata L.) and relatedness to D. nummularia Lam. and D. transversa Br. as revealed with AFLP markers

UMR DAPInternational audienceAmplified fragment length polymorphism markers were used to assess the genetic relatedness between Dioscorea alata and nine other edible Dioscorea. These species include D. abyssinica Hoch., D. bulbifera L., D. cayenensis-rotundata Lamk. et Poir., D. esculenta Burk., D. nummularia Lam., D. pentaphylla L., D. persimilis Prain. et Burk., D. transversa Br. and D. trifida L. Four successive studies were conducted with emphasis on the genetic relationship within D. alata and among species of the Enantiophyllum section from Vanuatu. Study 1 was carried out to select a set of polymorphic primer pairs using 11 combinations and eight species belonging to five distinct sections. The four most polymorphic primer pairs were used in study 2 among six species of the Enantiophyllum section. Study 3 focussed mainly on the genetic relationship among 83 accessions of D. alata, mostly from Vanuatu (78 acc.) but also from Benin, Guadeloupe, New Caledonia and Vietnam. The ploidy level of 53 accessions was determined and results indicated the presence of tetraploid, hexaploid and octoploid cultivars. Study 4, included 35 accessions of D. alata, D. nummularia and D. transversa and was conducted using two primer pairs to verify the taxonomical identity of thecultivars ‘langlang’, ‘maro’ and ‘netsar’ from Vanuatu. The overall results indicated that each accession can be fingerprinted uniquely with AFLP. D. alata is an heterogeneous species which shares a common genetic background with D. nummularia and ‘langlang’, ‘maro’ and ‘netsar’. UPGMA cluster analysis revealed the existence of three major groups of genotypes within D. alata, each assembling accessions from distant geographical origins and different ploidy levels. The analysis also revealed that ‘langlang’, ‘maro’ and ‘netsar’ clustered together with the cultivar ‘wael’ (D. transversa) from New Caledonia. Results are discussed in the pape

A Realization Optimality-Theoretic approach to affix order

10.1007/s11525-010-9181-2Morphology202381-41