The genetic diversity organization and evaluation of relationships within Tunisian date-palm cult... more The genetic diversity organization and evaluation of relationships within Tunisian date-palm cultivars were assessed using the random amplified microsatellite polymorphism (RAMPO) and amplified fragment length polymorphism (AFLP) methods. 18 combinations of random/ISSR primers and six AFLP primers combinations were tested with DNAs isolated from 40 date-palm cultivars. Our results show that using both markers systems, the Tunisian date-palm germplasm is characterized by a large and continuous genetic diversity. In addition, due to the greater number of markers per assay, the AFLP technique seems to be more informative than the RAMPO method. In fact, 186 and 428 polymorphic bands were detected using RAMPO and AFLP primers, respectively. Moreover, AFLP markers were found most polymorphic with the highest average PIC value (0.7) and marker index (50.54). In addition, independent as well as combined analyses of the cluster analyses of the RAMPO and AFLP fragments showed that cultivars a...
Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite ... more Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite markers for the genetic characterisation and identification of cultivars. This characterisation will enable us to obtain an extensive understanding of the local genetic diversity and its distribution. Fourteen microsatellite loci of Phoenix dactylifera L. were tested to examine the genetic diversity in the Tunisian date palm germplasm; 74 female and 27 male cultivars were represented. A total of 136 alleles and 311 genotypes were detected based on 14 loci microsatellite. A high level of polymorphism was detected at the DNA level. The 101 date palms from three main oases exhibited a high degree of genetic diversity and were structured independently of their geographical origin and sex. All the local date palm accessions were successfully fingerprinted and easily distinguished based on only five loci. The possibility of using microsatellites in the large-scale molecular labelling of offshoots and in vitro plantlets and in the certification of plant material is discussed.
Random amplified microsatellite polymorphisms (RAMPOs) were used to assess genetic diversity amon... more Random amplified microsatellite polymorphisms (RAMPOs) were used to assess genetic diversity among 30 date-palm cultivars and 10 male trees. Using 18 primers combinations, 197 bands were scored and 186 were polymorphic suggesting the high level of polymorphism among studied cultivars. Moreover, taking into account the high percentage of polymorphic bands (ppb), the resolving power (R p ) together with the polymorphism information content (PIC) scored values, all the tested primer sets contribute strongly in the discrimination of date-palm genotypes. In addition, the topology of the derived UPGMA dendrogram exhibited cultivars' clustering made independently both from the geographical origin and/or from the sex of trees. The present data support the Mesopotamian origin of the date-palm domestication. Thus we assume that the used method is efficient to assess genetic diversity within date-palm cultivars. Data are discussed in relation with the opportunity of the RAMPO method to provide additional molecular markers suitable in the improvement of the date-palms germplasm characterisation. ß
Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite ... more Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite markers for the genetic characterisation and identification of cultivars. This characterisation will enable us to obtain an extensive understanding of the local genetic diversity and its distribution. Fourteen microsatellite loci of Phoenix dactylifera L. were tested to examine the genetic diversity in the Tunisian date palm germplasm; 74 female and 27 male cultivars were represented. A total of 136 alleles and 311 genotypes were detected based on 14 loci microsatellite. A high level of polymorphism was detected at the DNA level. The 101 date palms from three main oases exhibited a high degree of genetic diversity and were structured independently of their geographical origin and sex. All the local date palm accessions were successfully fingerprinted and easily distinguished based on only five loci. The possibility of using microsatellites in the large-scale molecular labelling of offshoots and in vitro plantlets and in the certification of plant material is discussed.
Whether sex chromosomes are differentiated is an important aspect of our knowledge of dioecious p... more Whether sex chromosomes are differentiated is an important aspect of our knowledge of dioecious plants, such as date palm (Phoenix dactylifera). In this crop plant, the female individuals produce dates, and are thus the more valuable sex. However, there is no way to identify the sex of date palm plants before reproductive age, and the sex-determining mechanism is still unclear.
Zehdi, S., Trifi, M., Billotte, N., Marrakchi, M. and Pintaud, J. C. 2004. Genetic diversity of T... more Zehdi, S., Trifi, M., Billotte, N., Marrakchi, M. and Pintaud, J. C. 2004. Genetic diversity of Tunisian date palms (Phoenix dactylifera L.) revealed by nuclear microsatellite polymorphism. */ Hereditas 141: 278 Á/287. Lund, Sweden. ISSN 0018-0661.
Mauritanian date palm cultivars and progenies of two controlled crosses were analyzed according t... more Mauritanian date palm cultivars and progenies of two controlled crosses were analyzed according to the identity of mitochondrial plasmid-like DNAs. Starting from total genomic DNA and appropriate primers, polymerase chain reaction was designed to amplify either a 373-bp or a 265-bp fragments corresponding to the S and the R-plasmid respectively. Data proved that 5 cultivars out of 10 studied have exhibited the R-plasmid suggesting their resistance to the fusariosis. The existence of intra-cultivar variability has also been revealed in the cv. Ahmar. In addition, analysis throughout progenies of two controlled crosses suggested the strict maternal transmission of the date palms' mitochondrial genome.
Specific microsatellites (SSRs) markers were used to characterize a set of 32 Tunisian pomegranat... more Specific microsatellites (SSRs) markers were used to characterize a set of 32 Tunisian pomegranate (Punica granatum L.) cultivars. Using 13 SSR primers, a total of 40 alleles and 46 genotypes have been identified. As a result, data proved that a high level of polymorphism characterizes the Tunisian pomegranate germplasm at the DNA level. The derived Neighbour-joining (NJ) dendrogram constructed using DAS genetic distances exhibited a genetic diversity structured independently from the geographical origin of cultivars and their denomination. This result suggested that a common genetic basis may characterize Tunisian pomegranate cultivars despite their phenotypic divergences. Furthermore, based on the multilocus genotypes a cultivar's identification key has been established and permitted to unambiguously differentiate between varieties. The obtained results are discussed in term of establishment and management of a national collection of pomegranate varieties, conformity checks, identification of homonyms and synonyms, and screening of the local resources. Furthermore, this microsatellite-based key is a first step towards a marker-assisted identification pomegranate database.
Background and Aims Date palms (Phoenix dactylifera, Arecaceae) are of great economic and ecologi... more Background and Aims Date palms (Phoenix dactylifera, Arecaceae) are of great economic and ecological value to the oasis agriculture of arid and semi-arid areas. However, despite the availability of a large date palm germplasm spreading from the Atlantic shores to Southern Asia, improvement of the species is being hampered by a lack of information on global genetic diversity and population structure. In order to contribute to the varietal improvement of date palms and to provide new insights on the influence of geographic origins and human activity on the genetic structure of the date palm, this study analysed the diversity of the species.
The genetic diversity organization and evaluation of relationships within Tunisian date-palm cult... more The genetic diversity organization and evaluation of relationships within Tunisian date-palm cultivars were assessed using the random amplified microsatellite polymorphism (RAMPO) and amplified fragment length polymorphism (AFLP) methods. 18 combinations of random/ISSR primers and six AFLP primers combinations were tested with DNAs isolated from 40 date-palm cultivars. Our results show that using both markers systems, the Tunisian date-palm germplasm is characterized by a large and continuous genetic diversity. In addition, due to the greater number of markers per assay, the AFLP technique seems to be more informative than the RAMPO method. In fact, 186 and 428 polymorphic bands were detected using RAMPO and AFLP primers, respectively. Moreover, AFLP markers were found most polymorphic with the highest average PIC value (0.7) and marker index (50.54). In addition, independent as well as combined analyses of the cluster analyses of the RAMPO and AFLP fragments showed that cultivars a...
Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite ... more Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite markers for the genetic characterisation and identification of cultivars. This characterisation will enable us to obtain an extensive understanding of the local genetic diversity and its distribution. Fourteen microsatellite loci of Phoenix dactylifera L. were tested to examine the genetic diversity in the Tunisian date palm germplasm; 74 female and 27 male cultivars were represented. A total of 136 alleles and 311 genotypes were detected based on 14 loci microsatellite. A high level of polymorphism was detected at the DNA level. The 101 date palms from three main oases exhibited a high degree of genetic diversity and were structured independently of their geographical origin and sex. All the local date palm accessions were successfully fingerprinted and easily distinguished based on only five loci. The possibility of using microsatellites in the large-scale molecular labelling of offshoots and in vitro plantlets and in the certification of plant material is discussed.
Random amplified microsatellite polymorphisms (RAMPOs) were used to assess genetic diversity amon... more Random amplified microsatellite polymorphisms (RAMPOs) were used to assess genetic diversity among 30 date-palm cultivars and 10 male trees. Using 18 primers combinations, 197 bands were scored and 186 were polymorphic suggesting the high level of polymorphism among studied cultivars. Moreover, taking into account the high percentage of polymorphic bands (ppb), the resolving power (R p ) together with the polymorphism information content (PIC) scored values, all the tested primer sets contribute strongly in the discrimination of date-palm genotypes. In addition, the topology of the derived UPGMA dendrogram exhibited cultivars' clustering made independently both from the geographical origin and/or from the sex of trees. The present data support the Mesopotamian origin of the date-palm domestication. Thus we assume that the used method is efficient to assess genetic diversity within date-palm cultivars. Data are discussed in relation with the opportunity of the RAMPO method to provide additional molecular markers suitable in the improvement of the date-palms germplasm characterisation. ß
Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite ... more Due to the economic importance of the date palm in Tunisia, we attempt to develop microsatellite markers for the genetic characterisation and identification of cultivars. This characterisation will enable us to obtain an extensive understanding of the local genetic diversity and its distribution. Fourteen microsatellite loci of Phoenix dactylifera L. were tested to examine the genetic diversity in the Tunisian date palm germplasm; 74 female and 27 male cultivars were represented. A total of 136 alleles and 311 genotypes were detected based on 14 loci microsatellite. A high level of polymorphism was detected at the DNA level. The 101 date palms from three main oases exhibited a high degree of genetic diversity and were structured independently of their geographical origin and sex. All the local date palm accessions were successfully fingerprinted and easily distinguished based on only five loci. The possibility of using microsatellites in the large-scale molecular labelling of offshoots and in vitro plantlets and in the certification of plant material is discussed.
Whether sex chromosomes are differentiated is an important aspect of our knowledge of dioecious p... more Whether sex chromosomes are differentiated is an important aspect of our knowledge of dioecious plants, such as date palm (Phoenix dactylifera). In this crop plant, the female individuals produce dates, and are thus the more valuable sex. However, there is no way to identify the sex of date palm plants before reproductive age, and the sex-determining mechanism is still unclear.
Zehdi, S., Trifi, M., Billotte, N., Marrakchi, M. and Pintaud, J. C. 2004. Genetic diversity of T... more Zehdi, S., Trifi, M., Billotte, N., Marrakchi, M. and Pintaud, J. C. 2004. Genetic diversity of Tunisian date palms (Phoenix dactylifera L.) revealed by nuclear microsatellite polymorphism. */ Hereditas 141: 278 Á/287. Lund, Sweden. ISSN 0018-0661.
Mauritanian date palm cultivars and progenies of two controlled crosses were analyzed according t... more Mauritanian date palm cultivars and progenies of two controlled crosses were analyzed according to the identity of mitochondrial plasmid-like DNAs. Starting from total genomic DNA and appropriate primers, polymerase chain reaction was designed to amplify either a 373-bp or a 265-bp fragments corresponding to the S and the R-plasmid respectively. Data proved that 5 cultivars out of 10 studied have exhibited the R-plasmid suggesting their resistance to the fusariosis. The existence of intra-cultivar variability has also been revealed in the cv. Ahmar. In addition, analysis throughout progenies of two controlled crosses suggested the strict maternal transmission of the date palms' mitochondrial genome.
Specific microsatellites (SSRs) markers were used to characterize a set of 32 Tunisian pomegranat... more Specific microsatellites (SSRs) markers were used to characterize a set of 32 Tunisian pomegranate (Punica granatum L.) cultivars. Using 13 SSR primers, a total of 40 alleles and 46 genotypes have been identified. As a result, data proved that a high level of polymorphism characterizes the Tunisian pomegranate germplasm at the DNA level. The derived Neighbour-joining (NJ) dendrogram constructed using DAS genetic distances exhibited a genetic diversity structured independently from the geographical origin of cultivars and their denomination. This result suggested that a common genetic basis may characterize Tunisian pomegranate cultivars despite their phenotypic divergences. Furthermore, based on the multilocus genotypes a cultivar's identification key has been established and permitted to unambiguously differentiate between varieties. The obtained results are discussed in term of establishment and management of a national collection of pomegranate varieties, conformity checks, identification of homonyms and synonyms, and screening of the local resources. Furthermore, this microsatellite-based key is a first step towards a marker-assisted identification pomegranate database.
Background and Aims Date palms (Phoenix dactylifera, Arecaceae) are of great economic and ecologi... more Background and Aims Date palms (Phoenix dactylifera, Arecaceae) are of great economic and ecological value to the oasis agriculture of arid and semi-arid areas. However, despite the availability of a large date palm germplasm spreading from the Atlantic shores to Southern Asia, improvement of the species is being hampered by a lack of information on global genetic diversity and population structure. In order to contribute to the varietal improvement of date palms and to provide new insights on the influence of geographic origins and human activity on the genetic structure of the date palm, this study analysed the diversity of the species.
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