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Hilary J Rogers - One of the best experts on this subject based on the ideXlab platform.

  • floral scent evaluation of segregating lines of Alstroemeria caryophyllaea
    Scientia Horticulturae, 2015
    Co-Authors: Danilo Aros, Carsten Theodor Muller, Natasha D Spadafora, Michela Venturi, Gerardo Nunezlillo, Claudio Meneses, Lisa Methven, Hilary J Rogers
    Abstract:

    Floral scent plays an important role in attracting and guiding pollinators and is composed of a bouquet of volatile organic compounds (VOCs). Alstroemeria is a commercially important cut flower, however breeding efforts have focussed on flower colour and size rather than scent. Recently analysis of two scented cultivars derived from the scented Alstroemeria caryophyllaea revealed a surprising divergence in VOC profiles. Here 13 scented lines of A. caryophyllaea derived from selfing were characterized including morphology, evaluation of the floral scent through GC–MS and sensorial analysis. Leaf shape, stem length, flower size, shape, colouration and productivity all varied between lines. Sensorial analyses indicated that two lines (C013 and C017) were most highly rated for their appearance and C017 was also scored highest for its scent contrasting with C004 which scored lowest. Analyses of scent bouquets from six of the lines revealed 23 terpenoid compounds. All lines showed the same most abundant compound putatively identified as β-trans-ocimene, and three further compounds were discriminatory amongst the lines following PCA. Genomic organization of AlstroTPS, a previously identified myrcene synthase, showed substantial polymorphism between lines. The multifactorial characterization performed in this study showed differences among the lines confirming parental heterozygosity.

  • volatile emissions of scented Alstroemeria genotypes are dominated by terpenes and a myrcene synthase gene is highly expressed in scented Alstroemeria flowers
    Journal of Experimental Botany, 2012
    Co-Authors: Danilo Aros, Veronica Gonzalez, Rudolf Konrad Allemann, Carsten Theodor Muller, Carlo Rosati, Hilary J Rogers
    Abstract:

    Native to South America, Alstroemeria flowers are known for their colourful tepals, and Alstroemeria hybrids are an important cut flower. However, in common with many commercial cut flowers, virtually all the commercial Alstroemeria hybrids are not scented. The cultivar ‘Sweet Laura’ is one of very few scented commercial Alstroemeria hybrids. Characterization of the volatile emission profile of these cut flowers revealed three major terpene compounds: (E)-caryophyllene, humulene (also known as α-caryophyllene), an ocimene-like compound, and several minor peaks, one of which was identified as myrcene. The profile is completely different from that of the parental scented species A. caryophyllaea. Volatile emission peaked at anthesis in both scented genotypes, coincident in cv. ‘Sweet Laura’ with the maximal expression of a putative terpene synthase gene AlstroTPS. This gene was preferentially expressed in floral tissues of both cv. ‘Sweet Laura’ and A. caryophyllaea. Characterization of the AlstroTPS gene structure from cv. ‘Sweet Laura’ placed it as a member of the class III terpene synthases, and the predicted 567 amino acid sequence placed it into the subfamily TPS-b. The conserved sequences R28(R)X8W and D321DXXD are the putative Mg2+-binding sites, and in vitro assay of AlstroTPS expressed in Escherichia coli revealed that the encoded enzyme possesses myrcene synthase activity, consistent with a role for AlstroTPS in scent production in Alstroemeria cv. ‘Sweet Laura’ flowers.

  • gene expression patterns to define stages of post harvest senescence in Alstroemeria petals
    Plant Biotechnology Journal, 2004
    Co-Authors: Emily Breeze, Hilary J Rogers, Carol Wagstaff, Brian Thomas, Anthony D Stead, Elizabeth Harrison, Irene Bramke, Vicky Buchananwollaston
    Abstract:

    Petal senescence in many species is regulated by ethylene but some flowers, such as those on the monocotyledonous plant Alstroemeria, var. Rebecca are ethylene insensitive. Changes in gene expression during the post-harvest senescence of Alstroemeria flowers were investigated using several different techniques. Suppressive subtractive hybridization (SSH) was used to obtain cDNA libraries enriched for genes expressed at selected stages of petal senescence. Sequencing of the EST clones obtained resulted in over 1000 sequences that represent approximately 500 different genes. Analysis of the potential functions of these genes provides a snapshot of the processes that are taking place during petal development. Both cell wall related genes and genes involved in metabolism were present at a higher proportion in the earlier stages. Genes encoding metal binding proteins (mostly metallothionein-like) were the major component of senescence enhanced libraries. This limited the diversity of genes identified showing differential expression at the later stages. Changes in the expression of all genes were analysed using microarray hybridization, and genes showing either up or down-regulation were identified. The expression pattern of a selection of genes was confirmed using Northern hybridization. Northern hybridization confirmed the up-regulation of metallothioneins after floral opening, however, this was not detected by the microarray analysis, indicating the importance of using a combination of methods to investigate gene expression patterns. Considerably more genes were up-regulated than down-regulated. This may reflect the need during Alstroemeria petal senescence for the expression of a whole new set of genes involved with degradation and mobilization. The potential uses of expression profiling to improve floral quality in breeding programmes or as a diagnostic tool are discussed.

  • programmed cell death pcd processes begin extremely early in Alstroemeria petal senescence
    New Phytologist, 2003
    Co-Authors: Carol Wagstaff, Patricia Malcolm, Arfhan Rafiq, Mike Leverentz, Gareth Griffiths, Brian Thomas, Anthony D Stead, Hilary J Rogers
    Abstract:

    -In the Liliaceous species Alstroemeria, petal senescence is characterized by wilting and inrolling, terminating in abscission 8-10 d after flower opening. -In many species, flower development and senescence involves programmed cell death (PCD). PCD in Alstroemeria petals was investigated by light (LM) and transmission electron microscopy (TEM) (to study nuclear degradation and cellular integrity), DNA laddering and the expression programme of the DAD-1 gene. -TEM showed nuclear and cellular degradation commenced before the flowers were fully open and that epidermal cells remained intact whilst the mesophyll cells degenerated completely. DNA laddering increased throughout petal development. Expression of the ALSDAD-1 partial cDNA was shown to be downregulated after flower opening. -We conclude that some PCD processes are started extremely early and proceed throughout flower opening and senescence, whereas others occur more rapidly between stages 4-6 (i.e. postanthesis). The spatial distribution of PCD across the petals is discussed. Several molecular and physiological markers of PCD are present during Alstroemeria petal senescence.

  • increasing flower longevity in Alstroemeria
    Postharvest Biology and Technology, 2003
    Co-Authors: Usawadee Chanasut, Hilary J Rogers, Carol Wagstaff, Gareth Griffiths, Brian Thomas, Michael K Leverentz, Anthony D Stead
    Abstract:

    The vase-life of Alstroemeria (cv. Rebecca) flowers is terminated when the tepals abscise. Abscission was accelerated by both chloroethylphosphonic acid (CEPA) and 1-aminocyclopropane-1-carboxylic acid (ACC). Petals abscised 24 h earlier compared with controls, when isolated cymes were placed in 340 nM CEPA, and earlier still when higher concentrations were used. This suggests that flowers of this Alstroemeria cultivar are very ethylene sensitive. Treatment with silver thiosulphate (STS) overcame the effects of exposure to CEPA and delayed perianth abscission of untreated isolated flowers by 3-4 days. The inclusion of 1% sucrose in the vase solution also extended longevity but not by as much as STS treatment; combined STS and sucrose treatments did not increase longevity beyond that of either treatment alone. However, removal of the young buds from the axil of the first flower was the most effective treatment to extend vase-life and encouraged the growth and development of the remaining flower. Flowers on cut inflorescences from which young axillary buds were trimmed more than doubled in fresh weight 6 days after flower opening compared with an increase of only 70-80% in those untreated or treated with STS and/or sucrose. Growth was less in isolated cymes but followed a similar pattern. The effect of STS and/or sucrose treatment was synergistic with the trimming treatment and thus the vase-life of trimmed, STS and sucrose-treated flowers was over 7 days longer than that for untreated controls.

Carlos M Baeza - One of the best experts on this subject based on the ideXlab platform.

  • Cytotaxonomic study of the Chilean endemic complex Alstroemeria magnifica Herb. (Alstroemeriaceae)
    2018
    Co-Authors: Carlos M Baeza, Eduardo Ruiz, Patricio Novoa, Víctor Finot, Pedro Carrasco, Marcelo Rosas, Oscar Toro-núñez
    Abstract:

    Abstract Alstroemeria L. (Alstroemeriaceae) represents one of the most diverse genera of vascular plants in Chile. It contains approximately 54 taxa, 40 of which are endemic. The “complex” Alstroemeria magnifica is endemic to Chile, and it comprises four varieties: A. magnifica var. magenta, A. magnifica var. magnifica, A. magnifica var. sierrae, and A. magnifica var. tofoensis. It is distributed from Coquimbo to the Valparaíso Region. We analyzed karyotypes of 10 populations along its natural distribution. All the populations presented an asymmetric karyotype, with 2n = 16 chromosomes but with three different karyotypic formulae. Alstroemeria magnifica var. magnifica and A. magnifica var. sierrae presented the same karyotypic fomula, and A. magnifica var. magenta, and A. magnifica var. tofoensis each had a different formula. The scatter plot among CVCL vs. MCA shows different groupings between populations of the four varieties. Based on the results, it is possible to consider raising Alstroemeria magnifica var. magenta to species level (A. magenta) and A. magnifica var. tofoensis to subspecies level (A. magnifica subsp. tofoensis); A. magnifica var. magnifica and A. magnifica var. sierrae should each remain as varieties. Nevertheless, these taxonomic changes should be considered tentative, as additional sources of evidence become available.

  • comparative karyotype analysis of populations in the Alstroemeria presliana herbert Alstroemeriaceae complex in chile
    Genetics and Molecular Biology, 2015
    Co-Authors: Carlos M Baeza, Víctor Finot, Eduardo Ruiz
    Abstract:

    Alstroemeria L., one of the most diverse genera of the Chilean flora and of high floricultural value, is represented by 35 species, most of them distributed between 28-38° S in the Mediterranean zone of Central Chile. There are 24 complex-forming taxa, of which 18 have conservation problems (8 are considered "endangered" and 10 as "vulnerable"). One of these complexes is Alstroemeria presliana Herb. with two subspecies: subsp. presliana and subsp. australis Bayer. Alstroemeria presliana grows in Chile and Argentina: subsp. presliana is distributed from Reserva Nacional Siete Tazas (35°27' S, Region of Maule) to Antuco, (37°25' S, Region of Bio-Bio), and is also found in Neuquen, Argentina; subsp. australis is endemic to the Cordillera of Nahuelbuta. A comparative karyotype study was carried out among six populations of A. presliana subsp. presliana and five populations of A. presliana subsp. australis. The eleven populations presented an asymmetric karyotype, with 2n = 2× = 16 chromosomes but with different karyotype formulae. A. presliana subsp. presliana shows the haploid formula 2m + 2m-sat + 1sm-sat + 1st-sat + 1t + 1 t-sat, and A. preslianasubsp. australis presents a formula 1m + 2m-sat + 1sm + 2t + 2t-sat chromosomes. The architecture of the karyotype between the subspecies is very different. The scatter plot among CVCL vs. MCA shows different groupings between populations of the two subspecies. According to the results obtained it is possible to consider raising Alstroemeria presliana subsp. australis at species level.

  • Alstroemeria marticorenae Alstroemeriaceae a new species from central chile
    Systematic Botany, 2015
    Co-Authors: Maria A Negritto, Carlos M Baeza, Eduardo Ruiz, Patricio Novoa
    Abstract:

    Abstract A new species, Alstroemeria marticorenae (Alstroemericaceae), from central Chile is described and illustrated. Diagnostic morphological characters that allow the distinction of A. marticorenae from similar taxa are presented. It differs from these in its flower shape, size, and color. The plants are small, reaching up to 35 cm tall, the flowers are pink, the upper inner tepals are rhomboidal and narrow, with a yellow stripe and a pattern of purple lines in the two upper tepals, varying from yellow to white in the basal portion; the anthers are yellow. It grows in hard, reddish soils, never in dunes. It is endemic to the Valparaiso Region of central Chile. A comparative cytological analysis of other sympatric species of Alstroemeria was conducted. The most important karyotypic characteristic for A. marticorenae is the presence of a submetacentric chromosome 3.

  • ribosomal dna distribution and a genus wide phylogeny reveal patterns of chromosomal evolution in Alstroemeria Alstroemeriaceae
    American Journal of Botany, 2012
    Co-Authors: Juliana Chacon, Aretuza Sousa, Carlos M Baeza, Susanne S Renner
    Abstract:

     Premise of the study: Understanding the fl exibility of monocot genomes requires a phylogenetic framework, which so far is available for few of the ca. 2800 genera. Here we use a molecular tree for the South American genus Alstroemeria to place karyological information, including fl uorescent in situ hybridization (FISH) signals, in an explicit evolutionary context.  Methods: From a phylogeny based on plastid, nuclear, and mitochondrial sequences for most species of Alstroemeria , we selected early-branching (Chilean) and derived (Brazilian) species for which we obtained 18S-25S and 5S rDNA FISH signals; we also analyzed chromosome numbers, 1C-values, and telomere FISH signals (in two species).  Key results: Chromosome counts for Alstroemeria cf. rupestris and A. pulchella confi rm 2 n = 16 as typical of the genus, which now has chromosomes counted for 29 of its 78 species. The rDNA sites are polymorphic both among and within species, and interstitial telomeric sites in Alstroemeria cf. rupestris suggest chromosome fusion.  Conclusions: In spite of a constant chromosome number, closely related species of Alstroemeria differ drastically in their rDNA, indicating rapid increase, decrease, or translocations of these genes. Previously proposed Brazilian and Chilean karyotype groups are not natural, and the n = 8 chromosomes in Alstroemeria compared to n = 9 in its sister genus Bomarea may result from a Robertsonian fusion.

  • variabilidad genetica y morfologica y estructuracion poblacional en Alstroemeria hookeri subsp hookeri Alstroemeriaceae endemica de chile
    Revista Chilena de Historia Natural, 2010
    Co-Authors: Eduardo Ruiz, Carlos M Baeza, Karen Balboa, Maria A Negritto, Glenda Fuentes, Veronica F Briceno
    Abstract:

    El genero Alstroemeria es exclusivamente sudamericano y consta de 82 taxa distribuyendose, principalmente en Chile y Brasil. La gran importancia economica que han adquirido las Alstroemerias chilenas como plantas ornamentales ha despertado gran interes en la variabilidad morfologica de las flores y variabilidad genetica en especies con potencial valor economico. Una de ellas es Alstroemeria hookeri que posee cuatro subespecies, de las cuales, la subespecie tipo, es endemica de las regiones del Maule y Biobio. Su distribucion geografica consiste de dos rangos, separados por la Cordillera de la Costa. Asi, existen poblaciones costeras, creciendo, entre los 5-20 m de altura en las provincias de Arauco, Concepcion, Nuble y Cauquenes y poblaciones del interior creciendo entre los 100-150 m de altura, en las provincias de Biobio y Nuble. Evidencias preliminares senalan diferencias fenotipicas entre poblaciones costeras y del interior, relacionadas con el color y forma de los tepalos. Por esta razon, se realizo un estudio morfologico comparativo en el rango completo de distribucion de esta subespecie y estudiar su genetica poblacional, especialmente los niveles de estructuracion poblacional. Se analizaron 33 caracteres florales, mediante metodos de ordenacion. El estudio morfologico indica una tendencia a separar las poblaciones en dos grupos, coincidiendo con los extremos de la variacion morfologica y con ambos rangos de distribucion, existiendo caracteres que aportan a ello. Los indices de variabilidad genetica fueron determinados usando 17 loci aloenzimaticos. Ademas, se estimaron los valores de estructuracion poblacional y se realizo un analisis de AMOVA. Se estimaron valores de distancia genetica de Nei, entre todos los pares de poblaciones para construir un dendrograma que refleje las relaciones de similitud genetica. Los resultados indican altos valores de estructuracion entre poblaciones y baja variabilidad genetica intrapoblacional en esta subespecie. Los resultados del AMOVA indican que la variabilidad se da principalmente entre poblaciones. Sin embargo, estos resultados variaron cuando se analizan las poblaciones de ambos rangos de distribucion separadamente. La similitud genetica no coincide con la divergencia morfologica entre individuos de la costa e interior, indicando que algunas poblaciones del interior estan mas relacionadas geneticamente, con poblaciones costeras que con aquellas de su mismo rango geografico.

Eduardo Ruiz - One of the best experts on this subject based on the ideXlab platform.

  • Cytotaxonomic study of the Chilean endemic complex Alstroemeria magnifica Herb. (Alstroemeriaceae)
    2018
    Co-Authors: Carlos M Baeza, Eduardo Ruiz, Patricio Novoa, Víctor Finot, Pedro Carrasco, Marcelo Rosas, Oscar Toro-núñez
    Abstract:

    Abstract Alstroemeria L. (Alstroemeriaceae) represents one of the most diverse genera of vascular plants in Chile. It contains approximately 54 taxa, 40 of which are endemic. The “complex” Alstroemeria magnifica is endemic to Chile, and it comprises four varieties: A. magnifica var. magenta, A. magnifica var. magnifica, A. magnifica var. sierrae, and A. magnifica var. tofoensis. It is distributed from Coquimbo to the Valparaíso Region. We analyzed karyotypes of 10 populations along its natural distribution. All the populations presented an asymmetric karyotype, with 2n = 16 chromosomes but with three different karyotypic formulae. Alstroemeria magnifica var. magnifica and A. magnifica var. sierrae presented the same karyotypic fomula, and A. magnifica var. magenta, and A. magnifica var. tofoensis each had a different formula. The scatter plot among CVCL vs. MCA shows different groupings between populations of the four varieties. Based on the results, it is possible to consider raising Alstroemeria magnifica var. magenta to species level (A. magenta) and A. magnifica var. tofoensis to subspecies level (A. magnifica subsp. tofoensis); A. magnifica var. magnifica and A. magnifica var. sierrae should each remain as varieties. Nevertheless, these taxonomic changes should be considered tentative, as additional sources of evidence become available.

  • Comparative karyotype analysis of populations in the Alstroemeria presliana Herbert (Alstroemeriaceae) complex in Chile
    2016
    Co-Authors: Carlos Baeza, Víctor Finot, Eduardo Ruiz
    Abstract:

    Alstroemeria L., one of the most diverse genera of the Chilean flora and of high floricultural value, is represented by 35 species, most of them distributed between 28-38 ° S in the Mediterranean zone of Central Chile. There are 24 complex-forming taxa, of which 18 have conservation problems (8 are considered “endangered ” and 10 as “vulnera

  • Comparative karyotypic analysis in the Alstroemeria hookeri Lodd. (Alstroemeriaceae) complex sensu Bayer (1987)
    2016
    Co-Authors: Carlos Baeza, Eduardo Ruiz, María Negritto
    Abstract:

    Alstroemeria L. (Alstroemeriaceae) is an American genus of monocots with two principal distribution centers in Chil

  • comparative karyotype analysis of populations in the Alstroemeria presliana herbert Alstroemeriaceae complex in chile
    Genetics and Molecular Biology, 2015
    Co-Authors: Carlos M Baeza, Víctor Finot, Eduardo Ruiz
    Abstract:

    Alstroemeria L., one of the most diverse genera of the Chilean flora and of high floricultural value, is represented by 35 species, most of them distributed between 28-38° S in the Mediterranean zone of Central Chile. There are 24 complex-forming taxa, of which 18 have conservation problems (8 are considered "endangered" and 10 as "vulnerable"). One of these complexes is Alstroemeria presliana Herb. with two subspecies: subsp. presliana and subsp. australis Bayer. Alstroemeria presliana grows in Chile and Argentina: subsp. presliana is distributed from Reserva Nacional Siete Tazas (35°27' S, Region of Maule) to Antuco, (37°25' S, Region of Bio-Bio), and is also found in Neuquen, Argentina; subsp. australis is endemic to the Cordillera of Nahuelbuta. A comparative karyotype study was carried out among six populations of A. presliana subsp. presliana and five populations of A. presliana subsp. australis. The eleven populations presented an asymmetric karyotype, with 2n = 2× = 16 chromosomes but with different karyotype formulae. A. presliana subsp. presliana shows the haploid formula 2m + 2m-sat + 1sm-sat + 1st-sat + 1t + 1 t-sat, and A. preslianasubsp. australis presents a formula 1m + 2m-sat + 1sm + 2t + 2t-sat chromosomes. The architecture of the karyotype between the subspecies is very different. The scatter plot among CVCL vs. MCA shows different groupings between populations of the two subspecies. According to the results obtained it is possible to consider raising Alstroemeria presliana subsp. australis at species level.

  • Alstroemeria marticorenae Alstroemeriaceae a new species from central chile
    Systematic Botany, 2015
    Co-Authors: Maria A Negritto, Carlos M Baeza, Eduardo Ruiz, Patricio Novoa
    Abstract:

    Abstract A new species, Alstroemeria marticorenae (Alstroemericaceae), from central Chile is described and illustrated. Diagnostic morphological characters that allow the distinction of A. marticorenae from similar taxa are presented. It differs from these in its flower shape, size, and color. The plants are small, reaching up to 35 cm tall, the flowers are pink, the upper inner tepals are rhomboidal and narrow, with a yellow stripe and a pattern of purple lines in the two upper tepals, varying from yellow to white in the basal portion; the anthers are yellow. It grows in hard, reddish soils, never in dunes. It is endemic to the Valparaiso Region of central Chile. A comparative cytological analysis of other sympatric species of Alstroemeria was conducted. The most important karyotypic characteristic for A. marticorenae is the presence of a submetacentric chromosome 3.

E. Jacobsen - One of the best experts on this subject based on the ideXlab platform.

  • efficient somatic embryogenesis in Alstroemeria
    Plant Cell Tissue and Organ Culture, 2006
    Co-Authors: J B Kim, E. Jacobsen, C J J M Raemakers, Richard G. F. Visser
    Abstract:

    In Alstroemeria high frequencies of compact embryogenic callus (CEC) induction (40%) and friable embryogenic callus (FEC) induction (15%) were obtained from nodes with axil tissue cultured first on a Murashige and Skoog (MS) medium supplemented with 10 μM thidiazuron and 0.5 μM indole-3-butyric acid and after that on a Schenk and Hildebrandt (SH) medium supplemented with 9.1 μM 2,4-dichlorophenoxy acetic acid and 2.2 μM benzylaminopurine (BA). Both types of callus were maintained on modified MS medium supplemented with 20.8 μM picloram. CEC and FEC formed somatic embryos and subsequently plants when transferred to MS medium supplemented with 2.2 μM BA. Plants were produced after 12 weeks (CEC) or after 16 weeks (FEC) of culture. Regenerated plants were established in the greenhouse and flowered normally.

  • occurrence of numerically unreduced 2n gametes in Alstroemeria interspecific hybrids and their significance for sexual polyploidisation
    Euphytica, 2003
    Co-Authors: M.s. Ramanna, A G J Kuipers, E. Jacobsen
    Abstract:

    The F1 hybrids of seven diploid Alstroemeria species (2n=2x=16) were investigated for the production of numerically unreduced (2n) gametes and their mode of origin. Based on a survey of 17 interspecific hybrid combinations,consisting of 119 genotypes, it was found that the F1 hybrids of Chilean-Brazilian species mostly produced first division restitution (FDR) 2n gametes. These F1 hybrids were self-pollinated in order to obtain F2 seeds, which was an indication that the F1 plants also produced 2neggs simultaneously. All the F2 progeny plants were typical allotetraploids, most of which formed 16 bivalents and a small proportion formed multivalents during metaphase I stages of meiosis. Through genomic in situ hybridisation (GISH) it was proved that multivalent formation in F2plants, derived from A. inodora ×A. pelegrina hybrid, was due to homoeologous recombination but not from reciprocal translocations. In order to test the segregation pattern of the recombinant chromosomes, an F3 population from one genotype, P6C49-6, was investigated. The recombinant chromosomes assorted independently from each other supporting the hypothesis that the segregation of chromosomes in ring quadrivalents did not behave like those in translocation heterozygotes. It was concluded that in allopolyploids of Alstroemeria,bilateral sexual polyploidisation could accomplish genetic recombination by both homoeologous crossing-over as well as through the assortment of chromosomes.

  • genetic diversity of chilean and brazilian Alstroemeria species assessed by aflp analysis
    Heredity, 2000
    Co-Authors: Taeho Han, Marjo J De Jeu, Herman J Van Eck, E. Jacobsen
    Abstract:

    One to three accessions of 22 Alstroemeria species, an interspecific hybrid (A. aurea x A. inodora), and single accessions of Bomarea salsilla and Leontochir ovallei were evaluated using the AFLP-marker technique to estimate the genetic diversity within the genus Alstroemeria. Three primer combinations generated 716 markers and discriminated all Alstroemeria species. The dendrogram inferred from the AFLP fingerprints supported the conjecture of the generic separation of the Chilean and Brazilian Alstroemeria species. The principal co-ordinate plot showed the separate allocation of the A. ligtu group and the allocation of A. aurea, which has a wide range of geographical distribution and genetic variation, in the middle of other Alstroemeria species. The genetic distances, based on AFLP markers, determined the genomic contribution of the parents to the interspecific hybrid.

  • direct shoot regeneration from excised leaf explants of in vitro grown seedlings of Alstroemeria l
    Plant Cell Reports, 1997
    Co-Authors: H. S. Lin, M.j. De Jeu, E. Jacobsen
    Abstract:

    A two-step protocol for the induction of shoots from Alstroemeria leaf explants has been developed. Leaf explants with stem node tissue attached were incubated on shoot induction medium for 10 days, and then transferred to regeneration medium. Shoots from the area adjacent to the region between the leaf base and node tissue regenerated within 3 weeks after transfer to the regeneration medium, without a callus phase. The best induction was obtained with Murashige and Skoog medium containing 10 µm thidiazuron and 0.5 µm indole butyric acid. The regeneration medium contained 2.2 µm 6-benzylaminopurine. After several subcultures of the leaf explants with induced shoots, normal plantlets with rhizome were formed. In Alstroemeria, the percentage of responding leaf explants is more important than the number of shoots regenerated per leaf explant, because rhizome formation is the most important factor for micropropagation. The effect of other compounds in the induction medium, including glucose, sucrose, silver nitrate, and ancymidol, on regeneration was also investigated.

  • plant regeneration through somatic embryogenesis from callus induced on immature embryos of Alstroemeria spp l
    Plant Cell Reports, 1996
    Co-Authors: C E Van Schaik, M.j. De Jeu, A Posthuma, E. Jacobsen
    Abstract:

    The plant regeneration ability of callus obtained from zygotic embryos of the monocot Alstroemeria spp. was studied. The best explants for somatic embryogenesis were immature zygotic embryos in half-ovules when the endosperm was still soft and white. For 2 genotypes embryogenic callus was induced on callus induction medium with a success rate of 54%. The best callus induction period was 10 weeks. The morphology of embryogenic callus was nodular. Somatic embryos were formed after transfer of the callus to regeneration medium. These somatic embryos revealed later on the typical features of zygotic Alstroemeria embryos. The total duration of the plant regeneration protocol, from inoculation till rooted plantlets ready for transfer to the greenhouse, was 28 weeks.

M.s. Ramanna - One of the best experts on this subject based on the ideXlab platform.

  • occurrence of numerically unreduced 2n gametes in Alstroemeria interspecific hybrids and their significance for sexual polyploidisation
    Euphytica, 2003
    Co-Authors: M.s. Ramanna, A G J Kuipers, E. Jacobsen
    Abstract:

    The F1 hybrids of seven diploid Alstroemeria species (2n=2x=16) were investigated for the production of numerically unreduced (2n) gametes and their mode of origin. Based on a survey of 17 interspecific hybrid combinations,consisting of 119 genotypes, it was found that the F1 hybrids of Chilean-Brazilian species mostly produced first division restitution (FDR) 2n gametes. These F1 hybrids were self-pollinated in order to obtain F2 seeds, which was an indication that the F1 plants also produced 2neggs simultaneously. All the F2 progeny plants were typical allotetraploids, most of which formed 16 bivalents and a small proportion formed multivalents during metaphase I stages of meiosis. Through genomic in situ hybridisation (GISH) it was proved that multivalent formation in F2plants, derived from A. inodora ×A. pelegrina hybrid, was due to homoeologous recombination but not from reciprocal translocations. In order to test the segregation pattern of the recombinant chromosomes, an F3 population from one genotype, P6C49-6, was investigated. The recombinant chromosomes assorted independently from each other supporting the hypothesis that the segregation of chromosomes in ring quadrivalents did not behave like those in translocation heterozygotes. It was concluded that in allopolyploids of Alstroemeria,bilateral sexual polyploidisation could accomplish genetic recombination by both homoeologous crossing-over as well as through the assortment of chromosomes.

  • molecular cytogenetics of Alstroemeria identification of parental genomes in interspecific hybrids and characterization of repetitive dna families in constitutive heterochromatin
    Chromosome Research, 1997
    Co-Authors: Anja G J Kuipers, D P M Van Os, J H De Jong, M.s. Ramanna
    Abstract:

    The genus Alstroemeria consists of diploid(2n=2x=16) species originating mainly from Chile and Brazil. Most cultivars are triploid or tetraploid interspecific hybrids. C-banding of eight species revealed obvious differentiation of constitutive heterochromatin within the genus. The present study focused on the molecular (cyto)genetic background of this differentiation. Genomic slot-blot analysis demonstrated strong conservation of major parts of the genomes among six species. The chromosomes of A. aurea and A. ligtu, species with pronounced interstitial C-bands, were found to contain large amounts of highly repetitive and species-specific DNA. The variation in size,number and intensity of strongly probed bands of major repetitive DNA families observed in genomic Southern blots of Sau3A, HaeIII, and MseI digests indicated a strong correlation between variation in genomic DNA composition and different C-banding patterns among Alstroemeria species. Genomic in situ hybridization (GISH)revealed a clear distinction between parental chromosomes in the hybrids between Chilean and Brazilian species and also between Chilean species, as long as at least one of the parental species possessed prominent C-banding. Regarding the latter, discriminative hybridization resulted from highly repetitive species specific DNA in the heterochromatic chromosome regions of A. aurea and A. ligtu, and caused GISH banding patterns that coincided with the C-banding patterns.

  • giemsa c banded karyotypes of eight species of Alstroemeria l and some of their hybrids
    Annals of Botany, 1996
    Co-Authors: J.h. Buitendijk, M.s. Ramanna
    Abstract:

    Abstract Karyotype analysis of Alstroemeria angustifolia ssp. angustifolia, A. aurea, A. inodora, A. ligtu spp. ligtu, A. magnifica ssp. magnifica, A. pelegrina, A. philippii and A. psittacina using Feulgen-staining and Giemsa C-banding techniques revealed for each species a characteristic chromosome morphology and C-banding pattern. These characteristics could be used to identify many individual chromosomes in diploid interspecific hybrids. Besides interspecific variation, some degree of intraspecific variation in C-banding pattern was observed within A. angustifolia ssp. angustifolia, A. aurea, A. ligtu ssp. ligtu, A. magnifica ssp. magnifica and A. philippii . All species had large chromosomes (2 n =2 x =16) and asymmetric karyotypes. In many species the short arms of the acrocentric chromosomes were darkly stained upon Giemsa C-banding. These telomeric bands seemed satellites. B-chromosomes were observed in one species, A. angustifolia ssp. angustifolia . A variable number of large intercalary and telomeric C-bands was present in the Chilean species, whereas the Brazilian species showed only small C-bands. The differences in karyotypes suggest an early separation of the Chilean and Brazilian species, after which speciation followed different evolutionary pathways. In Alstroemeria the Giemsa C-banding technique can be valuable to plant taxonomists for unravelling species relationships.

  • Embryo rescue by half-ovule culture for the production of interspecific hybrids in Alstroemeria
    Scientia Horticulturae, 1995
    Co-Authors: J.h. Buitendijk, N. Pinsonneaux, A.c. Van Donk, M.s. Ramanna, A.a.m. Van Lammeren
    Abstract:

    Abstract Interspecific hybridization in the genus Alstroemeria is hindered by post-fertilization barriers. Histological analysis revealed poor endosperm development from 18 days after pollination onwards, followed by malformation and abortion of embryos. To create interspecific hybrids between Alstroemeria aurea, Alstroemeria pelegrina, Alstroemeria magnifica, Alstroemeria inodora and Alstroemeria psittacina in diallelic combinations, an ovule culture technique was developed. Influence of age of ovules, sucrose concentration of medium and temperature and light during culture were tested. Harvesting ovules before the onset of endosperm degeneration, i.e. at 14 days after pollination, cutting them into halves and culturing the micropylar halves in a rotating liquid culture medium containing 6% sucrose at 21 °C in the dark, led to successful embryo rescue. Germinated embryos were subcultured in vitro until rhizomes were formed, a prerequisite for successful transfer to the greenhouse. Full grown plants all showed interspecific morphological traits and analysis of chromosome complement confirmed their hybrid nature. Diploid hybrid plants were obtained in all the 20 interspecific 2 x -2 x combinations. A total of 260 interspecific hybrid plants was produced. Half-ovule culture of 2 x -4 x and 4 x -2 x crosses resulted in 43 triploid hybrid plants. Because interspecific hybrids were obtained in 100% of the interspecific combinations, it is expected that the described technique can be applied to overcome post-fertilization barriers in most crosses within the genus Aktroemeria .