scholarly journals D�veloppement de mod�les pr�dictifs des proportions de duramen et d'�corce des esp�ces de m�l�ze cultiv�es en zones de basse altitude en Europe de l'Ouest (Larix kaempferi (Lambert) Carr., Larix decidua Miller et Larix eurolepis Henry)

2003 ◽  
Vol 60 (3) ◽  
pp. 227-235
Author(s):  
Dominique Pauwels ◽  
Philippe Lejeune ◽  
Luc E. P�ques ◽  
Jacques Rondeux
Keyword(s):  
Larix Decidua ◽  
Larix Kaempferi

A novel approach for the operational production of hybrid larch seeds under northern climatic conditions

2008 ◽  
Vol 84 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Fabienne Colas ◽  
Martin Perron ◽  
Denise Tousignant ◽  
Carol Parent ◽  
Monique Pelletier ◽  
...  
Keyword(s):  
Wood Quality ◽  
Time Lag ◽  
Seed Orchard ◽  
Larix Decidua ◽  
Climatic Conditions ◽  
Snow Accumulation ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
Hybrid Larch ◽  
European Larch

Hybrid larch ([Larix × marschlinsii Coaz], HL) is sought after by the forest industry because of its growth characteristics, excellent wood quality and disease resistance. However, the difficulty in obtaining HL seeds limits the production of seedlings for reforestation. Both European larch (Larix decidua Mill.) and Japanese larch (Larix kaempferi [Lamb.] Carrière) produce few seeds and the time lag in their flowering phenology complicates their natural pollination. We have developed a novel type of sheltered seed orchard, dedicated to the production of HL seeds from grafts grown in pots. Inverting the arches of a conventional tunnel provides a sturdy structure which is easy to maintain. Because of its height, the tunnel can accommodate the rapid growth of the trees, which reduces the need for pruning. The tunnels are covered in the winter and spring. In the winter, the covers prevent snow accumulation. In the spring, they create a "greenhouse effect" inside the tunnels, accelerating flower development, preventing pollen contamination from trees outside the tunnels and protecting the flowers from late spring frosts. Over the past five years, flowering has been regular and abundant. Bagging the crowns for pollen harvest is cost-effective and yields large quantities of high quality pollen. Pollination operations are conducted using an electrostatic pistol. Because of the large number of available clones, large quantities of seeds with a high genetic variability can be produced at a competitive cost. In 2006, this seed orchard concept was implemented operationally at the Berthier forest nursery (Québec, Canada). Key words: Japanese larch (Larix kaempferi [Lamb.] Carrière), European larch (Larix decidua Mill.), seed production, electrostatic pollination, indoor seed orchard

scholarly journals Comparative Repeat Profiling of Two Closely Related Conifers (Larix decidua and Larix kaempferi) Reveals High Genome Similarity With Only Few Fast-Evolving Satellite DNAs

2021 ◽  
Vol 12 ◽  
Author(s):  
Tony Heitkam ◽  
Luise Schulte ◽  
Beatrice Weber ◽  
Susan Liedtke ◽  
Sarah Breitenbach ◽  
...  
Keyword(s):  
Genome Evolution ◽  
Large Scale ◽  
Larix Decidua ◽  
Larix Kaempferi ◽  
Base Pairs ◽  
Satellite Dnas ◽  
Genomic Changes ◽  
Repeat Class ◽  
Organizational Patterns ◽  
Low Coverage

In eukaryotic genomes, cycles of repeat expansion and removal lead to large-scale genomic changes and propel organisms forward in evolution. However, in conifers, active repeat removal is thought to be limited, leading to expansions of their genomes, mostly exceeding 10 giga base pairs. As a result, conifer genomes are largely littered with fragmented and decayed repeats. Here, we aim to investigate how the repeat landscapes of two related conifers have diverged, given the conifers’ accumulative genome evolution mode. For this, we applied low-coverage sequencing and read clustering to the genomes of European and Japanese larch, Larix decidua (Lamb.) Carrière and Larix kaempferi (Mill.), that arose from a common ancestor, but are now geographically isolated. We found that both Larix species harbored largely similar repeat landscapes, especially regarding the transposable element content. To pin down possible genomic changes, we focused on the repeat class with the fastest sequence turnover: satellite DNAs (satDNAs). Using comparative bioinformatics, Southern, and fluorescent in situ hybridization, we reveal the satDNAs’ organizational patterns, their abundances, and chromosomal locations. Four out of the five identified satDNAs are widespread in the Larix genus, with two even present in the more distantly related Pseudotsuga and Abies genera. Unexpectedly, the EulaSat3 family was restricted to L. decidua and absent from L. kaempferi, indicating its evolutionarily young age. Taken together, our results exemplify how the accumulative genome evolution of conifers may limit the overall divergence of repeats after speciation, producing only few repeat-induced genomic novelties.

Two highly divergent 5S rDNA unit size classes occur in composite tandem array in European larch (Larix decidua Mill.) and Japanese larch (Larix kaempferi (Lamb.) Carr.)

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 837-848 ◽  
Author(s):  
Jean-François Trontin ◽  
Catherine Grandemange ◽  
Jean-Michel Favre
Keyword(s):  
Sequence Analysis ◽  
Pinus Radiata ◽  
Sequence Comparison ◽  
5S Rdna ◽  
Larix Decidua ◽  
Tandem Array ◽  
Rrna Genes ◽  
Larix Kaempferi ◽  
Unit Size ◽  
Size Classes

The 5S ribosomal DNA unit structure and organization have been investigated in Larix decidua and Larix kaempferi using selective amplification of gene and spacer, sequence analysis and homologous probe hybridization. Two highly divergent unit size classes of approximately 650 and 870 bp were detected in both species. Sequence analysis in Larix decidua revealed that length variations occur in the middle spacer region and are the result of duplications (in the long spacers) and considerable sequence heterogeneity. Conversely, the transcribed region is of uniform length (120 bp), and the nucleotide sequence of one Larix decidua clone is similar to that reported for other gymnosperms. Sequence comparison of the larch spacers with two other Pinaceae species (Pinus radiata and Picea glauca) showed that the 5' and 3' regions flanking the gene (40 and 60 bp, respectively) are quite conserved, suggesting a regulatory role. Moreover, a small element of about 70 bp located in the middle spacer region was found to be common to the larch long units and the six Pinus radiata spacer clones previously sequenced (64% sequence identity). The short and long unit size classes are mainly organized in composite tandem array(s) with evidence of extensive zones of strict alternation in both species. Mechanisms underlying this unusual association of divergent units in larch 5S rDNA arrays are discussed.Key words: 5S rRNA genes, spacer variations, cluster organization, sequence comparison, Gymnosperms.

scholarly journals Comparative repeat profiling of two closely related conifers (Larix decidua and Larix kaempferi) reveals high genome similarity with only few fast-evolving satellite DNAs

2021 ◽  
Author(s):  
Tony Heitkam ◽  
Luise Schulte ◽  
Beatrice Weber ◽  
Susan Liedtke ◽  
Sarah Breitenbach ◽  
...  
Keyword(s):  
Genome Evolution ◽  
Large Scale ◽  
Larix Decidua ◽  
Larix Kaempferi ◽  
Satellite Dnas ◽  
Genomic Changes ◽  
Repeat Class ◽  
Organizational Patterns ◽  
Low Coverage

ABSTRACTIn eukaryotic genomes, cycles of repeat expansion and removal lead to large-scale genomic changes and propel organisms forward in evolution. However, in conifers, active repeat removal is thought to be limited, leading to expansions of their genomes, mostly exceeding 10 gigabasepairs. As a result, conifer genomes are largely littered with fragmented and decayed repeats. Here, we aim to investigate how the repeat landscapes of two related conifers have diverged, given the conifers’ accumulative genome evolution mode. For this, we applied low coverage sequencing and read clustering to the genomes of European and Japanese larch, Larix decidua (Lamb.) Carrière and Larix kaempferi (Mill.), that arose from a common ancestor, but are now geographically isolated. We found that both Larix species harbored largely similar repeat landscapes, especially regarding the transposable element content. To pin down possible genomic changes, we focused on the repeat class with the fastest sequence turnover: satellite DNAs (satDNAs). Using comparative bioinformatics, Southern, and fluorescent in situ hybridization, we reveal the satDNAs’ organizational patterns, their abundances, and chromosomal locations. Four out of the five identified satDNAs are widespread in the Larix genus, with two even present in the more distantly related Pseudotsuga and Abies genera. Unexpectedly, the EulaSat3 family was restricted to L. decidua and absent from L. kaempferi, indicating its evolutionarily young age. Taken together, our results exemplify how the accumulative genome evolution of conifers may limit the overall divergence of repeats after speciation, producing only few repeat-induced genomic novelties.

Aneuploidy and polyploidization in haploid tissue cultures of Larix decidua

1993 ◽  
Vol 88 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Patrick von Aderkas ◽  
Parker Anderson
Keyword(s):  
Larix Decidua ◽  
Tissue Cultures

Estimation of Carbon Stock and Uptake for Larix kaempferi Lamb.

2016 ◽  
Vol 7 (4) ◽  
pp. 499 ◽  
Author(s):  
Jin-Taek Kang ◽  
Yeong-Mo Son ◽  
Jong-Su Yim ◽  
Ju-Hyeon Jeon
Keyword(s):  
Carbon Stock ◽  
Larix Kaempferi

Community Structure of Soil Macrofauna of Larix kaempferi Plantation in Western Qinling Mountains

2013 ◽  
Vol 19 (4) ◽  
pp. 611-617
Author(s):  
Jiliang LIU ◽  
Jing CAO ◽  
Xiaoyang ZHANG ◽  
Shijie LI ◽  
Chunlin PAN
Keyword(s):  
Community Structure ◽  
Larix Kaempferi ◽  
Qinling Mountains ◽  
Soil Macrofauna ◽  
Western Qinling
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