The Experts below are selected from a list of 61809 Experts worldwide ranked by ideXlab platform
Nathalie Isabel - One of the best experts on this subject based on the ideXlab platform.
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A set of polymorphic EST‐derived markers for Picea species
Molecular Ecology Notes, 2006Co-Authors: Manuel Lamothe, Patrick G. Meirmans, Nathalie IsabelAbstract:A pooled DNA method was used to produce fully informative EST (expressed sequence tag)-derived markers for the Picea genus. Nine markers were produced from 10 cDNA identified as candidates for cold tolerance or embryogenesis. Indels and SNPs (single nucleotide polymorphisms) were characterized from sequences obtained from pools of 10 individuals for each of the three species: Picea glauca (white spruce), Picea mariana (black spruce) and Picea abies (Norway spruce). Indels were present in 28% of the sequences and SNPs with a frequency greater than 10% were present on average in 1.2% of the positions.
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Somatic Embryogenesis in Red Spruce (Picea Rubens Sarg.)
Somatic Embryogenesis in Woody Plants, 1995Co-Authors: Nathalie Isabel, Francine TremblayAbstract:Picea rubens Sarg. (red spruce) is a member of the family Pinaceae, the largest family of conifers. Like the other spruce species, Picea rubens has long straight trunks with a scaly bark, and dense narrow branches that can extend to the ground in open-grown trees (Hosie, 1980). The root system is shallow and the trees are not usually wind-firm. Picea rubens can grow to approximately 21 to 24 m in height and 30 to 60 cm in diameter (Fig. 1). Good cone production usually begins after the tree is 30 years old, with good seed crops every 3 to 8 years (Fowells, 1965).
Yu Fukasawa - One of the best experts on this subject based on the ideXlab platform.
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effects of forest dieback on wood decay saproxylic communities and spruce seedling regeneration on coarse woody debris
Fungal Ecology, 2019Co-Authors: Yu Fukasawa, Yoko Ando, Yoshitaka Oishi, Kimiyo Matsukura, Kunihiro Okano, Zewei Song, Daisuke SakumaAbstract:Abstract Picea is one of the most dominant conifer genera in the Northern Hemisphere and includes species which require coarse woody debris (CWD) as a seedbed for regeneration. To understand the future of forest distribution under global climate change, it is important to investigate regeneration mechanisms in Picea forests on the borders of its distribution. In the present study, we evaluated the biotic factors affecting the establishment of Picea jezoensis var. hondoensis seedlings on CWD in one of its southernmost populations in central Japan, where there is dieback of Picea forest. Amplicon sequencing of the fungal ITS1 region of rDNA obtained from wood samples showed that forest dieback increased the frequency of brown rot fungi in CWD. The frequency of brown-rotted wood, in which wood holocellulose is decayed, increased with dieback intensity. The domination of brown-rotted wood in dieback forests was negatively associated with bryophyte cover which was positively associated with Picea seedling density. Forest dieback itself also had other strong negative effects on bryophytes. Thus, linkages between dead wood and spruce seedlings via bryophytes had collapsed after the dieback event, which may partly be a reason that the spruce forest shifted to and is staying as open grassland.
Peter Engström - One of the best experts on this subject based on the ideXlab platform.
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Molecular evolution of cdc2 pseudogenes in spruce (Picea)
Plant Molecular Biology, 1998Co-Authors: Anders Kvarnheden, Victor A. Albert, Peter EngströmAbstract:The p34cdc2 protein and other cyclin-dependent protein kinases (CDK) are important regulators of eukaryotic cell cycle progression. We have previously cloned a functional cdc2 gene from Picea abies and found it to be part of a family of related sequences, largely consisting of pseudogenes. We now report on the isolation of partial cdc2 pseudogenes from Picea engelmannii and Picea sitchensis, as well as partial functional cdc2 sequences from P. engelmannii, P. sitchensis and Pinus contorta. A high level of conservation between species was detected for these sequences. Phylogenetic analyses of pseudogene and functional cdc2 sequences, as well as the presence of shared insertions or deletions, support the division of most of the cdc2 pseudogenes into two subfamilies. New cdc2 pseudogenes appear to have been formed in Picea at a much higher rate than they have been obliterated by neutral mutations. The pattern of nucleotide changes in the cdc2 pseudogenes, as compared to a presumed ancestral functional cdc2 gene, was similar to that previously found in mammalian pseudogenes, with a strong bias for the transitions C to T and G to A, and the transversions C to A and G to T.
Daisuke Sakuma - One of the best experts on this subject based on the ideXlab platform.
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effects of forest dieback on wood decay saproxylic communities and spruce seedling regeneration on coarse woody debris
Fungal Ecology, 2019Co-Authors: Yu Fukasawa, Yoko Ando, Yoshitaka Oishi, Kimiyo Matsukura, Kunihiro Okano, Zewei Song, Daisuke SakumaAbstract:Abstract Picea is one of the most dominant conifer genera in the Northern Hemisphere and includes species which require coarse woody debris (CWD) as a seedbed for regeneration. To understand the future of forest distribution under global climate change, it is important to investigate regeneration mechanisms in Picea forests on the borders of its distribution. In the present study, we evaluated the biotic factors affecting the establishment of Picea jezoensis var. hondoensis seedlings on CWD in one of its southernmost populations in central Japan, where there is dieback of Picea forest. Amplicon sequencing of the fungal ITS1 region of rDNA obtained from wood samples showed that forest dieback increased the frequency of brown rot fungi in CWD. The frequency of brown-rotted wood, in which wood holocellulose is decayed, increased with dieback intensity. The domination of brown-rotted wood in dieback forests was negatively associated with bryophyte cover which was positively associated with Picea seedling density. Forest dieback itself also had other strong negative effects on bryophytes. Thus, linkages between dead wood and spruce seedlings via bryophytes had collapsed after the dieback event, which may partly be a reason that the spruce forest shifted to and is staying as open grassland.
Martin Lascoux - One of the best experts on this subject based on the ideXlab platform.
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Origin and demographic history of the endemic Taiwan spruce (Picea morrisonicola)
Ecology and evolution, 2013Co-Authors: Sofia Bodare, Michael Stocks, Jeng-chuann Yang, Martin LascouxAbstract:Taiwan spruce (Picea morrisonicola) is a vulnerable conifer species endemic to the island of Taiwan. A warming climate and competition from subtropical tree species has limited the range of Taiwan spruce to the higher altitudes of the island. Using seeds sampled from an area in the central mountain range of Taiwan, 15 nuclear loci were sequenced in order to measure genetic variation and to assess the long-term genetic stability of the species. Genetic diversity is low and comparable to other spruce species with limited ranges such as Picea breweriana, Picea chihuahuana, and Picea schrenkiana. Importantly, analysis using approximate Bayesian computation (ABC) provides evidence for a drastic decline in the effective population size approximately 0.3–0.5 million years ago (mya). We used simulations to show that this is unlikely to be a false-positive result due to the limited sample used here. To investigate the phylogenetic origin of Taiwan spruce, additional sequencing was performed in the Chinese spruce Picea wilsonii and combined with previously published data for three other mainland China species, Picea purpurea, Picea likiangensis, and P. schrenkiana. Analysis of population structure revealed that P. morrisonicola clusters most closely with P. wilsonii, and coalescent analyses using the program MIMAR dated the split to 4–8 mya, coincidental to the formation of Taiwan. Considering the population decrease that occurred after the split, however, led to a much more recent origin.
