The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Daniel R Lineberger - One of the best experts on this subject based on the ideXlab platform.
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in vitro rejuvenation of betula Betulaceae morphological evaluation
American Journal of Botany, 1992Co-Authors: Mark H Brand, Daniel R LinebergerAbstract:The extent of rejuvenation that occurs during in vitro culture and propagation of Betula was determined. Comparisons were made between half-sib seedlings and micropropagated, grafted, and cutting-propagated mature-phase birch plants grown under similar conditions. To measure relative levels ofjuvenility, three clones were examined at 1, 4, and 8 mo postpropagation, for differences in stem and leaf morphology and the presence or absence of reproductive structures. Numerous morphological indicators of phase change in Betula were identified. Micropropagated plants are not initially morphologically identical to conventionally propagated mature plants and display many featurcs characteristic of seedlings. Micropropagated plants that exhibited juvenile morphology developed mature morphology more rapidly than did plants grown from seed. However, some mature-phase morphological characteristics did not return to micropropagated plants during the time frame of the study. Rejuvenation of Betula appears to occur during in vitro micropropagation, but the level of juvenility that is regained may not be equivalent to that of a seedling. Not all morphological indicators of phase change are affected equally by in vitro rejuvenation.
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in vitro rejuvenation of betula Betulaceae biochemical evaluation
American Journal of Botany, 1992Co-Authors: Mark H Brand, Daniel R LinebergerAbstract:The pattem of protein production during rejuvenation of in vitro cultured Betula was determined. Comparisons were made between half-sib seedlings and micropropagated, grafted, and cutting-propagated mature-phase birch grown under similar conditions. Three clornes were examined at 1, 4, and 8 mo postpropagation, for differences in total denatured protein and peroxidase and esterase isozymes. Polyacrylamide gel electrophoresis was employed to produce protein banding patterns representative of each type of plant at each time postpropagation. Evaluation of total denatured protein banding patterns indicated that micropropagated plants are initially more like seedlings than mature plants. Peroxidase and esterase isozyme analyses detected differences in isozyme activity and composition between the variously propagated plants and supported evidence provided from the denatured protein patterns. The type of plant part that is evaluated is critical in determining if isozyme banding patterns can be seen. Specific proteins or enzymes that mediate phase change in birch could not be detected consistently between clones or tissue types.
Mark H Brand - One of the best experts on this subject based on the ideXlab platform.
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in vitro rejuvenation of betula Betulaceae morphological evaluation
American Journal of Botany, 1992Co-Authors: Mark H Brand, Daniel R LinebergerAbstract:The extent of rejuvenation that occurs during in vitro culture and propagation of Betula was determined. Comparisons were made between half-sib seedlings and micropropagated, grafted, and cutting-propagated mature-phase birch plants grown under similar conditions. To measure relative levels ofjuvenility, three clones were examined at 1, 4, and 8 mo postpropagation, for differences in stem and leaf morphology and the presence or absence of reproductive structures. Numerous morphological indicators of phase change in Betula were identified. Micropropagated plants are not initially morphologically identical to conventionally propagated mature plants and display many featurcs characteristic of seedlings. Micropropagated plants that exhibited juvenile morphology developed mature morphology more rapidly than did plants grown from seed. However, some mature-phase morphological characteristics did not return to micropropagated plants during the time frame of the study. Rejuvenation of Betula appears to occur during in vitro micropropagation, but the level of juvenility that is regained may not be equivalent to that of a seedling. Not all morphological indicators of phase change are affected equally by in vitro rejuvenation.
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in vitro rejuvenation of betula Betulaceae biochemical evaluation
American Journal of Botany, 1992Co-Authors: Mark H Brand, Daniel R LinebergerAbstract:The pattem of protein production during rejuvenation of in vitro cultured Betula was determined. Comparisons were made between half-sib seedlings and micropropagated, grafted, and cutting-propagated mature-phase birch grown under similar conditions. Three clornes were examined at 1, 4, and 8 mo postpropagation, for differences in total denatured protein and peroxidase and esterase isozymes. Polyacrylamide gel electrophoresis was employed to produce protein banding patterns representative of each type of plant at each time postpropagation. Evaluation of total denatured protein banding patterns indicated that micropropagated plants are initially more like seedlings than mature plants. Peroxidase and esterase isozyme analyses detected differences in isozyme activity and composition between the variously propagated plants and supported evidence provided from the denatured protein patterns. The type of plant part that is evaluated is critical in determining if isozyme banding patterns can be seen. Specific proteins or enzymes that mediate phase change in birch could not be detected consistently between clones or tissue types.
Zhe-kun Zhou - One of the best experts on this subject based on the ideXlab platform.
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Fossil involucres of Ostrya (Betulaceae) from the early Oligocene of Yunnan and their biogeographic implications
Palaeoworld, 2019Co-Authors: Teng-xiang Wang, Jian Huang, Wen-na Ding, Cédric Del Rio, Zhe-kun ZhouAbstract:Abstract A new fossil occurrence of Ostrya (Betulaceae) is reported based on 14 involucre impressions from the lower Oligocene of Lohe Basin, Yunnan Province, Southwest China. They are characterized by their bladder-like shape with longitudinal veins and perpendicular or branched intercostal veins that form a reticulate venation. The discovery of these fossil involucres represents the earliest unequivocal fossil record of Ostrya in East Asia and the record at the lowest latitude. Its fossil history suggests that the modern distribution pattern of Ostrya might have been established since the early Oligocene, and that this genus has inhabited low altitude areas since then.
G. N. Aleksandrova - One of the best experts on this subject based on the ideXlab platform.
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Microbiota and Paleoenvironments of the Turtas Paleobasin, Late Oligocene, Western Siberia
Paleontological Journal, 2019Co-Authors: T. V. Oreshkina, G. N. AleksandrovaAbstract:The Turtas Formation (the Upper Oligocene of Western Siberia), uncovered by the Zyryanka-1 Borehole, contain diverse assemblage of microfossils. The ecological composition (freshwater diatoms, spicules and gemmuloscleres of freshwater sponges, spores and pollen, as well as zygospores of Zygnematales algae) indicates the nonmarine nature of the Early Turtas Basin. In contrast to the assemblage of the Zhuravka horizon (southern regions of Western Siberia), the absence of Fagaceae and dinocysts of the genus Pseudokomewuia , as well as low numbers of Taxodiaceae–Cupressaceae and Betulaceae, are probably explained by local characteristics.
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Microbiota and Paleoenvironments of the Turtas Paleobasin, Late Oligocene, Western Siberia
Paleontological Journal, 2019Co-Authors: T. V. Oreshkina, G. N. AleksandrovaAbstract:The Turtas Formation (the Upper Oligocene of Western Siberia), uncovered by the Zyryanka-1 Borehole, contain diverse assemblage of microfossils. The ecological composition (freshwater diatoms, spicules and gemmuloscleres of freshwater sponges, spores and pollen, as well as zygospores of Zygnematales algae) indicates the nonmarine nature of the Early Turtas Basin. In contrast to the assemblage of the Zhuravka horizon (southern regions of Western Siberia), the absence of Fagaceae and dinocysts of the genus Pseudokomewuia , as well as low numbers of Taxodiaceae–Cupressaceae and Betulaceae, are probably explained by local characteristics.
Tiantian Zhao - One of the best experts on this subject based on the ideXlab platform.
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the complete chloroplast genomes of three Betulaceae species implications for molecular phylogeny and historical biogeography
PeerJ, 2019Co-Authors: Zhen Yang, Guixi Wang, Lisong Liang, Tiantian ZhaoAbstract:Background Previous phylogenetic conclusions on the family Betulaceae were based on either morphological characters or traditional single loci, which may indicate some limitations. The chloroplast genome contains rich polymorphism information, which is very suitable for phylogenetic studies. Thus, we sequenced the chloroplast genome sequences of three Betulaceae species and performed multiple analyses to investigate the genome variation, resolve the phylogenetic relationships, and clarify the divergence history. Methods Chloroplast genomes were sequenced using the high-throughput sequencing. A comparative genomic analysis was conducted to examine the global genome variation and screen the hotspots. Three chloroplast partitions were used to reconstruct the phylogenetic relationships using Maximum Likelihood and Bayesian Inference approaches. Then, molecular dating and biogeographic inferences were conducted based on the whole chloroplast genome data. Results Betulaceae chloroplast genomes consisted of a small single-copy region and a large single copy region, and two copies of inverted repeat regions. Nine hotspots can be used as potential DNA barcodes for species delimitation. Phylogenies strongly supported the division of Betulaceae into two subfamilies: Coryloideae and Betuloideae. The phylogenetic position of Ostryopsis davidiana was controversial among different datasets. The divergence time between subfamily Coryloideae and Betuloideae was about 70.49 Mya, and all six extant genera were inferred to have diverged fully by the middle Oligocene. Betulaceae ancestors were probably originated from the ancient Laurasia. Discussions This research elucidates the potential of chloroplast genome sequences in the application of developing molecular markers, studying evolutionary relationships and historical dynamic of Betulaceae.It also reveals the advantages of using chloroplast genome data to illuminate those phylogenies that have not been well solved yet by traditional approaches in other plants.
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comparative genomics and phylogenetic analysis revealed the chloroplast genome variation and interspecific relationships of corylus Betulaceae species
Frontiers in Plant Science, 2018Co-Authors: Zhen Yang, Lisong Liang, Tiantian Zhao, Guixi WangAbstract:Corylus L. is an economically and phylogenetically important genus in the family Betulaceae. Taxonomic and phylogenetic relationships of Corylus species have long been controversial for lack of effective molecular markers. In this study, the complete chloroplast (cp) genomes of six Corylus species were assembled and characterized using next-generation sequencing. We compared the genome features, repeat sequences, sequence divergence, and constructed the phylogenetic relationships of the six Corylus species. The results indicated that Corylus cp genomes were typical of the standard double-stranded DNA molecule, ranging from 160,445 base pairs (bp) (C. ferox var. thibetca) to 161,621 bp (C. yunnanensis) in length. Each genome contained a pair of inverted repeats (IRs), a large single-copy (LSC) region and a small single-copy (SSC) region. Each of the six cp genomes possessed 113 unique genes arranged in the same order, including 80 protein-coding, 29 tRNA, and 4 rRNA genes. C. yunnanensis contained the highest number of repeat sequences, and the richest SSRs in six cp genomes were A/T mononucleotides. Comparative analyses of six Corylus cp genomes revealed four hotspot regions (trnH-psbA, rpoB-trnC, trnF-ndhJ, and rpl32-trnL) that could be used as potential molecular markers. Phylogenetic analyses of the complete chloroplast genomes and 80 protein-coding genes exhibited nearly identical topologies that strongly supported the monophyly of Corylus and simultaneously revealed the generic relationships among Betulaceae. The availability of these genomes can offer valuable genetic information for further taxonomy, phylogeny, and species delimitation in Corylus or even Betulaceae plants.
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Table_1_Comparative Genomics and Phylogenetic Analysis Revealed the Chloroplast Genome Variation and Interspecific Relationships of Corylus (Betulaceae) Species.XLSX
2018Co-Authors: Zhen Yang, Lisong Liang, Tiantian Zhao, Guixi WangAbstract:Corylus L. is an economically and phylogenetically important genus in the family Betulaceae. Taxonomic and phylogenetic relationships of Corylus species have long been controversial for lack of effective molecular markers. In this study, the complete chloroplast (cp) genomes of six Corylus species were assembled and characterized using next-generation sequencing. We compared the genome features, repeat sequences, sequence divergence, and constructed the phylogenetic relationships of the six Corylus species. The results indicated that Corylus cp genomes were typical of the standard double-stranded DNA molecule, ranging from 160,445 base pairs (bp) (C. ferox var. thibetca) to 161,621 bp (C. yunnanensis) in length. Each genome contained a pair of inverted repeats (IRs), a large single-copy (LSC) region and a small single-copy (SSC) region. Each of the six cp genomes possessed 113 unique genes arranged in the same order, including 80 protein-coding, 29 tRNA, and 4 rRNA genes. C. yunnanensis contained the highest number of repeat sequences, and the richest SSRs in six cp genomes were A/T mononucleotides. Comparative analyses of six Corylus cp genomes revealed four hotspot regions (trnH-psbA, rpoB-trnC, trnF-ndhJ, and rpl32-trnL) that could be used as potential molecular markers. Phylogenetic analyses of the complete chloroplast genomes and 80 protein-coding genes exhibited nearly identical topologies that strongly supported the monophyly of Corylus and simultaneously revealed the generic relationships among Betulaceae. The availability of these genomes can offer valuable genetic information for further taxonomy, phylogeny, and species delimitation in Corylus or even Betulaceae plants.