The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Xiangyang Kang - One of the best experts on this subject based on the ideXlab platform.
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oryzalin induced chromosome doubling in triploid populus and its effect on plant morphology and anatomy
Plant Cell Tissue and Organ Culture, 2019Co-Authors: Qingqing Zeng, Kang Du, Xiangyang KangAbstract:Populus is an important economical woody species due to its fast growth. In vitro induction of Hexaploidy and investigation of morphological and anatomical characteristics in ((Populus alba × P. glandulosa) × P. tomentosa) were conducted in this study. Chromosome doubling was induced in vitro in a triploid clone ((Populus alba × P. glandulosa) × P. tomentosa) with oryzalin as a tubulin inhibitor. Nodal sections of 5 and 10 mm were exposed to 2.5 and 5.0 mg l−1 oryzalin for 24, 48 and 72 h. No significant differences in survival rates were observed between the different oryzalin dose, exposure time or nodal length; however, all rates were significantly lower than those in the no-oryzalin controls. The highest frequency of Hexaploidy was 100% for the treatment of 5-mm nodes with 5 mg l−1 oryzalin for 72 h and the treatment of 10-mm nodes with 5 mg l−1 oryzalin for 24 h. The hexaploid plants were distinguishable from the triploid plants by morphological and anatomical characteristics. Chromosome doubling was accompanied by increases in the thickness and chlorophyll content of leaves. The stomata of hexaploids were larger and had a lower density than those of the original triploids. In particular, in triploid-to-hexaploid conversion, roots were less abundant, were shorter and had larger diameters. Root characteristics were determined to be suitable parameters for identifying putative hexaploids because they can be easily and quickly assessed. In vitro induction of Hexaploidy and investigation of morphological and anatomical characteristics of ((Populus alba × P. glandulosa) × P. tomentosa) at different ploidy levels were conducted in this study.
V K Sieber - One of the best experts on this subject based on the ideXlab platform.
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oryzalin induced chromosome doubling in rosa and its effect on plant morphology and pollen viability
Theoretical and Applied Genetics, 2003Co-Authors: Maryam Jafarkhani Kermani, Viswambharan Sarasan, A V Roberts, K Yokoya, J Wentworth, V K SieberAbstract:Shoot tips of the diploid rose Therese Bugnet were treated in vitro to oryzalin at concentrations of 5 and 15 μM. Tetraploid shoots were obtained in highest frequencies (40%) after exposure to 5 μM oryzalin for 14 days. Thin (1 mm) nodal sections were treated with 5 μM oryzalin and the highest frequency of tetraploids (66%) was obtained after exposure for only 1 day. The shorter exposure times required to induce chromosome doubling in thin nodal sections is attributed to the more efficient delivery of oryzalin to the meristem. Tetraploids were obtained from four diploid roses and hexaploids from two triploid roses. Chromosome doubling was accompanied by increases in thickness and a darker green colouration of the leaves and, in all diploid to tetraploid and one triploid to hexaploid conversion, the breadth/length ratio of leaflets was significantly increased. Internodes were longer in tetraploids than diploids but significantly shorter in hexaploids than triploids. The number of petals per flower in the tetraploid form of Therese Bugnet was double that of the diploid. Significant increases in pollen viability accompanied chromosome doubling of all four diploids and one of the two triploids.
Qingqing Zeng - One of the best experts on this subject based on the ideXlab platform.
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oryzalin induced chromosome doubling in triploid populus and its effect on plant morphology and anatomy
Plant Cell Tissue and Organ Culture, 2019Co-Authors: Qingqing Zeng, Kang Du, Xiangyang KangAbstract:Populus is an important economical woody species due to its fast growth. In vitro induction of Hexaploidy and investigation of morphological and anatomical characteristics in ((Populus alba × P. glandulosa) × P. tomentosa) were conducted in this study. Chromosome doubling was induced in vitro in a triploid clone ((Populus alba × P. glandulosa) × P. tomentosa) with oryzalin as a tubulin inhibitor. Nodal sections of 5 and 10 mm were exposed to 2.5 and 5.0 mg l−1 oryzalin for 24, 48 and 72 h. No significant differences in survival rates were observed between the different oryzalin dose, exposure time or nodal length; however, all rates were significantly lower than those in the no-oryzalin controls. The highest frequency of Hexaploidy was 100% for the treatment of 5-mm nodes with 5 mg l−1 oryzalin for 72 h and the treatment of 10-mm nodes with 5 mg l−1 oryzalin for 24 h. The hexaploid plants were distinguishable from the triploid plants by morphological and anatomical characteristics. Chromosome doubling was accompanied by increases in the thickness and chlorophyll content of leaves. The stomata of hexaploids were larger and had a lower density than those of the original triploids. In particular, in triploid-to-hexaploid conversion, roots were less abundant, were shorter and had larger diameters. Root characteristics were determined to be suitable parameters for identifying putative hexaploids because they can be easily and quickly assessed. In vitro induction of Hexaploidy and investigation of morphological and anatomical characteristics of ((Populus alba × P. glandulosa) × P. tomentosa) at different ploidy levels were conducted in this study.
David A Baum - One of the best experts on this subject based on the ideXlab platform.
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whole genome duplication in coast redwood sequoia sempervirens and its implications for explaining the rarity of polyploidy in conifers
New Phytologist, 2016Co-Authors: Alison Dawn Scott, Noah Stenz, Par K Ingvarsson, David A BaumAbstract:Polyploidy is common and an important evolutionary factor in most land plant lineages, but it is rare in gymnosperms. Coast redwood (Sequoia sempervirens) is one of just two polyploid conifer species and the only hexaploid. Evidence from fossil guard cell size suggests that polyploidy in Sequoia dates to the Eocene. Numerous hypotheses about the mechanism of polyploidy and parental genome donors have been proposed, based primarily on morphological and cytological data, but it remains unclear how Sequoia became polyploid and why this lineage overcame an apparent gymnosperm barrier to whole-genome duplication (WGD). We sequenced transcriptomes and used phylogenetic inference, Bayesian concordance analysis and paralog age distributions to resolve relationships among gene copies in hexaploid coast redwood and close relatives. Our data show that Hexaploidy in coast redwood is best explained by autopolyploidy or, if there was allopolyploidy, it happened within the Californian redwood clade. We found that duplicate genes have more similar sequences than expected, given the age of the inferred polyploidization. Conflict between molecular and fossil estimates of WGD can be explained if diploidization occurred very slowly following polyploidization. We extrapolate from this to suggest that the rarity of polyploidy in gymnosperms may be due to slow diploidization in this clade.
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whole genome duplication in coast redwood sequoia sempervirens and its implications for explaining the rarity of polyploidy in conifers
bioRxiv, 2015Co-Authors: Alison Dawn Scott, Noah Stenz, David A BaumAbstract:Whereas polyploidy is common and an important evolutionary factor in most land plant lineages it is a real rarity in gymnosperms. Coast redwood (Sequoia sempervirens) is the only hexaploid conifer and one of just two naturally polyploid conifer species. Numerous hypotheses about the mechanism of polyploidy in Sequoia and parental genome donors have been proffered over the years, primarily based on morphological and cytological data, but it remains unclear how Sequoia became polyploid and why this lineage overcame an apparent gymnosperm barrier to whole-genome duplication (WGD). We sequenced transcriptomes and used phylogenetic inference, Bayesian concordance analysis, and paralog age distributions to resolve relationships among gene copies in hexaploid coast redwood and its close relatives. Our data show that Hexaploidy in the coast redwood lineage is best explained by autopolyploidy or, if there was allopolyploidy, this was restricted to within the Californian redwood clade. We found that duplicate genes have more similar sequences than would be expected given evidence from fossil guard cell size which suggest that polyploidy dates to the Eocene. Conflict between molecular and fossil estimates of WGD can be explained if diploidization occurred very slowly following whole genome duplication. We extrapolate from this to suggest that the rarity of polyploidy in conifers may be due to slow rates of diploidization in this clade.
Kang Du - One of the best experts on this subject based on the ideXlab platform.
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oryzalin induced chromosome doubling in triploid populus and its effect on plant morphology and anatomy
Plant Cell Tissue and Organ Culture, 2019Co-Authors: Qingqing Zeng, Kang Du, Xiangyang KangAbstract:Populus is an important economical woody species due to its fast growth. In vitro induction of Hexaploidy and investigation of morphological and anatomical characteristics in ((Populus alba × P. glandulosa) × P. tomentosa) were conducted in this study. Chromosome doubling was induced in vitro in a triploid clone ((Populus alba × P. glandulosa) × P. tomentosa) with oryzalin as a tubulin inhibitor. Nodal sections of 5 and 10 mm were exposed to 2.5 and 5.0 mg l−1 oryzalin for 24, 48 and 72 h. No significant differences in survival rates were observed between the different oryzalin dose, exposure time or nodal length; however, all rates were significantly lower than those in the no-oryzalin controls. The highest frequency of Hexaploidy was 100% for the treatment of 5-mm nodes with 5 mg l−1 oryzalin for 72 h and the treatment of 10-mm nodes with 5 mg l−1 oryzalin for 24 h. The hexaploid plants were distinguishable from the triploid plants by morphological and anatomical characteristics. Chromosome doubling was accompanied by increases in the thickness and chlorophyll content of leaves. The stomata of hexaploids were larger and had a lower density than those of the original triploids. In particular, in triploid-to-hexaploid conversion, roots were less abundant, were shorter and had larger diameters. Root characteristics were determined to be suitable parameters for identifying putative hexaploids because they can be easily and quickly assessed. In vitro induction of Hexaploidy and investigation of morphological and anatomical characteristics of ((Populus alba × P. glandulosa) × P. tomentosa) at different ploidy levels were conducted in this study.