Topic
Tiarella
About: Tiarella is a research topic. Over the lifetime, 27 publications have been published within this topic receiving 331 citations.
Papers
TL;DR: The results demonstrate the importance of brief seasonal periods of strong irradiance to the growth of deciduous forest herbs, even shade-tolerant, summer and evergreen species.
Abstract: Summary 1. We evaluated the potential for three species of deciduous-forest herbs to exploit seasonal periods of direct irradiance. In particular, we investigated the importance of photosynthetic acclimation as a mechanism for shade-tolerant herbs to utilize direct light reaching the forest floor before canopy expansion in the spring and after canopy leaf drop in the autumn. 2. We measured the photosynthetic and growth characteristics of three co-occurring herbs of a northern hardwood forest: the spring ephemeral Allium tricoccum Ait., the summer-green Viola pubescens Ait., and the semi-evergreen Tiarella cordifolia L. 3. Leaf CO 2 exchange, leaf mass per area, and leaf biochemistry differed among species and seasonally within species to match the changing light environment below the forest canopy. From spring to summer, as irradiance dropped with the expansion of the overstorey canopy, Viola leaves exhibited reduction of both photosynthetic capacity and light compensation point. Weaker acclimation of less magnitude occurred in Tiarella leaves over the spring‐summer light transition; this was followed by further acclimation to the stronger autumn irradiance. 4. Viola ’s greater range of photosynthetic acclimation was associated with shifts in allocation between Rubisco and chlorophyll, as well as changes in total leaf nitrogen (N) concentration and leaf mass per area (LMA). In contrast, Tiarella ’s narrow range of acclimation was associated solely with changes in allocation to Rubisco versus chlorophyll, with no changes in total leaf N or LMA. 5. Seasonal changes in leaf chemistry and structure in Viola suggest a stepwise ontogeny whereby individual leaves are able to function as ‘sun leaves’ for 3‐5 weeks in the spring, and then as ‘shade leaves’ for up to 3 months in the summer. 6. Whole-plant biomass accumulation showed that all three species accumulated most of their annual biomass increment during periods of direct irradiance. These results demonstrate the importance of brief seasonal periods of strong irradiance to the growth of deciduous forest herbs, even shade-tolerant, summer and evergreen species.
140 citations
TL;DR: Investigation of plastome evolution across the Saxifragaceae family, reconstructed the phylogeny of the Heuchera group and examined putative plastid capture between Heucera and Tiarella revealed multiple plastids capture events have occurred through putative ancient hybridization, and developed numerous molecular markers for Tiarella.
Abstract: Saxifragaceae, a family of over 600 species and approximately 30 genera of herbaceous perennials, is well-known for intergeneric hybridization. Of the main lineages in this family, the Heuchera group represents a valuable model for the analysis of plastid capture and its impact on phylogeny reconstruction. In this study, we investigated plastome evolution across the family, reconstructed the phylogeny of the Heuchera group and examined putative plastid capture between Heuchera and Tiarella. Seven species (11 individuals) representing Tiarella, as well as Mitella and Heuchera, were selected for genome skimming. We assembled the plastomes, and then compared these to six others published for Saxifragaceae; the plastomes were found to be highly similar in overall size, structure, gene order and content. Moreover, ycf15 was lost due to pseudogenization and rpl2 lost its only intron for all the analyzed plastomes. Comparative plastome analysis revealed that size variations of the plastomes are purely ascribed to the length differences of LSC, SSC, and IRs regions. Using nuclear ITS + ETS and the complete plastome, we fully resolved the species relationships of Tiarella, finding that the genus is monophyletic and the Asian species is most closely related to the western North American species. However, the position of the Heuchera species was highly incongruent between nuclear and plastid data. Comparisons of nuclear and plastid phylogenies revealed that multiple plastid capture events have occurred between Heuchera and Tiarella, through putative ancient hybridization. Moreover, we developed numerous molecular markers for Tiarella (e.g., plastid hotspot and polymorphic nuclear SSRs), which will be useful for future studies on the population genetics and phylogeography of this disjunct genus.
52 citations
TL;DR: Generic relationships suggest generic relationships that agree with those based on morphology, flavonoid chemistry, and crossability of Saxifraginae genera.
Abstract: A base chromosome number of x = 7 characterizes many genera of the Saxifraginae. A high degree of karyotypic constancy was found among species representing six of these genera (Boykinia, Heuchera, Mitella, Sullivantia, Tiarella, and Tolmiea). Boykinia aconitifolia and six species of Sullivantia are characterized by the same karyotype. Four species of Heuchera, Mitella diphylla, Tiarella cordifolia, and Tolmiea menziesii (the last at the tetraploid level) possess a second karyotype that differs from the first in the position of the centromere of only one chromosome pair. These karyological observations suggest generic relationships that agree with those based on morphology, flavonoid chemistry, and crossability.
52 citations
TL;DR: In all three species, there was a balance between acquisition of N and building of biomass over the annual growth cycle, despite dramatic disjunctions between the tissue-specific rates of carbon and N acquisition in Allium and Tiarella.
Abstract: Summary
1
We compared nitrogen (N) uptake and whole-plant N dynamics in three deciduous-forest herbs of contrasting life histories: the spring ephemeral Alliumtricoccum, the summergreen Violapubescens and the semievergreen Tiarellacordifolia. We predicted that differences in above-ground physiology would translate into differences in N acquisition and partitioning, such that nitrogen-use efficiency (NUE) would increase from Allium to Viola to Tiarella.
2
Patterns of N uptake were generally the opposite of our predictions. Allium had the lowest N uptake capacity in both laboratory and field experiments whereas roots of Tiarella had the highest specific N uptake capacity.
3
Viola was the only species in which the specific uptake capacity of roots was related to photosynthetic activity of leaves, both decreasing by a factor of two from spring to summer. In contrast, Tiarella consistently had the lowest photosynthetic capacity and the highest specific uptake capacity whereas Allium maintained substantial root uptake capacity throughout the summer when it had no photosynthetic activity.
4
There were no significant differences between species in overall NUE. However, there were differences in the components of NUE: nitrogen productivity (A) and mean residence time of N in the plant (MRT). Nitrogen productivity increased, and MRT decreased, from Allium to Viola to Tiarella.
5
In all three species, there was a balance between acquisition of N and building of biomass over the annual growth cycle, despite dramatic disjunctions between the tissue-specific rates of carbon and N acquisition in Allium and Tiarella. The variation in A and MRT we observed among co-occurring species of a single N-rich habitat was comparable with that observed by other researchers studying plants adapted to habitats of widely varying N availability.
30 citations
TL;DR: Chromosomal data, as well as evidence from morphology, intergeneric hybridization, flavonoid chemistry, and the host preferences of Puccinia rusts, suggest that Conimitella, Lithophragma, Miteslla, Heuchera, Tiarella, and Tolmiea form the core of a natural group of genera having x = 7.
Abstract: With the exception of Mitella breweri and M. trifida, all North American species of Mitella, Conimitella williamsii, and species of Lithophragma possess essentially identical chromosome morphology. The high degree of karyotypic similarity among genera is further indicated by normal bivalent formation and high pollen stainability in intergeneric hybrids involving Conimitella wil- liamsii and Mitella stauropetala. Conimitella, Lithophragma, and most species of Mitella possess karyotypes that are indistinguishable from those of species of Heuchera, Tolmiea, and Tiarella. Chromosomal data, as well as evidence from morphology, intergeneric hybridization, flavonoid chemistry, and the host preferences of Puccinia rusts, suggest that Conimitella, Lithophragma, Mitella, Heuchera, Tiarella, and Tolmiea form the core of a natural group of genera having x = 7. The monotypic Bensoniella, as well as Elmera and Tellima, differ in chromosome morphology from species of these six genera. Other lines of evidence, including morphology and flavonoid chemistry, indicate, however, that all of these genera are closely allied. A second natural group of genera having x = 7 is composed of Bolandra, Boykinia, Suksdorfia, and Sullivantia. Studies of species throughout Saxifrageae indicate that chromosome morphology is highly conserved in the tribe. Chromosomal data, in conjunction with insights from enzyme electrophoresis, suggest that this group radiated rapidly in North America with little accompanying chromosomal or genetic divergence.
14 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2018 | 1 |
| 2017 | 1 |
| 2016 | 1 |
| 2014 | 1 |
| 2010 | 1 |