Author: Bernard Goffinet

Curation of South African plants

Pelargonium barklyi is one of many species endemic to South Africa. Life plants are grown in the BRC greenhouse.

The Biodiversity Research Collection endowment funded major progress in the curation of South African Pelagornium. Dr. Kerri Mocko checked labels for accuracy and digitally imaged ~730 herbarium sheets. Currently comprising ~160 species of the approximately 200 species native to Southern Africa, the CONN collection was assembled in support of the research programs of Dr. Cynthia Jones and Dr. Carl Schlichting. Dr. Mocko, who was present when many of the specimens were collected, verified the accuracy of GPS coordinates and other data entered on each label, a process that was essential prior to adding the collection to the Virtual Herbarium.  While not the largest collection of Pelargonium specimens in the United States, it is the most recent of any of the more extensive collections.

New publication on lichens

Further results from ongoing studies on the diversity of the lichen forming fungal genus Peltigera is being published. Vouchers will be deposited in CONN. Magain N., C. Truong, T. Goward, D. Niu, B. Goffinet, E. Sérusiaux, O. Vitikainen, F. Lutzoni & J. Miadlikowska. 2018. Global species delimitation of Peltigera section Peltigera (lichenized Ascomycota, Lecanoromycetes) reveals high species richness with complex biogeographical history and symbiotic patterns of associations. Taxon 67: 836–870. pdf

Abstract reads: This comprehensive phylogenetic revision of sections Peltigera and Retifoveatae of the cyanolichen genus Peltigera is based on DNA sequences from more than 500 specimens from five continents. We amplified five loci (nrITS, β-tubulin and three intergenic spacers part of colinear orthologous regions [COR]) for the mycobiont, and the rbcLX locus for the cyanobacterial partner Nostoc. Phylogenetic inferences (RAxML, BEAST) and species delimitation methods (bGMYC, bPTP, bPP) suggest the presence of 88 species in section Peltigera, including 50 species new to science, hence uncovering a surprisingly high proportion of previously unnoticed biodiversity. The hypervariable region in ITS1 (ITS1-HR) is a powerful marker to identify species within sections Peltigera and Retifoveatae. Most newly delimited species are restricted to a single biogeographic region, however, up to ten species have a nearly cosmopolitan distribution. The specificity of mycobionts in their association with Nostoc cyanobionts ranges from strict specialists (associate with only one Nostoc phylogroup) to broad generalists (up to eight Nostoc phylogroups uncovered), with widespread species recruiting a broader selection of Nostoc phylogroups than species with limited distributions. In contrast, species from the P. didactyla clade characterized by small thalli and asexual vegetative propagules (soredia) associate with fewer Nostoc phylogroups (i.e., are more specialized) despite their broad distributions, and show significantly higher rates of nucleotide substitutions.

New study on CT plants

The taxonomic status of a putative endemic taxon of Prunus, of which individuals are kept in the UCONN rainforest (i.e., greenhouse) was investigated. The specimens are also deposited in the CONN herbarium.

Klooster M.R., B.A. Connolly, E.M. Benedict, L.C. Gruisha & G.J. Anderson. 2018. Resolving the taxonomic identity of Prunus maritime var. gravesii (Rosaceae) through genotyping analyses using micro satellite loci. Rhodora 120: 187–201. pdf

Abstract reads: Graves’ Beach Plum (Prunus maritima var. gravesii) has been notable for its unique morphological form since a single individual was first discovered on Esker Point in Groton, Connecticut and formally described in 1897. This original clone is now extinct in the wild and is presently kept in cultivation on the University of Connecticut campus, with no additional wild plants discovered in 120 years. It was distinguished morphologically based primarily on its distinctive orbicular leaves, which differ from the ovate leaves found in P. maritima var. maritima. Prior studies have shown few morphological differences between P. maritima var. gravesii and P. maritima var. maritima and full reproductive compatibility has been experimentally observed between the two taxa. However, the few unique characteristics of P. maritima var. gravesii merit further investigation to determine if it has unique molecular differences relative to var. maritima that might lead to the prioritization of conservation and possible reintroduction efforts. Twelve polymorphic microsatellite markers were used to evaluate the genetic composition of 40 P. maritima var. maritima plants from three regional populations (Milford, Connecticut, Waterford, Connecticut, and Weekapaug, Rhode Island) and one additional individual from the type locality of P. maritima var. gravesii. High levels of allelic diversity and heterozygosity were observed among the forty-one samples. Additionally, low levels of genetic differentiation were observed among populations sampled, suggesting regular gene flow occurs among populations. Of the 12 loci studied, P. maritima var. gravesii possessed only one private allele existing in the heterozygotic condition, sharing all other alleles across loci with the P. maritima var. maritima samples. Further evaluations of genetic structure, including principal coordinates analysis and population assignment analysis, revealed the genotypic identity of P. maritima var. gravesii placed it within populations of P. maritima var. maritima and not as a discrete taxon. Therefore, we propose that the current variety classification be changed, and P. maritima var. gravesii should now be considered a naturally occurring but exceptionally rare morphological variant of the widespread P. maritima var. maritima, as P. maritima forma graves.

New publication on plant evolution

Pelargonium barklyi  is not one of the studied species, but it is growing in the UCONN greenhouse.

Tim Moore, a graduate student in the Schlichting lab, led a study now published in the New Phytologist: Moore T.E., C.D. Shlichting, M.E. Aiello-Lammens, K. Mocko& C.S. Jones. 2018. Divergent trait and environment relationships among parallel radiations in Pelargonium (Geraniaceae): a role for evolutionary legacy? New Phytologist 219: 794-807. pdf

The vouchers of the South African plants studied are deposited in the CONN herbarium.

 

 

The abstract reads:

  • Functional traits in closely related lineages are expected to vary similarly along common environmental gradients as a result of shared evolutionary and biogeographic history, or legacy effects, and as a result of biophysical tradeoffs in construction. We test these predictions in Pelargonium, a relatively recent evolutionary radiation.
  • Bayesian phylogenetic mixed effects models assessed, at the subclade level, associations between plant height, leaf area, leaf nitrogen content and leaf mass per area (LMA), and five environmental variables capturing temperature and rainfall gradients across the Greater Cape Floristic Region of South Africa. Trait–trait integration was assessed via pairwise correlations within subclades.
  • Of 20 trait–environment associations, 17 differed among subclades. Signs of regression coefficients diverged for height, leaf area and leaf nitrogen content, but not for LMA. Subclades also differed in trait–trait relationships and these differences were modulated by rainfall seasonality. Leave‐one‐out cross‐validation revealed that whether trait variation was better predicted by environmental predictors or trait–trait integration depended on the clade and trait in question.
  • Legacy signals in trait–environment and trait–trait relationships were apparently lost during the earliest diversification of Pelargonium, but then retained during subsequent subclade evolution. Overall, we demonstrate that global‐scale patterns are poor predictors of patterns of trait variation at finer geographic and taxonomic scales.

 

Student interns in the BRC

Three talented, motivated undergraduates worked in the BRC invertebrate collections for 8 weeks this summer, on various tasks associated with the NSF-sponsored project to rehouse and digitize the Rettenmeyer Army Ant Guest Collection. Andrew Doucette, an MCB major with an EEB minor, Mia Nahom, a rising sophomore with an as-yet undecided major, and Rebecca Trouern-Trend, a rising senior Illustration major.

Mia and Andrew interpreted and entered field card records, transferred and labeled vialed specimens, and ran the “Find the Mite” game for our very successful AntU day. Beck continued the work started by intern Sam Stine, and mounted examples of several hundred army ant colonies to be imaged for the AAGC database. She also is establishing an imaging protocol and taking images.

Mia Nahom was an integral part of the AAGC team this summer. Although she had finished only a year of college, Mia proved exceptionally capable at a variety of tasks associated with NSF-sponsored project to rehouse and digitize the Rettenmeyer Army Ant Guest Collection. She mastered interpreting hand-written field cards and entering pertinent data from them; she learned how to scan microscope slides and edit the images for web access. Mia also tracked down taxonomic changes and organized specimens.

For more stories about the students’ work during this summer visit our  facebook page.

Escape to the UCONN rainforest

As part of AntU activities held July 26, during BugWeek, visitors were invited to escape to the UCONN rainforest, and participate in a pollination scavenger hunt. Close to 300 visitors explored the diverse collection of about 3000 plant species in search of plants developing flowers pollinated by insects. The warm, rainy and humid weather enhanced the experience of a tropical rainforest! Visitors would leave with a free potted plant such as coffee, Cuban oregano or sugar cane! Great day for all involved.

Special thanks to Lauren Stanley, Henry Frye and visiting high school senior from Chicago, Alexandra Kwiecien, for inspiring visitors during their discovery of our local and highly diverse rainforest.