S. P. Vander Kloet’s research while affiliated with Acadia University and other places

The efficacy of using vegetative clumps derived from seeds with a variety of origins to establish nuclei for regeneration of bog vegetation on abandoned peat mines in Nova Scotia and New Brunswick (Canada) was tested using seeds within scats (excrement) and seeds from berries, various techniques for creating clumps, and different clump sizes. Direct placement of scat pieces on peat in the field did not produce successful colonisation. Vegetative clumps begun in a greenhouse, whether from seeds extracted from scats or berries, were 60-100 % successful when transplanted into abandoned peat mines depending on the initial size of the transplant. Based on annual growth rate, Vaccinium oxycoccos has the greatest capacity to quickly colonise abandoned peat mines. Other promising taxa were Vaccinium vitis-ideae and the genus Empetrum.

In this report, the inhibition of advanced glycation endproducts (AGEs) by extracts of leaves from a collection of six, mainly tropical, Vaccinium L. spp. (Ericaceae) was examined. Indigenous Peoples have used Vaccinium species to treat symptoms of type I and II diabetes. Sustained hyperglycaemia, often associated with diabetes, facilitates crosslinking of sugars with proteins, producing AGEs. AGEs are a therapeutic target since they are responsible for many diabetes symptoms and contribute to ageing and the development of atherosclerosis, kidney, vascular, and neurological diseases. Vaccinium barandanum S. Vidal, Vaccinium consanguineum Klotzsch, Vaccinium gaultheriifolium (Griff.) Hook. f. ex C.B. Clarke, Vaccinium poasanum Donn. Sm., Vaccinium tonkinense Dop, and Disterigma rimbachii (A.C. Sm.) Luteyn (outgroup) were collected from Sam Vander Kloet’s common garden collection. Ethanolic extracts of leaves of these Vaccinium spp. were potent inhibitors of AGEs. Vaccinium and outgroup species extracts tested in an AGE inhibition assay demonstrated concentration dependent inhibition, with a half maximal inhibitory concentration (IC50) ranging from 4.2 to 16.2 µg·mL–1. Phenolic content ranged from 258 to 626 (µg quercetin equivalents·mg extract–1). Activity and phenolic content show that these tropical accessions have a higher phenolic content (p < 0.001, t test) and AGE inhibition (p < 0.03, t test) than six temperate species from our collections in eastern North America. Significant relationships were found between IC50 and latitude of geographic origin.

The reproductive cycle of the black crowberry (Empetrum nigrum L., Ericaceae) was investigated on exposed headlands on the Atlantic coast of Nova Scotia. At the main study site, Gaff Point, aerial photographs revealed a shoreline retreat rate from 1976 to 2011 (ca. 0.3 m·y–1), with a threefold increase in the rate of heath area loss in the last 10 years relative to the previous 25 years (1976–2001). Empetrum nigrum produces a large crop of berries and sets up seedlings via three main dispersers (gulls, passerines, and mink) at the sea edge and woodland margin. Laboratory study demonstrated that seed germination was scant and slow in the season of berry production but that it was rapid and substantial (mean 33%–50% from berry or scat) for seeds that incubated overwinter in berry or in scat. The largest seed bank coincides with the site of greatest berry production in the heath, but seedlings were not observed in its mat. Most of the scat rain (77%) is deposited at the shore edge and seedlings here are lost to coastal erosion over-winter. Spruce tree understories are the only safe sites for seedling establishment, and if these juveniles become adults of heathland formed after the death of edge trees, the crowberry has an ontogenetic niche shift adapted to climate change. A preliminary checklist is provided for conservation managers of coastal heaths.

The floral volatile composition of four species of Vaccinium was profiled to asses the diversity of the floral chemistry within this genus. Flowers of Vaccinium angustifolium Aiton, Vaccinium varingiaefolium Miq., Vaccinium arboreum Marsh., and Vaccinium poasanum Donn. Sm. were sampled from three or more plants, and volatiles were collected and analyzed by gas chromatography – mass spectroscopy. A total of 45 volatile compounds were detected in the air (headspace) surrounding flowers including 40 from V. angustifolium, 34 for V. varingiaefolium, 37 for V. arboreum, and 17 for V. poasanum. Of the volatile compounds identified, 34 were terpenoids, 6 were benzoids and phenylpropanoids, 4 were aliphatics, and 1 was a miscellaneous cyclic compound. Terpenoids accounted for 98%, 80%, 76%, and 67% of the total volatiles for V. angustifolium, V. varingiaefolium, V. arboreum, and V. poasanum, respectively. The most abundant volatile compound emitted from the flowers of each species was α-pinene for V. angustifolium (23%) and V. arboreum (63%), methyl benzoate for V. varingiaefolium (18%), and ethyl benzene for V. poasanum (21%). Substantial variation was observed in the floral volatile composition of these four Vaccinium species, which may reflect their diverse ecological origins.

The genus Vaccinium contains a wide array of plants distributed throughout the world including several commercial species as well as epiphytic shrubs and lianas in the tropics. Vaccinium dumosum Andrews was reclassified as Gaylussacia dumosa (Andrews) Torr. & A. Gray in 1843 owing to its single seeded 10-locular ovary. Since then, evidence suggests G. dumosa be returned to Vaccinium. In this study, fruit composition of G. dumosa was compared with that of Vaccinium corymbosum L., Vaccinium angustifolium Aiton, Vaccinium gaulteriifolium (Griff.) Hook. f., Vaccinium acrobracteatum K. Sch., and Vaccinium hirsutum Buckley. Ripe fruit from each species were collected and analyzed. In each of the species, primary sugars were glucose and fructose, and acids were quinic, malic, and citric. Total phenolic content correlated with antioxidant capacity. Anthocyanin profiles showed that fruit from each of the species studied contained no pelargonidin glucosides, which are common in fruit of other genera. A total of 27 volatile compounds, dominated by terpenes and several esters, were detected. These volatiles were all found in four of the species including G. dumosa. No volatile compounds were detected in G. dumosa that were not found in the Vaccinium species. Gaylussacia dumosa showed no chemical composition that was significantly different than that of the Vaccinium species surveyed, suggesting that G. dumosa is aligned with Vaccinium.

Seeds extracted from fresh, stratified, and rotting fruit, belonging to seven taxa of Vaccinium as well as from robin scats, were incubated individually on soil agar and potato dextrose agar so that the extent of penetration of fruit rotting agents onto the testa and the effect these rotting agents had on germination could be determined. Micro-organisms grew from the testa in 61% of the 919 vials examined. The maximum of micro-organism species per vial was four, invariably found on seeds from rotting berries and from scats. Few micro-organisms were isolated from fresh fruit. Yeasts were isolated from vials from most treatments, but most frequently from Vaccinium uliginosum. Among the filamentous fungi, Allantophomopsis cytisporea and Botryosphaeria vaccinii were isolated only from cranberries. These fungi were most often associated with decreased germination. Key words: Vaccinium, seed, fruit, fungi, bacteria.

A suite of eight foliar venation characteristics from two closely related sections of Vaccinium L., sect. Macropelma Klotzsch and sect. Myrtillus Dumortier, were analyzed to assess the level of similarity between these sister sections, address the questionable classification of Vaccinium cereum (L.f) Forster, and assess the diagnostic ability of venation characteristics. Our analysis revealed no significant differences in foliar venation characteristics between V. cereum and the Hawaiian species from sect. Macropelma. In addition, all the leaves of V. cereum examined contained the attenuated extended bundle sheath system as found in other representatives from sect. Macropelma. Taximetric analysis showed that these quantitative foliar venation characters were diagnostic at the sectional level but not at the species level. A cluster analysis of 108 operational taxonomic units did separate the two sections but did not discriminate among the 12 individual species. However, a similar taximetric analysis using the character means for each species (for the eight foliar characters), which "smoothed out" the variation due to environmental plasticity, produced a dendrogram which closely resembled the currently accepted Vaccinium classification. Although further investigations into the constancy and reliability of foliar venation characters in the remaining sections of Vaccinium are desirable, our results clearly show that these quantitative vegetative foliar characters do have diagnostic value and can be utilized in taximetric analyses. Key words: Vaccinium, venation, leaf, systematics.

Twenty-nine Vaccinium species were scored for 14 stem and twig characters to determine whether or not vegetative features would support current taxonomic delimitations within the genus. The data obtained show not only that the verrucose characteristic of the twigs, one of the character states that defines Vaccinium section Cyanococcus, is caused by the presence of raised stomata, but also that members of this section have a peculiar mode of periderm development. In addition to the type of periderm development, the occurrence of lignification in twigs and stems was also noted, but was found not to be taxonomically useful at the sectional rank.

Vegetative cover, fruiting phenology, and seed production was estimated from six Vaccinia heathlands on the Avalon Peninsula of Newfoundland so that the efficacy of the Vaccinium seed bank could be ascertained. Out of the six species of Vaccinium present in this vegetation, only V. angustifolium and V. boreale were recovered from 120 soil cores taken; V. uliginosum and V. vitis-idaea, two of the most common species on these heaths, were not represented in the seed bank at all, yet experimentally buried seeds from both these taxa will successfully germinate when exhumed after 6 years of burial. Indeed, 81% of the germinants were from taxa with dry fruits such as Kalmia, Luzula, Juncus, and Agrostis. Paucity of Vaccinium seed in the soil column may be due in part to fungal rot and avian predation. Key words: Vaccinium, seed production, seed banks, heaths.

Self pollen of Vaccinium corymbosum germinates as well as outcross (compatible) pollen from the same population and more rapidly than compatible pollen from more distant populations. When a mixture of self and compatible pollen, either from the same or incontiguous populations, is applied to the stigma, the time required for berry ripening is significantly reduced compared with compatible pollen alone, although seed set also decreases significantly. Adding compatible pollen from different pollen donors significantly increased seed set but also increased the time for berry maturation by 5 days. Self pollen in conjunction with compatible pollen resulted in a 50% loss of viable seed production and an 8% gain in berry maturation time. Self-pollination resulted in embryo abortion in V. corymbosum. Key words: pollination, Vaccinium, seed set, outcrossing.