Growth of Common Plants of Boreal Reclamation Sites in Cake Mixes and Process Water of Oil Sands Tailings

Oil sands surface mining and processing in Alberta generate large volumes of fluid tailings and process water high in salts and metals, which must be reclaimed. We investigated growth of four common plants (two native and two non-native) found in boreal oil sands reclamation sites as influenced by substrate type (tailings cake, and mixtures of cake-sand, cake-peat, and cake-forest floor mineral mix) and water quality (0%, 50%, and 100% oil sands process water). Overall, cake-peat supported the highest aboveground biomass among substrates whereas cake and cake-sand performed poorly, possibly due to high sodium and chloride concentrations. Adding process water to substrates generally reduced growth or increased mortality. Grasses had greater growth than forbs, and for each functional group, non-native species performed better than native species. Hordeum vulgare had the highest overall growth with no mortality followed by Agropyron trachycaulum with negligible (0.5%) mortality. Chamerion angustifolium was most affected by the treatments with the lowest growth and highest mortality (56%). Sonchus arvensis had higher growth than C. angustifolium but its slow growth makes it less suitable for reclaiming tailings. Our results indicate that H. vulgare and A. trachycaulum could be good candidates for use in initial reclamation of oil sands tailings.

Threatened dry grasslands in the continental boreal forests of Wood Buffalo National Park: commentary

There are three primary types of graminoid-dominated communities in or near Wood Buffalo National Park, Canada: freshwater meadows and marshes composed of Calamagrostis canadensis (Michx.) Beauv., Carex atherodes Spreng., Carex aquatilis Wahlenb., Scolochloa festucacea (Willd.) Link, and Poa L.; saline meadows composed of Hordeum jubatum L., Puccinellia nuttalliana (Schult.) A.S. Hitchc.,Agropyron trachycaulum (Link) Malte, Calamagrostis stricta (Timm) Koeler, and Calamagrostis inexpansa A. Gray; and dry grasslands composed of Agropyron trachycaulum, Stipa L., Carex siccata Dewey, Carex obtusata Lilj., and Koeleria macrantha (Ledeb.) J.A. Schultes f. Except for the Peace Point area, it is not known whether dry grasslands have declined in areal extent. Including various wetlands under "dry grasslands", and concluding that these areas no longer support dry grassland is misleading. Dry grasslands exist in Wood Buffalo National Park, but most graminoid-dominated communities in the park are, and have been, freshwater and saline meadows and marshes. A clear understanding of the ecological factors operating in these different ecosystems is critical to informed management.Key words: fire, grassland, prairie, vegetation, wetland, Wood Buffalo National Park.

Association of salt tolerance at seedling emergence with adult plant performance in slender wheatgrass

Regrowth of 15 slender wheatgrass (SWG, Elymus trachycalus sp. Trachycalus (= Agropyron trachycaulum Link Malte) lines was evaluated after 3 (harvest-one) and 11 wk (harvest-two) after clipping at four salinity levels. Lines were previously categorized into salt-tolerant (TOL) and non salt-tolerant (NT) accessions based on percent emergence at 15 mS cm−1 relative to a salt-tolerant control, tall wheatgrass (TWG, Agropyron elongatum (Host) Beauv. [= Thinopyron ponticum (Podpera) Lu & Wong]. Regrowth of five TOL, five NT, five untested (UT) SWG lines and TWG were compared in a greenhouse with nutrient solutions salinized to ECe values of 2, 7, 15, and 23 mS cm−1. Regrowth of all SWG lines decreased from 68 to 98% as salinity increased. Orbit tall wheatgrass shoots were about threefold larger than SWG shoots at 15 and 23 mS cm−1. Phenological development of NT lines was slower (P ≤ 0.05) than that of TOL and UT lines at all ECe levels. However, shoot growth of NT lines exceeded (P ≤ 0.05) that of TOL lines at 23 mS cm−1. Regrowth after 3 and 11 wk were correlated within ECe levels, (r = 0.22 to r = 0.34, P ≤ 0.01). Lack of a positive relationship between lines selected for emergence in saline media and their subsequent growth under saline conditions indicates that improvements in adult plant growth under saline conditions will require additional selection for appropriate traits in SWG. Key words: Slender wheatgrass, Elymus trachycalus sp. trachycalus (= Agropyron trachycaulum Link Malte), tall wheatgrass, Agropyron elongatum (Host) Beauv. (= Thinopyron ponticum (Podpera) Lu & Wong), salt tolerance, genetic screening, emergence

Forage Fibre Analyses: a Comparison of Two Techniques.

Forage fibre content is frequently used as index of forage quality where high fibre content indicates low forage quality. Fibre content is usually estimated by the familiar ADF technique. An alternative method, the acid-pepsin digestibility (AP) technique, provides an estimate of forage digestibility where low digestibility indicates a high fibre content. Fibre content estimates in herbaceous forage (Carex atherodes, C. aquatilis, Phalaris arundinacea, Calamagrostis spp., Agropyron trachycaulum [Elymus trachycaulus] and Hordeum jubatum) were compared by the ADF and AP techniques. There was a strong negative correlation between the fibre content, as determined by ADF, and the digestibility, as determined by AP, in a wide variety of herbaceous forages. This suggests that both techniques provide a very similar estimate of forage quality in herbaceous forages. Contrastingly, a similar analysis on Salix spp. and lichen showed a poor correlation between techniques, suggesting dissimilar estimates of fibre content of these forages.

Phenology of northern populations of halophytic C3 and C4 grasses

Phenological analyses of halophytic grasses in Saskatchewan (52°N latitude) showed that regrowth began earlier in the C3 species, Agropyron trachycaulum (Link) Malte and Puccinellia nuttalliana (Schulte.) Hitchc. than in the C4 species, Spartina gracilis Trin. and Distichlis stricta (Torr.) Rydb. Maximum plant height was reached at about the same time in both C3 and C4 species. C3 grasses had the maximum number of green leaves per plant during spring and autumn, and C4 grasses had these during midsummer. Species on a strongly saline site (P. nuttalliana and D. stricta) began flowering earlier than those on a moderately saline site (A. trachycaulum and S. gracilis). Within each site, C3 and C4 species flowered almost simultaneously. The results indicate that at cool northern latitudes temporal niche separation in C3 and C4 grasses is most evident in vegetative characteristics. Key words: phenology, C3, C4, halophytes, temporal niche separation.

A study on genomic relationships of Agropyron trachycaulum with Elymus scabriglumis, E. innovatus, and Hordeum procerum

Synthetic hybrids of Agropyron trachycaulum (2n = 4x = 28) with Elymus scabriglumis (2n = 6x = 42), E. innovatus (2n = 4x = 28), and Hordeum procerum (2n = 6x = 42) were produced through the embryo rescue technique, at relative frequencies of 7.1, 4.2, and 1.8%, respectively, of pollinated florets. The mean chromosome associations in two hybrids with E. scabriglumis was 11.71II + 1.47III + 0.15IV (mean chiasma frequency = 22.75), in one hybrid with H. procerum was 7.27II + 0.63III + 0.09IV (mean chiasma frequency = 10.20) and in a hybrid with E. innovatus was 2.8II (2.19 chiasma frequency). The data suggested two common genomes (S and H) with E. scabriglumis, one common genome (H) with H. procerum, and no common genome with E. innovatus. The evidence obtained suggested a SSHHYY genomic constitution for E. scabriglumis and two genomes different from SH for E. innovatus. The evidence also suggested that in H. procerum there may not be two related genomes present (derived from H. jubatum) as speculated in some earlier studies.Key words: intergeneric hybrids, Agropyron, Elymus, Hordeum, chromosome pairing.

Genomic affinities of individual chromosomes based on C- and N-banding analyses of tetraploid Elymus species and their diploid progenitor species

Giemsa C- and N-banding techniques were used to identify individual somatic chromosomes in the tetraploid (2n = 28) species Elymus trachycaulus (= Agropyron trachycaulum) (genome designation SH) and E. ciliaris (= A. ciliare) (SY) and five diploid progenitor species (2n = 14), Pseudoroegneria spicata (= A. spicatum) (S), P. libanotica (= A. libanoticum) (S), P. stipifolia (= A. stipifolium) (S), Critesion bogdanii (= Hordeum bogdanii) (H), and C. californicum (= H. californicum) (H). Comparisons based on banding patterns of E. trachycaulus and E. ciliaris with parental donor species P. spicata indicated a common S genome origin. The heterochromatin composition of several E. trachycaulus chromosomes were similar to chromosomes of both Critesion species. However, the possible origin of characteristic C- and N-banded chromosomes of E. ciliaris remained undetermined. These patterns of evolution among genomes of E. trachycaulus, E. ciliaris, and their progenitor species proved valuable for the allocation of individual chromosomes into specific genomes. This approach may be useful for the genomic allocation of wheat-Elymus addition lines. Key words: C-banding, N-banding, Elymus, Triticeae, genome.

Chromosome pairing at five ploidy levels in Elymus trachycaulus

An autoallooctaploid (2n = 56) form of Elymus trachycaulus (Link) Gould ex Shinners (previously Agropyron trachycaulum (Link) Malte ex H. F. Lewis) was induced by treating allotetraploid shoots with 0.2% colchicine. Successive backcrossing to tetraploid pollen parents was successful and yielded five hexaploid (2n = 42), one pentaploid (2n = 35), and three hyperploid (2n = 31, 32, 33) plants. Metaphase I of the tetraploids was normal and 14 II chromosomes were observed, almost all of which were ring bivalents. Chromosome pairing in one octaploid, four hexploids, and one pentaploid were 4.38 IV + 0.65 III + 17.84 II + 0.85 I, 13.16 III + 0.84 II + 0.84 I, and 5.82 III + 8.18 II + 1.18 I, respectively. Efficiency of chromsome pairing (chiasmata per chromsome) was highest in tetraploids (1.29), lowest in hexaploids (0.75), and intermediate in both octaploid (0.95) and pentaploid (0.93) plants. The octaploid produced longer and broader leaves than the tetraploid, although the total dry matter produced was 14.3% lower. Total dry matter yield of the hexaploid was on an average 30.04% higher than the tetraploid and the leaves were significantly larger. The hexaploid plants were taller than both the tetraploid and the octaploid plants. Metaphase I pairing in hyperploid 1 (2n = 33) was 4.34 III + 9.66 II + 0.66 I, hyperploid 2 (2n = 32) was 2.98 III 11.03 II + 1.00 I; hyperploid 3 (2n = 30 + 1 t) was 1.97 III + 12.05 II + 0.66 I + 0.33 t. The pattern of chromosome pairing in these hyperploids suggest that they are a quintupal trisomic, a quadrupal trisomic, and a triple trisomic respectively. Backcrossing these hyperploids to euploid pollen parents was successful. Backosses and their progeny should result in a series of primary trisomiclines and some monosomic plants, which would be useful for gene mapping. Key words: octaploid, hexaploid (double triploid), pentaploid, tetraploid, hyperploid, trisomic monosomic, Agropyron.