A method to differentiate summer-dormant from summer-active tall fescue and orchardgrass accessions at germination stage

2008 ◽  
Vol 59 (12) ◽  
pp. 1092 ◽  
Author(s):  
Dariusz P. Malinowski ◽  
David P. Belesky ◽  
Betty A. Kramp ◽  
Joyce Ruckle ◽  
Jaime Kigel ◽  
...  
Keyword(s):  
Tall Fescue ◽  
Weather Conditions ◽  
Perennial Grasses ◽  
Cool Season ◽  
Instantaneous Rate ◽  
Validation Test ◽  
Cultivar Development ◽  
Summer Dormancy ◽  
Mediterranean Origin ◽  
Dactylis Glomerata L

Summer-dormant, cool-season perennial grasses are being used in place of traditional, summer-active cultivars for high-quality winter forage. One reason for this change is the ability of cultivars with summer-dormant attributes to tolerate increasing annual temperature, decreasing precipitation, and repeated severe summer droughts. The mechanism of summer dormancy is still not understood in detail. Cultivar development for summer dormancy typically is conducted under field conditions in environments where summer-active types do not survive summer weather conditions. We developed a method based on germination responses to photoperiod to differentiate summer-dormant from summer-active types of tall fescue [Lolium arundinaceum (Schreb.) S. J. Darbyshire] and orchardgrass (Dactylis glomerata L.). Seed of cultivars with known summer dormancy characteristics was germinated at a constant temperature of 24°C under a range of photoperiods (0–24 h) for 14 days. Total germination, modelled cumulative germination, instantaneous rate of germination, and relative germination (to that in the dark) were analysed. Germination of summer-dormant orchardgrass was similar in the dark and short photoperiods (4–12 h), but it was inhibited by a photoperiod longer than 12 h. Germination of summer-active orchardgrass was promoted by any photoperiod compared with the control (0 h). Short photoperiods (4–12 h) promoted germination of summer-dormant tall fescue, while long photoperiods (>12 h) inhibited germination compared with germination in the dark. Summer-active types of tall fescue did not respond to photoperiod, regardless of length. A validation test using two Mediterranean origin cultivars of orchardgrass with contrasting summer dormancy characteristics and experimental lines of Mediterranean origin tall fescue with known expression of summer dormancy characteristics supported the use of seed germination analysis to differentiate among lines for this trait.

Measuring dehydration tolerance in pasture grasses to improve drought survival

2014 ◽  
Vol 65 (8) ◽  
pp. 828 ◽  
Author(s):  
M. R. Norton ◽  
the late F. Lelièvre ◽  
F. Volaire
Keyword(s):  
Perennial Grasses ◽  
Cool Season ◽  
Breeding Programs ◽  
Dehydration Tolerance ◽  
Pasture Grasses ◽  
Summer Dormancy ◽  
Specific Variation ◽  
Drought Survival ◽  
Dactylis Glomerata L ◽  
Dehydration Avoidance

Cool-season grasses, both annual and perennial, typically employ the strategies of dehydration avoidance and dehydration tolerance to help them to survive extended periods of low soil moisture. Summer dormancy is an extra trait employed by perennial grasses particularly adapted to regions experiencing extended hot, dry summers. Of the three strategies, it appears that least is known about dehydration tolerance. Using and extending a methodology developed for cocksfoot (Dactylis glomerata L.), this study compared a range of cultivars of cocksfoot, tall fescue and phalaris differing in expression of summer dormancy. Both inter- and intra-specific variation in dehydration tolerance was observed, with cocksfoot expressing the trait strongly, whereas it was least evident in phalaris. The trait was more strongly evident in cultivars originating in drier environments, and the ability to express dehydration tolerance appeared to be independent of summer dormancy. It has been confirmed that dehydration tolerance is a powerful drought-survival trait, one that warrants increasing attention in plant breeding programs for drying environments.

Cool season performance of some tall fescue (Festuca arundinacea) lines at Canberra, A.C.T

1969 ◽  
Vol 9 (38) ◽  
pp. 304 ◽  
Author(s):  
CA Neal-Smith ◽  
LG Wright
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Dactylis Glomerata ◽  
Total Production ◽  
Cool Season ◽  
Plant Survival ◽  
Mediterranean Origin ◽  
The Mediterranean

Two trials to compare the seasonal and total production of a selected number of lines of tall fescue (Fescuca arundinacea) were conducted at Canberra, A.C.T., over the period 1961-1967. In the first trial 19 lines, 10 of Mediterranean and 9 of non-Mediterranean origin, were compared under replicated spaced plant conditions for two years. The yields of three Mediterranean lines C.P.I. 18948 (Algeria), 18952, and 18954 (Morocco) were significantly greater than any other line except in 1962 when C.P.I. 26996 (Scotland) and Goar's fescue (C.P.I. 27202) were as productive. In the second trial four of the most productive Mediterranean lines of tall fescue, CV. Demeter, one line of Dactylis glomerata and two lines of Phalaris tuberosa were compared in simulated sward conditions at Canberra from 1965 to 1967. In 1966, a favourable year, production in the Mediterranean tall fescues was little below that of the two phalaris lines, but in 1965 and 1967, both drought years, winter and total production were significantly less. Plant survival in the Algerian and Moroccan tall fescues was greater than in all other grasses in the trial.

Effects of grazing interval on basal cover of four perennial grasses in a summer-dry environment

2000 ◽  
Vol 40 (2) ◽  
pp. 299 ◽  
Author(s):  
J. M. Virgona ◽  
A. Bowcher
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Grass Species ◽  
Basal Cover ◽  
South Wales ◽  
Supplementary Irrigation ◽  
Movement Index ◽  
Dactylis Glomerata L

The response to variation in grazing interval over the spring–autumn period in southern New South Wales was examined on 4 perennial grass species over 2 years. Plots of phalaris (Phalaris aquatica L. cv. Sirolan), cocksfoot (Dactylis glomerata L. cv. Porto), tall fescue (Festuca arundinacea Shreb cv. Demeter) and a native danthonia (Danthonia richardsonii cv. Taranna), were grazed by sheep every 2, 5 or 8 weeks, either rainfed or given supplementary irrigation. Basal cover was monitored over this period and is combined with measurements of phenological development and herbage mass to explain differences in persistence. The seasons differed with respect to rainfall, 1994–95 being dry compared to 1995–96. Over the 1994–95 season, the relative change in basal cover [RCBC, the ratio of final (May 1995) to initial (September 1994) basal cover] of the 3 introduced perennial grasses was significantly less than 1, which indicated a decline in basal cover over the measurement period. In contrast, RCBC was 1.55 for danthonia. Grazing interval treatments significantly affected RCBC in 1994–95, RCBC increasing with grazing interval. In the 8-week grazing interval, RCBC did not significantly differ from 1. Changes in density were also measured in 1994–95 and followed a similar pattern to RCBC for species effects although there was no significant effect of grazing interval. In 1995–96, there were interactions between watering and both species and grazing interval. The RCBC (September 1995–May 1996) was significantly greater than 1 for cocksfoot and tall fescue under irrigated conditions but not under rainfed conditions. The response to grazing interval depended on water supply. The 5-week grazing interval led to the highest RCBC under both rainfed and irrigated conditions. However, when rainfed, the 5- and 8-week treatments were not significantly different, whereas under irrigation, the 2- and 5-week treatments did not significantly differ. For the 1995–96 season, a movement index (MI, ratio of newly colonised area to that occupied throughout the season) was measured. There was a strong interaction between species and watering but phalaris was the most mobile (highest MI) of the 4 species under both rainfed and irrigated conditions. The absence of any interaction between species and grazing interval in either 1994–95 or 1995–96 suggests that response to grazing of these species may be similar despite differences in survival mechanisms.

Perennial grasses of Mediterranean origin offer advantages for central western Victorian sheep pasture

1999 ◽  
Vol 39 (3) ◽  
pp. 275 ◽  
Author(s):  
M. W. Anderson ◽  
P. J. Cunningham ◽  
K. F. M. Reed ◽  
A. Byron
Keyword(s):  
Tall Fescue ◽  
Dry Matter ◽  
Nutritive Value ◽  
Growing Season ◽  
Perennial Grasses ◽  
Selected Lines ◽  
Matter Production ◽  
Mediterranean Origin ◽  
Western Victoria ◽  
Rainfall Region

Perennial ryegrass, tall fescue, cocksfoot and phalaris were evaluated under a rotational grazing regime in the 600 mm rainfall region of western Victoria. Over 4 years, seasonal dry matter production, persistence and nutritive value were assessed. Several selected lines and commercial cultivars were compared. Melik selection tall fescue and Sirosa phalaris significantly (PPP The benefits of Mediterranean genotypes of perennial grasses for improving winter yield and plant longevity is discussed in relation to the need to maximise pasture productivity and improve pasture longevity in environments with a short growing season.

The effect of bovine saliva on growth attributes and forage quality of two contrasting cool season perennial grasses grown in three soils of different fertility

2011 ◽  
Vol 33 (3) ◽  
pp. 307 ◽  
Author(s):  
M. Kerim Gullap ◽  
H. Ibrahim Erkovan ◽  
Ali Koc
Keyword(s):  
Sandy Soil ◽  
Crude Protein ◽  
Sandy Loam ◽  
Forage Quality ◽  
Belowground Biomass ◽  
Perennial Grasses ◽  
Cool Season ◽  
Acid Detergent Fibre ◽  
Dactylis Glomerata L

The aim of this study was to determine the response of Dactylis glomerata L. (Orchardgrass) and Festuca ovina L. (Sheep fescue), to bovine saliva application in a loamy soil (most fertile), a sandy loam and a sandy soil (least fertile). The effects of cutting and cutting + saliva on relative height growth rate (RHGR), above- and belowground biomass and forage quality attributes [crude protein, NDF (neutral detergent fibre) and ADF (acid detergent fibre)] were investigated. The results showed that the cutting and cutting + saliva treatments resulted in greater RHGR than the control, but only with D. glomerata in the sandy soil did the application of saliva increase the RHGR. However, saliva applied after cutting increased the aboveground biomass averaged over all species and all three soils. Saliva applied to D. glomerata increased the belowground biomass in the sandy loam and sandy soils but decreased it in F. ovina in the sandy soil. The application of saliva had no effect on the crude protein or the NDF content of either species in any of the soils. On the other hand, the application of saliva after clipping increased the ADF of F. ovina but decreased that of D. glomerata averaged over all three soils. Averaged over both species, the ADF was increased by the addition of saliva in the sandy soil, had no significant effect in the sandy loam (P > 0.05) and was slightly increased in the loam.

Identification and Measurement of Summer Dormancy in Temperate Perennial Grasses

Crop Science ◽  
2009 ◽  
Vol 49 (6) ◽  
pp. 2347-2352 ◽  
Author(s):  
Mark R. Norton ◽  
F. Volaire ◽  
F. Lelièvre ◽  
S. Fukai
Keyword(s):  
Perennial Grasses ◽  
Summer Dormancy

Use of tall fescue EST-SSR markers in phylogenetic analysis of cool-season forage grasses

Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 637-647 ◽  
Author(s):  
M A. Rouf Mian ◽  
Malay C Saha ◽  
Andrew A Hopkins ◽  
Zeng-Yu Wang
Keyword(s):  
Phylogenetic Analysis ◽  
Ssr Markers ◽  
Tall Fescue ◽  
Related Species ◽  
Grass Species ◽  
Forage Grass ◽  
Forage Grasses ◽  
Cool Season ◽  
Phylogenetic Relations ◽  
Wide Range

Microsatellites or simple sequence repeats (SSRs) are highly useful molecular markers for plant improvement. Expressed sequence tag (EST)-SSR markers have a higher rate of transferability across species than genomic SSR markers and are thus well suited for application in cross-species phylogenetic studies. Our objectives were to examine the amplification of tall fescue EST-SSR markers in 12 grass species representing 8 genera of 4 tribes from 2 subfamilies of Poaceae and the applicability of these markers for phylogenetic analysis of grass species. About 43% of the 145 EST-SSR primer pairs produced PCR bands in all 12 grass species and had high levels of polymorphism in all forage grasses studied. Thus, these markers will be useful in a variety of forage grass species, including the ones tested in this study. SSR marker data were useful in grouping genotypes within each species. Lolium temulentum, a potential model species for cool-season forage grasses, showed a close relation with the major Festuca–Lolium species in the study. Tall wheatgrass was found to be closely related to hexaploid wheat, thereby confirming the known taxonomic relations between these species. While clustering of closely related species was found, the effectiveness of such data in evaluating distantly related species needs further investigations. The phylogenetic trees based on DNA sequences of selected SSR bands were in agreement with the phylogenetic relations based on length polymorphism of SSRs markers. Tall fescue EST-SSR markers depicted phylogenetic relations among a wide range of cool-season forage grass species and thus are an important resource for researchers working with such grass species.Key words: phylogeny, EST-SSR, forage grasses, tall fescue.

Trends and Variability of North American Cool-Season Extratropical Cyclones: 1979–2019

2021 ◽  
Author(s):  
Robert Fritzen ◽  
Victoria Lang ◽  
Vittorio A. Gensini
Keyword(s):  
North American ◽  
Research Question ◽  
Weather Conditions ◽  
Extratropical Cyclones ◽  
Mountain Range ◽  
Cool Season ◽  
The North ◽  
Primary Driver ◽  
Regional Reanalysis ◽  
Log Linear

AbstractExtratropical cyclones are the primary driver of sensible weather conditions across the mid-latitudes of North America, often generating various types of precipitation, gusty non-convective winds, and severe convective storms throughout portions of the annual cycle. Given ongoing modifications of the zonal atmospheric thermal gradient due to anthropogenic forcing, analyzing the historical characteristics of these systems presents an important research question. Using the North American Regional Reanalysis, boreal cool-season (October–April) extratropical cyclones for the period 1979–2019 were identified, tracked, and classified based on their genesis location. Additionally, bomb cyclones—extratropical cyclones that recorded a latitude normalized pressure fall of 24 hPa in 24-hr—were identified and stratified for additional analysis. Cyclone lifespan across the domain exhibits a log-linear relationship, with 99% of all cyclones tracked lasting less than 8 days. On average, ≈ 270 cyclones were tracked across the analysis domain per year, with an average of ≈ 18 year−1 being classified as bomb cyclones. The average number of cyclones in the analysis domain has decreased in the last 20 years from 290 year−1 during the period 1979–1999 to 250 year−1 during the period 2000–2019. Spatially, decreasing trends in the frequency of cyclone track counts were noted across a majority of the analysis domain, with the most significant decreases found in Canada’s Northwest Territories, Colorado, and east of the Graah mountain range. No significant interannual or spatial trends were noted with bomb cyclone frequency.

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