Festuca Ovina Research Articles

Restoration of foothills rough fescue grassland following pipeline disturbance in southwestern Alberta

The effects of pipeline construction and reclamation techniques on the restoration of rough fescue plant communities following pipeline construction in southwestern Alberta, Canada were evaluated after 7–40 years. The pipeline construction right-of-way (ROW) sites varied from no recovery of rough fescue grassland to moderate recovery. The ROW sites had a higher proportion of introduced grasses and forbs, less topsoil, and poorer rangeland health than the adjacent undisturbed grassland. Within the ROW sites, less topsoil was present on those with larger diameter pipe and which had topsoil fully stripped from the ROW during construction. Introduced grasses, Festuca ovina (sheep fescue) and Poa compressa (Canada bluegrass), succeeded in establishment following seeding and persisted for at least 40 years. Poa pratensis (Kentucky bluegrass) dominated many of the ROW sites. Contributing factors to moderate recovery of rough fescue grassland were related to post-growing season pipeline construction, ideally, between August and March, summer or fall seeding, and minimum disturbance trench-only stripping. Reclamation practices appeared more important than time since restoration in the restoration of rough fescue grassland.

Effects of excluding sheep from an alpine dwarf-herb community

Background: The Festuca ovina–Alchemilla alpina–Silene acaulis dwarf-herb community is a rare component of the few and scattered calcareous grasslands found at high altitude in the Scottish Highlands. It contains nationally scarce and rare arctic-alpine species. The community is often heavily grazed and it has been suggested that it is a plagioclimax maintained by herbivores, principally sheep. Aim: Determine the role of sheep grazing in conserving the dwarf-herb community on Ben Lawers, Perthshire, Scotland. Methods: Sheep-proof cages were erected each spring from 1987 to 1996 and dismantled again each autumn. Species cover, the height of the vegetation, the amount of litter and the extent of bare ground were estimated every summer. Data were analysed by repeated measures analysis of variance. Results: Excluding sheep caused major shifts in the balance amongst species. Initially, graminoids and some forbs increased in cover, the vegetation increased in height and the amount of bare ground decreased. However this was followed by a decline in the cover of graminoids as bryophytes proliferated and litter accumulated. Conclusion: Sheep grazing is essential to the maintenance of the dwarf-herb community. Permanent removal of sheep might lead to the development of bryophyte-rich, tall-herb and/or scrub vegetation.

STUDIEN ÜBER FESTUCA OVINA L. III

HereditasVolume 15, Issue 1 p. 13-16 Open Access STUDIEN ÜBER FESTUCA OVINA L. III WEITERE BEITRÄGE ZUR KENNTNIS DER CHROMOSOMENZAHLEN VIVIPARER FORMEN GÖTE TURESSON, WEIBULLSHOLM, LANDSKRONASearch for more papers by this author GÖTE TURESSON, WEIBULLSHOLM, LANDSKRONASearch for more papers by this author First published: March 1931 https://doi.org/10.1111/j.1601-5223.1931.tb02538.xCitations: 2AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Citing Literature Volume15, Issue1March 1931Pages 13-16 ReferencesRelatedInformation

Effects of Traditional and New Methods on Overcoming Lime-Induced Chlorosis of Grapevine

<i>Vitis vinifera</i> L. cv. Merlot clone R3 grafted on the hybrid <i>Vitis riparia</i> x <i>Vitis rupestris</i> 3309C rootstock was grown in pots containing either calcareous or noncalcareous soil. Three treatments were applied to the plants growing on the calcareous soil: soil application of EDDHA (iron chelate), groundcover with <i>Festuca ovina</i> grass cv. Aurora Gold, and soil application of vivianite (iron phosphate). Shoot growth was recorded and at veraison the chlorosis occurrence and mineral element concentrations of young leaves were analyzed. Grape yield and berry composition were checked at harvest, including soluble solids, titratable acidity, tartaric acid, anthocyanins, polyphenols, and stilbenes. All treatments alleviated chlorosis symptoms over the untreated vines growing on calcareous soil. Grape yield and soluble solids were not affected by the treatments, while acidity, anthocyanins, and polyphenols evolved differently according to treatment. <i>trans</i>-Resveratrol concentration was reduced by all treatments. The floor management with <i>Festuca ovina</i> seems to be an effective, sustainable method to overcome lime-induced chlorosis, as compared with chelate and vivianite application.

OVERCOMING IRON DEFICIENCY CHLOROSIS IN CITRUS THROUGH INTERCROPPING WITH PERENNIAL GRASS SPECIES

The objective of this experiment was to investigate the influence of intercropping with three different perennial grass species (Festuca ovina L., Festuca rubra subsp. tricophylla L. and Poa nemoralis L.) on the Fe nutritional status of citrumelo 'Swingle' (Citrus paradisi Macf. × Poncirus trifoliata), a highly Fe chlorosis susceptible citrus rootstock. One-year old citrumelo plants were grown in pots on calcareous soil-sand mixture under greenhouse conditions and treated as follows: 1) citrumelo plants grown in a monoculture system (without a companion crop); 2) citrumelo plants fertilized with 18.6 mg Fe per plant in form of FeEDDHA; 3) citrumelo plants separately intercropped with the three perennial grass species. These grasses were sown at a rate of 3 seeds cm -2 , mowed only one time and allowed to re-grow. The experiment lasted five months. Chlorophyll measurements were performed on the youngest fully expanded leaves in terms of SPAD index and at the end of the experiment leaf chlorophyll content (μg cm -2 ), leaf length and width and dry weight of young shoots were determined. Intercropping citrumelo plants with F. rubra was effective almost as FeEDDHA in preventing the development of leaf chlorosis and improving their growth compared to the control plants, while those intercropped with F. ovina overcame Fe deficiency symptoms only after mowing/clipping this grass species. The Poa nemoralis did not demonstrate any potential to prevent leaf chlorosis or improve the growth of citrumelo plants. These results indicate that only Fe-efficient perennial grass species can be utilized as an effective ecological orchard floor management practice to improve the Fe nutrition of fruit trees grown on calcareous soils.

THE EFFECTS OF EXCLOSURE ON PLANTS IN THE SEMI-ARID RANGELAND OF NORTH KHORASAN PROVINCE, IRAN

Abstract Over the last fifty years, most of the semi-arid rangeland in Iran has been converted to cropland without an equivalent reduction in grazing animals. This shift has led to heavy grazing pressure on rangeland vegetation. The present study has been conducted in Sisab Research Station in the North Khorasan Province to evaluate effects of long-term grazing exclosures on biodiversity of range plants. The study was initiated in May 2008 using three transects within the exclosure and another three transects near exclosure, each with 100m length in the vicinity of exclosure has been established to determine differences in plant composition between areas that have not been grazed in 22 years with neighboring grazed plant communities. The sampling method was randomized systematic one comprised of 10 plots, each of 1m2 in area. A total of 53 plant species were identified in the study area with the ungrazed plots containing 18 plants more than the grazed plots. The major species were Festuca ovina, Centurea depressa, Stachys turkamanica, Stipa barbata, Astragalus sp and Phelomis cancellata. Grazing impacts on forbs were more pronounced than for grasses and shrubs. Based on Jaccard’s index, there was only a 45% similarity of plant species between the two treatments. Our study led to four generalizations about the current grazing regime and long-term exclosures in the semi-arid rangeland around the study area: (1) exclosures will increase species richness, (2) heavy grazing may have removed some plant species, (3) complete protection from grazing for a prolonged period of time after a long history of grazing disturbance may not lead to an increase in desirable plant species with a concomitant improvement in range condition, and (4) research needs to be conducted to determine how these rangelands can be improved.

Seed Coating and Seeding Rate Effects on Turfgrass Germination and Establishment

A field experiment was conducted at New Mexico State University to investigate the effect of seeding rates and ZEBA polymer [starch-g-poly (2-propenamide-co-propenoic acid) potassium salt] seed coating on the germination and establishment of warm- and cool-season grasses, and cool-season blends and mixtures. Grasses were established at recommended and reduced (50% of recommended) seeding rates with coated and uncoated seeds under two irrigation regimes (98% and 56% reference evapotranspiration). With the exception of ‘Bengal’ creeping bentgrass (Agrostis stolonifera), the polymer coating did not improve germination of the turfgrasses tested 22 days after seeding (DAS). However, at the end of the establishment period (92 DAS), plots established with ‘Bengal’, Dunes Mix [mixture of ‘Hardtop’ hard fescue (Festuca longifolia), ‘Baron’ kentucky bluegrass (Poa pratensis), ‘Barok’ sheep fescue (Festuca ovina)], ‘Panama’ bermudagrass (Cynodon dactylon), and Turf Sense™ [mixture of ‘Baronie’ kentucky bluegrass, ‘Barlennium’ perennial ryegrass (Lolium perenne), and ‘Barcampsia’ tufted hairgrass (Deschampsia cespitosa)] achieved greater coverage (based on visual estimations) when coated seed was used compared with uncoated seed. Establishment was greater for ‘Bengal’, Dunes Mix, ‘Panama’, Turf Sense™, and Turf Saver™ [blend of ‘Barlexas II’, ‘Barrington’, and ‘Labarinth’ tall fescue (Festuca arundinacea)] when normal seeding rates were applied compared with reduced seeding rates. ‘Barleria’ crested hairgrass (Koeleria macrantha) plots did not establish, regardless of the treatments applied. Results showed that seed coating has the potential to improve establishment at recommended and reduced seeding rates and can compensate for less favorable conditions such as reduced irrigation, reduced seeding rate, or for a combination of both. At the end of the establishment period, not all grasses achieved coverage greater than 50%. Further research over a longer establishment period is needed to determine if coated seed can be beneficial in achieving full coverage.

PERFORMANCES OF SOME COOL SEASON TURFGRASS CULTIVARS IN MEDITERRANEAN ENVIRONMENT: II. Festuca arundinacea Schreb., Festuca ovina L., Festuca rubra spp. rubra L., Festuca rubra spp. trichophylla Gaud and Festuca rubra spp. commutata Gaud

The commitment to turf research is more recent and is challenged by the diversity of climatic conditions occurring in Anatolian peninsula of Turkey. These differences in climatic factors and environmental variation may determine the specific adaptation of species to certain areas and complicate the species and cultivar recommendations. In this present study, aiming to evaluate the adaptability and quality of newly introduced cultivars of different cool season turfgrass species in a Mediterranean environment in western Turkey, Bornova-¯zmir, four cultivars of Tall fescue (Festuca arundinacea Schreb), Sheep fescue (Festuca ovina L), Festuca rubra L. spp. trichophlylla Gaud (Slender creeping red fescue) and Festuca rubra spp. rubra commutata Gaud (Chewings red fescue) and six cultivars of Festuca rubra spp. rubra L. (Creeping red fescue) were tested for 3 years (2003-2005) in a replicated experimental block group design. Turf cover, colour and quality traits of these cool season turfgrass cultivars were evaluated by using a visual score (1-9) and the target of the generated information was the support turfgrass specialist in turfgrass cultivars selection and recommendations and research institutions for their breeding programs. Results indicated that tall fescue cultivars were the only genotypes maintaining high scores of cover, colour and quality in different seasons and years. Sheep fescue cultivars were also consistent throughout the experimental years, although their colour, cover and quality scores were not high. We also suggested that all red fescue sub-species were not fully adaptable to Mediterranean conditions and their usage had to be limited in turf mixtures.

Evaluation of Alternative Turfgrass Species for Low-input Golf Course Fairways

As restrictions on water use, fertilization, and pesticide applications continue to increase, golf course superintendents will need to use grass species that require reduced inputs. The objective of this study was to evaluate alternative turfgrass species under low-input fairways conditions. In 2005, 17 species were established on native soil in St. Paul, MN. Each species was evaluated at three levels of traffic (zero, three, or six passes per week using a drum-type traffic simulator) and two mowing heights (1.90 and 2.54 cm). Data collected included turfgrass quality and percent living stand density. In 2006, velvet bentgrass (Agrostis canina L.), colonial bentgrass (Agrostis capillaris L.), and creeping bentgrass (Agrostis stolonifera L.) maintained acceptable quality in all treatment combinations. In 2007, Chewings fescue (Festuca rubra L. ssp. fallax) and sheep fescue (Festuca ovina L.) were the top-performing species regardless of treatment. Hard fescue (Festuca brevipila Tracey) performed poorly in Year 1 and well in Year 2. All other species did not perform at an acceptable level during the study. The results of this study indicate that sheep fescue, Chewings fescue, colonial bentgrass, and velvet bentgrass should be studied further for use on low-input golf course fairways in the northern United States.

Measuring the importance of competition: a new formulation of the problem

Summary 1. Currently, there is a debate among plant ecologists on the concepts of the intensity of competition and the importance of competition, which is central to many issues of modern plant population ecology and plant community ecology. 2. It is problematic that the current measures of intensity and importance of competition, typically, are reported as dimensionless indices because they hide the fact that both indices are functions of plant density and the level of the environmental gradient. 3. Here, a new formulation of the concepts is suggested, which explicitly highlights the functional dependencies on plant density and the level of the environmental gradient. The new measures are a generalization of the previous indices and correspond to the previous indices in the case of a simple experimental design. 4. The suggested measures of the intensity and importance of competition are exemplified using data from a response surface competition experiment between Agrostis capillaris and Festuca ovina along a herbicide gradient, where the expected clear effect of plant density was demonstrated. 5. Synthesis. As the suggested measures of the intensity and importance of competition explicitly highlight the functional dependencies on plant density and the level of the environmental gradient, we think that they will help to ensure a closer connection between experimental plant ecology and the attempts to model plant populations and communities.

Contribution of ploidy‐level variation and adaptive trait diversity to the environmental distribution of taxa in the ‘fine‐leaved fescue’ lineage (genus Festuca subg. Festuca)

AbstractAim We assessed the relative contribution of ploidy‐level variation and adaptive trait diversity to the diversity of taxon realized niches in a plant lineage with several ploidy levels.Location A large number of sites covering a wide range of environmental conditions in France.Methods Our material comprised a collection of populations from several taxa of the ‘fine‐leaved fescue’ lineage, namely section Aulaxyper (Festuca rubra s.l.) and subsection Festuca (Festuca ovina s.l.) of the subgenus Festuca. This collection was assessed for several traits related to vegetative growth, investment in seed production, morphology and phenology. Environmental parameters that best differentiate taxon‐realized niches were identified by multivariate ordination and logistic regression. Canonical correlation analyses were performed to relate plant traits and ploidy‐level variation to these environmental parameters. Taxon differentiation was assessed along the first canonical directions of the plant descriptor (plant‐trait and ploidy‐level) space.Results The climatic summer water balance, soil texture and land use were identified as the main environmental parameters differentiating taxon realized niches. Canonical correlation analyses revealed associations between plant traits and these environmental parameters, independent of ploidy‐level variation. More specifically, the production of long and abundant rhizomes appeared to be an efficient adaptation to poor climatic summer water balance. In contrast, the ploidy level was rather weakly associated with environmental parameters. The marked prevalence of high ploidy levels in the collection suggests that they could have a competitive advantage in the range of environmental conditions investigated.Main conclusions Adaptive trait diversity appears to contribute more than ploidy‐level variation to the present diversity of realized niches for fine‐leaved fescue taxa, although plant‐trait variations were associated to some extent with ploidy‐level variation. However, cytotypes with high ploidy levels could have been efficient colonizers and competitors, favouring the expansion of the lineage and leading to their present prevalence. Furthermore, adaptive trait diversification may have been an efficient factor in niche diversification for the present cytotypes with high ploidy levels.

Pioneer vegetation on glacier forelands in southern Norway: emerging communities?

AbstractQuestion: How variable is the pioneer plant community on glacier forelands in southern Norway, both in terms of species composition and geographical distribution?Location: The Jotunheim and Jostedalsbreen regions of southern Norway (61°‐62°N, 6°‐9°E).Methods: The relative frequencies of vascular plant species were recorded in the pioneer zones of 43 glacier forelands, with an altitudinal range of 80‐1860 m (boreal to high alpine) and an east‐west range of 100 km. Classification and ordination techniques were used to search for evidence of consistently recurring communities, variability along a continuum or stochasticity.Results: Mean variability in species composition between all glacier forelands sampled was 65% (Sørensen dissimilarity). Poa alpina, Oxyria digyna, Deschampsia alpina and Festuca ovina had the highest frequency, occurring on over 80% of forelands. Non‐metric multidimensional scaling did not reveal clear divisions between groups of sites, but cluster analysis, multi‐response permutation procedures and indicator species analysis suggested two sub‐communities: the Saxifraga cespitosa‐Trisetum spicatum sub‐community is restricted to forelands above 1100 m in the Jotunheim region; whereas the D. alpina‐O. digyna sub‐community has a wider altitudinal range of 80‐1780 m. Variance partitioning indicated that altitude alone accounts for 24%, distance east for 18%, and the component shared by altitude and distance east for 17% of the variance in species composition.Conclusions: At the broadest scale, pioneer vegetation on the glacier forelands can be viewed as a single P. alpina‐O. digyna community of predominantly wind‐ and water‐dispersed perennials. However, this community shows a high degree of variability, with dominant species missing from a number of sites, and is poorly structured, suggesting a degree of stochasticity. Furthermore, the pioneer vegetation can be dissected within a continuum of variation to produce two emerging sub‐communities, reflecting the influence of environmental factors and, possibly, early successional development within the pioneer zone. Variance partitioning indicates that altitudinal and continentality gradients are important in accounting for a significant proportion of the variability within this dataset.

Blue Fescue Overseeding Improves Performance of Fairway Height Buffalograsses

Buffalograss [Buchloe dactyloides (Nutt.) Engelm.] use as a fairway turfgrass is limited in northern portions of its adaptation zone by its extended winter dormancy and tan coloration in early spring and late fall. Cool-season grasses mixed with buffalograss could enhance turfgrass appearance and performance in fall and early spring. Research was conducted near Mead, NE, with eight buffalograss genotypes maintained under fairway conditions to determine the effect of blue fescue (Festuca ovina L. var. glauca Lam.) overseeding rate on turfgrass performance. Interactions were nonsignificant in most cases so main effects are emphasized. Differences were observed between seeding rates and genotypes for most traits studied. Overseeding blue fescue enhanced spring green-up, fall color retention, stand density, and turfgrass quality. These effects were most pronounced in late fall and early spring, when buffalograss plants were entering or exiting winter dormancy. The 5 g·m−2 blue fescue overseeding rate improved all performance traits studied when compared with the nonoverseeded buffalograss control and was not different from the 10 g·m−2 seeding rate treatment. Thus, the 5 g·m−2 blue fescue overseeding rate appeared to be near optimum for overall turfgrass performance, offering reduced seed cost and decreased potential for species interference. The ‘Legacy’ buffalograss and ‘SR-3200’ blue fescue mixture had the best performance of the genotypes studied as a result of their visual compatibility in terms of color similarity.

Soil nutrient heterogeneity and competitive ability of three grass species (Festuca ovina, Arrhenatherum elatius and Calamagrostis epigejos) in experimental conditions

We studied the effects of differences in root growth and nutrient pool on the competitive ability of Festuca ovina (short grass), Arrhenatherum elatius and Calamagrostis epigejos (tall grasses) grown in monocultures and in mixtures of homogeneous and heterogeneous environments during two growing seasons. Analysis of variance revealed a significant effect of plant species on nutrient concentrations in above-ground biomass and of substrate type on contents of N, K, Ca, Mg in biomass. The ANOVA also confirmed the significant effect of competitive environment on the concentration of N, K in above-ground biomass. In heterogeneous environments, both tall grasses (in competition with F. ovina) were able to produce more roots in the nutrient-rich patches and to accumulate more nitrogen in plant tissues, which was associated with higher yield of their above-ground biomass. Thus, the relative competitive ability for nutrients of both tall grasses was higher than that of F. ovina. This competitive ability of A. elatius to C. epigejos increased in heterogeneous treatments.

Assessment of grazing effect on sheep fescue ( Festuca valesiaca) dominated steppe rangelands, in the semi-arid Central Anatolian region of Turkey

In the semi-arid steppe rangelands of Central Turkey, Festuca valesiaca and Thymus sipyleus ssp rosulans have become the dominant species on degraded pastures. We hypothesized that decreases in species richness and abundance are correlated with increasing prevalence of these two species. Therefore, our objectives were to determine whether there are patterns in examined vegetation; how dominant species contribute to these patterns; and how patterns differ between grazed and ungrazed vegetation. We determined that protection from grazing increased species richness. Grazing significantly changed composition through decreasing total plant, forb, grass and F. valesiaca covers, while substantially increasing T. sipyleus cover. Topography, soil and grazing appear to impact the dominance of plant communities where F. valesiaca and T. sipyleus prevail. These two dominant species had a significant effect in shaping vegetation patterns. Based on regression analysis, alterations in species richness with changes in cover of forbs and shrubs were evident, and spatial heterogeneity of F. valesiaca and T. sipyleus indicated unstable vegetative patterns in heavily grazed pastures and successional changes in protected pastures. Our study results identify F. valesiaca and T. sipyleus as indicator species of vegetation suppression in condition assessments of degraded steppe rangelands.

Interspecific interactions in binary mixtures of Elymus nutans, Festuca sinensis and Festuca ovina on the eastern Qinghai‐Tibetan plateau

The relative competitive abilities of Elymus nutans, Festuca sinensis and Festuca ovina were studied in the east Qinghai‐Tibetan plateau. Emergence percentage, numbers of plants established, establishment rate and the relative competitive intensity (RCI) based on harvested shoot biomass were measured for the three species as monocultures and in all possible combinations of mixtures in four randomised complete blocks. In the seedling stage, ANOVA showed that emergence percentage was density independent and was greatest for E. nutans, somewhat lower for F. sinensis, and least for F. ovina. The multiple comparisons (Tukey HSD) showed that the emergence percentage was significantly different among the three species. In the adult stage, the result of correlation analysis showed that the establishment rate of a species was density dependent. The multiple comparisons show that the established numbers and establishment rate were significantly different am ong the three species. At the same time, the competitive ability between E. nutans and F. sinensis and between E. nutans and F. ovina was significantly different, and between F. sinensis and F. ovina was not significantly different based on the RCI. The relative competitive ability of a species depended on density. For low densities, E. nutans was most competitive, followed by F. ovina and lastly by F. sinensis. In higher densities, the competitive order was reversed. E. nutans was most competitive, followed by F. sinensis and, lastly by F. ovina. A three‐way ANOVA on RCI showed that clipping and fertilisation changed the competition intensity among the three species but did not change the relative competitive order in mixtures.

Impacts of silica-based defences in grasses on the feeding preferences of sheep

Grasses, which dominate many terrestrial ecosystems, sustain high densities of grazing mammals, so are of great economic and ecological importance. Traditionally, grasses are thought to be adapted to tolerate grazing rather than defend against it; however, silica deposited in the leaves of grasses has recently been shown to act as a feeding deterrent to invertebrate herbivores and small mammals. This study assesses whether silica is effective as a feeding deterrent to larger mammalian herbivores. We assess the impact of manipulated silica levels in five grass species on the feeding preferences of sheep both within and between grass species. Sheep feeding behaviour was driven by between-species differences in palatability. Hence, within a single species silica addition did not cause significant changes in feeding preference. However, there were significant differences in both the feeding preferences and bite rates between grass species, and these differences were much more marked when the grasses had been exposed to high levels of silica. The impacts that silica had on preference were least pronounced in palatable species (e.g. Poa annua) compared with less-palatable species (e.g. Brachypodium pinnatum and Festuca ovina). Sheep fed for longer, took more bites and had a higher bite rate on the grass species with the lowest leaf silica concentrations, namely P. annua. Sheep were less affected by silica defences than smaller, non-ruminant herbivores, but the changes in species preference rankings caused by silica suggest it may lead to changes in sward composition. Further, in species that are already relatively low in palatability, silica-induced reductions in bite rate could potentially reduce forage intake rates, with consequences for sheep performance.

High Dynamic Range Images and Tone Mapping Operator

The resource qualities of 11 natural grassland types in Zhaosu Horse Farm were evaluated using the theory and technology of grey relational analysis by the major parameters including edible herbage production,stocking capacity,forage coverage,soil moisture content,soil bulk density,soil organic matter,and soil nutrient content.The results show that mid-mountain meadow(Trisetum spicatum(L.) Richt+Phlomis oreophila Kar.et Kir.+ Herbarum variarum) and alpine meadow(Kobresia capillifolia(Decne.) Clarke+Alchemilla tianschanica Juz.+ Herbarum variorum) had the best resource quality,the correlating degree was 0.736 and 0.691,respectively.The valley meadow(Carex oxyleuca V.Krecz+Bromus inermis Leyss.) and the low mountain hill grassland(Festuca ovina L.+Carex liparocarpos Gaudin+Stipa capillata L.;F.ovina+S.capillata+C.liparocarpos;S.capillata+C.liparocarpos+Artemisia frigida Willd.) had the worst resource quality,the correlating degree was 0.475,0.461,0.475,and 0.465,respectively.Based on the analysis results,the quality classification scheme of natural grassland in Zhaosu Horse Farm was put forward to five grades which provided a basis to the full,effective,and rational use of the grassland resources of Zhaosu Horse Farm in the future.

Screening of High kcat Rubisco among Poaceae for Improvement of Photosynthetic CO2 Assimilation in Rice

The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a major limitation of photosynthetic CO2 assimilation in C3 plants. In order to find useful Rubisco for improvement of photosynthesis in rice under elevated CO2, we analyzed the catalytic turnover rate (kcat) of Rubisco in Poaceae including C3 alpine plants, C3 cold-resistant plants and C4 plants. Rubisco in these plants showed 1.1- to 2.8-fold higher kcat than that in rice. However, the most of high kcat Rubisco also showed a higher km for CO2 (Kc) than that of rice, indicating that increase in kcat led to decrease in the affinity for CO2. Rubisco in Festuca ovina, Phleum pratense and Sorghum bicolor showed relatively high kcat to Kc. Although the kcat of Rubisco in F. ovina and P. pratense was not so high (1.5-1.6 fold relative to rice), the Kc was comparable to that in rice and the amino acid sequence of RbcL shared higher identity to that in rice than that in S. bicolor. By contrast, Rubisco of S. bicolor showed considerably high kcat (2.5-fold relative to rice), which is considered to be the most important factor for improvement of photosynthesis. In our estimation, the expression of high kcat Rubisco of F. ovina and S. bicolor in rice could significantly enhance CO2 assimilation at Ci of 50 Pa, the level assumed to be reached by the middle of this century.

Low maintenance turf - quality and weed aspects

Turfgrass va ri et ies of Fes tu ca rubra ssp. rubra, F.r. ssp. trichophylla, F. nigrescens, F.arundinacea, F.ovina ssp. vulgaris, F.o. ssp duriuscula, Lolium perenne and Poa pratensis as well as mix tures of high and low share of Lolium perenne were tested in low main te nance con di tions dur ing 5 years and eval u ated for: shoot den sity, vi sual merit and for weed in fes ta tion. None of tested en tries was able to keep ini tial qual ity. Only for few of them (mostly va ri et ies of Fes tu ca ovina ssp. duriuscula and F.arundinacea) vi sual merit af ter 5 years was still close to the level of min i mal user-ac cepted value (5 in 1-9 scale). The least vi sual merit val ues were noted for Poa pratensis and Fes tu ca rubra ssp. rubra. Twenty weed spe cies of dif fer ent liv ing forms (geophytes, hemicryptophytes and terophytes) were de scribed. Con sid er ing gen eral turf per for mance, low num ber of weed spe cies and low num ber of terophytes, turf mix tures with low share of pe ren nial ryegrass could be rec om mended for low-main te nance turf.