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Background: Poa pratensis is a predominant cool-season turfgrass utilized in urban landscaping and ecological management. It is extensively employed in turf construction and in the regulation of ecological environments. However, it is susceptible to powdery mildew, a prevalent disease in humid regions. Currently, the primary control measure for powdery mildew involves the application of pesticides, a practice that is both costly and environmentally detrimental. Developing superior disease-resistant cultivars represents a more cost-effective and sustainable strategy for managing turfgrass diseases. Furthermore, an in-depth investigation into the response mechanisms of P. pratensis to powdery mildew infection could significantly advance research on the identification of disease resistance genes and the molecular breeding of resistant varieties. Results: In this study, we first assessed the disease incidence across various disease-resistant P. pratensis cultivars and subsequently examined alterations in their in vivo redox states. We employed isobaric tags for relative and absolute quantification (iTRAQ) proteomics alongside non-targeted metabolomics to elucidate the response mechanisms of P. pratensis to powdery mildew invasion. A comprehensive analysis of the shared KEGG pathways among differentially abundant proteins (DAPs) and differentially enriched metabolites (DEMs) led to the identification of four common KEGG pathways. Notably, the phenylpropanoid biosynthesis pathway, enriched in both examined P. pratensis cultivars, was selected for further investigation. This analysis indicated that lignin biosynthesis plays a crucial role in the response of P. pratensis to powdery mildew infection. Conclusions: The findings of this study enhance our understanding of the mechanisms underlying powdery mildew resistance in P. pratensis and serve as a valuable reference for the selection of powdery mildew-resistant cultivars, as well as for the identification and application of associated disease resistance genes. Clinical trial number: Not applicable. [ABSTRACT FROM AUTHOR]

Kentucky bluegrass (Poa pratensis L.) is a valuable cool-season turfgrass widely utilized for forage, turf, and ecological purposes; however, its productivity and ornamental value are significantly compromised by powdery mildew, caused by Blumeria graminis f. sp. Poae, which negatively affects turf quality. In the present study, we examined the interactions between P. pratensis varieties and B. graminis, focusing on primary haustorium formation at 24 h post-inoculation and the formation of germ tubes at 48 h post-inoculation. We explored the molecular mechanisms underlying the response of different P. pratensis varieties at 48 h post-inoculation via transcriptomic techniques. Our results revealed that the primary haustorium formation rate in 'Taihang' at 24 h after B. graminis inoculation was significantly lower than that in 'Explorer' and 'Black Jack'. The conidia of B. graminis could form two to five germ tubes, and the proportion of conidia that formed five germ tubes in 'Taihang' at 48 h post-inoculation was significantly lower than that in the other two varieties. Transcriptome analysis revealed 680,765 transcripts as unigenes. A total of 9983 unigenes were identified as differentially expressed genes in one or more varieties of P. pratensis after inoculation with powdery mildew compared with the control. In total, 6284 differentially expressed genes were upregulated in 'Taihang', which was substantially greater than those in 'Black Jack' (4530) and 'Explorer' (4666). Moreover, 2843 differentially expressed genes were specific to 'Taihang', whereas 1644 and 1590 unique differentially expressed genes were specific to 'Explorer' and 'Black Jack', respectively. The specifically expressed genes play crucial roles in determining the disease resistance of powdery mildew. Notably, the expression of genes encoding chitinase, gamma-glutamyltranspeptidase 1, UDP-arabinopyranose mutase 1, oxalate oxidase 2, mitogen-activated protein kinase kinase 1-like, tryptophan decarboxylase, and aromatic L-amino acid decarboxylase was closely related to powdery mildew resistance in 'Taihang', making them promising candidate genes for studying resistance to powdery mildew in P. pratensis. This study identified critical genes involved in powdery mildew resistance in P. pratensis, providing a basis for future gene mining and molecular breeding to increase disease resistance in P. pratensis. [ABSTRACT FROM AUTHOR]

Native fescue grassland degradation and reductions in plant species diversity due to smooth brome (Bromus inermis Leyss.) invasion and dominance have far ranging consequences for both human and ecological systems. A study was undertaken to reduce smooth brome which was invading foothills fescue grassland in Canada and displacing native species. Sheep and cattle grazing, mowing, glyphosate, and burning were applied to control smooth brome-dominant grasslands over three growing seasons. Defoliation (5 to 10 cm, 2 to 4 times) did not reduce smooth brome tiller density, etiolated regrowth, or total non-structural carbohydrates; however, the three heaviest defoliation treatments (sheep 3×, cattle 3×, mowing 4×) reduced smooth brome composition by year 3. Repeated glyphosate wicking (1× year 1, 2× year 2) was the most effective treatment and reduced smooth brome tiller density by 50% by year 3. Early-spring burning, as smooth brome began to grow, stressed the plants and reduced tiller density. Kentucky bluegrass (Poa pratensis L.), the subdominant species, increased in all treatments except the reference; thus, reducing smooth brome may result in another undesirable species becoming dominant. [ABSTRACT FROM AUTHOR]

The present study reports the effective removal of benzene in aqueous phase onto biochar. The adsorption capacity of benzene onto biochars made at different pyrolytic temperatures (e.g., 350, 550, and 750 °C) and from various feedstocks (e.g., grape pomace, rice husk, and Kentucky bluegrass) were investigated. The adsorption capacity of Kentucky bluegrass-derived biochar (KB-BC) prepared at 550 °C for benzene was better than other biochars, owing to the higher surface area and functional groups. The adsorption isotherms and kinetics model for benzene by KB-BC550 fitted the Freundlich and pseudo-first order, respectively. In addition, the results of response surface methodology (RSM) designed with biochar dose, reaction time, and benzene concentration showed the maximum adsorption capacity (ca. 136 mg BZ/g BC) similar to that from kinetic study. KB-BCs obtained as waste grass biomass may be a valuable adsorbent, and RSM may be a useful tool for the investigation of optimal conditions and results. [ABSTRACT FROM AUTHOR]

Plant and soil C:N:P stoichiometry reflects the element content and energy flow, which are important for biogeochemical cycling in ecosystems. Although plantation age has been verified to affect leaf C:N:P stoichiometry in alfalfa plants, its effect on plant and soil C:N:P stoichiometry in grass remains poorly documented. A 10-year field experiment of Kentucky bluegrass (Poa pratensis) was used to test how plantation age affect plant and soil C:N:P stoichiometry in a perennial rhizomatous grass pasture. This study demonstrated that leaf C:N, C:P, and N:P ratios exhibited a rapid increasing trend from2 to 6 years of age, whereas leaf C:N showed a slight decreasing trend, and leaf C:P and N:P maintained stability from 6 to 9 years of age. Stem C:N and N:P were not different among plantation ages, while stemC:P increased from2 to 4 years of plantation age and thenmaintained stability from4 to 9 years of plantation age. Root N:P showed an increasing trend from2 to 6 years of plantation age and relative stability from6 to 9 years of plantation age, whereas root C:N and C:P showed decreasing trends from 2 to 9 years of plantation age. Although soil C:P did not differ among nine plantation ages, soil C:N and N:P remained relatively stable from 2 to 6 years of plantation age. However, soil C:N showed a decreasing trend, while soil N:P showed an increasing trend after 6 years of plantation age. The results from an ecological stoichiometric homeostasis analysis further showed that N in the leaf, stem, and root and P in the stemhad strict homeostasis, whereas P in the leaf and root showed plastic and weakly homeostatic status, respectively. These results present a pattern concerning the plantation age in relation to plant and soil C:N:P stoichiometry in a perennial grass and provide useful information for N and P management in Kentucky bluegrass pastures. [ABSTRACT FROM AUTHOR]

Kentucky bluegrass (Poa pratensis L.) is an important cool season turfgrass species with a high cold tolerance, but it is sensitive to drought. It is valuable for the applications of Kentucky bluegrass to improve its drought tolerance. However, little is known about the underlying drought mechanism. In the present study, transcriptomic profiling in the roots and leaves of the Kentucky bluegrass cultivar 'Qinghai', in response to osmotic stress in the form of treatment with 2 h and 50 h of 25% (v/v) PEG-6000, was analyzed. The results showed that a large number of genes were significantly up-regulated or down-regulated under osmotic stress. The majority of genes were up-regulated in leaves but down-regulated in roots after 2 h and 50 h of osmotic stress, among them were 350 up-regulated DEGs and 20 down-regulated DEGs shared in both leaves and roots. GO and KEGG analysis showed that carbohydrate metabolism, polyamine and amino acid metabolism and the plant hormone signaling pathway were enriched in the leaves and roots of 'Qinghai' after osmotic stress. The genes involving in carbohydrate metabolism were up-regulated, and sucrose, trehalose and raffinose levels were consistently increased. The genes involved in polyamine and amino acid metabolism were up-regulated in leaves in response to osmotic stress and several amino acids, such as Glu, Met and Val levels were increased, while the genes involved in photosynthesis, carbon fixation and citrate cycle in leaves were down-regulated. In addition, the genes involved in plant hormone biosynthesis and signal transduction were altered in leaves after osmotic stress. This study provided promising candidate genes for studying drought mechanisms in 'Qinghai' and improving the drought tolerance of Kentucky bluegrass and drought-sensitive crops. [ABSTRACT FROM AUTHOR]

Introduction: Evaluation of the effects of water-limited conditions on the photosynthetic characteristics and forage yield is important for enhancing the forage productivity and drought tolerance in Kentucky bluegrass (Poa pratensis L.). Methods: In the present study, 100 P. pratensis ecotypes collected from different geographical areas in Iran were assessed under well-watered and drought stress conditions. Genetic variation and response to selection for the photosynthetic characteristics [i.e., net photosynthesis rate (A), stomatal conductance (gs), transpiration rate (Tr), chlorophyll content (Chl), and photochemical efficiency (Fv/Fm)] and forage yield [fresh forage yield (FY) and dry forage yield (Dy)] traits were analyzed during the 2018 and 2019 growing seasons. Results and discussion: Drought stress had negative effects on evaluated photosynthesis parameters and significantly reduced dry and fresh forage yields. On average, FY with a 45% decrease and gs with a 326% decrease under drought stress conditions showed the highest reduction rate among forage yield and photosynthesis traits, respectively. Genotypic coefficients of variation (GCV) for FY were lower under drought stress. The estimates of heritability, genetic advance, and genetic advance as percentage of mean showed the predominance of additive gene action for the traits. Overall, the results showed that "Ciakhor", "Damavand", "Karvandan", "Basmenj", "Abr2", "Abrumand", "Borhan", "Hezarkanian", "LasemCheshmeh", "Torshab", and "DoSar" have higher forage yield production with little change between two irrigation regimes, which makes them promising candidates for developing high-yielding drought-tolerant varieties through breeding programs. [ABSTRACT FROM AUTHOR]

Simple Summary: Rhizomes are underground stems that grow horizontally from the base of the stem and confer competitive, reproductive, foraging, and regenerative advantages to plants. They are especially important for forage and turfgrasses. Different phytohormones influence the growth and development of plant rhizomes in a variety of ways. Here, we compare the phytohormonal and metabolomic profiles of rhizomes from two contrasting Kentucky bluegrass (Poa pratensis), a perennial herb with variable rhizome traits materials: multi-rhizome and few-rhizome. We found that zeatin (ZT) was abundant in the multi-rhizome material, while indole-3-acetic acid (IAA), gibberellic acid (GA3), and abscisic acid (ABA) showed the opposite trend. Metabolomics revealed that the ABC transporter pathway and the histidine metabolism pathway, both related to cytokinin, were significantly expressed in the comparison group. Rhizomes are an ideal plant trait. Our findings provide new insights into the development of perennial rhizomatous herbs and a theoretical basis for the future breeding of rhizomatous plants. Rhizome growth and development is regulated by phytohormone. However, endogenous phytohormones affect rhizome initiation, and sustained growth in perennial grass species remains elusive. In this study, we investigated the morphological characteristics and the content of indole-3-acetic acid (IAA), zeatin (ZT), gibberellic acid (GA3), and abscisic acid (ABA) in the rhizomes of two different Kentucky bluegrass. Using ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS), we performed metabolite analysis of two different rhizomes. In our study, the multi-rhizome Kentucky bluegrass material 'Yuzhong' had an average of 1113 rhizomes, while the few-rhizome material 'Anding' had an average of 347 rhizomes. The diameter of rhizome and length of rhizome internode in 'Yuzhong' were 1.68-fold and 1.33-fold higher than that of the 'Anding', respectively. The rhizome dry weight of 'Yuzhong' was 75.06 g, while the 'Anding' was 20.79 g. 'Yuzhong' had a higher ZT content (5.50 μg·g−1), which is 2.4-fold that of 'Anding' (2.27 μg·g−1). In contrast, the IAA, ABA, and GA3 content of rhizome were markedly higher in 'Anding' than 'Yuzhong'. Correlation analysis revealed significant correlations between ZT and ZT/ABA with the number of rhizomes, diameter of rhizome, and length of rhizome internode, whereas IAA, ABA, GA3, and IAA/ZT were opposite. In the metabolic profiles, we identified 163 differentially expressed metabolites (DEMs) (60 upregulated and 103 downregulated) in positive ion mode and 75 DEMs (36 upregulated and 39 downregulated) in negative ion mode. Histidine metabolism and ABC transporters pathways were the most significantly enriched in the positive and negative ion mode, respectively, both of which are involved in the synthesis and transport of cytokinin. These results indicate that cytokinin is crucial for rhizome development and promotes rhizome germination and growth of Kentucky bluegrass. [ABSTRACT FROM AUTHOR]

Global energy production is in high demand and is expanding its development into new landscapes, including grasslands. This expansion has intensive impacts on aboveground and belowground components of grasslands which need to be addressed during reclamation to promote long‐term ecological integrity. This study was conducted to ascertain how alternative reclamation practices may improve soil structure (i.e., compaction) while aiding in the creation of conditions that are conducive to both the establishment and continued growth of native grassland plant species. The grassland was reclaimed with different combinations of seeding mixtures (grass or grass and forb), ripping techniques (subsoil ripping or topsoil ripping), and the integration of mulch into the soil profile. Year, seed mixtures, and ripping techniques and their interactions significantly affected community composition and species diversity. Topsoil‐ripping and grass‐forb treatment had a higher association with native, perennial grasses while subsoil‐ripping and grass treatment favor more short‐lived species. Similar trends persisted across penetration resistance and soil moisture readings where topsoil‐ripping and grass‐forb treatment were different from subsoil‐ripping and grass treatments (p ≤ 0.10). Additionally, Kentucky bluegrass, an invasive grass species, increased by 76% over 1 year and was more common in the topsoil‐ripping and grass‐forb treatments. While early in the reclamation process, results suggest topsoil‐ripping and grass‐forb treatment are promising combination reclamation practices that can establish a native grassland community and initiate the improvement of compacted soil conditions. [ABSTRACT FROM AUTHOR]

Kentucky bluegrass (Poa pratensis L.) has become dominant in many portions of the northern Great Plains. During hot and/or dry periods, pastures consisting of mostly cool‐season grasses will most likely lack the productivity and diversity needed to provide sufficient forage for livestock. Determining the impact of weather conditions on the variation of forage production and nutritive response of Kentucky bluegrass is becoming increasingly important to agricultural producers. Sampling occurred at the USDA Northern Great Plains Research Laboratory near Mandan, North Dakota, USA. Kentucky bluegrass samples were clipped every 2–3 weeks in mowed and unmowed unfertilized rangeland plots during the growing seasons of 2017 and 2018. Samples were dried, weighed, ground to pass a 1‐mm sieve, and analysed for nutritive value. There are differences between the modelled supply of metabolizable energy and metabolizable protein and the requirements for cow‐calf pairs for all years and most months. Early defoliation of Kentucky bluegrass decreases productivity and nutritive value as the grazing season progresses. Adjusting management to allow an adequate growth interval and plant canopy cover throughout the year can ensure a more consistent supply of Kentucky bluegrass. Our data and models provide a glimpse into future scenarios, which allow producers to be more proactive in dealing with Kentucky bluegrass and projected changes in climate. [ABSTRACT FROM AUTHOR]

Fine fescues (Festuca spp.) and tall fescue (Schedonorus arundinaceus) are low-input turfgrass species that perform well under less water, pesticides, and fertilizers when compared to commonly cultivated species in the Midwestern US. There are numerous benefits in increasing the use of low-input turfgrasses: lowering resource usage, reducing maintenance costs, improving the landscape aesthetic, and contributing to residents' health and general wellbeing. However, increasing the market share of these grasses requires an understanding of what influences buyers to purchase these turfgrasses. These grasses are usually purchased by consumers as seed; however, sod is a preferred method of establishment for many professional end users. To better understand the economic potential of low-input turfgrass sod, we surveyed sod buyers (landscapers, golf courses, sports turf managers) who purchased sod in 2020 to investigate (1) the factors impacting them to purchase low-input turfgrasses, and (2) the factors influencing the quantity purchased of low-input turfgrasses. The results from our model showed that larger businesses are the most likely to purchase low-input turfgrasses, and, once they purchase them, they tend to acquire a larger amount than their smaller counterparts. Landscaping businesses were more likely to purchase low-input turfgrasses, and factors such as availability, distance, drought, and shade tolerance impacted the decision to purchase low-input turfgrasses. Finally, turfgrass density, the ability to purchase directly from the sod grower, and availability impacted the amount of turfgrasses that buyers purchased. [ABSTRACT FROM AUTHOR]

Introduction Dandelion with the scientific name cTaraxacum sp.) from the Asteraceae family is one of the common weeds of turfgrasses and pastures. Post-growth control of weeds in established turfgrasses is crucial and ignoring it severely damages the aesthetic aspect of turfgrass. Chemical methods are commonly used to control weeds in established turfgrass (Karimmojeni et al, 2012). The use of herbicides helps in the management of weed control in damaged turf fields along with non-chemical methods such as correct mowing height, effective irrigation, sufficient fertilization, and timely weeding. Perennial broad-leaf weeds can be selectively controlled with herbicides. U-46 Combi Fluid, Duplosan super, and Ioxynil are suitable herbicides for controlling broadleaf weeds in narrow-leaf fields. Materials and Methods In order to control the dandelion in Kentucky bluegrass turf, a factorial experiment was conducted based on a completely randomized design with 3 replications and 9 treatments in September 2022, at the green space of Shahrekord University. Replications included lxl m2 plots and the factors included two herbicides of U46-Combi Fluid and Duplosan Super and their interaction with Ioxynil. All selected plots were infested with dandelion weed. The treatments included U46-combi fluid at two levels of 1.5 and 2 L ha"! (Ui.5 and u), Duplosan Super at two levels of 2 and 2.5 L ha"! (D2 and D2.5), their interaction with Ioxynil herbicide at two levels (0 and 2 L ha) (Io and I2), and the control (use of distilled water instead of herbicide). U-46 Combi Fluid and Duplosan Super herbicide treatments were applied at the end of September. Then, Ioxynil was applied 10 days after the first spraying. Finally, 15 days later, the effect of the treatments on the biomass characteristic of the dandelion shoots and the visual quality of turfgrass were recorded. After 50 days, the last spraying, the percentage of regrowth, herbicide control efficiency, and the biomass of turfgrass shoot were measured during the experiment. Variance analysis of data was done using SAS 9.1 statistical program and the comparison of means was conducted using LSD test (P<0.05). Results and Discussion The results showed the lowest fresh and dry weight of dandelion and the highest efficiency of herbicide were found in treatments u 2ل ب and D2.5+ 2ل. However, these treatments had not significantly different from D2I2 and U1.5+I treatments. The lowest percentage of regrowth was obtained in D2 2ل ب. The highest fresh weight of turfgrass was found in the control which had no significant difference with D2 2ل ب and Ui.5 2ل ب. Moreover, total chlorophyll in turfgrass leaves was improved by removing weeds. The amount of chlorophyll a, b, and total was higher in the Ul.5 treatment than in other treatments. Therefore, improving the greenness of turf could be due to more light being provided to turf leaves as a result of dandelion leaf removal or positive physiological effects of 2,4-D or MCPA. There were no differences among treatments for total chlorophyll, carotenoid, visual quality, dry weight of turfgrass, and dandelion control percentage. Therefore, D2 2ل ب and Ul.5 + 2ل can be recommended, due to the higher fresh turf weight, the good control of dandelion, and the low rate of regrowth of weed. Conclusion Application of Duplosan Super and then Ioxynil, both with a concentration of 2.0 L ha"! and/or U-46 Combi Fluid with a concentration of 1.5 L ha"! and then Ioxynil with a concentration of 2.0 L ha"! treatments are recommended due to the high weight of turfgrass, the reasonable control of dandelions, and their reduction of regrowth. In addition, leaf chlorophyll of Kentucky bluegrass treated with of u-46 Combi Fluid with a concentration of 1.5 L ha"1 was higher than in other treatments. It also had a higher turfgrass fresh weight than the 2.0 L ha"1 of u-46 Combi Fluid treatment. Duplosan Super (2.5 L ha"1) and then Ioxynil (2.0 L ha"1) treatment led to a decrease in turfgrass fresh weight compared to the same treatment without Ioxynil. In conclusion. Ioxynil concentrations at high levels did not cause visible damage, but had adverse effects on turfgrass growth, suggesting that a lower dose should be studied. [ABSTRACT FROM AUTHOR]

Plant growth regulators (PGRs) are widely used in turfgrass management. This study aimed to find the influence of different rates of PGRs on Kentucky bluegrass visual quality. Six PGRs were applied, Trinexapac Ethyl, Paclobutrazol, Flurprimidol, Mefluidide, Ethephon, and Gibberellic Acid. The measurement of the leaf color was performed using a spectrophotometer. The turfgrass visual quality was judged using a visual rating system. Trinexapac Ethyl and Flurprimidol applications improved the overall appearance of turfgrass. Paclobutrazol and Gibberellic Acid decreased the overall appearance of investigated Kentucky bluegrass cultivars. The leaf texture assessment was only improved by Gibberellic Acid. The color assessment was enhanced with Paclobutrazol but deteriorated with Gibberellic Acid. PGRs affected the wavelength in a range of 520 to 630 nm. Gibberellic Acid caused lighter leaves with higher green and yellow hues. Paclobutrazol caused darker leaves with a lower green and a reddish hue. Trinexapac Ethyl application resulted in a more reddish hue. PGR rates also affected the visual quality of Kentucky bluegrass turfgrass. [ABSTRACT FROM AUTHOR]

The inflorescence is composed of spikes, and the spike is the carrier of grass seed formation and development, so the development status of inflorescence implies grass seed yield and quality. So far, the systematic analysis of inflorescence development of Kentucky bluegrass has not been reported. The development process of the female gametophyte of wild germplasm materials of Kentucky bluegrass in Gannan, Gansu Province of China (KB-GN), was observed. Based on this, the key developmental stages of inflorescence in KB-GN were divided into premeiosis (GPreM), meiosis (GM), postmeiosis (GPostM), and anthesis (GA), and four stages of inflorescence were selected to analyze the transcriptome expression profile. We found that its sexual reproduction formed a polygonum-type embryo sac. Transcriptome analysis showed that 4256, 1125, 1699, and 3127 genes were highly expressed in GPreM, GM, GPostM, and GA, respectively. And a large number of transcription factors (TFs) such as MADS-box, MYB and NAC, AP2, C2H2, FAR1, B3, bHLH, WRKY, and TCP were highly expressed throughout the inflorescence development stages. KEGG enrichment and MapMan analysis showed that genes involved in plant hormone metabolism were also highly expressed at the entire stages of inflorescence development. However, a few TFs belong to stage-specific genes, such as TRAF proteins with unknown function in plants was screened firstly, which was specifically and highly expressed in the GPreM, indicating that TRAF may regulate the preparatory events of meiosis or be essential for the development of megaspore mother cell (MMC). The expression patterns of 15 MADS-box genes were analyzed by qRT-PCR, and the expression results were consistent with that of the transcriptome. The study on the inflorescence development of KB-GN will be great significant works and contribution to illustrate the basic mechanism of grass seeds formation and development. [ABSTRACT FROM AUTHOR]

Understanding the effect of water heterogeneity on the growth and water integration of clonal plants is important for scientific water management. In controlled field plots, we conducted a study by creating three different soil water treatments comprising four patches with different soil water supplies using Kentucky bluegrass (Poa pratensis L.) as the materials. The objective was to explore the differences in the growth indices and morphological attributes, and the possible water integration in 'Arcadia' Kentucky bluegrass in plots and patches with different soil water availabilities. Soil water deficit resulted in the declined biomass, root/shoot ratio and leaf relative water content of the whole genet, decreased leaf length and height of mother ramet, reduced leaf width and height of daughter ramets, and significant changes in the structures of vascular bundles in rhizomes and leaves. However, the leaf length, leaf width, height and leaf relative water content of daughter ramets in heterogeneous water-poor patches were recovered to the levels in water-rich patches. In addition, the diameter of the vessel in the xylem and percentage of the xylem area in leaf vascular bundles of daughter ramets in the heterogeneous water-poor patch were insignificantly different from those in water-rich patches. These results demonstrated that water integration among interconnected ramets promoted the growth status of daughter ramets in heterogeneous water-poor patches. However, the water translocation in interconnected ramets subjecting to heterogeneous water supplies was not investigated using stable isotope labelling in this study. Thus, the directions and patterns of water translocation among ramets necessitate further research. [ABSTRACT FROM AUTHOR]

Kentucky bluegrass (Poa pratensis L.) is a cool-season turfgrass species that responds strongly to nitrogen (N), but the metabolomic responses of this grass species to N supply is unknown. The N-tolerant cultivar Bluemoon and N-sensitive cultivar Balin were exposed to normal N (15 mM) and low N (0.5 mM) for 21 days for identification of differentially expressed metabolites (DEMs) between normal N and low N treatments. Balin had more reductions of chlorophyll and total soluble protein concentrations and a higher accumulation of superoxide radicals under low N stress. A total of 99 known DEMs were identified in either cultivar or both including 22 amino acids and derivatives, 16 carbohydrates, 29 organic acids, and 32 other metabolites. In Bluemoon, β-alanine metabolism was most enriched, followed by alanine, aspartate, and glutamate metabolism, biosynthesis of valine, leucine, and isoleucine biosynthesis, and glycine, serine, and threonine metabolism. In Balin, alanine, aspartate, and glutamate metabolism were most enriched, followed by the tricarboxylic acid (TCA), glyoxylate and decarbohydrate metabolism, and carbon fixation. Bluemoon generally maintained higher TCA cycle capacity and had more downregulated amino acids, while changes in more organic acids occurred in Balin under low N stress. Some metabolite changes by low-N stress were cultivar-specific. The results suggested that regulation of metabolites related to energy production or energy saving could contribute to low N tolerance in Kentucky bluegrass. [ABSTRACT FROM AUTHOR]

The durability of four grass living mulches, population of annual and perennial weeds, and their biodiversity in tree rows and tractor alleys were evaluated in the first 4 years after cover crop sowing. The experiment was established in a young semi-dwarf apple orchard 1 year after the planting of the tree 'Chopin' cv. Soil coverage was satisfactory for the three cover crops: red fescue, Kentucky bluegrass, and perennial ryegrass. The sods of the grasses exhibited 100% soil surface cover in the tree rows and drive alleys, starting from 1 year after sowing to the end of the study period. Only the maintenance of the blue fescue resulted in low average soil development. Annual and perennial weed populations were lower in the tree rows than in the drive alleys. It was determined meticulous and manual soil preparation prior to all grass sowing under tree crowns, followed by precise mowing of grasses and nitrogen fertilization in subsequent years. The highest soil surface cover by the total annual taxa was observed immediately after the emergence of the living mulch. Total perennial weed populations increased in the following vegetation seasons. Trifolium repens L. and Taraxacum offcinale (L.) Web. dominated all the grass living mulches evaluated. Only the red fescue sod effectively limited the infestation of perennial weed after 4 years of living mulch maintenance in the tree row. More than half of the annual and perennial weed taxa occurred sporadically in all living mulches. In both the tree rows and tractor alleys, the soil surface cover was not more than 1%, and these species contributed to the increase in orchard biodiversity. [ABSTRACT FROM AUTHOR]

In 2020, a greenhouse experiment was conducted to investigate the suppression of annual bluegrass (Poa annua), which is a difficult weed to manage in cool-season in turfgrass mixtures on football pitches. The efficacy of prohexadione calcium (Pc), ethephon (Eth) and Pseudomonas fluorescens against P. annua, Lolium perenne and Poa pratensis was tested, as the latter two most commonly occur in turfgrass mixtures on football pitches. Mesotrione (Mes) was used as a positive control, and nontreated grass was used as a negative control. Only a single grass species was sown in each pot. Treatments were randomly distributed for two experiments conducted separately: first – unmown grass before the beginning of spraying and second – grass mowed before the beginning of spraying. In both experiments, plant height and the number of tillers were measured/counted several times during the growing season. In both experiments, grasses were sprayed six times with Pc, Eth and P. fluorescens, while Mes was applied twice. Based on the performed study, the efficacy of the tested products is connected to grass species and whether the grass was mowed/cut before spraying. It has been detected in the present study that spraying with Pc could reduce the height of annual bluegrass, while spraying with P. fluorescens has reduced the number of tillers. Spraying was more effective on grasses that were mowed/cut before the beginning of spraying. Mes should cause severe damage to annual bluegrass but without confirmation in this study. Results of this study have indicated that the application of Pc and P. fluorescens can inhibit the spread of annual bluegrass in football pitches; however, testing their effectiveness against P. annua under field conditions should be performed as well. [ABSTRACT FROM AUTHOR]

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The introduction of well-adapted species, such as Trifolium subterraneum (subclover) and Poa pratensis (Kentucky bluegrass), might enhance the forage yield and quality of dehesa pastures for feeding livestock. However, the climatic hardness and poor soils in these agrosystems may limit plant establishment and development. Since fungal endophytes have been found to alleviate the environmental stresses of their host, the aim of this study was to assess the effect of five isolates on forage yield, nutritive value, and plant mineral uptake after their inoculation in the two abovementioned plant species. Two experiments were established (under greenhouse and field conditions) using plants inoculated with two isolates in 2012/2013 (Epicoccum nigrum, Sporormiella intermedia) and three isolates in 2013/2014 (Mucor hiemalis, Fusarium equiseti, Byssochlamys spectabilis). Fusarium equiseti (E346) increased the herbage yield of T. subterraneum under greenhouse conditions, and B. spectabilis improved the forage quality of T. subterraneum by reducing fiber content and of P. pratensis by increasing crude protein. S. intermedia increased the mineral uptake of Ca, Cu, Mn, Pb, Tl, and Zn in subclover, and M. hiemalis increased the uptake of K and Sr in Kentucky bluegrass. These results evidence the potential of the studied fungal endophytes to enhance herbage yield and nutritional value of forage, although further studies should include all of the target forage species as certain host specificity in the effect was observed. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Agricultural Research / Turkiye Tarimsal Arastirmalar Dergisi is the property of Siirt University, Faculty of Agriculture / Siirt Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Commagene Journal of Biology is the property of Adiyaman Scientific Research Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sugars will eventually be exported transporters (SWEET) gene family is a glycoprotein gene family that can regulate the transport of sugar in plants and plays an important role in plant growth and development, as well as in response to environmental stress. In this study, Kentucky bluegrass (cv. Baron) seedlings were grown in various treatments, including heavy metal cadmium, salt, drought, cold, and heat stress for 6 h, 24 h, 48 h, and 7 day. The relative expression of the identified PpSWEET genes in Kentucky bluegrass was measured. The results showed there were a total of 13 SWEET genes, which could be divided into four clades by phylogenetic analysis. Most PpSWEET genes are alkali proteins with seven transmembrane helices. Moreover, almost all PpSWEET proteins possess similar conserved motifs and active sites. In addition, an analysis of the relative expression of PpSWEET genes under various stress treatments indicated that PpSWEET12 and PpSWEET15 had very high expression under the five types of stress, meaning they can be used as important candidate genes for studying responses to environmental stresses of turfgrass. Furthermore, certain genes only showed changes in expression under one or two specific stress treatments. This study provides important insight into the SWEET gene family in Kentucky bluegrass and its functional roles in responses to various environmental stresses. [ABSTRACT FROM AUTHOR]

Background: Low temperature limits the growth and development and geographical distribution of plants. Poa pratensis is a cool-season turfgrass mainly grown in urban areas. However, low winter temperature or cold events in spring and autumn may cause P.pratensis mortality, affecting the appearance of lawns. P.pratensis var. anceps cv. Qinghai (PQ) is widely distributed in the Qinghai-Tibet Plateau above 3000 m. PQ has greater cold tolerance than the commercially cultivated P.pratensis varieties. However, existing studies on the response mechanism of PQ to low temperatures have mainly focused on physiological and biochemical perspectives, while changes in the PQ transcriptome during the response to cold stress have not been reported. Results: To investigate the molecular mechanism of the PQ cold response and identify genes to improve the low-temperature tolerance of P.pratensis, we analyzed and compared the transcriptomes of PQ and the cold-sensitive P.pratensis cv. 'Baron' (PB) under cold stress using RNA sequencing. We identified 5996 and 3285 differentially expressed genes (DEGs) between the treatment vs control comparison of PQ and PB, respectively, with 5612 DEGs specific to PQ. Based on the DEGs, important Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as "starch and sucrose metabolism", "protein processing in endoplasmic reticulum", "phenylalanine metabolism" and "glycolysis/gluconeogenesis" were significantly enriched in PQ, and "starch and sucrose metabolism", "phenylpropanoid biosynthesis", "galactose metabolism" and "glutathione metabolism" were significantly enriched in PB. In addition, the "glycolysis" and "citrate cycle (TCA cycle)" pathways were identified as involved in cold tolerance of P.pratensis. Conclusions: As we know, this is the first study to explore the transcriptome of P.pratensis var. anceps cv. Qinghai. Our study not noly provides important insights into the molecular mechanisms of P.pratensis var. anceps cv. Qinghai responds to cold stress, but also systematically reveals the changes of key genes and products of glycolysis and TCA cycle in response to cold stress, which is conductive to the breeding of cold-tolerance P.pratensis genotype. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The growth and functionality of turfgrasses are often challenged by high soil salinity. Previous research mainly focused on plant responses to Cl- salt-induced saline conditions (e.g., NaCl). However, in some regions, including California and North Dakota, in salt-affected soils the predominant cation is Mg2+ and the predominant anion is SO4. The responses of turfgrass species to such salinity conditions have not been well documented. In this research, the responses of Kentucky bluegrass (Poa pratensis L.) cultivars Kenblue and Moonlight at the seedling growth and the vegetative growth stages to different salt type (NaCl, Na2-. The responses of turfgrass species to such salinity conditions have not been well documented. In this research, the responses of Kentucky bluegrass (Poa pratensis L.) cultivars Kenblue and Moonlight at the seedling growth and the vegetative growth stages to different salt type (NaCl, Na2SO4, MgCl2, and MgSO4) and concentration (5-20 dS m-1) were investigated. Results showed that shoot dry weight (SDW), root dry weight (RDW), root length (RL), and visual quality of the two turf cultivars decreased with increasing salt concentration at both growth stages. Specific root length increased to 235.7% of the control at the seedling growth stage but decreased to 71.6% of the control at the same salt concentration at the vegetative growth stage. Under the saline condition, Kenblue showed higher SDW (52.1%), RDW (74.4%), and RL (20.6%) than Moonlight at the seedling growth stage; however, Moonlight performed better than Kenblue at the vegetative growth stage. The two turf cultivars were more tolerant to Na2SO4 and MgSO4 stress than to NaCl and MgCl2 stress. Our research indicates that turfgrass managers need to consider plant material (cultivar and growth stage), salt type, and salt concentration to develop a successful salinity management plan. [ABSTRACT FROM AUTHOR]

Aims Studies along environmental gradients have shown that intraspecific trait variation (ITV) may contribute considerably to community-level trait variation. However, we lack knowledge about how the extent of ITV varies on a local scale and whether a varying extent of ITV is related to differences in local environmental site and plant community characteristics. Methods We investigated plant height, specific leaf area (SLA), leaf dry matter content (LDMC) and leaf greenness of three common grass species (Arrhenatherum elatius, Dactylis glomerata, Poa pratensis) in 12 mown grasslands in a local study area around Jena (Thuringia, Germany) across three spatially hierarchical sampling levels: between sites, between subplots within site and within subplots. Important Findings Arrhenatherum elatius and D. glomerata had higher means in plant height and a lower variation in leaf traits than P. pratensis. The major proportions of variation in leaf traits of P. pratensis and D. glomerata were found within subplots, while the traits of A. elatius varied mainly between sites. Trait correlations across the hierarchical sampling levels were highly consistent in A. elatius, but more variable in D. glomerata and P. pratensis. Environmental site and plant community characteristics mostly explained a larger proportion of variation in trait means in A. elatius than in D. glomerata and P. pratensis, while metrics of ITV were generally less predictable. Our results suggest that trait variation in P. pratensis and D. glomerata is more strongly related to within-site conditions (i.e. biotic interactions), while differences in local environmental conditions between sites have a strong impact on trait variation in A. elatius. Since our study was limited to three grass species, further studies with a greater number of species are required to make generalizations about the importance of biotic interactions and environmental conditions as drivers of ITV at local scale. [ABSTRACT FROM AUTHOR]

A series of bioassays involving a four-choice olfactometer were conducted to assess the behavioral responsiveness of adult hunting billbugs (Sphenophorus venatus vestitus Chittenden) towards odors emanating from samples of three different turfgrasses: tall fescue (Festuca arundinacea Schreb. (Poales: Poaceae)), Kentucky bluegrass (Poa pratensis L. (Poales: Poaceae)), and zoysiagrass (Zoysia japonica Steud. (Poales: Poaceae)). When exposed to the three turf species simultaneously, the majority of billbugs preferred the zoysiagrass treatment over the tall fescue and Kentucky bluegrass treatments. When billbugs of both sexes were added to the three turf treatments, their presence with the turf did not enhance the released billbugs preference towards any of the treatments. Without the presence of turf, the released female billbugs were strongly attracted towards the male-only billbug treatment; however, a similar phenomenon was not observed for males. When a single turf type and/or mixed-sex adult billbugs were presented, treatments that contained the turf, especially zoysiagrass and tall fescue, strongly attracted the released billbugs compared with treatments that contained billbugs only. In the final bioassay experiment when billbugs were exposed to treatments of zoysiagrass and zoysiagrass + billbugs (with either sex), the released billbugs showed a significant preference towards the zoysiagrass + male billbugs treatment. Collectively, this series of experiments demonstrated the hunting billbugs preference to all three turf species tested, and their attraction to male conspecifics. This overall study was the first to investigate some basic aspects of the chemical ecology of the hunting billbug; specifically, the role turfgrass and adult billbug volatiles might have in billbug orientation and host selection. [ABSTRACT FROM AUTHOR]

Abstract Invasive species control requires understanding the mechanisms behind their establishment and their interactions with other species. One potential ecosystem alteration influencing the establishment and spread of invasive species is anthropogenic nitrogen enrichment, from sources like introduced or invasive nitrogen (N)-fixing legumes, which can alter competition between native, non-native, and invasive plants. Kentucky bluegrass (Poa pratensis) and N-fixing yellow sweet clover (Melilotus officinalis) are exotic to the Great Plains and are currently invading and degrading native rangelands by altering ecosystem processes and displacing native plants. Therefore, we investigated how N enrichment from yellow sweet clover affects the aboveground biomass production of Kentucky bluegrass and western wheatgrass (Pascopyrum smithii), a native cool-season grass, the ranges of which overlap in the northern Great Plains. In a controlled greenhouse environment, we conditioned experimental pots by growing yellow sweet clover and terminating each plant after 8 wk. Conditioned soils contained ≈ 340% more plant-available N than untreated soils 2 wk after yellow sweet clover death. We then grew Kentucky bluegrass and western wheatgrass transplant seedlings in interspecific and intraspecific pairs in pots conditioned either with or without yellow sweet clover for 12 wk. Aboveground biomass production of both Kentucky bluegrass and western wheatgrass grown in interspecific and intraspecific pairs increased in conditioned soils. However, when grown together in conditioned pots, the increase in Kentucky bluegrass biomass relative to untreated pots (520%) was double that of the increase in western wheatgrass biomass (260%). Our results reveal that Kentucky bluegrass can use increased soil N to produce proportionally more aboveground biomass than western wheatgrass, a native grass competitor. Thus, our results suggest yellow sweet clover and other sources of N enrichment may facilitate the invasion of Kentucky bluegrass. [ABSTRACT FROM AUTHOR]

Turfgrasses have been widely utilized by humans to enhance the environment for more than several centuries. Seed germination is of great importance in the development of the turfgrass industry. In this study, the seed germination models of the responses of three types of turfgrasses to water were studied. The results indicated that irrigation water was mainly related to the variation of seed volume rather than a fixed value in this experiment. The maximum k value of tall fescue, Kentucky bluegrass and perennial ryegrass is 1.1548, 1.6946 and 4.0940, respectively. The optimal value of k is 1.0617 for tall fescue, 1.4610 for Kentucky bluegrass, and 1.6614 for perennial ryegrass. Perennial ryegrass seeds are more sensitive to water than those of tall fescue and Kentucky bluegrass, and this turfgrass is the fastest to reach the maximum value of the germination rate. Based on the results from the present experiment, the seed germination function can describe the response of turfgrass seed germination to external water content variation and their sensitivities. The function obtained could be used to perform quantitative studies on the dynamic changes of seed germination under different water conditions that will contribute to improved predictions of the optimal fitting curves of the germination over a range of water. [ABSTRACT FROM AUTHOR]

Gibberellin 2-oxidases (GA2oxs) irreversibly convert bioactive gibberellins (GAs) and their immediate precursors into inactive GAs via 2-β hydroxylation and so regulate gibberellin content in plants. However, to the best of our knowledge, little has been known about the GA2oxs and its function in cool season turfgrass Poa pratensis. In this study, rapid amplification of cDNA end (RACE) was employed to isolate PpGA2ox from P. pratensis. The open reading frame of PpGA2ox was 1 047 bp in length, corresponding to 348 amino acids. PpGA2ox was localized in both nucleus and cytoplasm. The expression of PpGA2ox could be up-regulated by 10 μM gibberellic acid, 5 μM methyl jasmonate, or 10 μM indole-3-acetic acid. In addition, its native promoter could drive GUS expression in both leaf apex and shoot apical region. Moreover, overexpression of PpGA2ox in Arabidopsis led to GA-deficiency leading to dwarf phenotype, delayed flowering time, and increased chlorophyll content. Our study suggests that PpGA2ox could be a candidate gene for breeding new cultivars of P. pratensis. [ABSTRACT FROM AUTHOR]

Easy handling and low unit N cost make prilled urea (46-0-0) a popular fertilizer. While incomplete recovery of granular urea applications by turfgrass is documented, field evaluations of NH3 volatilization mitigation by coatings or bioinhibitor efficiency enhancements are limited. Meanwhile, NH3 emissions reduce air quality and contribute to nutrient loading of water resources. Our objectives were to quantify 3- and 6-d ammonia emission and 9-week turfgrass recovery of unincorporated granular fertilizer application to turfgrass. In 2014 and 2015, commercial urea-N fertilizers were broadcast over a mature Kentucky bluegrass (Poa pratensis L. 'Midnight') lawn at 43 kg ha-1. Treatments included conventional urea and three enhanced-efficiency fertilizers; a blended fertilizer with 25% of its urea-N supplanted by polymer- and polymer-/sulfur-coated prills, or two stabilized urea fertilizers both amended by N-(n-butyl) thiophosphoric triamide (NBPT) and dicyandiamide (DCD) inhibitors. Using a 51% 'trapping-efficiency' flux chamber system under the field conditions described, 23.1 or 33.5% of the conventional urea-N was lost as NH3 over the respective 3- or 6-d period following application. Alternatively, dual amendment by NBPT and DCD resulted in approximately 10.3 or 19.6% NH3-N loss over the respective 3- or 6-d periods, and greater fertilizer-N recovery by the turfgrass over the 9-week experiments. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess soil conditioners' effects on the colour intensity of lawn grass. The field experiment was conducted in the experimental facility between 2013 and 2015 in Poland. The following grass species were used in the experiment (factor B): Lolium perenne, Festuca rubra, and Poa pratensis. Another experimental factor tested in the research was soil conditioners (factor A) as Substral, Humus Active Papka, Eko-Użyźniacz, UGmax. At the end of each growing season between 2013 and 2015 the colour of grasses was assessed in accordance with the methodology using a 9-point rating scale. This assessment was conducted in three seasons: spring, summer, and autumn. In all seasons of the year smooth-stalked meadow-grass had the most favourable colour when treated with Substral in spring and summer seasons, and with Eko-Użyźniacz in autumn. Comparing all soil conditioners, grass treated with UGmax had the best colour. From a practical point of view, of all grass species tested in the study, perennial ryegrass had the smallest, most favourable, colour variation during the whole period. [ABSTRACT FROM AUTHOR]

The field experiment was conducted in Poland between 2013 and 2015. The research was carried out in the split plot design with three replications. The following grass species were used in the experiment (factor B): Lolium perenne, Festuca rubra and Poa pratensis. Another experimental factor tested in the research was soil conditioners (factor A) as Substral (S), Humus Active Papka (HAP), Eko- Użyźniacz (EU), UGmax (UG). In each year of the experiment, among other things, grass growth, i.e. its slow rate of growth, was assessed. It was based on measurements of the height of plants before harvest. A 9-point scale was used. This assessment was conducted in three seasons (spring, summer, autumn). In all seasons red fescue had the most desirable intensity of growth (the slowest) and permanent ryegrass the fastest, both determined as an average effect of all soil conditioners. Of the applied soil conditioners, lawns treated with Humus Active Papka, grew the most slowly, taken as an average for all grass species and for all seasons. Of all grass species tested in the experiment red fescue had the smallest variation of growth intensity during the research. [ABSTRACT FROM AUTHOR]

Owing to high water requirements of turfgrass, it is essential to find suitable turfgrasses for cultivation in arid and semi-arid conditions. For this purpose, physiological responses of Agropyron desertorum and Poa pratensis cv. “Barimpala” that were subjected to outdoor with holding irrigation were evaluated. Seeds of these two genuses were cultured in polyvinyl chloride tubes and were irrigated daily until drainage occurred. After establishment, irrigation was stopped until leaf wilting occurred. P. pratensis and A. desertorum were wilted during 15 and 20 days after drought treatment, respectively. Turf quality and relative water content were decreased due to drought stress, butthe extent of decrease in A. desertorum was less than that it was in P. pratensis. Five days after stress, malondialdehyde levels increased in P. pratensis more quickly than A. desertorum, while electrolyte leakage rose immediately after with holding irrigation in these genuses. Superoxide dismutase and catalase activities in the two stressed plants increased and then decreased with stress development. In these conditions activities of AT, 3-amino-1,2,4-triazole, peroxidase and glutathione peroxidase had a similar pattern in P. pratensis, while A. desertorum showed continuous increase in these enzyme activities. [ABSTRACT FROM AUTHOR]

Abstract: Despite evidence that prior exposure to drought can increase subsequent plant freezing tolerance, few studies have explored such interactions over ecologically relevant time spans. We examined the combined effects of drought and subsequent freezing on tiller growth and leaf sugar concentrations in the grass, Poa pratensis. We exposed tillers to no drought (−0.04 MPa), moderate drought (−0.19 MPa) or severe drought (−0.42 MPa) for 3 weeks in summer. Tillers were then frozen in autumn or spring at −5 °C (frost damage) or at 0 °C (control) for 3 days and harvested after a re‐growth period. For shoot growth, there was a significant interaction between drought and autumn freezing, whereby the relative effect of freezing on growth was least for the plants previously exposed to severe drought; however, there was no significant interaction between drought and spring freezing. For root growth, there were no significant interactions between drought and freezing in either season. Leaf sugar concentrations increased significantly with drought intensity, but these effects dissipated within a month, prior to the onset of the autumn freezing treatment. Overall, our results suggest that interactions between prior drought and subsequent freezing in P. pratensis may be most relevant in the context of autumn freezing, and despite the important role of soluble sugars in increasing both drought and freezing tolerance in this species, the retention of these compounds after drought stress does not appear to explain the occurrence of drought–frost interactions at ecologically relevant time scales. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Institute of Science & Technology / Iğdır Üniversitesi Fen Bilimleri Enstitüsü Dergisi is the property of Igdir University, Institute of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Kentucky bluegrass (Poa pratensis L.) is a highly adapted and important turfgrass species in cool-season climates. It has high and variable polyploidy, small and metacentric chromosomes, and a facultative apomictic breeding system. As a result of the polyploidy and apomixis, identifying hybrids for Mendelian selection, identifying fixed apomictic progeny of desirable hybridizations for cultivar development, or differentiating among cultivars with subtle phenotypic differences is challenging without the assistance of molecular markers. Herein, we show data and review previous research showing the uses and limitations of using molecular markers for hybrid detection, apomixis assessment, and cultivar discrimination. In order to differentiate among different apomictic offtypes, both molecular markers and flow cytometry are necessary. For assessing similarity among progeny of hybridizations, as well as discriminating among cultivars, sets of markers are necessary and cryptic molecular variation must be considered. High throughput genotyping platforms are critical for increased genotyping efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Invasion by the rhizomatous grass Kentucky bluegrass (Poa pratensis) is a global phenomenon, including into foothills rough fescue (Festuca campestris) grasslands of southwestern Alberta, Canada. In order to better understand the competitive relationships between these species, we conducted a fallow field study where rough fescue bunchgrass tussocks were transplanted at one of three planting densities (15, 30, or 45 cm spacing), and then subject to various treatments in a factorial design, including one‐time intensive summer defoliation and seeding of bluegrass into adjacent bare soil. Rough fescue plants exhibited marked intraspecific competition, as high planting densities increased tussock mortality, while decreasing plant tiller counts and relative inflorescence production, together with plant and tiller‐specific mass. However, high densities of the bunchgrass also reduced the cover and biomass of encroaching bluegrass, coincidental with reduced resource (soil moisture and light) availability in mid‐summer. Although summer defoliation increased rough fescue tiller counts, this disturbance reduced plant and tiller mass, and also increased Kentucky bluegrass. We conclude that while high densities of nondefoliated stands of rough fescue may increase resistance to bluegrass encroachment, a reduction in either fescue plant density or vigor via defoliation can increase the risk of bluegrass invasion within northern temperate grassland. [ABSTRACT FROM AUTHOR]

We investigated the effect of water deficiency in soil on the morphological features and photosynthetic efficiency of Kentucky bluegrass during the early phase period of plants growth. Plants grown under stress-free conditions until tillering. Three levels of soil capillary water capacity (% CWC) were applied: (70%, 50% and drought stress at 35%). Plants were grown under these conditions for 21 days. Subsequently, all of them were subjected to well-watered conditions for 14 days (recovery). The study showed that values of relative water content, chlorophyll fluorescence parameters and morphological traits were lower under conditions of soil water deficiency and drought stress relative to the optimal soil moisture. Restoration of optimal soil water conditions increased all parameters characterizing the above ground part of biomass, while values of root traits did not vary. Plants subjected to well-watered post drought soil conditions, showed a rapid recovery of photosynthetic efficiency of Kentucky bluegrass. This work suggests that, this plant can survive short periods of drought stress and thus can be recommended for cultivation in the regions where drought conditions are expected to occur. Moreover, plant photosynthetic efficiency can substitute classical evaluation method of plant tolerance to drought stress based on plant water status. [ABSTRACT FROM AUTHOR]

Prairie reconstructions are a critical component of preservation of the imperiled tallgrass prairie ecosystem in the Midwestern United States. Sustainability of this endeavor depends on establishment of persistent cover of planted native species and resistance to noxious weeds. The goal of this study was to understand the influence of early reconstruction practices on long-term outcomes. Twelve replicates of three planting methods (dormant-season broadcast, growing-season broadcast, and growing-season drill) and three seed mix richness levels (10, 20, or 34 species), fully crossed in a completely randomized design were planted in 2005 on nine former agricultural fields located in Iowa and Minnesota. Cover by species was estimated in 2005-2007, 2010, and 2015. In 2015, cover of planted species, native nonplanted species, and exotic species were similar to those recorded in 2010. Cover of the noxious weed Cirsium arvense had also declined by an average of 49% without herbicide from a peak in 2007 to low stable levels from 2010 to 2015. Richness of planted forbs, on the other hand, were still increasing in high-richness broadcast treatments (e.g. 17-59% increase 2010-1015 in Minnesota). Two results in 2015 are reasons for concern: cover of planted species is only slightly over 50% in both Minnesota and Iowa, though with forbs still increasing, this may improve; and the cool-season exotic grasses Poa pratensis and Bromus inermis are increasing at both Minnesota and Iowa sites. Control of these invasive grasses will be necessary, but care will be needed to avoid negative impacts of control methods on natives. [ABSTRACT FROM AUTHOR]

Drought stress occurs frequently and severely as a result of global climate change, and it exerts serious effects on plants. 5-Aminolevulinic acid (5-ALA) plays a crucial role in conferring abiotic stress tolerance in plants. To enhance the drought tolerance of turfgrass and investigate the effects of 5-ALA on antioxidant metabolism and gene expression under drought stress conditions, exogenous 5-ALA was applied by foliar spraying before Kentucky bluegrass ( Poa pratensis L.) seedlings were exposed to drought [induced by 10% polyethylene glycol (PEG)] stress for 20 days. 5-ALA pretreatment increased turf quality (TQ) and leaf relative water content (RWC) while reducing reactive oxygen species (ROS) production including HO content and O generation rate, lipoxygenase (LOX) activity, and malondialdehyde (MDA) content under drought stress. 5-ALA pretreatment maintained ascorbate (AsA) and glutathione (GSH) contents and the ASA/DHA and GSH/GSSG ratios at high levels, and it enhanced the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), dehydroascorbate reductase (DHAR), and glutathione reductase (GR), which are crucial for scavenging drought-induced ROS. In addition, 5-ALA upregulated the relative expression levels of Cu/ZnSOD, APX, GPX, and DHAR but downregulated those of CAT and GR under drought stress. These results indicated that the application of 5-ALA might improve turfgrass quality and promote drought tolerance in Kentucky bluegrass through reducing oxidative damage and increasing non-enzyme antioxidant levels and antioxidant enzyme activity at transcriptional and posttranscriptional levels. [ABSTRACT FROM AUTHOR]

Climatic changes and the need to reduce water consumption for irrigation have led to expanded use of warm-season turf species in transitional zones. Turf managers are often hesitant to use warm-season species because they undergo dormancy for a long period during the winter. Although this issue might be addressed by mixing cool- with warm-season species, there is a lack of information on the performance and dynamics of species succession in such turfgrass mixtures. A 2-yr investigation was conducted in Legnaro, Italy, and Fayetteville, AR, to test the turf quality and species succession in mixtures of various cultivars of bermudagrass (BG) [Cynodon dactylon (L.) Pers.] with Kentucky bluegrass (KBG) (Poa pratensis L.). Bermudagrass cultivars, Yukon and Veracruz, were seeded in June 2011 at 5 g m-2 and KBG cultivars Brooklawn, Mystere, and Nublue Plus were overseeded in September 2011 at 30 g m-2. Across both studies, the frequency of BG in the mixture was generally higher for Yukon and ranged from 40 to 95%. However, the mixtures with Veracruz had superior turf quality in Legnaro from October 2012 to March 2013. The species succession was influenced by BG cultivars, whereas KBG cultivar had little effect on the rate of plant composition change. On the basis of these results, the choice of BG cultivar appears critical for establishing functional KBG and BG mixtures in transitional zones. [ABSTRACT FROM AUTHOR]

Copyright of Genome is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Poa pratensis L. is a turf grass and forage crop used worldwide. Being a facultative apomictic species, P. pratensis has a highly variable chromosome number. Chromosomal markers constitute a powerful tool for chromosome identification and for various aspects of genomic research. However, currently, no chromosomal markers are available for P. pratensis. Results: Four novel chromosome markers were isolated from a screen of Cot-1 DNA libraries, combined with fluorescence in situ hybridization (FISH) in Poa pratensis. Three tandemly repetitive sequences (PpTR-1, PpTR-2, and PpTR-3) were characterized as subtelomeric. Monomers of 318 bp, 189 bp and 189 bp were identified in PpTR-1, PpTR-2, and PpTR-3, respectively. One tandemly repetitive sequence (PpCR-1) was shown to be centromeric or pericentromeric, and it had a monomer of 27 bp. The distribution patterns of PpTR-1, PpTR-2, and PpTR-3 were highly conserved across different P. pratensis cultivars and in the distantly related Poa species, whereas PpCR-1 was conserved across different P. pratensis cultivars, but less conserved across Poa species. Conclusion: In this study, we report the identification and characterization of four novel chromosomal markers in P. pratensis. These chromosomal markers are powerful tools for accurate assessment of chromosome count, genomic and phylogenetic analyses, as well as studies of apomixis in P. pratensis. [ABSTRACT FROM AUTHOR]

Kentucky bluegrass (Poa pratensis L.) belong to Gramineae and is widely used in lawns, golf courses, landscapes, and sport fields as a prominent cool-season grass. Gene expression patterns during different stages of plant development can provide clues toward the understanding of its biological functions. The selection and validation of reference genes are the first steps in any real-time quantitative PCR gene expression study. Therefore, suitable reference genes are necessary for obtaining reliable results in real-time quantitative PCR analyses of Kentucky bluegrass. In the present study, 9 candidate reference genes were chosen, and their expression stability in the leaves and roots of Kentucky bluegrass under different stresses (drought, salt, heat, and cold) were evaluated using the GeNorm, NormFinder, BestKeeper, and RefFinder programs. The results showed that the expression stability of the candidate reference genes was dependent on the experimental conditions. The combination of SAM with GAPDH was the most stable in leaves under salt stress and cold stress, while TUB combined with ACT or GAPDH was stable in roots under salt or cold stress, respectively. ACT and SAM maintained stable expression in drought-treated leaves, and GAPDH combined with ACT was stable in drought-treated roots. SAM and TUB exhibited stable expression in heattreated leaves. ACT and RPL were stable in heat-treated roots. In addition, the expression patterns of PpFEH in response to drought and cold stress were used to confirm the reliability of the selected reference genes, indicating that the use of an inappropriate reference gene as the internal control will cause erroneous results. This work is the first study on the expression stability of reference genes in Kentucky bluegrass and will be particularly useful in the selection of stress-tolerance genes and the identification of the molecular mechanisms conferring stress tolerance in this species. [ABSTRACT FROM AUTHOR]

Phytoremediation efficiency mainly depends upon mechanisms in the uptake and translocation of soil contaminants. Cadmium (Cd) distribution and translocation in roots and shoots of tall fescue (Festuca arundinacea) and Kentucky bluegrass (Poa pratensis) were observed using fluorescence spectroscopy with a laser confocal scanning microscope. No difference in root Cd accumulations was detected between these two turfgrass species. Kentucky bluegrass transported more Cd into the stele for root-to-shoot translocation and resulted in significantly higher Cd concentration in leaves. In tall fescue, less Cd was transported into the stele in roots and more Cd was excreted to the cuticle layer in leaves. These results suggested that both turfgrass species were hypertolerant to Cd through distinct distribution patterns in leaves and roots. [ABSTRACT FROM AUTHOR]