scholarly journals Differential Effectiveness of Doubling Ambient Atmospheric CO2 Concentration Mitigating Adverse Effects of Drought, Heat, and Combined Stress in Kentucky Bluegrass

2014 ◽  
Vol 139 (4) ◽  
pp. 364-373
Author(s):  
Yali Song ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
Poa Pratensis ◽  
Relative Effectiveness ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Combined Stress ◽  
Cool Season ◽  
Positive Effects ◽  
Effects Of Drought ◽  
Drought And Heat Stress

Drought and heat stress can limit the growth of cool-season grass species, whereas doubling ambient CO2 has been shown to promote plant growth. The objectives of this study were to examine differential responses of shoot and root growth as well as photosynthesis and respiration to doubling ambient CO2 during drought or heat stress alone or the two stresses combined and to determine the relative effectiveness of doubling ambient CO2 in mitigating negative effects of drought or heat stress alone and in combination in a cool-season perennial grass species. Kentucky bluegrass (Poa pratensis cv. Baron) plants were exposed to ambient CO2 (400 μL·L−1) or doubling ambient CO2 (800 μL·L−1) concentrations while subjected to the following stress treatments in growth chambers: drought stress by withholding irrigation, heat stress (35 °C), or the combined two stresses for 28 days. Doubling ambient CO2 increased root and shoot growth as well as root/shoot ratio under all treatments. Doubling ambient CO2 enhanced leaf net photosynthetic rate (Pn) to a greater extent under drought or heat alone, whereas it reduced respiration rate (R), to a larger degree under heat and the combined stress, leading to a greater ratio of Pn/R. Doubling ambient CO2 mitigated adverse physiological effects of drought or heat stress alone, whereas fewer effects were observed under the combined drought and heat stress. The positive effects of doubling ambient CO2 were associated with the development of roots biomass and the maintenance of a positive carbon balance under either stress alone or the combined drought and heat stress.

scholarly journals Differential Responses of Nutrients to Heat Stress in Warm-season and Cool-season Turfgrasses

HortScience ◽  
2009 ◽  
Vol 44 (7) ◽  
pp. 2009-2014 ◽  
Author(s):  
Hua Shen ◽  
Hongmei Du ◽  
Zhaolong Wang ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Poa Pratensis ◽  
Warm Season ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Cool Season ◽  
Temperature Conditions ◽  
Differential Responses ◽  
K Concentration

The objective of this study was to compare differential nutrient responses to heat stress in relation to heat tolerance for warm-season (C4) common bermudagrass [Cynodon dactylon (L.) Pers.] and cool-season (C3) kentucky bluegrass (Poa pratensis L.). Both species were exposed to two temperature regimes in growth chambers: optimal day/night temperature conditions (24/20 °C for kentucky bluegrass and 34/30 °C for bermudagrass) or heat stress (10 °C above the respective optimal temperature for each species). Heat injury in leaves was evaluated and the concentrations of several major macronutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] in both grass species were measured at 0, 7, 14, 21, and 28 days of treatment. Heat stress reduced leaf photochemical efficiency and cellular membrane stability in both species, but bermudagrass leaves exhibited less damage in these parameters than kentucky bluegrass. Heat stress caused a significant decline in N, P, and K concentration, beginning at 7 days in kentucky bluegrass, but had no significant effects on N, P, and K concentration in bermudagrass during the 28-day treatment period. The concentration of Ca and Mg increased under heat stress in both kentucky bluegrass and bermudagrass, but there were no significant differences between the species under optimal or high-temperature conditions, suggesting they were not involved in heat responses in either species. The differential responses of N, P, and K to heat stress could at least partially account for the differences in heat tolerance between the two species and demonstrate the importance of sufficient N, P, and K in turfgrass adaptation to heat stress.

scholarly journals Differential Effects of Abscisic Acid and Glycine Betaine on Physiological Responses to Drought and Salinity Stress for Two Perennial Grass Species

2012 ◽  
Vol 137 (2) ◽  
pp. 96-106 ◽  
Author(s):  
Zhimin Yang ◽  
Jingjin Yu ◽  
Emily Merewitz ◽  
Bingru Huang
Keyword(s):  
Abscisic Acid ◽  
Salinity Stress ◽  
Glycine Betaine ◽  
Foliar Application ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Antioxidant Metabolism ◽  
Positive Effects ◽  
Turf Quality

Abscisic acid (ABA) and glycine betaine (GB) may regulate plant responses to drought or salinity stress. The objectives of this controlled-environment study were to determine whether foliar application of ABA or GB improves turf quality under drought or salinity and whether improved stress responses were associated changes in antioxidant metabolism in two C3 turfgrass species, creeping bentgrass (Agrostis stolonifera) and kentucky bluegrass (Poa pratensis). Physiological parameters evaluated included turf quality, leaf relative water content, membrane electrolyte leakage (EL), membrane lipid peroxidation [expressed as malondialdehyde (MDA) content], and activity of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX). Abscisic acid and GB were both effective in mitigating physiological damage resulting from drought or salinity for both grass species, but effects were more pronounced on kentucky bluegrass. The most notable effects of ABA or GB application were the suppression of EL and MDA accumulation and an increase in APX, POD, and SOD activities after prolonged periods of drought (21 days) or salinity stress (35 days). These results suggest foliar application of ABA or GB may alleviate physiological damage by drought or salinity stress in turfgrass and the maintenance of membrane stability and active antioxidant metabolism could contribute to the positive effects in the stress mitigation effects.

scholarly journals Differential Responses to Heat Stress in Activities and Isozymes of Four Antioxidant Enzymes for Two Cultivars of Kentucky Bluegrass Contrasting in Heat Tolerance

2010 ◽  
Vol 135 (2) ◽  
pp. 116-124 ◽  
Author(s):  
Yali He ◽  
Bingru Huang
Keyword(s):  
Antioxidant Enzymes ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Defense Mechanisms ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Guaiacol Peroxidase ◽  
Cool Season ◽  
Chl A ◽  
Antioxidant Mechanisms

Understanding antioxidant mechanisms for heat stress is important for improving heat tolerance in cool-season plant species. The objective of this study was to identify antioxidant enzymes associated with cultivar variations in heat tolerance in kentucky bluegrass (Poa pratensis) by comparing heat responses of activity and isoforms of antioxidant enzymes in two cultivars contrasting in heat tolerance. Plants of heat-tolerant ‘Eagleton’ and heat-sensitive ‘Brilliant’ were exposed to 20 °C (control) or 40 °C (heat stress) for 28 days in growth chambers. Chlorophyll (Chl) a content remained unchanged and Chl b content increased in ‘Eagleton’, while both of them decreased in ‘Brilliant’, and by 28 days, ‘Eagleton’ had significantly higher Chl a and b content than ‘Brilliant’. The activities of superoxide dismutase (SOD) were significantly higher in ‘Eagleton’ than in ‘Brilliant’ by 28 days of heat stress. An isozyme SOD2 was induced early during heat stress in ‘Eagleton’, while isozyme SOD3 degraded, to a lesser extent in ‘Eagleton’ than in ‘Brilliant’. Catalase (CAT) activity significantly increased in ‘Brilliant’ but remained constant in ‘Eagleton’, and ‘Brilliant’ had a significantly higher CAT activity and isozyme CAT1 than ‘Eagleton’ during heat stress. Significant increases in ascorbate peroxidase (APX) activities occurred under heat stress, to a greater extent in ‘Eagleton’, whereas isozymes did not exhibit difference between cultivars. Guaiacol-peroxidase (POD) activity declined during heat stress in both cultivars. The intensity of POD isozymes in ‘Brilliant’ remained constant, while ‘Eagleton’ showed a transient increases in POD1 at 7 days of heat stress. Our results indicated that antioxidant defense mechanisms for heat tolerance in kentucky bluegrass could be mainly associated with changes in activity and forms of isozymes of SOD for O2 scavenging and APX activity for H2O2 scavenging under heat stress.

scholarly journals Differential Responses of Hybrid Bluegrass and Kentucky Bluegrass to Drought and Heat Stress

HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 2191-2195 ◽  
Author(s):  
Eleni M. Abraham ◽  
William A. Meyer ◽  
Stacy A. Bonos ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Transpiration Rate ◽  
Soil Depth ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Optimal Temperature ◽  
Turf Quality ◽  
Differential Responses ◽  
Drought And Heat Stress

This study was designed to investigate differential responses of hybrids from Texas bluegrass (Poa arachnifera Torr.) × Kentucky bluegrass (Poa pratensis L.) (KBG) and KBG genotypes to drought and heat stress. Plants of two hybrids, ‘845’ and ‘BDF’, and two KBG genotypes (‘Midnight’ and ‘C-74’) were grown under optimal temperature (22/18 °C) and well-watered (control) or unwatered (drought) or superoptimal temperatures (35/30 °C; heat stress) conditions for 35 days in growth chambers. Under optimal conditions, the two hybrids and two KBG genotypes were not significantly different in turf quality, leaf photochemical efficiency expressed as chlorophyll fluorescence ratio (Fv/Fm), leaf net photosynthetic rate (Pn), transpiration rate, water use efficiency (WUE), root dry matter, or root viability. The results suggest that the interspecific hybridization resulted in similar growth and physiological traits in the hybrid bluegrass as in a turf-type species under optimal temperature and irrigation regimes. Under drought stress, all these parameters were comparable to those for KBG ‘Midnight’, but significantly higher than the corresponding parameters for KBG ‘C-74’. Under heat stress, both hybrids had significantly higher turf quality, Fv/Fm, Pn, transpiration rate, WUE, root dry weight in deeper soil depth (40 to 60 cm), and root viability in the upper 40-cm layer compared with both KBG genotypes. These results suggested that hybrid bluegrass exhibited improvement in drought and heat tolerance, particularly in comparison with KBG ‘C-74’, but to a great extent for heat tolerance. The maintenance of higher transpiration and photosynthesis, WUE, and root viability was associated with the improvement in heat tolerance in hybrid bluegrass.

scholarly journals Antioxidant and Hormone Responses to Heat Stress in Two Kentucky Bluegrass Cultivars Contrasting in Heat Tolerance

2014 ◽  
Vol 139 (5) ◽  
pp. 587-596 ◽  
Author(s):  
Feifei Li ◽  
Da Zhan ◽  
Lixin Xu ◽  
Liebao Han ◽  
Xunzhong Zhang
Keyword(s):  
Heat Stress ◽  
Antioxidant Enzyme ◽  
Heat Tolerance ◽  
Poa Pratensis ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Limiting Factor ◽  
Antioxidant Enzyme Activities ◽  
Aba Content

Heat stress is a major limiting factor for growth of cool-season perennial grass species, and mechanisms of heat tolerance have not been well understood. This study was designed to investigate antioxidant enzyme and hormone metabolism responses to heat stress in two kentucky bluegrass (Poa pratensis L.) cultivars contrasting in heat tolerance. The plants were subjected to 20/20 °C [day/night (control)] or 38/30 °C [day/night (heat stress)] for 28 days in growth chambers. Heat stress increased leaf electrolyte leakage (EL) and malondialdehyde (MDA) with heat-tolerant cultivar EverGlade exhibiting lower levels of EL and MDA relative to heat-sensitive cultivar Kenblue under heat stress. Superoxide dismutase (SOD) and catalase (CAT) activity increased and then declined during 28 days of heat stress. Peroxidase (POD) and ascorbate peroxidase (APX) activity declined and then increased during heat stress. ‘EverGlade’ had greater activities of SOD, CAT, POD, and APX relative to ‘Kenblue’ under heat stress. In addition, ‘EverGlade’ had two additional SOD isozymes and three additional POD isozymes relative to ‘Kenblue’ under heat stress. Leaf abscisic acid (ABA) increased in response to heat stress. Leaf indole-3-acetic acid (IAA) increased and then declined during heat stress. ‘OverGlade’ had higher ABA and IAA content relative to ‘Kenblue’. At the end of heat stress, leaf IAA and ABA content were 27.8% and 73% higher in ‘EverGlade’ relative to ‘Kenblue’, respectively. The results indicated that antioxidant enzymes and the hormones (ABA and IAA) were associated with kentucky bluegrass heat tolerance. Selection and use of cultivars with higher IAA and ABA content and greater antioxidant enzyme activities may improve kentucky bluegrass growth and quality under heat stress.

scholarly journals Additional Host Plants of Four Species of Billbug Found on New Jersey Turfgrasses

1990 ◽  
Vol 115 (4) ◽  
pp. 608-611 ◽  
Author(s):  
Jennifer M. Johnson-Cicalese ◽  
C.R. Funk
Keyword(s):  
New Jersey ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Host Plants ◽  
Cynodon Dactylon ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Red Fescue

Studies were conducted on the host plants of four billbug species (Coleoptera:Curculionidae: Sphenophorus parvulus Gyllenhal, S. venatus Chitt., S. inaequalis Say, and S. minimus Hart) found on New Jersey turfgrasses. A collection of 4803 adults from pure stands of various turfgrasses revealed all four billbugs on Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and perennial ryegrass (Lolium perenne L.), and S. parvulus, S. venatus, and S. minimus on Chewings fescue (F. rubra L. ssp. commutata Gaud.). Since the presence of larvae, pupae, or teneral adults more accurately indicates the host status of a grass species, immature billbugs were collected from plugs of the various grass species and reared to adults for identification. All four species were reared from immature billbugs found in Kentucky bluegrass turf; immatures of S. venatus, S. inaequalis, and S. minimus were found in tall fescue; S. venatus and S. minimus in perennial ryegrass; and S. inaequalis in strong creeping red fescue (F. rubra L. ssp. rubra). A laboratory experiment was also conducted in which billbug adults were confined in petri dishes with either Kentucky bluegrass, perennial ryegrass, tall fescue, or bermudagrass (Cynodon dactylon Pers.). Only minor differences were found between the four grasses in billbug survival, number of eggs laid, and amount of feeding. In general, bermudagrass was the least favored host and the other grasses were equally adequate hosts. The results of this study indicate a need for updating host-plant lists of these four billbug species.

scholarly journals Salt Stress-induced Injury is Associated with Hormonal Alteration in Kentucky Bluegrass

HortScience ◽  
2018 ◽  
Vol 53 (1) ◽  
pp. 97-101 ◽  
Author(s):  
Xunzhong Zhang ◽  
Wenli Wu ◽  
Erik H. Ervin ◽  
Chao Shang ◽  
Kim Harich
Keyword(s):  
Salt Stress ◽  
Cell Membrane ◽  
Poa Pratensis ◽  
Membrane Damage ◽  
Kentucky Bluegrass ◽  
Zeatin Riboside ◽  
Cool Season ◽  
Cell Membrane Damage ◽  
Turf Quality ◽  
Isopentenyl Adenosine

Plant hormones play an important role in plant adaptation to abiotic stress, but hormonal responses of cool-season turfgrass species to salt stress are not well documented. This study was carried out to investigate the responses of hormones to salt stress and examine if salt stress-induced injury was associated with hormonal alteration in kentucky bluegrass (KBG, Poa pratensis L.). The grass was grown in a growth chamber for 6 weeks and then subjected to salt stress (170 mm NaCl) for 28 days. Salt stress caused cell membrane damage, resulting in photosynthetic rate (Pn), chlorophyll (Chl), and turf quality decline in KBG. Salt stress increased leaf abscisic acid (ABA) and ABA/cytokinin (CK) ratio; reduced trans-zeatin riboside (ZR), isopentenyl adenosine (iPA), and indole-3-acetic acid (IAA), but did not affect gibberellin A4 (GA4). On average, salt stress reduced ZR by 67.4% and IAA by 58.6%, whereas it increased ABA by 398.5%. At the end of the experiment (day 28), turf quality, Pn, and stomatal conductance (gs) were negatively correlated with ABA and ABA/CK ratio, but positively correlated with ZR, iPA, and IAA. Electrolyte leakage (EL) was positively correlated with ABA and ABA/CK and negatively correlated with ZR, iPA, IAA, and GA4. GA4 was also positively correlated with turf quality and gs. The results of this study suggest that salt stress-induced injury of the cell membrane and photosynthetic function may be associated with hormonal alteration and imbalance in KBG.

Wind-mediated seed dispersal of invasive forage grasses from agricultural grasslands in Hokkaido, Japan

2019 ◽  
Vol 12 (02) ◽  
pp. 133-141
Author(s):  
Chika Egawa ◽  
Atsushi Shoji ◽  
Hiroyuki Shibaike
Keyword(s):  
Seed Dispersal ◽  
Poa Pratensis ◽  
Plant Cover ◽  
Kentucky Bluegrass ◽  
Dispersal Distance ◽  
Phleum Pratense ◽  
Grass Species ◽  
Forage Grass ◽  
Forage Grasses ◽  
Number Of Seeds

AbstractAlthough introduced pasture grasses are essential for forage production in current livestock farming, some species cause serious impacts on native biodiversity when naturalized. Information on the seed dispersal of invasive forage grasses from cultivated settings to surrounding environments can inform management efforts to prevent their naturalization. In this case study, we quantified the wind-mediated seed dispersal distance and amount of dispersed seed of invasive forage grasses from agricultural grasslands in Hokkaido, northern Japan. In total, 200 funnel seed traps were installed around three regularly mown grasslands and one unmown grassland where various forage grass species were grown in mixture. Seeds of each species dispersed outside the grasslands were captured from May to October 2017. Based on the trapped distances of seeds, the 99th percentile dispersal distance from the grasslands was estimated for six species, including timothy (Phleum pratense L.), orchardgrass (Dactylis glomerata L.), and Kentucky bluegrass (Poa pratensis L.). For two dominant species, P. pratense and D. glomerata, the numbers of seeds dispersed outside the field under mown and unmown conditions were determined under various plant cover situations. The estimated dispersal distances ranged from 2.3 m (P. pratense) to 31.5 m (P. pratensis), suggesting that areas within approximately 32 m of the grasslands are exposed to the invasion risk of some forage grass species. For both P. pratense and D. glomerata, the number of seeds dispersed outside the unmown grassland exceeded 100 seeds m−2 under high plant cover situations, while the number of seeds dispersed from the mown grasslands at the same plant cover level was less than one-third of that number. The results suggest that local land managers focus their efforts on frequent mowing of grasslands and monitoring of the areas within approximately 32 m of the grasslands to substantially reduce the naturalization of invasive forage grasses.

There Is No Evidence of Geographical Patterning among Invasive Kentucky Bluegrass (Poa pratensis) Populations in the Northern Great Plains

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 409-420 ◽  
Author(s):  
Lauren A. Dennhardt ◽  
Edward S. DeKeyser ◽  
Sarah A. Tennefos ◽  
Steven E. Travers
Keyword(s):  
Genetic Diversity ◽  
Great Plains ◽  
Propagule Pressure ◽  
Poa Pratensis ◽  
Natural Populations ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Northern Great Plains ◽  
Wild Populations ◽  
High Genetic Diversity

The study of colonizing and of dominant grass species is essential for prairie conservation efforts. We sought to answer how naturalized Kentucky bluegrass in the northern Great Plains has become successful in the last 20 yr despite its long history in the northern Great Plains. We tested for evidence of geographical differentiation using flow cytometry and microsatellite markers to ascertain the population genetics of Kentucky bluegrass. Across all tested wild populations, high levels of genetic diversity were detected along with moderate levels of structure. Mantel tests of geographical patterns were not significant. Using clonal assignment, we found two major clones that made up the majority of the tested wild populations. When we compared the wild individuals to pedigree cultivars, we found virtually no genetic overlap across all tests, which did not support our hypothesis of developed cultivars contributing to high genetic diversity in natural populations. Furthermore, DNA content tests indicated a narrow range in ploidy in wild populations compared with lawn cultivars, further supporting a hypothesis of divergence between wild and pedigree cultivars. These results indicate the recent invasion of Kentucky bluegrass in the northern Great Plains is not because of adaptation or propagule pressure, but rather likely an environmental or land use shift.

scholarly journals Transcriptome Sequencing of Two Kentucky Bluegrass (Poa pratensis L.) Genotypes in Response to Heat Stress

2018 ◽  
Vol 47 (2) ◽  
pp. 328-338
Author(s):  
Qiong LI ◽  
Yali HE ◽  
Mingyue TU ◽  
Junhui YAN ◽  
Liangliang YU ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
De Novo ◽  
Average Length ◽  
Poa Pratensis ◽  
Brachypodium Distachyon ◽  
Enrichment Analysis ◽  
Basic Mechanism ◽  
Kentucky Bluegrass ◽  
Summer Stress

Kentucky bluegrass (Poa pratensis L.) (KBG) is a major cool-season turfgrass. However, as its complex genetic background and production modes, limited genomic and transcriptomic information of KBG was known so far. In this study, a transcriptome study between wild type material Ninglan (summer stress sensitive) and cultivar material KBG03 (summer stress tolerant) was conducted, under optimal (25 °C) and high (40 °C) temperatures. A total of 81.42 Gb clean reads were generated and de novo assembled into 110,784 unigenes with an average length of 1,105 bp. About 50% KBG unigenes were similar to the non-redundant (NR) database. Among the NR BLASTx top hits, 27.47% unigenes were matched to Brachypodium distachyon. After heat stress, a massive amount of unigenes showed significantly differential expression in both genotypes. After 2h heat stress, more specially up-regulated differentially expressed unigenes (DEGs) and less down-regulated DEGs were detected in Ninglan than in KBG03. At 24h, the expression of 1710 and 730 unigenes were increased and decreased uniquely in Ninglan, and 1361 up-regulated DEGs and 757 down-regulated DEGs were just found in KBG03. More heat shock proteins (HSPs) and heat shock transcription factors (HSFs) DEGs were also identified at 2h than 24h in both genotypes. In addition, by Gene Ontology (GO) enrichment analysis, three core terms (“protein folding”, “response to heat”, and “response to hydrogen peroxide”) of biological process (BP) ontology were found in both genotypes under different heat stress time. The DEGs shared in both genotypes might be related to the basic mechanism of thermal response in KBG.

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