Photosynthesis was reduced by 85% to 90% in perennial ryegrass (Lolium perenne L. cv. Derby) following a one-day chilling exposure at 8C day (450 μmol·s-1·m-2 PPF) and 5C night. Seven days of recovery at 22/17C day/night were required for full recovery of photosynthesis. More than 75% of the limitation in photosynthesis following chilling was due to non-stomatal factors, and reduced initial slopes of CO2 assimilation vs. intercellular CO, indicate that photosynthetic capacity was reduced for 5 days following chilling. Carbon dioxide assimilation at saturating intercellular CO2 (>500 μmol·mol-l) was also reduced by chilling, indicating again that stomatal limitations were a minor contributor to the photosynthetic reduction observed under ambient CO2.
J.W. Moon Jr., D.M. Kopec, E. Fallahi, C.F. Macino, D.C. Slack and K. Jordan
E.H. Ervin and A.J. Koski
A growth chamber and a greenhouse study were conducted to determine if successive applications of trinexapac-ethyl (TE) to developing perennial ryegrass (Lolium perenne L.) plants would reduce leaf elongation rate (LER) while increasing tiller number and root mass. Growth parameters measured were LER, tiller number, and root mass. In the growth chamber, developing perennial ryegrass plants were sprayed twice with TE at 0.24 kg·ha-1 a.i. at 20 and 40 days after emergence. Leaf elongation rate was reduced by ≈35% following two applications of TE in both growth chamber experiments. This treatment increased the number of tillers per plant in the growth chamber at 60 days after emergence and in the greenhouse at 150 days after emergence, but had no effect on root or shoot mass in either location. Multiple applications of TE to developing perennial ryegrass turfs may favor quicker establishment in terms of tillering, while substantially reducing mowing requirement. Chemical names used: 4-cyclopropyl-α-hydroxy-methylene-3,5-dioxo-cyclohexanecarboxylic acid ethyl ester (trinexapac-ethyl).
Alejandro Alarcon*, Frederick T. Davies, David Wm. Reed, Robin L. Autenrieth and David A. Zuberer
Arbuscular mycorhizal fungi (AMF) have been used in phytoremediation and can increase tolerance and growth of plants in contaminated environments. However, little is known about the influence AMF on plant growth to organic contaminants in soils. A greenhouse experiment was conducted to study the response of seedlings of annual ryegrass (Lolium perenne L.) var. Passerel Plus inoculated with Glomus intraradices Schenck & Smith in soil contaminated with sweet Arabian median crude oil. Inoculated (AMF) and non-inoculated (Non-AMF) plants were established in an pasteurized and artificially contaminated sandy loam soil with 0; 3000; 15,000; or 45,000 mg of petroleum kg-1 soil (n = 20). Plants were inoculated with 500 spores of G. intraradices (Mycorise® ASP, PremierTech Biotechnologies, Canada). After 90 days, plant growth of AMF or Non-AMF plants, was drastically affected at all petroleum concentrations. However, G. intraradices enhanced plant growth, chlorophyll content, and gas exchange of plants grown at 3,000 mg kg-1 compared to Non-AMF plants. Total leaf area, chlorophyll, and net photosynthesis were also higher (+380%, +63%, and +81%, respectively) at this concentration. Water use efficiency (net photosynthesis/stomatal conductance) of AMF-plants was three times greater than Non-AMF at 3,000 mg·kg-1. At concentrations of 15,000 and 45,000 mg kg-1 AMF did not have effect, but colonization was observed (11.8% and 18.6%, respectively). These values of colonization were significantly lower than those observed in AMF-plants at 0 (42.5%) and 3,000 mg·kg-1 (55.6%). Studies are currently being conducted to understand the physiological role of AMF on plants exposed to organic contaminants.
Yu Cui, Jinsheng Wang, Xingchun Wang and Yiwei Jiang
stress tolerance Crop Sci. 54 355 365 Brazauskas, G. Xing, Y. Studer, B. Schejbel, B. Frei, U. Berg, P.R. Lübberstedt, T. 2013 Identification of genomic loci associated with crown rust resistance in perennial ryegrass ( Lolium perenne L.) divergently
Huiying Li, Hongji Luo, Deying Li, Tao Hu and Jinmin Fu
.S. 2002 Role of superoxide dismutase (SODs) in controlling oxidative stress in plants J. Expt. Bot. 53 1331 1341 Arienzo, M. Adamo, P. Cozzolino, V. 2004 The potential of Lolium perenne for revegetation of contaminated soil from a metallurgical site Sci
Peter H. Dernoeden, Steven J. McDonald and John E. Kaminski
creeping bentgrass [ Agrostis stolonifera L. (CBG)] and perennial ryegrass [ Lolium perenne L. (PRG)]. Ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate (ETHO)] effectively controls annual bluegrass without significant
Yiwei Jiang, Yu Cui, Zhongyong Pei, Huifen Liu and Shoujun Sun
FEBS Lett. 390 113 118 Turner, L.R. Holloway-Phillips, M.M. Rawnsley, R.P. Donaghy, D.J. Pembleton, K.G. 2012 The morphological and physiological responses of perennial ryegrass ( Lolium perenne L.), cocksfoot ( Dactylis glomerata L.) and tall fescue
Zhuangjun Zhao, Margaret Mukami Gitau, Tao Hu, Yan Xie, Longxing Hu and Jinmin Fu
. 2007 Nucleotide diversity and linkage disequilibrium in 11 expressed resistance candidate genes in Lolium perenne BMC Plant Biol. 7 43 Xiong, Y.W. Fei, S.Z. Arora, R. Brummer, E.C. Barker, R.E. Jung, G.W. Warnke, S.E. 2007 Identification of
Marco Fontanelli, Michel Pirchio, Christian Frasconi, Luisa Martelloni, Michele Raffaelli, Andrea Peruzzi, Nicola Grossi, Lisa Caturegli, Simone Magni, Monica Gaetani and Marco Volterrani
Appl. Eng. Agr. 29 663 673 Rask, A.M. Andreasen, C. Kristoffersen, P. 2012 Response of Lolium perenne to repeated flame treatments with various doses of propane Weed Res. 52 131 139 Rask, A.M. Kristoffersen, P. 2007 A review of non-chemical weed
Yiwei Jiang, Yaoshen Li, Gang Nie and Huifen Liu
( Lolium perenne ) to alterations in nitrogen supply Metabolomics 9 145 156 Gao, K. Chen, F. Yuan, L. Zhang, F. Mi, G. 2015 A comprehensive analysis of root morphological changes and nitrogen allocation in maize in response to low nitrogen stress Plant Cell