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.
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).
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.
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
chlorophyll degradation genes and senescence marker genes is not well-documented. We hypothesized that SL may affect leaf senescence in perennial ryegrass ( Lolium perenne ) exposed to dark conditions by affecting chlorophyll biosynthesis and/or degradation
( Schedonorus arundinaceus ), KBG, and perennial ryegrass [PR ( Lolium perenne )] were improved by the incorporation of a mixed-source compost at a volume of 20% to 33% ( Evanylo et al., 2016 ). Establishment of KBG was increased with the incorporation of as
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
.S. 2002 Role of superoxide dismutase (SODs) in controlling oxidative stress in plants J. Expt. Bot. 53 1331 1341 10.1093/jexbot/53.372.1331 Arienzo, M. Adamo, P. Cozzolino, V. 2004 The potential of Lolium perenne for revegetation of contaminated soil
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
Total germination of 6 cultivars of perennial ryegrass (Lolium perenne L.) was unaffected by up to 10,000 ppm of salinity in the germination medium, but rate of germination decreased quadratically with increased salinity. No interactions of cultivar × salinity were found.