Fig 1.
Experimental setup in the greenhouse.
(A) Control; (B) Waterlogging treatment; (C) Four waterlogging treatments and four controls were arranged in a randomized complete block design in the greenhouse study.
Fig 2.
Representative images used in digital quantification of aerenchyma area.
(A) Original digital image of a tall fescue root cross section; (B) root cross section covered with black ink on a new image layer; (C) total cross sectional area; (D) aerenchyma spaces. Percentage of aerenchyma (44%) was calculated by dividing the number of pixels in (C) (pixels: 104932) by the number of pixels in (D) (pixels: 46917).
Table 1.
Soil redox potential, (Eh), readings during experiment.
Table 2.
Turf quality, leaf number, height, aboveground dry biomass, root dry biomass, root length, and root distribution of tall fescue (TF) and roughstalk bluegrass (RB) under control and waterlogging conditions.
Fig 3.
Images of root cross sections in roughstalk bluegrass (RB).
Examples of root cross sections with 0 (A, control), 18 (B, control), 34 (C, waterlogged), and 51% (D, waterlogged) aerenchyma by area. Aerenchyma occurred in both control and waterlogged plant roots.
Fig 4.
Images of root cross sections in tall fescue (TF).
Examples of root cross sections with 0 (A, control), 24 (B, control), 29 (C, waterlogged), and 48% (D, waterlogged) aerenchyma by area. Aerenchyma occurred in both control and waterlogged plant roots.
Table 3.
Changes in aerenchyma area in the root cross sections of tall fescue (TF) and roughstalk bluegrass (RB) during the 4 week greenhouse study.
Fig 5.
ADH activity changes in leaves of tall fescue (TF) and roughstalk bluegrass (RB).
ADH activity changes in leaves of control tall fescue (TF-cnt), control roughstalk bluegrass (RB-cnt), waterlogged tall fescue (TF-wl), and waterlogged roughstalk bluegrass (RB-wl) during the 4-week greenhouse study. Data represent means of 32 individuals. Means in the same week with the same letter are not different based on Duncan’s multiple range test at 0.05 probability.
Fig 6.
ADH activity changes in roots of tall fescue (TF) and roughstalk bluegrass (RB).
ADH activity changes in roots of control tall fescue (TF-cnt), control roughstalk bluegrass (RB-cnt), waterlogged tall fescue (TF-wl), and waterlogged roughstalk bluegrass (RB-wl) during the 4-week greenhouse study. Data represent means of 32 individuals. Means in the same week with the same letter are not different based on Duncan’s multiple range test at 0.05 probability.
Fig 7.
LDH activity changes in leaves of tall fescue (TF) and roughstalk bluegrass (RB).
LDH activity changes in leaves of control tall fescue (TF-cnt), control roughstalk bluegrass (RB-cnt), waterlogged tall fescue (TF-wl), and waterlogged roughstalk bluegrass (RB-wl) during the 4-week greenhouse study. Data represent means of 32 individuals. Means in the same week with the same letter are not different based on Duncan’s multiple range test at 0.05 probability.
Fig 8.
LDH activity changes in roots of tall fescue (TF) and roughstalk bluegrass (RB).
LDH activity changes in roots of control tall fescue (TF-cnt), control roughstalk bluegrass (RB-cnt), waterlogged tall fescue (TF-wl), and waterlogged roughstalk bluegrass (RB-wl) during the 4-week greenhouse study. Data represent means of 32 individuals. Means in the same week with the same letter are not different based on Duncan’s multiple range test at 0.05 probability.
Table 4.
Leaf water soluble carbohydrate (LWSC) content and root water soluble carbohydrate (RWSC) content in tall fescue (TF) and roughstalk bluegrass (RB) during the 4 week greenhouse study.
Fig 9.
Response of leaf net photosynthetic rate in tall fescue (TF) and roughstalk bluegrass (RB).
Response curves of leaf net photosynthetic rate (A) as a function of photosynthetic photon flux density (PPFD) in control tall fescue (TF-cnt), control roughstalk bluegrass (RB-cnt), waterlogged tall fescue (TF-wl), and waterlogged roughstalk bluegrass (RB-wl) at 1 (●), 2 (■), 3(▲), and 4 (♦) weeks of treatment. Data represent means of 8 individuals ±SE.
Fig 10.
Chlorophyll concentration changes in tall fescue (TF) and roughstalk bluegrass (RB).
Chlorophyll concentration in control tall fescue (TF-cnt), control roughstalk bluegrass (RB-cnt), waterlogged tall fescue (TF-wl), and waterlogged roughstalk bluegrass (RB-wl) during the 4-week greenhouse study. Data represent means of 32 individuals ±SE. Means in the same time period with same letter are not different based on Duncan’s multiple range test at 0.05 probability.