Plant material and growth conditions
Eighteen C4 grasses (Table 1) representing the three
classical biochemical subtypes and 8 evolutionary lineages were selected
for this study. However, the aim of our study was not to look at subtype
or lineage effect but to maximize leaf physiological, structural and
anatomical trait diversity. Each species was given a unique
identification number (Table S1) for presentation in Fig. 1-5, 7 and
S2-S5.
As previously described by Pathare et al ., (2020) plants were
grown in 3-L free drainage pots in a controlled environment growth
chamber (model GC-16; Enconair Ecological Chambers Inc., Winnipeg, MB,
Canada). The photoperiod was 14 h including a 2 h ramp at the beginning
and end of the light period. Light and dark temperatures were maintained
at 26 and 22 °C, respectively. Light was provided by 400-W metal halide
and high-pressure sodium lamps with maximum photosynthetic photon flux
density (PPFD) of ca. 1000 µmol photons m-2s-1 at plant height. One individual per species was
grown per pot in a Sunshine mix LC-1 soil (Sun Gro Horticulture, Agawam,
MA, USA) with 6-7 replicate pots per species. The plants were irrigated
daily to pot saturation and fertilized twice a week with Peters 20-20-20
(2.5 g L-1). Plants were supplemented with Spring 330
iron chelate (BASF, Ludwigshafen, Germany) and Scott-Peters Soluble
Trace Element Mix (The Scotts Co., Marysville, OH, USA) once a week at
concentrations of 10 mg L-1. Pot locations were
randomized daily within the growth chamber.