A Comparison of the Growth of the C4GrassSpartina anglicawith the C3Grass Lolium perenne at Different Temperatures

Publisher Website
Google Scholar
Abstract
Dunn, R., Thomas, S. M., Keys, A. J. and Long, S. P. 1987. A comparison of the growth of the C4 grass Spartina anglica with the C3 grass Lolium perenne at different temperatures.—J. exp. Bot. 38: 433–441. S. anglica is one of the few C4 species which occurs naturally in cool temperate zones. It is known to attain photosynthetic rates which equal or exceed those of C3 grasses over the temperature range typical of the spring and summer in cool temperate climates. This study examines whether S. anglica can also attain comparable growth rates at these temperatures. Seedlings of S. anglica and L. perenne cv. S23 were grown in controlled environments at 10,15,20 and 25 °C. Quantitative growth analysis was conducted by taking frequent harvests to determine the progressions of leaf area and plant weight of individual plants with time. Quadratic regressions were found to describe these progressions well. Instantaneous derived growth parameters were calculated from the fitted regressions. Both absolute and relative growth rates of S. anglica were significantly lower than for L. perenne, this being largely attributable to a lower ratio of leaf area production per unit of plant dry weight. Although the amount of dry matter invested into leaves was similar, the leaf area per unit of leaf dry weight was lower in S. anglica. In comparison to L. perenne, the rate of dry matter accumulation per unit of leaf area (ULR) was higher in S. anglica at 25 °C and initially equal at 10 °C. Prolonged exposure to 10 °C steadily reduced ULR in S. anglica which approached zero at 80 d. Although growth in S. anglica is reduced more by low temperature than it is in L. perenne, by comparison to other C4 species the assimilatory capacity of S. anglica is more tolerant of low temperature exposure.