Effects of temperature, light and certain growth regulating substances on sprouting, rooting and growth of single-node rhizome and shoot segments of Paspalum distichum L.

The rate of sprouting, rooting and early growth of both single-node stem and rhizome segments of Paspalum distichum L. increased as incubation temperatures increase to about 30°C and then declined at 40°C. There was little growth at 10°C. Single-node shoots remained viable at cooler temperatures after 1 days’incubation at 45°C, and 35% remained viable after 2 days’incubation at 45°C. Both shoot and rhizome segments sprouted and rooted at alternating temperatures of 45°C/28°C and 45°C/22°C. Generally sprouting and rooting of shoot segments were faster than in rhizome segments, but the response to temperature was similar for both sprouting and rooting of single-node shoot and rhizome segments. Single-node shoot segments sprouted faster in 16-h day lengths than in the dark. Rooting was better in the dark at 10°C, unaffected by light at 22 and 28°C, and faster in the light at 35 and 40°C. Sprouting, rooting and early growth were enhanced by gibberellin A₃, kinetin and indole-3-acetic acid. Shoots collected at different seasons differed in their sprouting and rooting responses at various incubation temperatures. These patterns varying in response to seasonal temperature fluctuations may provide a survival mechanism for P. distichum.