2009 Volume 54 Issue 2 Pages 77-85
The differences in the germination, growth, and production of four seed types, large or small, aerial or subterranean, and in the emergence of two seed types, large or small subterranean, on tropical spiderwort (Commelina benghalensis L.) distributing in southern Kyushu Island, southwestern of Japan, were observed. The large aerial and subterranean seeds germinated higher at temperatures of 25 to 40°C, and the mean germination days were 3 to 4 days at a temperature of 30 to 40°C. The coefficient of uniform germination on the large aerial and subterranean seeds were 0.7 to 1.1 at a temperature of 30 to 35°C. The small aerial and subterranean seeds germinated higher at temperatures of 30 to 35°C, but the values of mean germination days and coefficient of uniform germination were longer and lower than those of the large aerial and subterranean seeds did, respectively. The seedlings from large aerial and subterranean seeds emerged the most from March to May. However, those from small aerial and subterranean seeds exhibited higher emergence intermittently from April to September. Seedlings from large aerial and subterranean seeds emerged from soil depths of 0 to 50 mm, and those from small aer-ial and subterranean seeds emerged from soil depths of 0 to 10 mm. Although the ratio of leaf length to leaf width in the first completely developed leaf blades is about 1.45 in all types of seeds, the leaf width of the seedlings was significantly different among the four seed types. The plant length, numbers of primary branches and leaves, and fresh weight of aerial parts of the plants obtained from the four seed types were almost the same. Furthermore, the numbers of spathes, and large and small aerial and subterranean seeds produced in those plants were also the same.