4. Rice types at a vestige site of Caoxie Hill in different ancient periods

Ling Hua TANG1, Dai-Hong ZHUO1, Jiang-Si Zuo1 and Hiroshi FUJIWARA2

1) Institute of Food Crops, Jiangsu Academy of Agric. Science, Nanjing, 210014, China
2) Faculty of Agric., Miyazaki University, Miyazaki, 889-21 Japan

Research workers in Nanjing Museum excavated the vestige site of Caoxie Hill in Wu county, Jiangsu province, in 1972 and 1973. A series of materials including fossil rice were unearthened, which represented different periods ranging from Ma iaban (4,000 BC) to Warring-States period (400 BC). These fossile rices were authenticated as remains of Japonica cultivars. The types of rice planted in those ancient periods would be significant in studying the origin and evolution of cultivated rice.

The present study was conducted by excavation and survey at the vestige site of Caoxie Hill. Three survey pits each 5 x 5 m2 were excavated. Examining the materials from different layers, the first layer was determined as the modern one, the second as the layer of Song Dynasty, the third as of Warring-States period, the fourth as of Songze, and the fifth as the late Majiaban period; the 6th and 7th layers are due to the middle and early periods of Majiaban, respectively. As an example, various cultural layers observed in a survey pit 92WCT0406 are shown in Fig. 1, in which the fourth layer is absent.

A total of 15 soil samples were taken from this pit and 50 plant opals from each sample were examined. Lengths at the top (a) and bottom (b), width (c) and thickness (d) were measured in each opal under microscope. For distinguishing between Japonica and Indica types of an opal, a function was constructed as follows: Z=0.049(a+b)-0.019c+0.197d-4.79(b/a)-2.614 (Sato et al. 1989). The results showed that more than 90% of plant opals belonged to the β type and were of Japonica type. This suggests that Japonica types were planted at the beginning of rice culture around the Caoxie Hill site.

References

Sato, Y. I., H. Fujiwara, T. Udatsu and H. Morishima, 1989. Plant opal analysis as a method of distingsuihing between subspecies indica and japonica of O. sativa. RGN 6: 67-69.