1) Yunnan Academy of Agric. Sciences, Kunming, 650205, China
2) Beijing Agric. University, Beijing, 100094, China
The common wild rice (Oryza rufipogon Griff.) found in Yuan-Jiang, Yunnan, is completely isolated from cultivated rice. To see whether it is differentiated into the indica (hsien) and japonica (keng) types, an enzymatic study was carried out with 45 plants or panicles collected from the natural habitat. In each sample, two seeds soaked for 12 hrs. at 37 deg C were analyzed individually.
In esterase, the bands expressed by locus Est-x attracted our attention, although it remains unknown to which of Est-1 to Est-9 listed by Morishima and Glaszmann (1990; RGN 7, p. 52) the Est-x locus corresponds, or to none of them. The locus for band 1A is unknown, But bands *A (Est51), 14A(Est-x14) and 11A (Est-x11) were found to belong to chromosome 1 by RFLP analysis. Band 14A is peculiar to the wild rice, and 7A (Est-21) is an auxiliary band of the Hsien type. All the 45 samples had these four bands i.e. IA, 7A, 8A and 14A, in common. Band 11A characterizing the Hsien type was found in 6.7% of the samples, in duplicate tests 4A (locus unknown) is an auxiliary band of the Keng type, and appeared in another 6.7% of the samples.
In catalase, 77.8% of the plants had Cat-12 characterizing the Keng type. Cat-11 representing the Hsien type was found in 4.4% of the samples only. This is observed in some of Chinese Keng cultivars having 14A characterizing the wild rice.
Thus, the esterase zymograms have indicated that the Yuan-Jiang wild rice belongs to the Hsien cline, in agreement with morphological classification. However, the catalase zymograms have suggested that it belongs to the Keng cline. Such discrepancy arouses questions in our mind as to the potentiality of the wild rice to evolve the Indica and Japonica cultivars.