D. Research Notes

National Institute of Agrobiological Resources, 2-1-2 Kannondai, Tsukuba, 305-8602 Japan

     Recently knowledge of the Oryza species in Latin America has increased greatly since the series of germplasm collecting missions in Brazil, Paraguay and Argentina and subsequent research on collected germplasm (Morishima and Martins 1994, Morishima et al. 1999, Akimoto 1999). However, there are very few accessions of Oryza germplasm from the countries of northwest South America, Equador, Colombia and Venezuela in the worlds germplasm banks. In the genetic resources handbook of wild rice (Vaughan 1994) only 13 herbarium specimens of wild rice were recorded for Venezuela. During a recent visit to Venezeula the 51 wild rice herbarium specimens in the Venezuela National Herbarium were observed and these provide a clearer picture of the distribution of wild rice in the Orinoco river basin.

     0. rufipogon (syn. 0. glumaepatula) is abundant in the middle reaches of the Orinoco particularly Apure and Guarinco provinces (Fig. 1). Considerable variation in morphology was apparent from specimens with large, long awned spikelets (Venezuela herbarium specimen Delascue and Ramie, 7758) also seen in many Amazonian AA genome wild rice specimens to a diminutive form (Venezuela Nat. Herb. No. 10474). Comments on specimens indicate that in Guarinco province 0. rufipogon is a weed of cultivated rice. Despite recent progress the status and relationships between Latin American AA genome wild rice and that of other regions remains highly confused. Studies of AA genome wild rice in the Orinoco basin would likely be highly instructive.