Biodiversity potential and conservation prospects of wild rices in the Philippines.

The Philippines lies along the geographic distribution of the world's rice biodiversity. Four wild species are known to occur which belong to 3 genome complexes. Oryza rufipogon (AA) is found only in Lake Apo in Musuan, Bukidnon. O. officinalis (CC) is widely distributed from Luzon to Mindanao. O. minuta (CCDD) has a select occurrence in Laguna, Sorsogon, and Leyte. O. meyeriana (GG) occurs in Nueva Vizcaya, Sorsogon, Palawan and Negros Occidental. O. rufipogon, O. minuta and O. officinalis share the wetland habitat of the cultivated rice. O. meyeriana is normally found within disturbed forest margins on well drained but moist upland environment. Genetic diversity assessment of 39 O. officinalis and 5 O. meyeriana composed of old and recent collections revealed substantial genetic diversity between and among populations and between collection sets. Further, the minuta-officinalis sympatric population in Leyte were confirmed to have produced natural hybrid in situ. From 1996-2008, new sites were added to the historically known sites indicating a much wider distribution of the wild rices in the country. The Philippine wild rices offer a rich genetic variability reserve for varietal genetic diversification. Hence, conserving these valuable resources is as important as any other wildlife. Conserving them in situ will allow the continuing genetic adaptation to changing environment and associated biological pattern. Unfortunately, lack of defined land use policy and unclear wildlife value appreciation and protection threatens their long-term survival. The UPLB Rice Varietal Improvement Program maintains a collection of ex situ 35 live plant samples of the Philippines population composed of O. officinalis, O. minuta and O. meyeriana. However, much remains to be done to explore the extent of distribution and variability, systematic collection and long-term conservation and utilization of the country's wild rice genetic resources