Peasant rice agriculture: Its character and mechanisms of genetic erosion of its germplasm

Abstract

Between 1986 and date, land races of rice (Oryza satwa Linn .) have been collected from rice-growing areas of Nigeria (Okposi in Abia state, Awgu in Enugu state, Ofada in Ogun state, Ijesa-Isu and Igbemo in Ekiti state, and Erinmo in Osun state) and they were characterized for their agronomic attributes.
Peasant rice holdings were studied for 4 years in Erinmo to elicit population dynamics of peasant rice germplasm. A model for the mechanism of erosion of genetic variability in the local germplasm of rice was constructed from this and earlier studies.
The factors implicated in the genetic erosion of peasant rice germplasm are; mode of harvesting, inherent population dynamics like choking up of late emergents, loss of lodging and shattering genotypes, loss of late-maturing genotypes, seed dormancy. Wholesale loss due to adoption of improved varieties and complete abandonment of rice farming are also important factor in genetic erosion of peasant rice agriculture.
These results suggest that conservation of rice local germplasm could be achieved through extensive survey, collection and characterization. Lack of encouragement of rice agriculture among peasants has contributed to the loss of genetic diversity in the landraces. This situation makes in situ conservation very difficult. It appears that peasant rice agriculture rather than large-scale agriculture will have a major role to play in our national food security programme for a long time.


Ife Journal of Science Vol. 8 (2) 2006: pp. 179-184