Genetic markers in the species of rice (Oryza L.) indigenous to Nigeria

Abstract

This paper reports the genetics of attributes that have marker values in the body of work done by the Rice Group at Ife in the last 28 years. Baseline works on the morphological and genetic markers in the genus Oryza were carried out in the last 28 years. The two major sources of materials for these studies are selections from local germplasm of peasant farmers (land races), wild relatives of cultivated rice indigenous to Nigeria and collections from the Gene Bank of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The accessions (both rootstocks and seeds) were collected, planted, screened, and desirable attributes were selected. Inter- and intra-specific crosses were carried out and the F plants generated were monitored to advanced 1 generations. Putative hybrids were collected from a hybrid swarm in the Jebba Fadama and planted alongside suspected parents. The morphological and genetic attributes of these rice plants, including backcross progenies, were studied. The results showed that certain minor morphological and genetic attributes such as ligule type; sterile lemma type; hairiness on sterile lemma; pigmentation of apiculus/awn, stigma, lower outer leaf sheath; and ripen-hull coloration have good value as markers in the identification of rice species and are also useful in tracing gene flow in a population of hybrid swarm. The use of these markers by our group has enhanced the understanding of the population dynamics in rice hybrid swarms as species, putative hybrids, and backcrosses can now be easily identified on the field.

Keywords: Markers, Indigenous Rice, Gene Flow, Hybrid Swarm, Population Dynamics.