Traore, Karim (2005-08). Characterization of novel rice germplasm from West Africa and genetic marker associations with rice cooking quality. Doctoral Dissertation. Thesis uri icon


  • Genetic resource enhancement is the foundation of any good breeding program.
    Landraces from West Africa, interspecifics between Oryza sativa and Oryza glaberrima
    and improved lines from the West African Rice Development Association and other
    research centers were introduced to the Beaumont Rice Research center for in situ
    evaluation and characterization. Beside the introduction of seeds, milled samples were
    also introduced for grain chemistry analysis. Field evaluation combined with physicochemical
    and molecular characterization revealed unique characteristics among African
    germplasm. New rice for Africa (NERICA) lines performed well in the USA
    environment. Varieties like Nerica 2, Nerica 3, Nerica 4, and Nerica 5 need more
    attention because of their superior performance in yield and grain quality. Landraces did
    not perform well due to their height and late maturity and their resulting problems with
    lodging. The rapid visco analyzer RVA profiles showed that the cultivar Jaya has
    unusually strong paste viscosity features. Comparing West Africa samples grown in
    Cote d??????Ivoire with those grown in Texas, parameters like AA, ASV, Hot, Cool, and CT
    were not stongly affected by the environment. According to the Stbk value, cultivars grown in Cote d??????Ivoire will cook softer than when they were grown in Texas. The lack
    of the environmental effect is somewhat surprising considering the difference in latitude,
    soil types, weather patterns, and management practices between the two locations.
    Apparent amylose is a key element to characterize a rice cultivar; however certain
    varieties like Cocodrie and Dixiebelle have similar apparent amylose content but
    dramatically different functional qualities. A population derived from Cocodrie and
    Dixiebelle was developed for genotypic and phenotypic analysis of grain chemistry traits
    that affect functionality. It was concluded that the amount of soluble amylose in the
    grain had a significant effect on flour pasting properties, even when total apparent
    amylose content did not vary. Marker association studies revealed that the Waxy
    microsatellite and the Waxy exon 10 SNP markers were associated with soluble amylose
    content and RVA characteristics. These markers will speed up the development of new
    rice cultivars with desirable quality characteristics in West Africa and in the USA.

publication date

  • August 2005