Assessment and Utilization of the Genetic Diversity in Rice (Orysa sativa L.)

Abstract

The basis for raising crop production and improving crop quality is to breed new varieties. The key to breed new varieties are largely depended on the breakthrough of mining the crop germplasm resources. Therefore, the research and utilization of crop genetic diversity plays an important role on crop improvement in the future. Previous researches have indicated that genetic bottleneck effects existed in the procedure of crop domestication and modern breeding, i.e. the allele variation within wild species and landrace would be lost and result in the reduction of gene diversity during domestication and breeding (Tanksly et al., 1997). The narrow genetic basis would lead to cultivars without resistance to new pets and virus and tolerance to bad environment as well as producing the platform effect of yield. These lost alleles in modern cultivars could only trace back to their original landrace and wild species and be recovered. The original landrace are close to cultivars and possess high genetic diversity and many exotic genes, therewith provide useful germplasm resources for crop breeding.