Genetic diversity among 49 Indian accessions of rice (Oryza sativa subsp. indica), including 29 landraces
from Jeypore, 12 modern cultivars, and 8 traditional cultivars from Tamil Nadu, was investigated using AFLP markers.
In total, nine primer combinations revealed 664 AFLPs, 408 of which were found to be polymorphic. The percentage
of polymorphic AFLPs was approximately the same within the cultivars and landraces. Similar results were obtained
when genetic diversity values were estimated using the Shannon–Weiner index of diversity. Genetic diversity was
slightly higher in the modern cultivars than in the traditional cultivars from Tamil Nadu. Among the landraces from
Jeypore, the lowland landraces showed the highest diversity. The present study showed that the process of breeding
modern cultivars did not appear to cause significant genetic erosion in rice. Cluster analysis and the first component of
principle component analysis (PCA) both showed a clear demarcation between the cultivars and landraces as separate
groups, although the genetic distance between them was narrow. The modern cultivars were positioned between the
landraces from Jeypore and the traditional cultivars from Tamil Nadu. The second component of PCA further separated
medium and upland landraces from lowland landraces, with the lowland landraces found closest to the traditional and
modern cultivars.

http://www.nrcresearchpress.com/toc/gen/45/3