within a few years of release. Thus, susceptible
old cultivars have gradually been eliminated
and more resistant ones are in wider use. A clear
picture of the genetic base to blast resistance, in
presently cultivated rice varieties, will provide
important indications to which approach and
strategy could be adopted to strengthen the degree
of blast resistance and to improve the durability of
resistance in future varieties. The objective of this
study was to identify blast-resistant rice varieties
from the landrace and improved rice (Oryza sativa
L.) in Thailand