The gene Pi-ar confers resistance to Pyricularia grisea race
IB-45 in a somaclone derived from immature panicles of the
susceptible rice (Oryza sativa) cultivar Araguaia. RAPD technique
was used to identify molecular markers linked to this gene utilizing
bulked segregant analysis. Initially, the two parental DNAs from
the resistant donor SC09 and 'Araguaia' were analyzed using
random primers. Of the 240 primers tested, 203 produced
amplification products. The two parental DNAs along with the
resistant and susceptible bulks of F2 population were screened
using 48 primers that differentiated resistant and susceptible
parents. Even though eight primers differentiated the resistant bulk
from the susceptible bulk, as well as somaclone SC09 and 'Araguaia',
only one primer, OPC02 ('GTGAGGCGTC'), was found to be tightly
linked (1.7cM) to the resistance gene of somaclone SC09