Abstract:
Abstract: This study evaluates the basis of Brown planthopper
(BPH) resistance in O. nivara (9864, WRAC 04), O. eichingeri
(TC 01, TC 02), IR 54751-2-34-10-6-2 (an introgression line
of Oryza officinalis), Ptb 33, Bg 380 and Bg 379/2 accessions
by screening for resistance, and characterizes the genes by
molecular techniques. Four BPH populations reared on Ptb33,
Bg 380, Bg 379/2, IR 54751-2-34-10-6-2 and a virulent BPH
population collected from rice fields in Kegalle area were used
for screening tests. Screening for resistance was conducted
following the standard honeydew test and molecular screening
was carried out using specific molecular markers for bph2,
Bph10 and Bph13 genes. Results of the screening tests for
resistance showed that the level of resistance of the tested
wild rice accessions (O. nivara and O. eichingeri) was not
significantly different from that of Ptb 33. These accessions
also showed high level of resistance to all the BPH populations
used in this study. Molecular screening revealed positive results
with O. nivara (WRAC 04) accession for bph 2 and Bph 13
markers and O. eichinigeri derived lines (TC 01 & TC 02) for
Bph 13 marker. Results showed that the emergence of virulent
biotype in field rice cultivations have the potential to overcome
the BPH resistance in Bg 379/2.
