Assessment of Rice Genotypes for Brown Plant Hopper Resistance Using Microsatellite Markers

Phenotypic response of the 16 rice genotypes to brown plant hoppers (BPH) was evaluated at flowering stage under field conditions. The results indicated that genotypes were classified into five groups from score 1 to score 9. A total of 88 alleles were detected by 37 polymorphic markers with an average of 2.17. Polymorphic information content (PIC) value varied from 0.92 for RM 483 to 0.98 for RM 84, with an average of 0.95. An efficient separation of 16 rice genotypes based on SSR data into three groups was achieved by using unweighted pair group method with arithmetic means (UPGMA) clustering procedure based on genetic similarity expressed by the Jaccard similarity coefficient (JSC). Genotypes that are derivatives of genetically similar type clustered more together. The results also indicated that land races which are potential sources for biotic stress exhibited wide range of reaction from score 1 (slight drying) to score 9 (all plants apparently dead) to brown plant hopper screening and therefore very useful for rice breeding programs, especially for genetic mapping studies and eventually for application of marker-assisted selection (MAS). From this study it was concluded that mapping population could be developed by using PTB 33 and BM 71 as donors to introgress genes for BPH resistance into cultivated high yielding rice cultivars