Reactions of peanut genotypes to Peanut bud necrosis virus (PBNV) under sap-inoculation and natural field conditions may be different. Ten peanut genotypes (KK 60-3, KKU 72-1, KKU 72-2, Luhua 11, Tainan 9, JL 24, IC 10, IC 34, ICGV 86031 and ICGV 86388) were evaluated for their reactions to PBNV under field conditions in Thailand in 2001. The objectives of this study were (i) to determine breeding potential of the selected peanut genotypes in terms of PBNV disease resistance, and (ii) to explore the usefulness of disease incidence, disease score and area under disease progress curve (AUDPC) as the assessments of resistance for effectively discriminating susceptible and resistant genotypes of peanut. Significant differences were found between susceptible and resistant peanut genotypes as identified by disease incidence, disease score and AUDPC. Disease score and AUDPC tended to be equally effective and slightly better than disease incidence in identifying peanut genotypes resistant to PBNV. None of the resistance parameters could differentiate genotypes in the resistant group. IC 10, IC 34, ICGV 86031 and ICGV 86388 were identified as good sources of PBNV resistance. Among susceptible genotypes, KK 60-3 was more resistant than the others and could be used as a parent in peanut breeding programs.
