| Sumario: | Five populations ofMeloidogyne graminicolaisolated from different rice-growing areas in the Philippines were characterised. The populations showed little phenotypic variability of second-stage juveniles and female perineal pattern. Differences in reproduction amongM. graminicolapopulations were not observed on mature resistantOryza glaberrimavarieties ‘TOG5674’, ‘TOG5675’, ‘RAM131’ and ‘CG14’, or on susceptibleO. sativavarieties ‘IR64’ and ‘UPLRi-5’. In all infected rice varieties, plant growth and yield-contributing traits showed no differences among the populations. A search onM. graminicolapopulations from the Philippines for single-nucleotide polymorphism on the sequences of Internal Transcribed Spacer (ITS) of rDNA genes and mtDNA indicated only few points of heteroplasmy. Nematode reproduction and disease induction of the fiveM. graminicolapopulations in the Philippines exerted the same level of aggressiveness and virulence. The absence of resistance-breaking populations ofM. graminicolais important for the maintenance of durability of resistance to this important rice pathogen.
|
|---|