Host status and phenotypic diversity of rice cultivars resistant to Meloidogyne species under glasshouse conditions
Five pot trials were carried out under glasshouse conditions to assess the host response of some selected rice cultivars to Meloidogyne javanica, M. paranaensis and M. enterolobii, based on nematode reproductive factor (RF) and number of nematodes (g root)−1. We also determined the broad-sense heritability and variance component estimations associated with M. paranaensis and M. incognita resistance. In addition, cluster analysis of cultivars was conducted. All cultivars were rated as susceptible or highly susceptible to M. javanica and highly resistant to M. enterolobii. To M. paranaensis, only cvs IAPAR 177 and BRS Caravela were resistant. From the principal component analysis and Ward’s cluster analysis, we obtained four conspicuous clusters of cultivars according to Meloidogyne species resistance, which demonstrates the variability of the genetic material studied. Higher broad-sense heritability values for RF and nematodes (g root)−1 were obtained. Taken together, our findings suggest that improvement of resistance of rice to Meloidogyne species resistance is possible. The implications for management programmes are also discussed.