Research Papers: Susceptibility of Various Tomato Lines to a Population of Meloidogyne incognita


  • N. Acosta
  • J. A. Negron


Root-Knot Nematode, Plant Breeding, Giant Cells, Resistant Cultivars


Comparative growth response and susceptibility of tomato cultivar Rutgers and nine tomato lines developed in Puerto Rico to a race 4 population of Meloidogyne incognita were studied in two greenhouse tests. In the first test eight, five-week old seedlings per line or cultivar were planted in steam-sterilized soil and inoculated with 10,000 eggs and second stage juveniles of M. incognita per plant. Thirty days after inoculation data on gall index, number of eggs from roots, and on larvae from 3.7 g of roots and 250 cm of soil, and dry shoot weight were recorded. In the second test, 3,000 M. incognita eggs per plant and three replicates per treatment were used and similar data collected, 45 days after inoculation. Results from both experiments indicated that line 290 F was resistant to the M. incognita population, whereas Rutgers was highly susceptible. Histological studies from roots of line 290 F demonstrated few small giant cells with reduced number of nuclei present. Many well deve