GENETIC-VARIATION AND RESPONSE TO SELECTION FOR RESISTANCE TO ROOT-KNOT NEMATODES IN OIL RADISH (RAPHANUS-SATIVUS SSP OLEIFERUS)

Based on a preliminary screening of a collection of cruciferous crops, such as oilseed rape (Brassica napus L. ssp. oleifera Metzg.), oil ra dish (Raphanus sativus L. ssp. oleiferus DC.), and yellow mustard (Sin apis alba L.), some plants within the oil radish varieties showed resi stance to the root-knot nematodes Meloidogyne hapla Chitwood and M. in cognita (Kofoid & White) Chitwood. Resistance tests of S-1 progeny of these selected genotypes revealed a quantitative nature of resistance to M. hapla. Only a few resistant individuals were found, but a signif icant effect of selection was observed. In contrast, the progenies of plants resistant to M. incognita showed a very low number of egg masse s, suggesting that this resistance may be conferred by dominant major gene(s). The results indicate that resistance of oil radish to root-kn ot nematodes may be effective and may thus provide new possibilities f or the management of M. hapla and M. incognita.