THE GENETIC CONTROL OF RESISTANCE TO THE BEET CYST NEMATODE (Heterodera schachtii Schm.) IN OIL RADISH (Raphanus sativus L.)

摘要

The genetic nature of the resistance to the Beet Cyst Nematode (Heterodera schachtii Schm) in oil radish was investigated. A segregating population consisted of 290 F_2 individuals derived from self-pollinated single FI plant of the radish cross 'Pegletta X Siletta nova' was used. Four oil radish populations and one Brassica napus cv. "Madora" as susceptible control were examined for the resistance to the Beet Cyst Nematode (BCN) by assessing the number of cysts found onthe root system and the attached soil. As the results of the resistance test indicated all FI plants appeared in the resistance parent classes, which reflected the dominant behavior of the gene(s) controlled the resistance trait. A bimodal distribution was observed for the F_2 population. The F_2 individuals distributed in two discreet phenotype classes, complying with the assumption of monogenic dominant inheritance of the BCN resistance in oil radish.