In the last years rice (Oriza sativa L.) production in Venezuela has
been negatively affected by Rhizoctonia solani causing sheath blight of
rice (ShB). In order to investigate the inheritance of resistance to the
fungus, two experimental populations were obtained from parents of rice
resistant and sensitive. At the beginning of the panicle emergence, four
leafs with fungus mycelium were applied within knot of sheath, then
being placed in humidity chamber for a week. According to the zone
affected by the disease, plants were grouped using the assessment scale.
The phenotypic reaction showed both progenies with transgressive
inheritance, explaining why the populations did not conform to the laws
of Mendelian inheritance; also a ratio of 1 resistant was observed: 1
sensitive. Therefore, R. solani resistance was influenced by several
genres, considering that resistance was quantitative.