Inheritance of resistance to Verticillium wilt in cotton

The control of genetic resistance to Verticillium wilt in cotton was studied by specific designs for mean andvariance analysis. It was found that the trait is highly heritable and mainly controlled by additive gene effects. According to themethod of disease evaluation and the procedure for calculation, two or three genes would be involved in the determination ofresistance. Although the results by the three methods used for disease evaluation were rather similar, a probable tolerancemechanism, observed mainly in the resistant parent, indicated the possibility of inconsistencies in studies of resistance to thisVerticillium wilt in cotton, in the case of evaluation based on external leaf symptoms.