Interrelationships among resistances to five major diseases and seed, seedling and plant characters in cotton

Abstract

Thirty-one strains and five commercial varieties were used to study the Interrelationships among resistances to five major diseases and seed, seedling and plant characters in cotton. Efforts were made to identify selection criteria that would be effective in indicating the presence of multi-resistance genes. Analyses of variance, simple and partial correlations, multiple regression, step-up analysis of variance and path coefficient analysis were utilized in studying data. The method of path coefficient analysis was useful in untangling direct and indirect causes of an association for Interpretation. Variability in concentrations of magnesium, calcium and carbohydrates, components of seed leachate, were found to be important in accounting for variability in seedling emergence, pre-emergence damping-off and final stand. Interrelationships of these leachate components with measurements of seedling disease indicate that the proper concentration and combination leaching from the seed coat may result in reduced incidence of seedling disease. The data indicates that these components will be important in studies of mechanisms of disease resistance, predisposition and host-pathogen interaction. ...