Principal Component Analysis of Striga-Tolerant Maize Varieties

Ten Striga-tolerant maize (Zea mays L.) inbreds were evaluated in striga-endemic area of Temidire in 2001, 2002 and 2003. The evaluation was done under artificial and natural striga infestation conditions with the objective of identifying parameters that contribute to striga tolerance and grain yield via principal component analysis, correlation coefficients and character mean performance. Grain yields of the infested maize plots were slightly lower than those of non-infested maize plots, but not significantly different. Similarly, pairs of maize characters, such as ear harvest and ear aspect; striga syndrome rating and ear aspect; striga syndrome rating and plant height; and, grain yield and plant stand were highly and significantly correlated (r varied between 0.70 and 0.82). For the infested maize plants, the first 4 components (plant stand, plant height, plant harvest and ear harvest) accounted for 96.06% of the total variation, whereas these 4 components jointly contributed 95.34% under non-striga infestation. Selecting for these 4 important traits in breeding for striga tolerance and grain yield would be better than breeding for striga-resistant varieties per se because they return higher eigen values than the other parameters.