ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 60 Number 3
Relationships among some morphological and physiological traits in tropical maize (Zea mays L.)
Because little information on genetic relationships of morphological and physiological traits of tropical maize is available, the inheritance of grain yield (GY), plant height (PH), ear height (EH), silking days (SD), plant leaf area (LA), lodging (Ldg), yield efficiency (YE), and grain moisture content at harvest (m%) and correlations among those traits were determined for two open-pollinated commercial cultivars that contrasted in morphological and physiological traits. 256 S1 lines were extracted in each population and evaluated at three locations in the area of adaptation of each cultivar in southeastern Zaire. Genetic and non-genetic variances and covariance components were separated, and genotypic and phenotypic correlation coefficients and heritabilities of traits were estimated. High heritabillties ( > 50%) were observed for most of the traits studied, suggesting that they would respond to selection pressure. The results also suggest that selections based on single traits, either PH, GY or YE, would produce different results in different populations depending on genetic associations of the traits. Caution must be exercised, therefore, with short tropical maize cultivars to prevent I.A, PH, EH, and m% from increasing because they are positively associated with GY and YE.
Keywords: Zea mays L.; Plant morphology; Physiology; Plant genetics