Genetic Variation of Four Anatomical Traits and Their Association with Stalk Quality Traits in Maize (Zea mays L.)1

Stalk quality traits, including crushing strength and rind thickness, were evaluated in 1967 and 1968. In addition, four anatomical traits of the stalk were evaluated in 1967 for 66 inter se crosses among 12 inbred lines of maize (Zea mays L.). The nature of the genetic variation of (i) area of the stalk cross‐section, (ii) area of rind, (iii) of pith, and (iv) the number of vascular bundles in the pith were determined by means of diallel analysis. Significant differences among the 66 F1 hybrids were obtained in each trait. General combining ability (gca) mean squares were significant in each instance, whereas specific combining ability (sca) mean squares were small and not statistically significant. Low genotypic correlation coefficients among three of the four characters studied and traits known to be diagnostic of stalk strength indicated that stalk cross‐section, pith area, and bundle number in the pith would have linfited merit in a selection program. Genotypic correlation coefficients of rind area with diagnostic stalk quality traits were higher, but rind area determinations would be prohibitively expensive and time consuming. The number of vascular bundles in the pith was a poor indicator of stalk strength. We concluded that rind attributes were better indicators of stalk strength than were traits associated with the pith of maize stalks.