Morphological traits associated with lodging resistance of spring wheat (Triticum aestivum L.)

Throughout the world, lodging in cereals causes great losses in yield each year. A two year held study was conducted to determine the relationship of morphological traits to lodging resistance in spring wheat (Triticum aestivum L.) breeding lines and to find easily measurable traits related to lodging resistance. A set of 15 breeding lines, representing a wide range of combinations of plant height and lodging resistance, was evaluated. During the first year, 29 morphological traits were measured at two growth stages and correlated with the lodging score. Higher correlations were found for traits measured at anthesis (DC 65) than for traits measured at maturity (DC 92); most of the fresh weight traits correlated better to lodging resistance than did the corresponding dry matter parameters. During the second year the six traits of plant height, stem length, stem diameter, ear weight, stem weight and stem weight per cm were measured at anthesis and correlated with the lodging score. From the pooled data of four experiments, significant correlations between the lodging score and single morphological traits were found for stem diameter and stem weight per cm. Thicker stems and heavier stems (mg per cm) were indicative for better lodging resistance. Stem diameter and stem weight cm-l explained 48.5 % and 49.7 %, respectively, of the phenotypic variation in lodging resistance. Multiple linear regression equations indicated that 77.2 % of the variation in lodging resistance was based on stem weight cm(-1) and on the weight of the ear.