SEEDLING TRAITS OF MAIZE AS INDICATORS OF ROOT LODGING

Research was undertaken to determine whether root lodging of maize (Zea mays L) can be predicted at the seedling stage. In the first experiment, seedlings from 9 central European flint x dent hybrids were tested under controlled conditions. At the 3-leaf stage, the diameter of the primary root was closely and negatively correlated with root lodging counts from field trials when plants were grown at 14-degrees-C, but not at 22-degrees-C. Attempts to test at an earlier seedling stage were only successful at 22-degrees-C and after 4 days of germination in the dark; the number of late/large metaxylem vessels in the primary root was closely and negatively correlated with root lodging. Experiment 2, with 14 hybrids tested for root lodging at one location for 2 years, partly confirmed the results of the first experiment. In experiment 3, root lodging data at anthesis and maturity were available from subsets of 10 to 17 hybrids from a total of 28 hybrids at 14 locations in Germany over 3 years. Root lodging at anthesis and at harvest were significantly negatively correlated with: a), the number of large metaxylem vessels in 21 out of 84 cases (range of significance r = - 0.51 to - 0.70); and b), with coleoptile length in 15 cases (range of significance r = -0.51 to - 0.79. We conclude that, in principle, a very early detection of root lodging resistance is possible. The same genetic systems seem to contribute to relevant root and shoot traits in seedlings and adult plants.