Caracterização morfo-anatômica do colmo de genótipos de milho

Abstract

The objective was to evaluate the morpho-anatomical characteristics of ten genotypes of corn to silage, five normal (F2, Lu16, F271, LU5 and LU6) and five bm3 (F2bm3, Lu16bm3, F271bm3, Lu5bm3 and Lu6bm3), grown in Druelle- France, in plots of 150 m² during the period from May 2002 to September 2002, totaling a period of 150 days. All evaluations were performed in internode below the primary ear. The experimental design was completely randomized, with five replications per treatment. The genotypes showed significant differences on the anatomical aspects evaluated, and that all bm3 genotypes showed lower amounts of both lignified cells in the medullar region (1.24) as in the cortex (1.72). The statistic analysis pointed positive correlation (r= 0.70) between the amount of lignified cells in the medullar region and the percentage of medullar region. There was also positive correlation (r= 0.67) between the thickness of the cell wall with the xylem % and negative correlation (r= -0.67) between the thickness of cell wall with the phloem %. The results are consistent to the types of strains studied, because the bm3 lines are characterized by smaller proportions of lignin compared to normal genotypes.