Morphogenesis of Panicum maximum jacq. cultivars

[摘要] - Four cultivars of Panicum maximum: Mombaça, Tanzânia, Centenário and Vencedor were grown in pots, under a transparent plastic cover, to evaluate the dynamic of leaf and tillers growth. Two growths, the establishment and the aftermath, after clipping at the age of 21 days, and two types of tiller, main and primary tillers, were studied. A completely randomized design with four replicates was used to compare the treatments resulting from a 4 x 2 x 2 factorial arrangement. The leaf blade length increased with insertion level until leaf number nine or ten, decreasing subsequently. The tillering process began during the second week of growth and continued until the 22nd day, when the number of tillers per plant stabilized. Tanzânia tillered the most (15 tillers/plant) while Mombaça and Vencedor tillered the least (10 tillers/plant). Higher leaf appearance and elongation rates were observed in the establishment growth. In either growth, the cultivar Vencedor showed the highest leaf appearance rate. In the aftermath growth, the number of green leaves per tiller stabilized at 6.5 for Vencedor and 3.5 for the remaining cultivars. In this growth the leaf life span ranged from 29 days, for the cultivar Centenário, to 36 days, for the remaining cultivars.

[学科分类] 兽医学

[关键词] leaf appearance;leaf elongation;leaf-life-span;tiller;senescence     IntroduçãoA produtividade das gramíneas forrageiras decorre da contínua emissão de folhas e perfilhos;processo importante para a restauração da área foliar após corte ou pastejo e que garante a perenidade à forrageira