Tropical forages: morphoanatomy of plants grown in areas with the death of pasture syndrome

Abstract

Roots and leaves of Panicum maximum Tanzânia, Mombaça and Massai; Urochloa brizantha Piatã, Marandu and Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II and Cynodon nlemfuensis Estrela-roxa were analyzed, seeking to identify characters for better adaptation to the environment that may interfere with digestibility of tissue from the point of view of the rumen in cattle. Were planted ten cultivars in a completely randomized blocks with three repetitions. Was collected vegetative material, which histological slides were prepared from middle third of the sections of roots and leaves. Were observed differences (p>0.05) in the roots: higher volume of epidermal cells (28.62 µm) and overall diameter (1926.41 µm) of Llanero; thicker vascular cylinder (975.09 µm) and more protoxylem (42.25) in Estrela-roxa and occurrence of aerenchyma in cultivars Piatã, Mulato II, Xaraés, Massai, Llanero and Estrela-roxa; Were found higher proportions of bulliform cells in the leaves (121.07 µm) and thicker leaf mesophyll in U. humidicola Llanero (263.63 µm); higher proportion of sclerenchyma fibers in Xaraés and Marandu; lower results for amount of fibers in P. maximum Massai. We conclude that the cultivars Estrela-roxa, Llanero and Massai have greater adaptability to the environment and better nutritional quality. Keywords

Nutritive value and anatomical characterization from Pennisetum purpureum genotypes

“…The vascular bundles present collateral disposition surrounded by sclerenchymatous tissue and xylem differentiated into protoxylem and metaxylem. According to Ribeiro Júnior et al (2017), a more extensive arrangement of the protoxylem may associate with the anatomy of the vascular cylinder, as the bundles of the metaxylem and phloem are smaller and do not occupy so much space.…”

Evaluation of Megathyrsus maximus genotypes under water stress conditions

“…Pastures in the Northern region of Brazil, mainly formed by Marandu grass, have been and are being degraded due to excess water in the soil (Andrade & Valentim, 2007). In M. maximus, cultivars BRS Tamani and BRS Quênia, recently released hybrids (Embrapa Gado de Corte, 2015; Jank et al, 2017), are susceptible to excess water in the soil, however, cultivars such as Mombaça, BRS Zuri and Massai (Schiavo, Laura, & Jank, 2009;Mass Junior, Domiciano, Ribeiro, & Pedreira, 2016;Ribeiro-Júnior et al, 2017) have been indicated to increase pasture persistence in poorly drained sites. Pasture death has also been observed after recurrent years of water deficit, mainly in transition areas with the Caatinga Biome, and M. maximus cultivars such as Massai and others (Veras et al, 2020) have been used as alternatives.…”